Extra trans Cooler

[Onebigcanuck]

I've just read an article in an RV magazine that claims an extra cooler will extend the life of your transmission by 50%.

Has anybody added one or what are your thoughts??

[More Power]

GM has the Allison cooling pretty well figured out, and most owners don't see excessive temperatures.

For the few who do see higher temps, I'd suggest running in T/H, which will lock the torque converter in second gear through 5th, reducing the amount of heat generated by an unlocked converter.

Beyond that, I have heard that there may be a more effective aftermarket cooler available before long - for those folks running aftermarket Allison's with higher pressures or those who tow heavy and have seen higher temps.

MP

[BozDMAX]

I was concerned about that a bit so I had an Allison Deep Pan installed by a Allison/Detriot Diesel dealer. I don't think I have seen the tranny temp pass 200 degrees since then.

I am still running the regular fluid (D-III?) and would go to the Transynd Allison Synthetic if I thought I was still running too hot.

Just how cool do you want your tranny fluid to be, anyway?

[Onebigcanuck]

I had to have the fluid replaced at 20,000 miles as it had turned almost black. The dealer found it while looking for a high pitched whine. They dropped the filter and found what looked like a paste in the fluid. The transmission was torn down and nothing was found. Warranty covered it. I was told not to do in gear idle in the future. I am close to the CGVW with a 5er and always tow in T/M.

Just looking to keep it working for a long time.

:rolleyes:

[tanker]

FYI, I installed the deep pan new filters (2) and installed "Transyn" fluid.
The other week we had a Kenworth/Allison in our shop with a PTO problem. The fluid was dark and had a burnt smell. I called our Allison Distributor and was advised that "Transyn" would turn a Golden Brown color with a burnt smell, and that this would be normal! :rolleyes: So that may be what was seen in the above postings. ;)

[Jim Brzozowski]

The cooler the better. If I see from the lights that I'm going to be sitting still for some time, I always bump mine into neutural. If you leave it in gear loaded against the TC, the rpm's are low enough at idle that very little circulation through the cooler of fluid or air is taking place. Once you start to move forward you are getting away from all of the hot air the vehicle is sitting in when standing still. The longer you sit there the harder the cooling system has to work to keep the temps from getting hotter. If its really hot like some places 110 or so, I'll even bring the rpm's up a bit to pull fresh air through and push the hot air toward the rear of the vehicle. It helps to watch the gauges when your pushing the system to its limits.

[hd90rider]

when pulling in high temps,my ally is always around 200. Throw in some serious grades & it will go higher.Forget the deep pan,doesnt help.. An additional tranny cooler is VERY desirable if doing a lot of pulling.My first tranny made it to 419,000 miles befor the tailshaft bearing disintegrated. Tuff tranny,but cooler is better. There is a guy in Ca.that has developed a drop-in cooler that is MUCH better than the stock cooler. Takes about 20 min to install & is around $400.

[a bear]

A couple of month ago I removed the OEM cooler from the cooler stack all together and installed a Setrab cooler behind the air dam with protection. The result is a solid 30 degree plus drop in tranny temps. Temp is now maintained around 160 to 165 degrees.
The added benefits are cooler AC output, lower intercooler temps and eliminated fan clutch engaugement. Previously with a 12K tow in summer months the fan clutch would engauge about every 3-5 minutes and stay engauged for about a minute. It was aggrivating as it was noisy and felt as though it consumed a considerable amount of HP. The absence of this was one of my goals in addition to lowering temps so I'm VERY pleased. Also for the first time since I purchased the truck I now have requests from the wife to raise the AC temp

[jjackson]

a bear, which "series" cooler did you purchase, and do you have the part # for it..? I pull a 5th wheel about 1K heavier than yours, and by the transmission gauge, I'm running between 165 - 190, but the fan does kick in frequently, and if your cooler upgrade has reduced that happening, it might be worth it.

Thanks, John

[a bear]

I'm running the Setrab 272D.
This is really too much cooler for the job at hand. I went with this one because of two reasons. One I had it on the shelf and two I was installing away from the radiator fan so the cooler would see minimal air flow at low speeds. This cooler is so large 8" x 22" that it dissipates more than enough heat with the size alone while seeing next to nothing in air flow.

Now that I know the setup will work with stopping fan activity while reducing temps on the cooler stack as a whole I will probably go to something smaller with a thermostat controlled fan set at 160-165 degrees. This way I can eliminate concerns of having too much cooling during the winter.

