just built and installed a SC Stage 4 shifts all gears trans is quiet in park 1st 2nd 3rd 4th and 5th under acceleration clean hard shifts up and down but whines in 1st and 2nd while coasting at slow speeds put only maybe 3 miles on trans and stopped driving it because of whining at coast I dont want do do any damage if this is not normal so im not driving truck until i get some feedback if anyone knows anything about this id like to hear about it thanks
:confused:

does it whine in only certain gears? Change pitch when changing gears? Typically a noise that is only there in certain ranges is a gear train noise. Perhaps a bearing is in wrong or something, if your unsure, pull it down before you tear up the planets, those are not cheap

its whining at a 10 mph to 20 mph coast
no noise below 10 mph or above 20

isolate it by gears. Pay close attention, not concerned with MPH really, see if it comes or goes when truck changes gears. Manually shift it if needed

it does it only in 2nd and 1st. when i was in 5th and i was stopping for a red light i had no noise when the truck was shifting down gears 5 no noise 4 nothing 3 none 2nd whine 1st whine below 10mph no more noise

got them torrington bearings in right side up? :eek:

1st and 2nd use c1 and c5-c4 respectively right? just thinking outloud. what are there for bearings back there?

Alright went back to the drawing board on this. I took the trans back out and broke it down. I found the problem. I wound up inverting the c-5 clutch pack and steels. I must have forgot to flip the clutch pack when i set it on the bench. when I assembled the c-5 clutch pack i started with the last #3 steel insted of the pressure plate. I bent the heck out of the #3 steel getting it out and had to go to inland allison in carolstream Illinois to get a new one. they had stacks of alli parts. so anyhow as long as the trans was out I checked everything else for damage or any more goofs and it was all perfect bearings and all. reinstalled trans and it is awesome! great shifts up and down and quiet. I got another one to do in a couple of weeks. want to say thanx to all that posted and a special thanks to Whitewhale, George from suncoast and to Jason and Jim at inland allison.

Glad to hear that you got it straightened out- that was my biggest fear when putting mine together- I checked everything at least 5 times, and i was still nervous. ;)