Hello all happy new year.I have a question about my trany that has me stumped.I just was in the trany (48re) to replace a broken output shaft while in there I replaced some of the clutch & steel plates that looked worn and put a new pump in and had the converter cleaned.The trany works but in high gear it slips now and it didn't before.Ive been told that its the converter doing it but if it was I think it would slip in first gear also since it controls that.any help on this would be great thanks. P.S. Put the truck on a dyno with new single turbo setup only one run (it was free) it made. 648hp @ 2134rpm 1127tq @ 1920 rpm e,g,t 1425 smarty on #4 tnt tune edge on #2 edge EZ not used methanol on no n.o.s
What is your pressure on the OD port? Line pressure and line rise are good? When you rebuilt the OD unit, what was your piston clearance? Which spacer did you use? I assume you used Alto Red Eagle frictions and Koleen steels.
I only did the R&R I didn't do the work in the trany.I know he used the alto red frictions and koleen steels other than that I can't answer the rest of your question.
Well, if the clutches stacked up a different thickness, and the OD piston spacer was not chaged, then you can have an issue there. Obviously the spacer is not too small, or you would have other issues. Thing is, the OD unit has an 800 lb spring in it, and that is also used to return the OD piston into its well when disengaged. If the selective spacer is too big, you are wasting a bunch of your clamp load on depressing the spring. Lets see if we can check out the OD pressure on the OD port. You will need a 300psi liquid filled gauge and a set up that allows you to tie into an 1/8npt port. other than that, how many miles did you have on the new clutches before it started slipping. You didn't install it and go hammer down did you?
I haven't been able to get a hold of the guy that did the work in the tranny to find out about the OD piston spacer. The tranny slipped from the day I put it back in and slip's in high gear and in normal conditions without hammering on it. So getting on it hard would be pointless and just damage it more. I keep getting told that this is all converter related and if I understand how the converter works I should be getting first gear slip release, but not experiencing nothing like that. Just the fourth gear slip.
If it didn't slip before you tore into the OD and now it does, and only in 4th, sounds like an OD problem. Get ahold of the guy and have him tear into it again.
Got it all figured out it was a bad brake light switch that was sending a brake on signal and unlocking the converter in high gear.
Wow. That came out of left field. Well, glad you are up and running again. Have to log that one in my memory bank. . . . .
Just dumb luck. I was racing a Friend on the freeway and he asked why I had my brakes on as I pulled away from him. He thought I was just trying to rub it in his face that my truck could beet his duramax even with my brakes on.See just dumb luck.
