View Full Version : Tech Tip - Transmission Temps
For those of you who have been diligently reading the "Transmision Temps" thread, started by denverdale, I read a Tech Bulletin found at http://service.gm.com/techlink/html_en/index.html
It stated "TIP: The owner’s manual states the Allison should not idle in gear for more than 5 minutes to avoid the possibility of overheating."
This would explain some of the higher temps we have all been noticing while driving around town. Hey, when it's hot outside, shift into neutral when your waiting at the light. I bet that will help keep the Allison from getting too hot.
I don't have an answer for those of you who are experiencing higher temps even when on the freeway, barring any heavy traffic.
Jake99Z71
07-15-2002, 17:30
CSDMAX,
I have been doing this once summer started. I still see temperatures around 200 degrees. I was hoping this would help but it still heats up. Thanks for reminding some.
I have been doing the same ~ seems like a logical procedure when the meter starts sliding pass the 200
Didn't make a difference on mine.
Before making the deflectors for the cooler I tried about everything to increase & decrease the tranny temp. I've let mine idle for 10-15 minutes in gear with no increase in temp.
As stated before, it's the shifting that runs up the temp (at least it does on mine). It takes about 30-45 minutes but I can drive around & around the sub-division shifting from 1st-4th over & over with a slow, but steady rise in temp. I can do this even with outside air in the mid to high 70's. Engine stays the same (190).
Billy
Billy,
Shy of putting in the air deflectors as you and I have done (which BTW has made a difference), OR relocating the tranny cooler as you are trying to do, I thought at the very least this tip might help a little bit. I have not been shifting out of gear, but since I came across the "tip", I would throw it out here on the BB.
JimErickson
07-16-2002, 09:02
Same problem here with my 2001 3500 EC.
I have seen temps as high as 250 when pulling heavy trailer in hilly conditions.
I'm using Transynd but still have shallow pan.
Without trailer in city traffic I see 200-205 usually (in hot weather).
Jim
Jim ~ Does/did the Transynd help hold temps down? As that is pretty much what I'm seeing in like conditions here in the Sacramento Valley on the factory fill. ~ odoh
More Power
07-16-2002, 10:26
Using Tow/Haul will greatly reduce trans temps when in city traffic or pulling slow winding grades with a load. The torque converter will lock in gears 2-5 while in Tow/Haul. An unlocked TC is the biggest heat generator.
That said, I've never seen above 210 while towing in 100+ heat up steep winding grades (Deadwood, SD to Mt Rushmore).
A couple of years ago, we were trying to make it back into the US on I-5 at the Canadian border. It was 2+ hours of inching along in miles of backed-up traffic. Our 6.5's 4L80-E did heat-up in this situation, and I had to put the trans in park/neutral at every opportunity. I suspect the Allison would have also heated up in this situation.
MP
JimErickson
07-16-2002, 10:30
I noticed about 5 deg difference with Transynd.
I have never gotten into red but a couple times I was close and had to back off the throttle.
One thing I have noticed is that once the tranny gets hot it stays that way for a long time. Even letting it idle it takes an hour to cool down from 210 to 190. Almost like the cooler is not functioning at all.
But off course when I told the dealer he said it was normal.
Jim
JimErickson
07-16-2002, 10:32
Tow/Haul seems to make no difference in my case.
Jim
CSDMAX
I sure hope you & others don't think I was trying to beat up on you, or your post. ANY information & input here is appreciated by all. That's how we can hopefully make a difference. smile.gif I think we're all discovering these trucks are like people. No two are alike.
Glad the deflector did some good.
Now, I have a confession to make I've been putting off. When I first dove into the tranny temp issue a few months ago the first thing I did was trace the lines. Knowing in advance almost all vehichles run lines through the engine radiator to help warm the trans fluid, this is where I started. From under the hood & on my back under the truck I couldn't find a line to the engine radiator. They appeared to go directly to the tranny cooler & back to the tranny. Well, I looked again last week & finally found the line to the radiator & then to the cooler. redface.gif It's like a barrel of snakes under there & hard to see.
