Allison slip in 1st gear

[TN farmer]

When I drive to the end of my driveway (50 yards) first thing in the morning I feel the trans slip or hesitate. I only notice first thing in the morning. It is like it is in neutral for about 2 seconds while the rpm comes up, then you put it in drive. Is this only because of the cold weather and it is not warmed up yet or is there another answer?

[Buckman]

TN farmer,

You didn't say how long you've had your truck or if it had been into the dealer regarding the problem. My first thought would be to get the truck into the dealer and have the transmission and engine calibrations checked to ensure they are the latest and greatest. There was a service calibration released for the trans in May, 2002 that addressed various shift complains. Keep us posted on the findings and whether there is any change. Also, has the truck always done this or is the problem recent? If recent, how cold has it been in your area?

[SteveO]

TN Farmer,

Does it do this everday?
Are you turning around in the driveway then forward?
You do relize that the Engine fan makes A lot of noise (fulling on) for the first few hundred feet that you accelerate when cold?
How long are you waiting until you take off?

[TN farmer]

I bought the truck new in Sept. and have about 12,000 miles on it. I have had the same tires the entire time also. I have noticed it about three times a week for the last month. The temp. in my area got down in the teens several nights this last week. On some of the colder nights when I crank up in the morning I let it idle for 5 or 10 minutes before driving.

Same procedure each morning: Back out of my parking spot 20 feet and then put it in drive and go to the end of my driveway (50 yards). I don't come to a complete stop at the end of my driveway but after looking for traffic I pull out. When I pull out is when I feel it hesitate and that is the only time all day that it will act up.

Hope this helps ,thanks for the advice.

[YZF1R]

Perhaps your catching it just as it's going from second back to first gear as you apply throttle to pull out.

Just a thought.

Steve

[CanadaKev]

TN,
My truck has done the same thing.(Maybe 4 or 5 times in the last 8 months). Same scenario except my driveway is longer. It feels like the transmission is still half asleep, and is searching for the right gear. You feel like a bit of an idiot when you are pulling out into traffic, you step on the go peddle and it hesitates for a couple of seconds. :(

Maybe it's just a symptom of a 'farm truck' :D ;) :D

Kev

[TN farmer]

Kev

I am glad to hear that my truck is not the only one that this has happened to.

I also want to ask you how you like your aFe intake and what is the "3" Front Suspension Torsion Bar Levelling Kit" that you mentioned on your signature?

Thanks

[CanadaKev]

TN,
I really like the AFE. It seems to increase airflow.
As far as the torsion bar kit goes, I changed out the torsion keys for a set that are cammed differently. It raised the front end 3". I purchased them from Hill4wheeldrive. Some folks on here think it's a waste of money, and you can almost achieve the same thing by just adjusting the torsion screws.
Whaddaya grow down there in TN? Got any bovines??

Kev

[Dave_WB3FYV]

I think YZF1R and Buckman have it right, it's not downshifting to first while still rolling, until you hit the gas and it isn't sure what to do. A lot of us with '01s had the problem quite severly and had to go back to get a TCM upgrade. Part of the problem is the throttle position sensor. If you even lay a feather on the pedal, it won't drop into first - even when stopped. Hit the gas and it will bang a downshift!
Notice if your foot is close to the pedal next time. Then get the TCM reflash, it's quick, painless, and free.

[TN farmer]

Dave thanks for the help I will probally go ahead and go to the dealer and make sure I have the latest updates.

Kev We grow cotton on most of our land but also grow wheat, beans, corn, and milo. My brother has all the cows, not interested in them myself.

[sixl]

Does any one know of a good strong tranny upgrade mine slips in 5th all of the time and puts the pickup in limp mode. :mad:

[Colorado Kid]

Yep. Talk to these guys:
http://www.thedieselpage.com/cgi-bin/banners/ebanners.cgi?ATS

[Rebel_Horseman]

My truck does the same thing to me quite regularly. It's more aggrivating than anything. I'm starting to think it's a farm truck thing too. :eek:

Reb [><]

[SteveO]

More questionns for both guys,

From the time you put it in drive (forward) to the end of the driveway, does the trans upshift into the next gear?

