Allison needs to be replaced

[4X496Dooley]

Just returned from a trip to the bay area. After decending a steep hill in tow/haul with grade breaking on I noticed a very faint high pitched whine from the tranny. Once I exited the freeway and slowed down the whine is very loud. Took it to a Chevy dealer this morning before heading home and don't believe the service manager even knew what the Allison trans was. So I went across the street to the GMC dealer and the shop foreman checked it out and even called GM tech support. They believe it is the pump but said it would probably get me back to L.A. It made it back fully functioning and with good temp. Dropped it off at my local dealer and will call tomorrow with details. But was sure it would be replaced without any problems. Anybody else experienced similar problems?

[Vincent]

Yep I went down that same road myself. My tranny was so noisy I couldnt hear my diesel anymore and driving with my windows down was truly annoying.

It happened after a couple of hard tow jobs of the travel trailer. I never experienced any shifting or temp problems, just excessive noise.

After much griping to my local service department and convincing/proving to them they dont all do that (they insisted they did!) I got it swapped out. They had to get the blessing from the GM Techline to swap it out.

Unfortunately, the replacement tranny they put in was new but developed a leak out of the bell housing after two tows. They replaced several stato-seals and loctited the bolts as per a GM Tech Bulletin and so far so good with several thousand miles of towing.

[Fatdaddy]

Four months after I got my first HD I had problems with my tranny. Was just driving down the road and all of a sudden it sound like it was slammed down into first gear. I had to drive 10mph all the way home and called the dealer to come get it. After they fixed the problem I asked what had happened. The tech told me that the planetary gear came loose inside the tranny and messed everything up in there. They did not replace the tranny, but they had to replace everything inside it. Never had another problem with it after that.

[Joe.G]

Fatdaddy
Your under arm deodorant ain't cuttin it. Something stinks here!

[hammer]

Joe G,I agree with you about Fat Daddy's forum article.If its that serious they would replace it.My dealer said that if something goes wrong with my Allis it would get replaced no questions asked.Hammer smile.gif smile.gif

[dcpdave]

fatdaddy,
obviously, you do not have an allison transmission in your truck. g.m. will NOT allow us to perform ANY internal repairs to the allison yet. if there is an internal failure, g.m. sends us an exchange transmission and we send them the defective one so that the engineers can investigate the cause of failure. as i posted in another subject(leaking transmission), the high pitch squeal noise may be from the torque converter bolts backing out. we have had only one failure of the transmission, and this was the cause. the bolts backed completely out, allowing the converter to "walk", damaging the front pump. two of the bolts penetrated the flywheel housing. g.m. sent us a new transmission assembly. if the bolts back out and is caught before any damage occurs, we can replace just the bolts, converter housing seals, and front pump seal, that is the extent of the "repairs" we are authorized to perform.
hope this helps

[BOWTIE DURAMAX]

4X496 DOOLEY
I know the exact whine you are talking about. Sometimes mine is so loud at a stop light I can't hear my Duramax running. Mine all started when I switched to the Allison deep pan, I have know idea why. Keep us posted on what Chevrolet does. I figured if it ain't broke they ain't going to fix it so I never took it to the dealer.

[hammer]

You guys are scaring me.I have 25,000 on mine now & havent had any trouble with the motor or Allis.I bene working it pretty good pulling my trailer & so far its working flawlessly.Sure wish you guys with troubles good luck & hope there isnt any more problems with them. Hammer smile.gif smile.gif

[4X496Dooley]

Good news (If you can call this situation good news)The dealer called today they will replace the tranny with no questions asked. they removed it today and should have the new one in three days. He also said Allison had changed things to remedy the problem in the new ones. Hopefully that is true. I just hope to get the truck back for 4th of July weekend. Thanks for the input.

[77TransAm]

There have been several small changes made to the pump assembly since the start of production to cut down on pump whine, so it's less common to hear a later '01 or an '02 truck whining than an early one.
BOWTIE DURAMAX - if yours wasn't whining at all before you changed to the deep pan and now it is, I'd look for a possible damaged seal on the suction filter. Your pump could be sucking air and cavitating, which would also cause a whine.

I have heard of transmissions that had an omitted snap ring, which allowed one of the ring gears to separate from its planetary carrier. I can't imagine a dealer being allowed to fix that problem, but that doesn't mean it hasn't happened.

[BOWTIE DURAMAX]

77TRANSAM
That's exactly what I thought the problem was to but I pulled the pan off 3 seperate times and checked and replaced the suction filter and seal only to end up with the same result. I then called my local Detroit Diesel/ Allison dealer and he told me to bring it by and he would have his best tech listen to it. The tech told me it is the pump and he has no idea why it started after switching pans. He then recommended I buy a new shallow pan suction filter and put the shallow pan back on so the General won't give me any problems with warranty issues. In fairness to Allison that was in April and it is still whining but it pulls my 14000# gooseneck with out any problems so far. I'll keep ya posted.

[4X496Dooley]

Well I finally got the truck back with a brand new trans (it is painted black for some reason)and everything seems to be normal. The day after I got it back it would not start. It would crank and fuel pump ran but it would not fire. Back to the dealer that night. Turns out it was a bad crank position sensor. I sure hope all the bad luck is over now.

[mackin]

4X496Dooley ,

Wow it took almost a month ? That's a long time to wait....... Do they ,or what is the warranty on the new,rebuilt ,replacement?

MAC

[ 07-18-2002: Message edited by: mackin ]</p>

[4X496Dooley]

Mackin,

It only took about one week from the time I dropped it off at the dealer. I was too busy and out of town for the 4th of July weekend so they had it about two weeks until I could pick it up. As far as the warrenty, I believe it is the same as it was originally. (I did not ask, but I will find out)