Bottom line from this discovery is the itty bitty tranny cooler has to bring down 190+ deg. fluid pre-warmed by the engine radiator plus the heat the tranny itself generates. I just don't think the existing cooler can do this. On the other hand, we still have folks reporting they have never reached 190 deg. regardless of driving conditions or towing. Go Figure!
If my hypothesis is wrong, someone please tell me.
Billy
Billy,
No beating or bruises on me! :cool: As you said, ANY information & input here is appreciated by all.
P.S. - I took some pics of the lower air deflector for those of you who are interested.
FirstDiesel
07-16-2002, 17:17
A few thoughts to add to this thread.
First, when I first got my 93 Suburban (gas) to tow our car trailer I went to the tranny shop and had it serviced. I wanted a big tranny cooler added. The INSISTED the only way to do this was to not route the tranny fluid through the radiator cooler. There logic was the engine heat only adds to the tranny fluid and if you ever overheat the engine you will also overheat the tranny. Made sense to me at the time. We did it and I never had a issue with the tranny.
Second, if there are people with the tranny temps getting to hot it would seem to me the solution would be either increase the size of the tranny cooler, disconnect the tranny from the radiator cooler or both.
I've not yet done any heavy towing, just towed the old trailer (1000 lbs??) empty to Virginia, so I don't have a feel for how my truck will do. But if it runs hot I know I will be changing the cooler to the biggest one I can fit.
SoCalDMAX
07-16-2002, 17:36
Great thread, lots of great info! I'm not suffering from excessive temps, (170-180* on fwy, up to 200* in city) but I think that everything Billy has said so far has made sense. It definitely looks like it's mounted in the wrong place. Perhaps an aux fan mounted over it would help.
The tranny cooler is the most efficient design I've seen, (stacked plate) but it does seem a little small (looks like 24 plate) and they make them as large as 96 plate. It definitely could be a little bigger. As for the routing thru the radiator, I'm trying to get this straight. If the engine coolant temp is higher than the tranny fluid temp, it will pick up heat from the radiator to equalize. If the tranny fluid is at 200* and the engine coolant is at 190*, then the heat will flow from the tranny fluid to the coolant. Not much since the differential is minor, but a little. So I'm still up in the air about rerouting the tranny fluid away from the radiator, perhaps it isn't hurting as much as it would appear.
What target temp are we trying to reach? 180* under all conditions? I'd be happy if it stabilized at 190-200* and never rose above that under any conditions. I think relocating the cooler, a larger cooler, then an aux fan would help, in that order, depending on severity of the heat problem.
My .02, .005 after taxes.
Regards, Steve
I don't think we should worry to much about a few degrees temp. spread.
I spent 26 years working at an oil refinery type of facility where 2 men worked 8 hour days trying to keep high quality gauges accurate.
Our Generous Motors gauges are not in the same league.
SoCalDMAX,
I agree with you 100%. Seems if the tranny was running at 210 or more & the engine at 190, the flow through the engine radiator SHOULD help bring down the tranny temp. Then again, if ambient air is 100 and the engine is at 190, the outside air through the cooler SHOULD be the logical source for temp reduction at the tranny given the spread difference between engine temp & ambient air.
I've stated several times before that my truck is the first vehichle I have ever owned with a temp gauge for the tranny fluid. What you don't know won't hurt you! For all I know every car and/or truck I've owned in the past ran tranny temps over 250 deg. Didn't bother me then because I didn't know. Just a thought.
ON EDIT: It's all Mackin's fault. That ^%$(*&+@@ post about transmission life versus temperature. Can't get it out of my head.
Best to all,
Billy
[ 07-16-2002: Message edited by: Billy14 ]</p>
I guess there is no quick fix to the problem, but it would only make sense to me that the target temp should only peak at the WATER temp.....If one's vehicle is running at 190* under load I would aspect my tranny to peak there.... It doesn't. Why?
In summary........
