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trans carnage... where to go from here?

1K views 10 replies 6 participants last post by  Reducedfat 
#1 · (Edited)
About a week ago the input shaft in my ats build trans let go and tore everything up pretty bad. It took out the triple disk ats converter, front pump and cracked the front drum( that might just be front 4 years of use).

Now i have questions but first let me describe the truck and its use. Its a 95 4x4 auto with 257k miles. trans has about 60k on it. Now here is where im not sure whats what and how much of what i was told was true. The trans was supposedly rebuilt by the previous owners trans shop using an ATS stage 4 kit. or that's what he said. He provided me with a part list and a price tag. about a year ago i broke the 2nd gear apply lever then shortly after tore the splines out of the front planetary. So i have been into it a couple times and it seemed to have been what he said was in it. it definitely has the ats triple lock, valve body that allows lock up in all forward gears, red alto clutches, chro-moly five pinion front planetary and the 5 pinion aluminum rear planetary. as for the billet input shaft im not so sure. its a 2 piece unit and i thought all billet shafts were one piece units.

The motor is just a tuned 160 pump on a stock hx35, running no more than 30 psi boost and probably 350 max to the rear wheels. it does have 4k gov springs as well. The truck does a lot of towing(mostly highway) and usually not heavier than 8-10k it does see the occasional trip off road but thats usually just ing around in 4x4 low.

Now what i plan is throw a billet shaft in there(input only as i see no power increases in the foreseeable future). triple disk torque converter(looking for suggestions here) and replacing the front pump.

Now i want to know if any of you use your trucks like me and have messed around with different stall speeds in your truck. Mine has always felt very loose and before the 4k governor springs wouldn't rev enough to make use of any of the power. towing was a pain unless it was locked up. which im ashamed to admit probably led to me irresponsibly using the lock up switch... oh yah it has that too.

as for the front pump... are the stock ones fine? do they fall short in any ways?

But mostly i want my reliable truck back. im tired of getting towed home. I only tuned it because i thought the trans would hold a little extra power... maybe that was my mistake.

Ill post pictures later... once i move into the lit garage
 
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#2 ·
I did a lot of reading before I tore in to my ATS. It was slipping clutches after 40k miles of beating it took from previous owner. I reused 5star TC and put regular clutches in with one extra in each pack.
With extra clitches everywhere, you dont really want to set you pressure to high if you staying at 350hp. Even at stock pressures, there is quite bit more clamping power. You dont need to be at 160psi, like the guys with stock clutch count.
I set mine to 140-145, and think even that is too much.
LU switch is violent if you dont let out in second. With too high pressure there is not enouph slippage while engaging multy clutch TC. Thats what break hard parts.

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#3 ·
You must have enough pressure to hold the clutches together to transmit the torque.
The company mentioned apparently keeps pressure down because of the harsh lock up.
They allow the clutches to slip absorbing the shock load at lock up.

BTW, there are better ways to do it !!

Few of these trucks even need a multi disc converter!!! ( if it is built right)

And a loose fluid coupling wastes your torque and useful power.
Feels cool when lock up happens though, right?
In the mean time all the traffic next to you is 2-3 block away--out in front!!!
 
#4 ·
yah there is definitely enough pressure to hold the power. and lock up is the onlly way the truck will move like i think it should.

so if i dont go with a multi disk converter who and what is my best option. every time i look at the single disk converters i always see them rated at mediocre power levels that are close to what a Cummins can make on almost all stock parts. i just dont want to a have to pull the trans again in a very very long time.
and what stall should i be looking at?

Also i stacked an extra clutch in there last time i was in the trans. its never slipped and ive always been happy with the shifts. they are firm but definitely not violent...
 
#7 ·
I seriously doubt your getting 350 to the rear wheels. Maybe 285 if that.
In the mean time I would go with a single if your really not planning to increase power beyond what you have. Stock inputs would handle it. So cheaper all around. Also, get a low stall stator, about 400 rpms lower. When I had an auto I had a lockup switch. When I got the revmax low stall single, I rarely used the switch.
 
#8 ·
i want to do this one time. and if im breaking input shafts already i dont want to be putting the same thing back in there only for it to break again. I am tired of building things that should hold and dont. i was always told i didnt have to worry about my input shaft so i didnt go billet when i had it open the first time... im thinking i will go lower stall but id rather go billet now and not worry about it then go stock and worry every time i go to pass someone. Then there always is the possibility i find a great deal on a turbo or something stupid that i can help myself with. I want something that wont sweat with the power its holding not something that just barely holds.

Im working on pictures right now.... i am guessing i have to go through photo bucket or something right?
 
#10 · (Edited)
The reason why your breaking inputs is that triple. If your truck is tuned like you said, with a 160 pump your only looking at maybe, just maybe 280hp and that's an exaggeration.
Naturally it's your rig so do as you please but breaking stock inputs with a single disk billet low stall is pretty rare unless your doing locked shifts. Even billet shafts don't like locked shifts.
 
#9 ·



This is hard to see but you can tell the inside is all chewed up



This one was the reason the trans came out last time. twisted those splines right out.
 
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