RDTA

iTrader: (1)

is there anything better than the 34 teeth ones? We have a 400 and it lasted 20 passes the first time. andafter the rebuild it lasted 4. Keep breaking the sprag for second gear. Any help would be nice.

TJ

iTrader: (10)

a stock th400 unit should be holding up for you, something is wrong somewhere.
tci makes a 36 element sprag now, but its not gonna be any stronger than a 34. just a lil update they seen fit i guess.
good luck with it.

RDTA

iTrader: (1)

thats what I figure. Its actually in a lighting. But it was suppost to be built to handle the power. but I guess not. Or the tranny builder is making short cuts, and charging out the ***. I mean its just a little 5.4 with a gt47-88.

WE TODD DID

iTrader: (2)

Nah, thats the week point in a 400. He might not be putting the 34 element in it though.

RDTA

iTrader: (1)

we looked at the last one and that is what was in it. so its breaking the good ones. i figure the drum is bad, or has a bad spot. but im no trans expert.

FLT

iTrader: (1)

I would try a different drum along with the outer race. There is a super hold sprag drum available although it is big bucks.

TJ

iTrader: (10)

i didnt know he was working on a powerful setup in a heavy truck. lacking info, i went off the information in his sig.
and your right, it is the week point in the tranny.
ive blown up 2 of them myself.
spinning the tires and shifting into second is what my builder says is the problem.
all the street fun.
i have been informed to give as lil throttle as possible in my burnout at the track(enough to get above the converter) and then give it power once its into 2nd gear.
this goes back to what i said earlier about breaking them. he says its too much of a shock and they ballon?? out.
good luck mang.
sounds like a nasty setup.
did you initally pic up with the th400 due to the massive weight reduction?
got a buddy here i razz about doing the swap, but he wants to keep OD.

8a8mfh

iTrader: (3)

Is he using the sprag and race? I have a bunch of old drums with 16 element sprags, they sell the sprags seperate, the stock race won't hold much because it's not hardened.
I used to have a '88 Sierra 2500 that would beat lightnings easy. Broke two rollers with that, then went with a 34 element 4L80E drum, etc, the races on those are slightly wider. like .040 but I didn't break another one.

RDTA

iTrader: (1)

I dont know what drum the builder is using. But will find out. The truck is alittle heavy, 3600lbs. But We are running a 3.73 gear and a 275/60 dr. But the truck picked up a lot with the swap. But we also went to the new motor/turbo combo to. But thanks for the info guys, keep it coming if u can think of more.

Frank02L

iTrader: (1)

Thanks guys for the info. The truck isnt really any heavier than a "full weight" type F body. The builder just told me to put in in high gear during the burnout. Maybe I dont need to get into the boost really until its in high gear, maybe I can do that... Actually just listening to the vid it may not be getting into the turbo until high gear.

Burnout

For the record, the ensuing pass

sucky 10.90@131 or something with a 2.09 60'

WE TODD DID

iTrader: (2)

Something else that kills the sprags is when they bang on the 1-2. When I build one, I usually keep the 1-2 toned down a little bit.

RDTA

iTrader: (1)

we need to fire the camera man. lol And the tranny builder. There has been a few people telling us about putting in 4l80 stuff. What year model parts do we need to be looking for? Or is there anything specific.

Frank02L

iTrader: (1)

He asked me if when it shifted 1-2 if it really banged, but I didnt think it was. He said he had it toned down pretty good. Listening closely to the video of the run it chirped the tires pretty good.

You take the cam back out of the TA tonight?

RDTA

iTrader: (1)

na, might this weekend. Depends on what u are doing. Hell I guess we might as well go to a bruno/linco. IF u cant let it bang gears with out breaking. After a years worth of racing, at 30bucks for fluid and 70 for sprags in 5 to 10 passes. we could buy one. Tell sara she needs some overtime, lol

Frank02L

iTrader: (1)

I will be down there taking junk apart again one evening this week and probably this weekend. I think I sold the rear bogarts and brakes. And some other misc stuff I have. That'll help pay for the 3rd member and 40 spline axles for the 9". Just wanna get the dual caliper brakes for the rear. I think I'm gonna get some of those "cheap" wheels instead of D10s for the rear, so I can get a set of 15x12s and 15x10s.

PBA

Make sure you keep the waved steel on the intermediate clutch pack, and do not leave out the checkballs on the intermediate apply circuit, and do not block the accumulator here either. Make sure the inner race on the direct drum is in good shape and is perfectly smooth, not rough. I have never had a 34 element break even in 1000+HP vehicles. If this is done right it should last for a long time.

Frank02L

iTrader: (1)

bringing this backup but use 3 clutches or 4 clutches in the intermediate?