The cooler is to small for a flow rate of 6 gallons per min,certainly NO time to chill it much, restricting it (flow)would be impossible, because apparently the ALLISON needs high volume.....If a bigger cooler was put in would it have adverse affects on the cooling (engine temp) because more surface area would covered there fore restricting more airflow over the radiator surface? Then resulting in higher temps in the Allison?
So IMHO, it is a design and positioning flaw of the cooler ...... We will see if GM moves it away from the position it's in now so the cooler can take full advantage of air flow through the grill..... More spy PICS needed.......
Have yet to have a VOLVO come in with a slush box for comparison photos, but eventually I will....... I could go stalk the truck stops, but I'm no homo lot lizard, with a camera in hand .........They could get the wrong idea...... :eek:
Sorry Billy,hope your not having NIGHTMARES of BOILING Tranny Blood... tongue.gif .... But the truth be know...... Temps kill...... The good things are our tranny is HD, =>With it's own Control Module, Clutch Packs that are numbered in sequence, no sprags or rollers or bands and engine braking in every gear, the Allison LCT 1000 is truly a departure from what you are used to seeing in the service bay!(from=>http://www.gmtcny.com/allison_lct_1000.htm)
It will take the heat and out live conventional tranny's that the competition has offered or offer, so sleep well........
Who is going to install an AUX. tranny guage to check accuracy? Did anyone drill a SWISS CHEESE BOW TIE????????? New SIG MOD.......LOL
MAC
:D
[ 07-17-2002: Message edited by: mackin ]</p>
pullinpower
07-17-2002, 06:31
I have a extra bowtie that I removed off my old grill when they installed a new one,I might go and swiss cheese it and see what that does.
I was taking a load of tree limbs to the dump and the temp was normal. While unloading the trailer, I left the truck running(need that AC here) and when I got back in the truck Trans. temp was 200 degrees. Drove home, and it never went under 200.
Anybody with the hot tranny's might want to try adding a seperate gauge just to make sure.
Installed the deflector yesterday and am leaving Fri. morn. for western Colo. where the temp. has been in the high 90`s & low 100. I`ll have my 5er behind me and will see what diff. there is in trans temp. Will post result.
P.S. Thanks Billy14 for the drawing, it went on fine.
Jomar
Searay90
07-17-2002, 16:35
The first piece of information we need is to know where the temp sensor is located. Discussions about tempatures is not relevant unless you know where you are measuring the temp at.
The radiator cooler is required on all tansmissions. If one were to measure the outlet temp of the oil leaving the transmission on its way to the radiator cooler, you would find that it will often exceed 240F if the torque converter is unlocked. That oil then goes to the radiator to be cooled down. You must remember that the radiator water will be cooler than the eng temp guage.
Our truck (and most all moder vehicles) uses a cross flow radiator. Hot water (@190F) leaves the top of the motor and enters the radiator on the Drivers side. The water then flows across the radiator to the passengers side of the truck. The water on the passengers side of the truck is "cooled" water that is then returned to the engine to cool it down.
The primary trans cooler is located in the passenger side of the radiator and is cooled by the "cooled" water in the radiator. I don't know what the temp of the water on the passenger side is, but it will be much lower than the 190F spoken of above. For purposes of discussion, let say the water temp has been cooled down to 150F after passing thru the radiator.
Now the primary trans cooler is sitting in water that is 150F. A liquid to liquid heat exchanger is more efficent (for a given size) than a liquid to air heat exchanger. Thats why all primary trans coolers are liquid to liquid heat exchangers located in the "cool" tank of a radiator.
So our hot oil from the trans is first sent to the primary trans cooler in the radiator to be cooled down first as this is the best heat exchanger for giving the greatest temp drop.
Now the oil leaves the primary heat exchanger and is routed to the auxillary (liquid to air) trans cooler where the temp of the oil is lowered again and then routed back to the transmission to start the cycle all over again.
DO NOT under any circumstances stop using the primary trans cooler located in the radiator.
Yes I agree that the aux cooler does not seem to be very large, and is located in a poor position under the "badge".
