Allison problems

[TexasDmax]

Truck left me stranded the other day had it towed to dealer, they got back to me to day and say it is trashed and needs to be replaced. has 46,000 miles. they gave me chevy customer service i called they are going to let me know if they can work something out.4300 to replace.
here is the symptoms: I was pulling about 10,000 lbs, juice in level one everything was fine the first 100 miles then i noticed tranny temp got about 215 but then went back to about 195 pulled up to light to make a turn i noticed no downshifting, rolled through light and hit the throttle, motor reved way up like it had a 3500 stall converter and went I went on about 3 miles trying to figure out what to do, I was about 40 miles to a dealer. i stopped checked fluid, turned truck off. fluid was nice and pink i had changed to Transsynd at about 20,000. it was not low but did smell a little burnt like it had gotten hot. I restarted the truck put in drive,it would not move, it would move in reverse,but it clanked into reverse. I then noticed the SES light on and then the shift indicator flashing. when the tech first checked it the code said a solniod on the valve body, he pulled the pan and there is much debry in the pan and that it seems a clutch pack is going bad and some other parts are burnt.
So tell me guys do you think it is really trash? the service guy mentioned the nsbs when i was on the phone before it got towed in. this is not a dealer in my area but I know some people that use them and have had good luck and they have been very helpful to me.am i going to get some help from the general?. Who do i call if the customer service doesn't work? if i don't get help should i use the gm allison or is it worth getting a suncoast or a bd.thank you to everyone on this board you all keep me very informed.

[DieselDixon]

I found out that the GM customer service is as high as you can go. They are actually very helpful and keep very good notes about every phone call. They will also keep in touch until the problem is solved.

Hope everything works out for you and keep us informed.

[WhiteDuramax]

If they are goin to charge you 4300$ to replace it, I would definately check with BD and suncoast first, they give warranties with theirs. Especially if you like to add power. Sorry about your luck with it, havent ever heard of one going out.

[dmaxalliTech]

You will have the best luck for goodwill assitance at your purchasing dealer. GM allows warr assistance up to 60k. You might get a deductable, but it is usually less then 500.00

[blakmax]

Texas! Your post sounds like calls i receive daily.I rebuild for a living, so sorry without more info, your supporters cannot help. Codes that are stored in tcm memory would be helpful.I do know that techs seem at times to exaggerate trash in the pan. Take a look for yourself.
Hope This

[TexasDmax]

I have not been able to see it as it is out of town about 100 miles, they did not give me the code number just that it was for a solniod on the valve body preventing me from having forward speeds. i will try to get the specific code i do know that the SES light only came on after i stopped to check it out and tried to move again.it seemed to be slipping of like the torque converter was out before i stopped but no limp mode and it has never been into limp either. if this sounds like something else and not the clutch packs let me know. iam notall that hard on the truck i never pull more than about 12,000 and only about 8 times a year. i drag raced a couple of times when the juice was new but that was 20,000 miles ago, I love this truck and am really dissapointed i could not comeplain one bit berfore last friday. My family and business has owned gm products only for generations with not one trouble like this with low miles. This is really breaking my heart.

[DmaxMaverick]

TexasDmax

These trannies are real hardy and will take a lot of abuse berore giving up the ghost.

It sounds like your "stall converter" symptom is more likely limp mode. The tranny will only engage in 2nd or 3rd gear, depending on which solenoid is having a fit. Due to your top speed, I'd say 2nd, which could indicate a 3rd gear solenoid. The result is a condition very similar to what you described. Most of the input torque is unloaded on the torque converter, lightening the load on the tranny. Beware though. Allowing it to rev up to high rpm's does create a lot of fluid heat. Ease into it.

Most solenoid problems will work themselves out, given a little time with no long term effects. The problem is usually a little debris causing it to stick. If it continues to fail, they are easily replaced and are not that expensive compared to an overhaul.

A "lot" of trash in the pan really doesn't say much unless you can identify where it came from. Wear materials are normal and will show up during the life of the tranny. It is possible that they accumulated somewhere in there and just decided to drop into the pan all at once. If that is the case, it is likely that the filter is plugged up and needs replaced. I would start there. Check the magnet on the filter. Most of the clutch material, if any, is non-ferous and will not be present on the magnet, most other wear materials are. Compare what you have in the pan with what is on the magnet.