[hd90rider]

abear, did you have to mod the cooler to fit at all?? Sounds like a good deal you got in there,would be interested if you have more.If not where can I find a seatrab cooler? thanks Bill

[a bear]

Bill,
There were no mods to the cooler but I did fab the mounting brackets along with anti-vibration mounts which can be purchased from most hardware suppliers. The 272D cooler is a tight fit so it took carefull planning to get it into place. I plan on going to a 920FP Fan Pack cooler which is smaller and also produced by Setrab. This one will be a much easier install and should not over cool in the winter months which makes it better suited for our application. Once I get the smaller cooler installed I can send you the details and parts list. A web search for these coolers gives quite a few results for information purposes and pricing. The main thing to remember is to choose a cooler that has good flow as the Allison moves plenty fluid.

If you would like I can send pics of my current install when I return home on Tuesday.

[William Lee Gingerich]

Hey hd90rider did you say 419000 miles on your first allison or was that a misprint???And also was this on one duramax engine? I hope you will excuse my curiosity but it sounds like you are having really good sucess with your truck.

[Ranch55]

I took the OEM trans cooler off my '02 Duramax Allison and installed a cooler I got from Mako (online). It is manufactured by the OEM supplier ( Long's, in Canada) that suplies GM with the stock cooler. It was the BIG 11 1/2" X 11 1/2" X 1 1/2" thick, #HB7, on their website. I used the OEM fittings from the stock cooler and the oil lines slipped back in. I made some aluminum tubing spacers for the top mounting (to the same OEM mounting holes) and some aluminum flat bar for the bottom brackets (to the same OEM mounting holes). I had a 30 to 40 degree drop when towing, depending on load and outside temperature. Temperature when not towing on a HOT day (95 degrees plus) stays around 165 to 170 degrees.
On my '05 Duramax Allison, I had to buy the '02 cooler fittings for the cooler, because the newer OEM fittings have gone metric (versus 1/2" npt on the '02 OEM cooler) and would not fit the Long's cooler. My '05 also runs cooler, about the same numbers as above.

[OC_DMAX]

Ranch55 - What did you have to do to the OEM lines to get them to align to the new cooler. The height of the OEM cooler is about 5 inches. The height of the cooler you reference is 11 inches. I am not sure if everything will fit in the space without some rearranging of the supply and return fluid lines. Looks interesting.

[Ranch55]

OC_DMAX......I had to remove the plastic separator bracket where the lines come up from below. I installed some heavy duty 5/8" heater hose (split lengthwise) around the aluminum lines (secured with multiple plastic electrical wire ties) where they contacted each other and touched the frame assembly so there would not be any rubbing or chaffing against each other to rub holes in the lines.I had my aluminum flat bar brackets pre-fabbed to length (about 8~9" long, measure for fit) and mounting holes drilled and my aluminum tubing extension mounts for the top ready (cut about 2 1/2" long). I installed the lines into the cooler fittings and secured, then pulled the cooler up into position and mounted with my four small cap screws/bolts. The top screws/bolts are S.S. 1/4" X 3"long. The Cooler comes with some brackets also to ensure some rigidity in the mount so as not to over flex the cooler. It worked out very good with very little work. My brother also mounted the same cooler on his '05 Duramax-Allison with the same results in temperature drop pulling his camping trailer in the Arkansas mountains 2 weeks ago.

[hd90rider]

a bear, thanks for the offer of the pics. If you think the next install will be better for the truck,lets wait on pics of that install

[hd90rider]

William Lee Gingerich, No the engine didnt last that long. Just the tranny. Engine went at 283k new one @ 170k just had to have injectors replaced,this week-end. Bosch needs to make these injectors more reliable, we have D***E trucks here running over 500k

[OC_DMAX]

Ranch55 -

So you essentially pushed the plumbing slightly lower to fit the larger cooler in. Did you have to cut the lines at all?

Also, what were your transmission temps during the winter?

Thanks.
Alan

[Ranch55]

OC_DMAX......Right, the lines are flexible below the front frame area. I pushed the lines down some and they also crossed each other some, that is the reason for the heating hose shielding, to keep from rubbing on each other or the frame area. Winter temperatures usually run (Texas) around 140 to 150 degrees with no pulling load. It'll heat up a little more when I put my low-boy on back (150~165 maybe).
I'll get some digital photos this afternoon and try to post. And OH,,, No, I did not have to cut the lines at all. They are still stock OEM. When I sold my '02 earlier this year to order my '05, I removed my Long's cooler and reinstalled the stock OEM cooler. Then I used it and installed on my '05 the exact same way (except for purchasing the "02 OEM cooler fittings I mentioned in my previous note).

[OC_DMAX]

Ranch55 - I would be interested in seeing any pictures you have. To post on this forum, you need to have the picture posted on another server and then you post a link to the picture. Your mod looks like a fun project (I just need to find the time).

A note - it appears as if the 2006 DMAX trucks now have a different tranny cooler and it is mount much lower (ala the ABEAR position). Hopefully, this eliminates some of the overheating problems the LLY owners have been experiencing.