Now, back to my first comment. Unless we know exactly where the temp sensor is, we don't know what the temp guage is telling us specifically. It just tells us that the temp changes under certain conditions, and to what degree.
I had a 35ft motorhome with a Ford E4OD with a trans temp quage installed. Problem was that the trans temp sensor was installed in a "pressure test port" on the side of the tranny. It was not located in an area where it was exposed to a good flow of fluid in which to read fluid temps. So all it told me was the temp of the aluminum case it was screwed into.
In a perfect world (yeah right), you would have a multiposition switch on your trans guage, and 3 temp sensors. 1-trans outlet oil temp (this is the best place to monitor trans temps... but would scare the hell out of the average consumer because of how much it would fluctuate, and how high it would go). 2-trans inlet temp (tells you how well your cooling system is working... look at the delta between the outlet temp and inlet temp to see how much temp drop is) 3- Trans sump temp (gives you an idea of average operating temps)
I believe our temp guage is probably of the "sump" variety as it does not fluctuate quickly. The downside of it is that it does not respond quickly to changes in temp that will damage your trans, or give you an indication (quickly) that something is going wrong. Watching the outlet temp on your transmission will tell you instantly if something is starting to go wrong inside the tranny... just like a quick acting EGT guage tells you when your overloading the motor. The engine temp guage won't tell you your overloading the motor until much later (if ever).
The allison is a large (mass wise) transmission. Once it is heated up, it takes a long time to cool it back down because of the amount of thermodynamic energy store in the metal and fluid.
Looked at a 2003 HD today, and they have moved the Transmission Cooler down to the bottom of the grill. The top of the cooler is sitting at the bottom of the bowtie. Looks like someone woke up and heard what we have been saying. Don't know why they couldn't have done that to ours. :eek:
Searay90,
Excellent info. Thanks for the enlightenment.
Mike
SoCalDMAX
07-17-2002, 18:14
searay90,
Great post, excellent info! That all makes sense. I'm not sure what the radiator outlet temp is, but it's nice to know the heat exchanger is on the outlet side.
To answer your question about where the factory sensor is, IIRC one of the Allison techs said it was a varistor mounted in the oil flow, possibly in the outlet of the pump. I remember thinking at the time that it must be a very accurate source, but who's to say how accurate the gauge on the dash is.
So what do you think of replacing the cooler with a 96 plate, same design, mounted lower?
Regards, Steve
Well, this has got to be good news. :D :D Maybe we did make a difference. Hope they don't have a couple of air deflectors stuck in there too on the 2003's. I'll be bangin on the General's door for a royalty. Bet I'd get a long ways with that one. smile.gif
Looks like when I have the time I'd better get back to lowering OUR TRANNY COOLERS. Going to take some pretty fancy bracket work because the front grille where the bowtie is located will need a replacement support bracket as well. With the cooler lowered, the existing plastic support would stab right through the center of the cooler. :eek:
Billy
[ 07-17-2002: Message edited by: Billy14 ]</p>
pullinpower
07-17-2002, 20:24
Took a good long look at a 03 dmax today and they didnt change the mount on the tranny cooler what they did was the bowtie and the chrome strip is smaller than ours allowing more airflow into the cooler.
Guess what you GMC owners the GMC logo on the grill completely covers the transmission cooler. Now the question is where can I buy a nice billet grille so I can get rid of the GMC? Stu
pullinpower,
SWISS CHEESE your bow tie ........ Were counting on ya..........
MAC smile.gif
Swisscheesin your bowtie?
If you do, be sure & remove the plastic grille bracket that snaps in below the tranny cooler. Also, be careful how much & where you remove the material for your cheese holes. Even if you have a spare bowtie the rigidity of the grille will be compromised if too much material or the location of the cheese holes remove material that strengthens the grille.
I almost did this myself but chose to remove the cooler from it's mounted position & just let it hang below the bowtie. Great results which prompted me to fabricate the lower air deflector.