Try this.. When you put the truck in forward for the first time, PULL the gear selector all the way down to the 1st position.. Drive to the end of your driveway and take off.. Does it still do the neutral thing? Also DO not drive with one foot on the gas and one foot on the brake.. NEVER do this...

[TN farmer]

Steve

I never go fast enough down my driveway to cause the tranny to shift out of first.

[hoot]

TN Farmer,

How many miles you got on it?

All driveway miles right? ;)

Are you guys having problems using two feet?

[ 01-31-2003: Message edited by: hoot ]</p>

[mackin]

Quote:"Also DO not drive with one foot on the gas and one foot on the brake.. NEVER do this..."


OH Man !!!!!!

Why, excessive tire wear??? !!!!!! :eek: :D :D :eek:

[ 01-31-2003: Message edited by: mackin ]</p>

[hoot]

Man, I'm a terrible speed reader. I flunked the Evelen Wood sped redding corse

[afp]

Yeah, how can you launch hard unless you stall the converter to about 1800 with one foot on the gas and the other on the brake? I guess we could all get tranny brakes. Anyone make those for the Allison yet?

I too ocassionally get that cold, first gear slip. If I complain about that and take it in, will the tranny reflash add in the OD lockout feature?

Blaine

[ 01-31-2003: Message edited by: afp ]</p>

[SteveO]

Hi Guys,

Been a busy weekend to say the least...

Doing burnouts and the subject at hand are not the samething..

Yes, If the TCM is updated you will get the OD lockout capability and all the other updates.. You will still need to wire it up, but the function will be turned on.. Two wires and a MOMENTARY switch and your fixed..

TN Famer, I do recommend the TCM and PCM updates if it's not been done already but I'm in doubt this is going to fix your complaint.. If you rev the truck up a few times (in Neutral) and then take off does it still do this? Or if your stop halfway down the driveway and take off again does it still slip as you pull out of the driveway?
Please update the outcome..

[mackin]

SteveO

I for one knew that, I was just yanking your TCM !!!!!! tongue.gif

MAC :D :D :D

[TN farmer]

SteveO, I have not tried any of the procedures you mentioned (reving in Neutral) because it does not do it every morning. Honestly I forget about it untill it happens which seems to be only in very cold weather. The problem has not happen in over a week and I hope to get the computer reflashed next week. Thanks, Robert

[Mike O.]

SteveO,
Are you refering to the tranny fluid "pressure-up" delay after start? This is a definite possibility if TNFarmer is dropping it into drive and taking off immediately after starting.

[SteveO]

Mike O,

I don't think so.. The reason I say this is the amount of time TNFarmer is waiting before he starts out in the morning.. He says 5-10 minutes... If it was a "Slow to Prime" problem he should get a Check Engine light way before the end of the driveway, Actually he should get a "Check Engine" light the moment he puts it in gear the first time...


TNFarmer,

keep me posted on the outcome

[Rebel_Horseman]

Here's what happens when I get the bump form the trannie. Crank up and letit idle for about 5 minutes. Back up about 10' then to drive for 30' with no upshift to 2nd and stop. Left turn and about 100' to another stop with an upshift to 2nd. Most of the time it happens when I'm stopped for the second time. It's a feeling like the trannie goes into neutral for a second. When I go to take off or even if I'm sitting i get a jerk of the truck as it realises that it shouldn't be in neutral, but in drive (1st). Sometimes it doesn't do this until I give it some go pedal to enter the highway then it almost chirps the tires as it remembers to shift into 1st gear.

TN Farmer, have you updated to the "newest" NBSU? Maybe the NBSU is faulty and is not shifting the truck correctly. Any thoughts?

[TN farmer]

I have not had any updates since I got the truck in September. The temps are falling and I will see if it is going to act up this weekend with the colder weather. I will keep you poisted.

[afp]

Is the "fluid pressure build up delay" a normal feature of the Allison? My father-in-law owned a tranny shop for 40 years. He noticed the slip right away and amsde me put more fluid in (I was maybe 1/4 pint low). I ocassionally feel this--just as described here--but always assumed it was the nature of the tranny.

