[bonnebird]

Im trying to reassenble a TH400 it came to be dissassembled in a box it is a 1976 transmission but has an early lower drum with the smooth inner drum and a sprag rather than the roller clutch im not sure which way the sprag it fits into the case, either with the inner lip on the sprag facing towards the rear or front of the case. Please see photos to reference which lip i mean

Thanks

[Schurkey]

Originally Posted by bonnebird

Im trying to reassenble a TH400 it came to be dissassembled in a box it is a 1976 transmission but has an early lower drum with the smooth inner drum and a sprag rather than the roller clutch im not sure which way the sprag it fits into the case, either with the inner lip on the sprag facing towards the rear or front of the case. Please see photos to reference which lip i mean

Thanks

The sprag does not go into the case. It goes onto the back of the Direct drum.

It's been years since I've assembled a 400. I'm thinking you need to find the second lip/washer.

This guy uses some incorrect terminology, but he shows the assembly pretty well.

https://www.youtube.com/watch?v=Mi-m_ZWyudE

IF (big IF) you were assembling at TH425 for an ElDorado or Toronado, that one-way clutch would be assembled backwards, so it slipped and grabbed in the opposite directions.

[chuckies76ta]

I noticed he put the stock snap ring back on, If building for higher horse power the spiral snap ring is usually used which does a better job of holding the sprag on.
https://www.ckperformance.com/View/G...UTCH-SNAP-RING

This guy shows installation.. https://www.youtube.com/watch?v=gg8hWNgJv0g

[bonnebird]

Can the spiral snap ring be used in place of the standard snap ring on the TH400 drum or only the 4L80 drum

[chuckies76ta]

Yes it will work on both drums. The 4L80E drum is the drum used for performance builds. I believe it will hold more clutches.

[ErikW]

Two small TIG weld tacks on each end of the stock snap ring to the sprag retainer works great also.