Billy
pullinpower
07-18-2002, 06:05
Billy14,we are only talking about a few holes :D If something happens I can always put my other one back on and act like it came that way :D :D
Mackin will do this weekend,I have a trip planned to the cabin in the hills and I can see the diff then.will post pics and temp readings.
Searay90
07-19-2002, 13:52
SoCalDMAX
I don't think any of GM's earlier trans coolers would work on our trucks. The earlier trans lines were 3/8 and our lines are 5/8 (i believe). Either way, the old coolers would restrict oil flow and damage the allison.
Now maybe someone could take a look at the aux coolers on the newer motorhome chasis that have use the t1000 allison in their applications. I would imagine that cooler is much larger than the one on our truck.
SoCalDMAX
07-20-2002, 07:14
Hi Searay,
LOL! I should've been more specific. It looks like I meant a cooler off of a '96. I actually meant a brand new cooler of exact same design, but it's comprised of 96 stacked plates instead of the 12 or 18 that ours are made of. This would give 8X the surface area and allow the oil velocity to slow down within the cooler. IIRC, they're available at the local parts store for about $90 or so.
I'm going to research finding the adapter fittings that will screw into the cooler and adapt it to the quick release on the lines, that way it's just a bolt-in. If anyone has any info on the cooler fittings or suppliers, that would be great, I don't know too much about them.
Regards, Steve
Searay90
07-20-2002, 10:15
Yes a 96 stack cooler would be a plus. As long as the adapters and inlet tubes on the cooler do not restrict the oil flow that our 5/8" lines provide.
Another possibility would be to mount another GM cooler in series with the existing aux cooler. Just mount it below the existing one and fabricate some lines to hook it up.
Hey Billy (or anyone with the drawing)
please send me your "deflector" drawing. my e-mail is XXXXXXXx
Hey thanks for the drawings!!!!!
[ 07-20-2002: Message edited by: Searay90 ]</p>
Searay 90,
I sent you an email with the drawings of the upper deflector that Billy made up and I have attached some pic of the modified lower deflector I made based on Billy's drawings for the upper.
Rgds,
Don
Jake99Z71
07-20-2002, 14:58
I was wondering if anyone has had a chance to look at the new C4500 or larger trucks with the Allison 1000 or 2000? What size air to oil cooler are they running? We might be able to use one from them. Just a thought for some of you that have seen these new trucks to look at this.
CSDMAX,
Can you send me the drawing of the upper deflector as well as pics of the lower deflector you sent to Searay 90??
We just purchased a 30ft 5er sooner than expected and I think I should seriously look into this.
my email is
robert_renwick@(no spam)hotmail.com
obviously remove the (no spam)
Thanks!
Bob
For those of you who don't trust the tranny gauge that GM puts in our trucks, there is a way to check your gauge accuracy very easily. When I went to put gauges is my last truck, the manufacturer wanted to know if I wanted to measure the temps through the dip stick. That sounded kind of jury rigged, so I opted to make a more permenent way to do it. The point is you can temporarily measure your tranny temps quick and dirty that way without a lot of expense, and see just what is going on with your very expensive transmission. FYI.
I can't remember who that manufacturer was, but other manufacturers were offering the same option, so it wouldn't be hard to find one. Just make sure they know the make vehicle you are going to put it in. I hope this helps.
Last few days has been hot and Nasty....... As MP made a suggestion of using the T/H in stop and go and such, I gave it a shot...... It does work, temp dropped a noticeable amount, stayed well off 200* even tho I was hotrodding around in Max Juice setting..... Sure is snotty, and not as smooth, but Eh, I didn't mind..... Also seen my first 03. Black smile.gif 2500 HD non D-Max.... I was in a hurry so I took no PICS but I'm going back .Thanks HD-BILL for the heads up on scouring the secret lot over the weekend.......I think they lowered the tranny cooler. I know the grill accents are smaller, but the cooler looks of center..... I'm looking closer at it soon....
MAC smile.gif
[ 07-30-2002: Message edited by: mackin ]</p>
Got a look at the Chevy 03' DMAX. They definitely dropped the tranny cooler. It is no longer behind the bow tie. I would say it has been dropped a good 4 to 5 inches. Sits right behind the lower grill and is barely obscured by the bow tie. Gee, I wish they thought of that sooner.