Blaine

[SteveO]

Rebel_Horseman

Your problem is easy to fix, and it's not the same as TNFarmer's.. That problem has been addressed in the latest software update.. It's called "Neutral feel at stop".. If the TCM has not been updated, do so, this will fix your problem..
--------------------
I'm going to say this again&gt;&gt; If you drive with TWO feet you will have all kinds of problems..
Right foot is for Brake and Gas..
--------------------

I honestly have not witnessed (felt) the 1st gear slip you guys are talking about...

[TN farmer]

--------------------
I'm going to say this again&gt;&gt; If you drive with TWO feet you will have all kinds of problems..
Right foot is for Brake and Gas..
--------------------

If you are refering to this as the cause of my problem I must not have stated that I don't do this.

How can you drive like this in a manual
:confused:

[afp]

SteveO,

Then I guess I need to respond again. Having one foot on the brake on one on the gas is not automatically (pun intended) a problem--if you are coordinated enough. The biggest danger is hitting the gas when you meant to hit the brake and vice-a-versa, for obvious reasons. I frequently put one foot on the gas and one foot on the brake when stopped at a light. This allows me to make a quicker launch. (No, I do not routinely stall the converter against the brake at a stoplight.) I have ZERO problems "launching" this way.

However, I do not drive about or come to a stop with one foot on the brake and one on the gas. This indeed causes problems for me PERSONALLY--I won't speak for others.

A lesser problem with having one foot on the brake and one on the gas is converter wear. if you ROUTINELY stall the converter against the brake, you can shorten the life of the converter. Ocassionally doing this won't likely cause any problems. Crud, converters used to last for years on Supergas cars (2500ish lb drag race cars generating 500ish ft lbs of torque and running 9.90 at 140s in the 1/4 mile). Every launch was highly stalled against the foot brake. When they invented transbrakes, converters did start wearing out quicker due to the dramatically increased stress (and much harder launch) the transbrake allowed.

Blaine

[SteveO]

TNFarmer,

No, I was not speaking to you personally.. Do you take your right foot ALL the way off the throttle and apply the brake fully at the end of your driveway?

afp,

True, the problems you have stated can happen, but that's not really what I was talking about...

The 2-1 bump or GM Bulletin calls it the "Neutral Feel at Stop" (software updated fixed it) is caused by a person leaving the right foot on the throttle as they come to a stop..
Remember, the throttle is VERY sensitive to movement..
It can also be caused by a person who uses both feet to apply the pedals.. The 2-1 Bump has been a MAJOR problem becuase people think they are taking therte foot off the gas as they come to a stop when in reality they are still applying the throttle just enough that the trans stayes in 2nd gear then when they go to take off it BANGS into first..
Believe me, I ride with people EVERYDAY, that say, "I'm only using one foot and I remove it completly from the throttle at a stop".. My laptop smile.gif tells the tail, 9 out of 10 customers are keeping a foot on the throttle..

BTW: Info some may not be aware of..
There are 17 different throttle positions for the TCM to calculate Up and Down shifts smile.gif First one starts at 0.00% last on is 100%..

[afp]

Steve,

Interesting. So the throttle has to be completely off before the tranny will shift into first............

I haven't had that particular problem when coming to a stop. The only time it has shown up is when going from reverse to forward, and every intermittantly even then.

I don't put my left foot on the brake until I am completely stopped, so when coming to a stop neither foot is on the throttle.

Blaine

[Geerrhead]

