Can I run dex6 in my th400.

[clinebarger]

2nd Accumulator Spring (78) https://www.tsr-racing.com/th400-rear-accumulator-piston-spring.html


The 3rd Accumulator Spring is hard to come by as they don't break, Have you checked with local trans shops?

 

[joegreen]

I purchased spring 78. I talked to hutch from hutch transmission in Canada on yellowbullet and he is going to send me the 305 spring

 

[joegreen]

So I have that spacer from ck performance for the reverse servo cover but when I have the spacer in place I can't fit the cover on because it runs into the valve body. I know in the picture only one valve body gasket is on. I have the other just haven't installed it yet. So what should I do about not being able to fit the cover on. Should I sand down the part of the cover that slides under the valve body?

 

[joegreen]

Also made a drain plug in the pan with a nut and bolt. First I welded it on then soldered over the weld just to seal up any pinhole leaks. I put the drain on the side so I could use the transmission Jack without having a huge lump on the bottom of the pan. I can probably get 90% of the fluid out of the pan.

 

[clinebarger]

I honestly forgot about the cover hitting the valve body when using the shim, Most TH400's I build these days have aftermarket aluminum full manual trans brake valve bodies. 4L80E's don't have this issue.

Take the material off the Valve Body! A End Mill would be best for this, But a drill press could be used with a end mill bit if your careful & lock the valve body down well.
A carbide bur bit would be my least favorite way of doing this correctly.

 

[joegreen]

Ok thanks I'll look at it tomorrow and figure something out. Just wanted to make sure I wasn't crazy

 

[joegreen]

Ok so I ground down where the servo cover was hitting the valve body. I now have enough clearance. Not the best job but it came out pretty decent.

 

[joegreen]

How do I air check the reverse servo once the cover is on? I know there is a way I just couldn't find it in my book or online

 

[clinebarger]

This is a 4L80E......Same location on a TH400, The hole is drilled sideways in the case.

Never apply air to the L/R servo on a unit that has/had fluid circulated through it......Whatever fluid is in the 2nd accumulator will shoot out of the accumulator feed at the speed of light & drench the entire zipcode in ATF, Ask me how I know!!!

 

[joegreen]

It's been a long time coming but the transmission is finally together.

 

[joegreen]

I do have a few questions though. I used the atsg and Ron sessions book simultaneously when putting back together so I could compare each step. In some places the atsg manual I feel was incorrect so I followed Ron's book. The atsg showed this blue spring going behind the accumulator between the accumulator and servo which I'm sure is incorrect. I installed the spring like so. Is that the correct way?


Second the atsg manual said to rotate the center support counterclockwise but Ron's book said to turn it clockwise. I did it the way ron said because going the other way did not seem correct. Did I turn the center support the correct way?

 

[clinebarger]

The way you have the 1-2 accumulator spring is correct!

Insert the tool in the 3rd clutch feed hole & leverage it toward the rear servo bore....(This IS correct!!!)
By doing this....You are rotating the Center Support counterclockwise.

ATSG is correct about the rotation & Ron is correct about the procedure.

 

[joegreen]

Originally Posted By: clinebarger
The way you have the 1-2 accumulator spring is correct!

Insert the tool in the 3rd clutch feed hole & leverage it toward the rear servo bore....(This IS correct!!!)
By doing this....You are rotating the Center Support counterclockwise.

ATSG is correct about the rotation & Ron is correct about the procedure.
Sweet good to know

 

[joegreen]

I took the brass fittings that the cooler lines screw into out of the transmission. Is there a torque spec for those?

 

[clinebarger]

There are so many different style cooler fittings installed on TH400's over the years. Steel gasket type, Brass gasket type, Brass tapered seat....etc


I use a anaerobic sealant or thread locker & just snug them.

 

[joegreen]

Ok. I have brass with straight non pipe thread. I'll seal and snug

 

[joegreen]

A few questions. I got the transmission in the truck. There is no way I'm going to get a torque wrench on the 6 bolts holding the case to the engine. Should I just get tight by hand? Also the vacuum modulator is the adjustable type. What should I initially set it at? Finally I measured the distance from the torque converter to flexplate and it's a little over a ¼ inch. What should I do? Most people are saying that's to far and to use washers and longer bolts.

 

[clinebarger]

I like 1/8" of converter spacing.

Take a small pry bar, Insert it in one of the flexplate teeth & let the starter nose cone hole the engine still. I use a Flexplate turning/holding tool but you don't need one for a one time thing.

Nice & snug with some blue loctite is fine!

 

[joegreen]

Forgot to update. I got the trans all back in for the july 4th weekend so i could surprise my dad. Made the maiden voyage around a 2.5 hour drive. Everything functions great. With all the check balls back in and the accumulator springs in it doesnt shift hard going into reverse anymore which is nice when you do alot of drive to reverse action for plowing. Very pleased with how it turned out. Thanks for everyones help especially clinebarger. Wouldnt have been able to do as good a job or be able to do some of the mods such as rollerize the rear without your help.

 

[clinebarger]

Your welcome.....Glad everything worked out!