DON
Somebody needs to come out with an adaptor kit that has short 5/8" lines and couplings with a bracket that will allow the relocation of the cooler.
FirstDiesel
07-31-2002, 19:42
JK
You listening???
SoCalDMAX
08-01-2002, 11:07
I looked at the factory cooler. The quick release fitting in the cooler is just screwed in.
One could buy a larger stacked plate cooler, screw in the fittings, mount it lower and insert the hoses. It looks pretty simple...
Regards, Steve
Billy14
Took my 5er from Gunnison, Co. to Ouray, blew by some Foretravel Motor Homes on Cerro summit and Trans temp never got to 200. Thanks again,
Jomar
Jomar,
Great news. smile.gif Know that country pretty well from when I lived in Denver. Got some pretty steep grades to pull.
Question: Have you ever made the same trip before & do you recall the peak tranny temp.
Billy
Billy,
We are planning a trip to Gunnison next weekend with the new 5er. I haven't yet made the deflector yet (thanks to both you and Don for sending the pics and instructions) so maybe I will wait on installing it till the next trip (of course I have to build it first!), then I would be able to get a good comparison.
Monarch is a hell of a climb, that is where I expect the tranny temps to climb the most, as well as climbing up Turkey Creek Canyon on 285.
Dealer states the 5er wieghs around 8,200lbs or so. I plan on having it weighed just for my own knowledge, but not sure if I can get it done before the trip...
Bob
Searay90
08-03-2002, 21:28
We need Indigodually to post a picture, or tell us what the trans cooler on his 8.1/allison motorhome chasis looks like! :D
4x4man,
I know Monarch is a bear to climb. You sould have no problem with the 8.1/Allison under you for the 8200 lb tow. I hauled a 37 ft 5er @ 12500 lbs with my 97' 454 CC dually from CA to CO. The pass east of SLC was tough but she held in there. You have a lot less weight with 50-60 hp more and the Allison to back you up. Since the deflectors have been installed on her I have yet to see tranny peak over 185-195*. Of course that is unloaded.
Have a safe and great trip. Don't forget the Tow/Haul mode!!
Don
Just posting back on this. We got back late last night. Trans temp stayed at 200 degrees the whole trip, except once when I forgot to turn the tow haul on after gasing the pig up (Got up to about 210 until I noticed it)...
I still plan on making the deflector, but looks like I don't have to be in as big of a hurry as I first thought.
Found out the unloaded weight of the trailer was 8,660lbs, and usually doesn't include options. I figure I was probably running close to 10,000lbs after loaded with our junk as well as trailer options. Only the scale will tell though.
Got a whoping 6.5 mpg going up to Gunnison and around 7 mpg coming back to town...
Bob
4x4man,
I knew you would have no problem with your 8.1/Allison combo...but you noticed I never said that you would get good gas mileage...what a HOG the 8.1 is....6.5/7 MPG. :( It still surprises me that GM, despite the new engine design, has not improved their fuel economy as compared to the 454. Pullin a 12000 lb 37 ft 5er from CA to CO I averaged about 7-8 MPG from a normal of 10-11 MPG.
LOL
DON
Don,
Your right, the only painful thing was the gas mileage....I guess you pay upfront for the diesel or you pay at the pump for the gas.
I did find myself wondering how the diesel would've done going up on the west side of Monarch pass. It was very steep and at one point had me down to 30-35mph!!
We hit strong head winds on the way back as well and the motor ran at 3000 rpms a lot, sometimes 4000 rpms. I could almost watch the gas gauge go with the rpms sometimes!! LOL
Oh well, maybe when I hit the end of the 3yr warranty I may look at a D/A... oh the wife would kill me!! The previous truck was supposed to be my last truck for a while, then I said this one would be!!! :D
Bob
IndigoDually
08-12-2002, 13:46
I'll look at the cooler and see if there is a difference. I would like to see my trans run a little cooler also.
