Allison whining noise

[akrockhound]

My '03 Chev 2500HD with an Allison trans has 38,000 miles.

I know these trannys whine a bit but mine is getting louder with time. Is this normal????

Reason I ask is that my dealer recently took the trans out to get access to the oil pan on my duramax and whn I picked it up it had a new oil pan on the tranny. They said it slid off the tranny jack in the shop. Is it possible that there was some internal damage to the tranny when they damaged the oil pan? Seemed the whine was more noticable as soon as I picked up the truck after the work was done.

The dealer says the damage was superficial to the pan but how would I know. Maybe I should ask them to take the pan off and have another look.

Is there anything internal that could be damaged when they damaged the pan???

[More Power]

Accidents happen.... but it sure doesn't inspire confidence when a dealer screwup happens to your own truck....

You've driven the truck long enough to know what is normal sounds for the Allison. Yes, these transmissions will whine, but it's mostly noticeable when cold - and mostly during the cold winter months. I can't hear mine when it's warmer outside or anytime during the summer.

If I thought the whine was abnormal, I'd pull the pan myself and have a look. If you take it to another shop, take along a camera to document what you "might" find.

Jim

[77TransAm]

One slim possibility that I can think of would be the filter. I can't imagine the height they would have had to drop the trans from in order to dent the pan deeply enough to damage the filter, but filter damage could cause a whine. If the pan did bend the filter enough to crack the neck or damage the seal, or if they had the filter off for some reason and damaged the seal, the pump could suck air around the seal and cause a whine due to cavitation. It's a slim possibliity, but a possibity nonetheless.

Something to look for while the pan is off next time, anyway...

[brainpause]

First post on the board, but I can't resist...

I would hate to have been around to see a big Ally sliding off a transmission stand!

Larry

[mrwolf]

Is your truck 2wd or 4wd? If it is 2wd, did the rear yolk hit the floor? If it did they may have damaged the bearings in the rear of the trans. The trans may still function with the damaged bearings for a while, however they will fail eventually. In a 4wd unit, this kind of damage is less likely, the 4wd output cover would have been damaged.

[JohnC]

If it started whining when the dropped it, I'd do some whining of my own...

[akrockhound]

I spoke with the service manager at the dealership where the tranny was "dropped". We made an appointment and he said he would make it right.

To answer the previous question...the truck is 4WD.

I spoke with allison who seem to think it unlikely that the drop could have done damage but they also suggested checking the transfer case (in case the guy forgot to re-fill it possilbly). anyway it was full of the right fluid.

they say that the first sign of damage to the valve body would be bad shifting...it shifts fine.

Another thing I notice is that my tranny is way overfilled with tranny fluid.....COULD THIS BE THE PROBLEM????The dip stick says don't overfill but it registers at least 3 inches above the "hatch area" on the stick. This is the way the dealership refilled it after the work.

Why does the stick warn you against overfillling the tranny????I would love to know.

[DmaxMaverick]

An overfilled tranny can cause noises, and terminal damage. The internals of the tranny are dynamic while in operation, and need air space above the fluid level to absorb shock pulses. Take away the "shock absorber", and seals, pump vanes, pistons, valves, etc, hammer against each other. This usually results in internal/external leaks and case damage, but you may be just short of that. I would think with it overfilled that much, it would have poured out of the vent, and made a huge mess on the ground and the underside of the truck.

[akrockhound]

I haven't dumped any tranny fluid.

It's another two weeks before I get into the dealer.

One of these deals where if I drain some fluid before i go to the dealer it might be hard to make the case that the damage was theirs but if I don't I might really scrw up my tranny.

I guess I'll just drive by there and show them the level and establish that's how they filled it last.

[DmaxMaverick]

Are you checking the fluid level with engine running, tranny at operating temp, and in P? Any of these conditions missing can cause a higher than normal reading.

[akrockhound]

Checked tranny fluid level properly this time and it is OK, so the whine isn't coming from an over-filled tranny.

[DmaxMaverick]

Well.......If fluid level is OK, the only thing left is damage. Don't let 'em off the hook!