My suggestion is to get a couple external filters and one internal filter. Replace them and do a drain/fill, or better yet, a flush (ala Hoot style), and try running it unloaded for a short while, maybe 1-2000 miles. Change the external filter again and do a drain/fill. Do not use a tranny additive. They only increase friction, decrease lubrocity (regardless of their claims), and soften seals. They won't work worth beans in the newer systems.

I have other options to offer, but give this some thought for now. Of course, if GM goes to bat for you, please disregard this. Let them throw their wallet at it.

Good luck with it.

[TexasDmax]

I talked to gm customer service this afternoon they offered to pay half. i talked to the tech and he says he was sure it was the solniod but when he got the pan down it has the usual clutch debry but also lots of metal fragments and that he has never seen an allison like this. this is a high volume truck dealer and he is there tranny specialist. problem is i need this truck and the way i see it a new tranny at 44,000 for half price is better than a new one at 100,000 and full price. i took it as it was all they would offer. I am in the a/c service business and a pretty good judge of bulls**t and it seems this tech know's what he is talking about. i will let you guys know what happens thank oyu for all your help.

[Bad Dawg]

This past weekend, while towing race rig on our flat bed the Alli started to chatter in first gear under load. As soon as it shifted it went away. Took in in with everything still hitched up to let the service manager feel it. He thinks it could be one of a few different things: "Lift Kit" related to drive line angle(I don't think so, we only added the Rancho 4" to the front with only the Air Bags in the rear). "Juice" related - too much HP and torque (I run the EZamp at 90hp in normal mode and 60hp in tow/haul). It isn't a street racer, I haul a 4000lb cab over camper along with the 6000lb trailer and race rig. It seems to run hot - 200+ around town.
The service manager suggested that the factory most likely will not warrenty it because of the mods, although I doubt the mods had anything to do with it. Has any one else had this chatter? First thought was the old driveline issue but I have a crew cab long box with the two piece drive shaft. :confused:

[77TransAm]

Your problem does sound like the launch shudder on acceleration condition that a lot of the early trucks experienced. The crew cab long beds were not eligible for a one-piece drive shaft because of their length, but they do sometimes still experience the condition.

GM did a lot of experimenting with carrier bearing placement to try to eliminate the condition - it's amazing how a change of only a few millimeters in height will make the shudder appear or disappear, so it wouldn't surprise me if a bigger change in angle would cause a problem for you.

[dmaxalliTech]

C/C SHORT box will accept the one piece shaft.
CC LONG box, will not. Unless you can put yokes on the end of a telephone pole.

[Bad Dawg]

:D "Can you hear me now?"
Another thought came to mind, on my 97 3/4 ton with limited slip I ended up having to put an extra bottle of limited slip fluid in the rear end because it was shuddering off the line. Maybe I might get lucky and this is the same.

[DmaxMaverick]

Bad Dawg

I would not suggest adding anything to the rear end. It is not recommended, and may cause damage over time and reduce the life of the lube. The 2500HD/3500 rear end is not designed like the old limited slip (although it still carries the G80 designation). The additives contain strong acids or phosphates that can damage clutch material, bearings and gear surfaces if they are not intended for additive use.

If the rear end (newer AA 11 1/2") is the source of shudder, it is either broke or the lube is contaminated or depleated. If the original synthetic lube is replaced with mineral based lube, or the wrong grade, it could also cause problems.

[tophog]

Bad Dawg,

I had a 2001 that had similar symptoms ...a chaddering/vibrating feeling during take off only, most noticably turning right/left. Felt kind a like rear end was slipping or something. Long story short, I never changed the rear diff fluid ... truck had 15K on it with lots of towing ... drained/refilled rear diff ... problem solved. Just a thought.

[Bad Dawg]

:eek: Wow, didn't know that. Thanks for the heads up. Guess I'll just have to take it in and have the experts look at it.
My first chance to drive it unloaded will be tomorrow. Curious how it will do.