John
denverdale
08-12-2002, 20:35
Well guys, when I asked the original question, I never thought it would generate this much knowledge and misc. information. Great stuff. Now I am just confused!!!
One thing! I did not pay $40K for a vehicle so that I could shift it into neutral at every stop light. If that is required, then Chevrolet has a major design problem.
How about a billet chrom bowtie with holes in it, or just move the tranny cooler to the same location as the 2003's. I have to go look at one of those. My temp doesn't seem to be going as hot as it originally did. Towing this weeekend, the temp only got up to about 200* going up the mountain passes. I think I can live with that.
Thanks again for the great response from everyone.
Denverdale
Ranger354
08-13-2002, 18:26
Just got back from the deer lease. I pulled my 16ft trailer with a tractor on it and my jeep behind that. The tranny temp guage never got to 190. It was 96 down here in South Texas. I didn't have any problems at all. I let the truck idle a while and checked it again. The tran temp went back down to 160. So far so good. This thing pull a heck of alot better then my old truck. I will have a 32ft gooseneck trailer behind it next week. That will be the ultimat test.
HD Hauling
08-13-2002, 18:42
Hi fellows,
The reason the tranny is over heating is because the so Called Engineers of GM that Want To Be Diesel Specialist have unlocked the T/C because their have been complaints about the 2-1 shifting on hills!!
I also have the same trouble when pulling my 5th wheel.
Last year I was out to Las Vegas and the temperature was always over a 100 degree's and never did I get close to 200 degrees on the tranny.
Again we can all thank the Smart Engineers Of GM for this Stupid Move.And what gets my temp up is that they told us that they couldn't unlock the T/C because it would over heat and they do it anyway.
I'm glad they solved the 2-1 shifting for those who didn't use the brake to hold the truck on a hill and what ever!
We should all just burn up the tranny's and be done with it but then they would say it would be our fault!
When are these people going to get Help?They sure do need it! :mad:
What I have found sense this topic started was that if you drive with the T/H mode engaged in stop and go,(MP mentioned this) in my case stop and fly, my T Temps have stayed in a comfort zone.....I've seen 175-185 tops blazin hot, AC on, empty, JUICE on FULL, stop sign to stop sign .......Works for me, for now......Downside fuel economy goes in the toilet......Partly do my FOOT I'm sure,that and ,It's to dam much fun.........
MAC :D
[ 08-13-2002: Message edited by: mackin ]</p>
GMC-2002-Dmax
08-13-2002, 21:25
Hey Everyone,
I too am experiencing 190-200 degree Tranny Temps. I had an aux. cooler that I was going to install in my previous truck and never did.
As soon as I get a little spare time I am going to fabricate some brackets and get some fittings to adapt this cooler to my truck.
This is a HD Copper core with 1/2" lines. The Fan is 10" and will pull or push air. When I wire it up it will be a thermal switch thru a relay so it will come on when I need it too. I am gonna try for a 140-160 degree switch with 2 poles so I can over ride it and keep it on constant if i need to.
If anyone wants to see it I uploaded 5 new shots tonight. Click on my link for pictures and look in the Accessories Album.
I will update everyone as soon as I get this thing in. Hopefully for the HOT WEATHER so I can see the difference.
GMC ;)
IndigoDually
08-16-2002, 07:47
I can try to take some pictures but I don't think that they will show much. The instrument cluster does lack a trans temp gauge which annoys me. But, I don't think that temps are going to be a problem. The trans has a deep pan from the factory ( I guess that WorkHorse figured out what GM has not). The cooler is not a stacked plate design it is a finned tube. The plus is that it is 29" wide, 20" high and 2" thick. The top 3/4 of the cooler is blocked by the A/C condenser but there is a shroud and 2 electric fans to push air in from the front to add to the air that is being pulled by the engine fan.
I may add a temp gauge to keep an eye on it but I don't think that there is going an issue.
My D/A runs up to and around 200 all of the time with a trailer and 180-190 empty. I don't think that it has gone above 210 ever.
John
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