Hello,

If you want my 2 cent's,here it is. I think the tranny is loosing it's prime. Updates have been unsuceesful. Dealer personal either can't or won't take the time to fix it. I back out of my driveway, shift 1-2, go 100ft or so, apply brake with right foot, coming to a rolling stop. use right foot to proceed, applying light throttle, the engine rev's to 1500 rpm's. Then the tranny decides to engage 1st gear with a bang. Drive 1/10 of a mile to the next stop sign. It happen's again. It will do it while turning at a stop sign or continuing straight. It drives fine during the highway trip to work.For me personally,here is the situation that leads me to believe the front pump is sucking air. Start truck cold,idle for a minute pull out of parking lot. Truck has not shifted out of 1st yet.Cross road and drive up a steep incline. If I am doing 5 mph and let completely off the throttle, then apply the throttle before i come to a complete stop, I will get a HUGE bang from nuetral into 1st gear. All of these situations will cause the fluid to slosh inside the tranny pan. I feel on the hill, all of the fluid has run to the back of the pan. After returning home with a fully warm truck, I decide to leave an hour or so later, the tranny will do the same thing at every stop sign, even with a warmed up transmission. It is definately easier to duplicate this concern while turning at an intersection. Don't worry guy's, if the guy's at the dealer can't fix it, eventually it will burn out the clutch pack. Then they will put a unit in it. It's a shame the tech's on the local level are not well versed in Allison's. I wish we had people of SteveO's caliber in the dealer's!! I read every one of your post's Steve! Thanks for sharing your experience and technical background. :D Sorry for the long post.

[Redhawk]

Not all dealers are aware that the problem you describe has a TSB on it, so when you go in be nice but be insistant. My dealer wasn't aware of the problem, so he researched it after I mentioned that there were many complaints out there. The reflash fixed the "bang into first" syndrome and also fixed the hunting and busy shifting when hitting a small grade in overdrive.

[tpitt]

Redhawk,
Who do you take your vehicle to, Fowlers? Mines never been in the shop. Thought about having the updates done and installing the o.d. lockout. We've had some of our State rigs to them and they were pretty poor to deal with. They do have the best parts people in the business though. Some day we should arrange a get together. Theres getting to be quite a few Duramaxs in the area anymore. tpitt

[Redhawk]

I go to Fowler for oil changes, tire rotation and other small things I pay for myself because they are much closer to me. I go to Silveira in Healdsburg for the major stuff like warranty work or to buy a vehicle. They are about 40 miles or so further than Fowler, but they are really good people and responsive to my needs.

You're right about more D/As around here, both GMC and Chevs. Another way to gauge the number of Duramax trucks is to check out how many more threads there are on the diesel page. Originally we were lucky to see ten topics and four or five replies.

Maybe you, George Burton in Willits and I could get together for coffee some time.

[ 03-17-2003: Message edited by: Redhawk ]</p>

[Diesel Crat]

My 02 CCSB 44,000 miles has done both things: The 2-1 bang or bump or lurch or whatever and also the rolling stop neutral state that Rebel Horsemen experienced.

A TCM update was performed when my Fuel Temp Sensor issue was fixed and I haven't noticed the 2-1 bump any longer. However, I'm still getting the neutral state at rolling stop or very short complete stop.

I do the same thing as Rebel Horseman every morning. After a 5-10 minute warmup, sometimes shorter sometimes longer, I back up 20-30 feet and pull forward about 50 yards to the end of driveway. When pushing pedal to go, the engine revs up then idles down and engages first gear. Truck is parked slightly uphill at night but is parked downhill all day at work. Problem also occurs leaving work. It has even occurred after driving 35 miles to Dr.'s office and leaving after a 30 minute sit. I don't believe it has anything to do with being "cold" although it may aggrivate the problem more often. Leaving work is the same procedure described for leaving the house except I don't use reverse. The problem first showed up last September after I got the truck in June. It's been doing it all winter and seems more frequent now and its been 70F + for several weeks now.

Also, I'm almost positive that I've been in first gear when hitting the end of the driveway as well as second gear and had it do the same thing. To that end I'm positive that I'm not a two footed driver though that's a very good diagnostic question since several folks do drive that way. smile.gif

"Steve O" I tried the stop halfway and it does it both places. It doesn't ever do it after reaching road speed and cycling through all of the gears once. Could it possibly be something related to the sticky solenoid valves or tranny prime issues?

Both my NSBU switch and fuel regulator have been replaced so I dont believe its related to either of the systems associted with those items.

Anyway, other than the 2-1 bump TCM software update, has anyone gotten resolution on the neutral state being described when first starting the truck and leaving the driveway, parking lot, etc.? Anyone with loose wiring connector or bad shaft speed sensors that might cause intermittent problems???? :confused:

Sorry for the long post.....