Saginaw 4 speed "pops" out of fourth gear during deceleration ; any clues

[rc68camaro]

Hello 1st Gen Nation!  I have a nagging problem with my 68.  I recently removed my powerglide and installed a Saginaw 4 speed that is period correct.  I installed it with a stock aluminum bell housing and a good quality reman 11" clutch set, along with a stock Muncie shifter. Worked awesome - until I shredded the friction disc and tore up the aluminum bell in the process.  I then installed a steel Lakewood bellhousing and a Centerforce 10.5" clutch kit, along with the same Muncie shifter. Well, everything is all good until I shift to fourth ; it will stay in gear as long as I am accelerating, but  the minute I let off the gas, the transmission pops out of gear to neutral.  I have adjusted the rod linkage, the shifter attachment point on the crossmember, all with no effect.  Anybody got a suggestion?  It's a pain to have to hold the shifter in 4th while I'm driving.  Thanks again for your support!!

[hotrod68]

  For my 2 cents--trash the weak Saginaw and find a Muncie M-20 or M-21, or a Borg-Warner T-10, and get a Hurst shifter. The Saginaw will self-destruct in short order if you abuse it with any kind of power, and those gadawful Muncie shifters were pieces of crap when new! Either way, sounds like you need a new transmission. One other thing--did you make sure and center the Lakewood scattershield to the crank pilot bearing? Strange as it sounds, that can cause problems with the transmission's input shaft and internal alignment. You don't just bolt a scattershield on like a factory bellhousing--it has to be carefully aligned. Good luck!

[GaryL]

I think that is a sign of bad syncros.

[melav8r]

Saginaws were equipped on vehicles with engines producing less than 300 HP's. Tranny popping out of gear is a sign of a bad syncro. either go with a period correct Muncie or have your Saginaw rebuilt.

[rc68camaro]

Thanks for all the input and info regarding my transmission issues!