Help: TH400 problems..

malibu795

malibu795

misspeelleerr
Apr 28, 2007
8,109
461
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in the buckeye state
engine is a 9.5:1 383 with ~400-450hp in a ~5500lb truck
i install the new drum with the 34 element sprag in my TH400.. torque converotr is a B&M hole shot 2400.. see link if need did.. http://www.bmracing.com/PRODUCTS/HoleShot-2400/HoleShot-2400_2
went for a test drive..
at WOT i can hold engine in 1st and 2nd gear..you wont feel 2-3 shift unless you have a very light throttle.. also when going up hill (6% or steeper)... it will pull though 3rd and free rev almost..
there is no burnt fluid smell.. since i dont have a tranny temp guage.. i used a Infra red temp gun.. tranny case is ~160-187.. and the torque convertor is 190-200*.. i plan on dumping the fluid next couple of days.. havent seen any clutch material..
forward, direct, intemeidiate, forward band are alto brown clutches. then VB is a TCI auot/manual shift unit.
 
duratothemax

duratothemax

<--- slippery roads
Aug 28, 2006
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did you mess with the screw adjustment on the vacuum modulator, and for that matter, are you sure the modulator is even good? No vacuum leaks?
 
Mike L.

Mike L.

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Put a pressure gage on it and pull the vacum line off to see if the pump can make pressure. pressure should go up with line off.
 
malibu795

malibu795

misspeelleerr
Apr 28, 2007
8,109
461
83
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in the buckeye state
JMDuramaxLB7 said:
Modulator is not used on a stick shift valvebody.
Click to expand...
that 200.00 i dont have right now.
Mike L. said:
Put a pressure gage on it and pull the vacum line off to see if the pump can make pressure. pressure should go up with line off.
Click to expand...

do it at idle, in gear right?

should i see what the pressure is when moving while in 3rd gear?

ben- brand new modualotr..... iirc if it messes wouldnt it affect 1-2 shft as well????? instead of just the the 3rd gear?
 
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malibu795

malibu795

misspeelleerr
Apr 28, 2007
8,109
461
83
42
in the buckeye state
got the pressure.. temp on TC was 160* when i did the test.... thats the closest thing to temp reading i can get.

@1000 with modulator disconnected.
R is 180psi
3 is 120
2 is 150
1 is 180

2000rpm
1st 210
2nd 200
3rd 130

1000rpm in P/N is 160psi


something is wrong with the direct clutch pack..
 
Mike L.

Mike L.

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malibu795 said:
got the pressure.. temp on TC was 160* when i did the test.... thats the closest thing to temp reading i can get.

@1000 with modulator disconnected.
R is 180psi
3 is 120
2 is 150
1 is 180

2000rpm
1st 210
2nd 200
3rd 130

1000rpm in P/N is 160psi


something is wrong with the direct clutch pack..
Click to expand...


Are all 3 lips seals installed? Did you mix up the forward and direct pistons by chance? One has a check ball and the other does not. Piston with check ball mates with the drum without ball and vise versa.
 
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malibu795

malibu795

misspeelleerr
Apr 28, 2007
8,109
461
83
42
in the buckeye state
Mike L. said:
Are all 3 lips seals installed?yes
Did you mix up the forward and direct pistons by chance?possibility.. i know the direct drum had a ball and the piston did not.. as for the forward drum.. IDK off the top of my head.
One has a check ball and the other does not. Piston with check ball mates with the drum without ball and vise versa.
Click to expand...

im looking at pulling it out and check ing tomorrow if theres time..
 
malibu795

malibu795

misspeelleerr
Apr 28, 2007
8,109
461
83
42
in the buckeye state
pulled it apart thurdays found 2 out of the 5 disc burnt in the direct clutch pack.. replaced the whole pack. with alto brown cltuches and new steels
checked the lip seals in said drum,
forward drum,
intermiedate piston,
check teflon seals on intermediate suport,
back of pump housing, all were good.
check all passages for cloggs with shop air.. no clogs...
cleaned all the parts as well.
got it up and runing today right as class was cleanign up.. didnt have time to pressure check the main line pressure... 1-2 shift is firmer then before.. and 2-3 or more noticable.... will hold cruising speed much better.. though ~1/2 vs 1/4-3/8th throtle it will blow through 3rd gear with a 600cfm carb vs the 750cfm that "should" be on the engine...

have of me is tempted to get a full manual VB.......
 
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Mike L.

Mike L.

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You must have a ball in the wrong place. Show me your ball placement. The rest of you guys STFU.:D
 
malibu795

malibu795

misspeelleerr
Apr 28, 2007
8,109
461
83
42
in the buckeye state
got the same problem...again.. steels slightly blued..

this time i have pulled about 150-200hp out of the engine by swaping heads froma 215cc intake with 2.05/1.6 vlv to a 170cc intake wiht a 1.94/1.5 and a 750 carb to a 600... pluss pull timeing

i got red clutches and kolene steals..

this is getting anoying :mad:
 
dmaxadermist

dmaxadermist

New member
Nov 11, 2009
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check the vacuum line to, sometimes those modules go bad and let trans fluid get sucked up into the line ive seen it happen good luck
 
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