Allison Tranny Problem

[Kib]

I left our "02" DURAMAX sitting for a week while on holidays in the sunny south. When I started it, let it warm up and tried to move the tranny wouldn't shift. Let it warm some more and was able to move ahead but with high revs and in reverse the "R" light blinked and it didn't move. Got out the manual and read how to cold check the tranny fluid. Performed the sequence several times and tranny worked ok. The temperature at night was low to mid 20s Fahrenheit while we were away. I talked with other DURAMAX/ALLISON people and they didn't have this problem with the cold/sitting but one diesel owner suggested the tranny filter may be plugging. The GM service manager suggested adding a conditioner and then performing the tranny service in 2-3000 miles. Suggestions? Truck only has 40k miles on it. :confused:

[cowboywildbill]

Sounds like it could be a drainback problem, because it happened after sitting for a week, and it may have lost it's prime. It takes a couple of minutes to prime back up and start moving and shifting normal again after that happens. Or it could be a NSBU problem, and that seems to be more of a frequent problem in the cold wet weather. Or maybe both. Changing the filter is a good place to start but I wouldn't think that adding an additive would be a good idea. I don't think allison recomends them any way. I would try and check out the previous post on these symtoms, there are Service bullitens on these issues. I am surprised your dealer didn't know that. I have had the drain back problem once, after my truck sat for two weeks. But it never happened again. And I replaced my NSBU switch last winter. Best of luck on your truck.

[ 04-28-2004, 05:28 PM: Message edited by: Cowboy Wild Bill ]

[Heartbeat Hauler]

Kib,
Did you change your spin-on tranny filter at 5000 miles? I had the same problem and the filter was plugged (restricted flow). I would not use an additive in the tranny, and it's scary that the GM dealer suggested it. Also, you might let the dealer check to see if any codes were stored.
JP

[Kib]

I just checked the Allsion web site and they make the recommendation that the spin on tranny filter be changed at 5000 mi. In there FAQ section they state GM in the 2003 year and after will change it at 7500 mi. I don't know if it was because I am the second owner, however it does sound suspicious. My GM maintenance manual only mentions changing the fluid and filters every 50,000 mi. Allison states emphatically that no additives are to be used. Another question? ---- Allison mentions a synthetic fluid called TranSynd. Reading the info they have concerning harsh conditions and with the late fall, winter, early spring temperatures (routinely below 20 deg F) in our area it may be helpful in the tranny performance. Has anyone had any experience with TranSynd?

[Dawg]

I wouldn't add any 'snake oil'. The Allison is a great transmission and most additives are not recommended. Sounds like you have the drain back condition. The dealer should do a little checking instead of recommending a conditioner. I don't recall if there was a fix or just what the deal was. It has been discussed before and you may find more info if you do a search under the drivetrain section. More Power might be able to give you more info.

[timssilverchevy2003]

I live in NY, I have had my truck parked since September (on assignment overseas). Left the keys with my old man, he starts it every two weeks and gives it a good run. No problems with anything like what your saying, Regular service completed on Allison/ Duramax. Can't wait to get home!!


2003 2500HD LT CC SB, Pyro, boost gauges, Quadzilla chip, TTT lighted/heated mirrors, Rancho 9000X shocks, Best truck ever built by GM!

[Sneaks]

Originally posted by Kib:
[QB] I left our "02" DURAMAX sitting for a week while on holidays in the sunny south. When I started it, let it warm up and tried to move the tranny wouldn't shift. Does this sound familiar? If so, tell your goodwrench to check TSB 02-07-30-011B (excerpt follows)

Some customers may comment on one or more of the following conditions.

^ The PRNDL display is flashing.

^ The engine will not start.

^ The Service Engine Soon" Indicator lamp is illuminated.

^ The transmission does not shift properly.

^ The vehicle will not move, transmission will not engage.


Cause

Moisture contamination within the Park Neutral Position (PNP) Switch may cause this condition.

This is sometimes referred to as the Neutral Start Back-up (NSBU) Switch. On a left turn, water spray from the left front tire is directed directly at this switch. Proper installation of the "Front Shield" and "Rear Shield" are essential for proper repairs.
_______________________________________________

You might also check 03-07-30-011 which deals with *just* the Allison delayed shift after sitting for long periods. Mine had that one, which entails replacing a couple of 69 cent parts but two days with the Goodwrenchers. Unless yours is an early build, I doubt if that's it since Allison began using stronger springs in early '02' and beyond.

[ 05-03-2004, 05:06 AM: Message edited by: Sneaks ]