PDA

View Full Version : Alison tranny noise...


godtool
01-03-2010, 07:31 AM
My Alison tranny in my 03 Silverado when it automatically up-shifts especially under load such as going uphill my tranny shift will be twice as long from 3rd to 4th or 4th to 5th can't be certain which shift it is but I think its 3rd to 4th. Along with the long shift it makes a noise, like a grating noise. Not loud but you can hear it... any ideas? Thought it may be a broken engine or tranny mount.

ROBO
01-03-2010, 09:52 AM
first things first... scanit.. oil check... see wats in the pan ... then open your wallet ...them things aint cheap!!

B
01-03-2010, 12:25 PM
id say it needs a band adjustment sooner than later or ones allready on it's way out either way id get on it quick or you will be stranded and then you dont got a choice but to spend to fix

Happypants
01-03-2010, 08:42 PM
Sounds like the bands are loose, I've wasted a few grand on the Allison in my diesel and ya catch it before you end up on the side of the road with no gears left

godtool
01-10-2010, 09:19 AM
Service Manager took it for a rd test on Wed. and said shifting is fine. We came up through the canyon on Sat. and I still heard the noise once or twice. Seems there may be slack in the system. I remember similar slack because of past loose rear u bolts and then worn out shocks. Maybe its a rear u-joint now? crown tooth maybe broken? Sometimes feel slack being taken up when leaving a stoplight or stop sign....

mus-Tard
01-10-2010, 11:52 AM
was ridding up to castlegar a couple years ago and the tranny grenaded in the chev just as we were getting on to the hope princeton outside of hope. ended up driving it all the way back to maple ridge in second gear. 5000 rpm and about 80kmh on the number 1.

yeah get it before it gets you

regulate34
01-10-2010, 09:46 PM
:D was ridding up to castlegar a couple years ago and the tranny grenaded in the chev just as we were getting on to the hope princeton outside of hope. ended up driving it all the way back to maple ridge in second gear. 5000 rpm and about 80kmh on the number 1.

yeah get it before it gets you

kuz its a chev

mus-Tard
01-11-2010, 06:23 PM
yeah your probly right and that truck was rat bagged far more than it deserved. fucking pulling out that 4L60E under 2 inches of dried mud.

godtool
03-20-2010, 09:03 PM
After I posted this a ways back I now remember the Service manager told me my Allison shifts way better than some and it has "no bands". Since then I notice that odd "sounding\feeling" shift occurs at exactly 80 km\h under load when it automatically shifting up. It has not changed or gotten worse. Sometimes it shifts normal.

Also before this odd shifting in the fall occured I had a problem in the summer where my internal rad tranny cooler was leaking tranny fluid into the rad system. It leaked about 4 liters since that is how much tranny fluid it took to top up my tranny when I noticed it slipping. I fixed that problem and then a month or so later the shifting "sound\feeling" occured. Neighbor said I should change the spin-on-filter on the tranny since it could be clogged with debris from when the slipping initially occured. No coolant never did leak into the tranny fluid. The slipping occured on a slight hill (0.5 km) from my driveway, then it goes downhill after that and once I got to the store I topped it up with the 4 liters.

Sometiumes my tranny feels sluggish off the line but I think thats mainly after start up in the cold morning. Fluid has stayed full since I fixed the tranny cooler. I figured maybe somebody here has some insight into this befoe I drive anoth tranny mechanic crazy with my questions...:p