Saginaw 3 speed wont shift

[kfactor239]

Ok this has got me wondering. With the engine off the transmission shifts into all 3 gears and reverse fine. If I have the engine running clutch fully engaged it wont shift into 1st reverse or 2nd. I have to kill the engine to get it into 1st or reverse it will shift into 3rd when I go out to the track. I have no idea any help would be appreciated. I am running a 7.25 3 disk clutch with it.

[fast_crew]

Does it grind?? Or just can't move shifter??

[dave41]

one of the clutch disc is not true

[kfactor239]

Yes it was grinding quite a bit in first and reverse before it quit not going in. And yes now when I try to shift into 1st reverse or 2nd it grinds. It goes into 3rd just fine though.

[fast_crew]

Could be a few things, bad pilot bearing or bushing, warped disc, or could possibly be just not enough travel on throw out bearing to not release clutch entirely.

[kfactor239]

So it's not the transmission itself then more than likely. When I push the clutch in with the transmission in gear the starter turns the engine just fine and the car doesn't move. If i have it in gear with the engine running and push the clutch everything seems ok. Just seems odd to me. I do have one problem I don't have a clutch pedal stop. Once before the clutch was making aweful noise and I found the hub on the center clutch disk was gone. I replaced the center disk and everything has been working fine. I've been careful since then not to push the clutch pedal too far.

[95shaw]

So it's not the transmission itself then more than likely. When I push the clutch in with the transmission in gear the starter turns the engine just fine and the car doesn't move. If i have it in gear with the engine running and push the clutch everything seems ok. Just seems odd to me. I do have one problem I don't have a clutch pedal stop. Once before the clutch was making aweful noise and I found the hub on the center clutch disk was gone. I replaced the center disk and everything has been working fine. I've been careful since then not to push the clutch pedal too far.

Good chance the clutch discs are warped from pushing the throwout bearing too far. Have seen the floater plates warp also.
Could also be floater plates binding on clutch shell. I always try to add a little clearance to these for dirt/rust.

[kfactor239]

Think if I shim it out a bit it will get at least a couple races?

[95shaw]

Take it apart. put straightedge on floater plates and clutch discs. If not warped too bad, may be able to get by. If plates are binding at all in clutch shell, add clearance to edges of floater plates and pressure plate with scotchbrite pad on drill or die grinder. make sure they will slip easily. Make sure clutch plates slide easily on trans input shaft. Make sure pilot bearing is lubed if bronze. make sure not locking up if roller bearing.
fabricate a clutch pedal stop. Adjust to just get clutch plates loose, and no further.
Good luck

[95shaw]

Take it apart. put straightedge on floater plates and clutch discs. If not warped too bad, may be able to get by. If plates are binding at all in clutch shell, add clearance to edges of floater plates and pressure plate with scotchbrite pad on drill or die grinder. make sure they will slip easily. Make sure clutch plates slide easily on trans input shaft. Make sure pilot bearing is lubed if bronze. make sure not locking up if roller bearing.
fabricate a clutch pedal stop. Adjust to just get clutch plates loose, and no further. for a pedal stop, I have removed bottom bolt of master cylinder. Find appropriate length bolt. Put a nut run all the way on, then insert into pedal/master cyl assembly. Adjust with 2 nuts to get correct pedal travel.
Good luck

[kfactor239]

I pulled the transmission out and bad news the top right ear is broken off. Can it be fixed at all? I know its cast iron and cant be welded is there any red neck fix for it? Could i get by a couple races with just 3 ears?

[kfactor239]

I checked the clutch out nothing is warped and nothing is sticking I did find a couple of pieces of broken off spline from the clutch disk that had let go and replaced one was jammed under the spring fingers I think the clutch is fine. But the tranny isn't good.

[95shaw]

There is a really good chance that the trans has been broken since the last clutch change.
That being said, cast iron can be welded. Either bronzed or welded with cast rod or even nickel 55.
All require lots of heat, necessitating trans disassembly.

Poor boy method. bolt it back in. A strap could be made from tailshaft bolt to that ear, helping hold it all together.
Main thing would be to determine what caused the ear to break in the first place.
I've race the same 3 speed for 15 years with no failures. Check things carefully when assembling.
good luck.

[kfactor239]

Yeah my rf ran over another cars lf I went airborne and hit another car about a month ago. That's when the clutch disk went out. It probably was cracked then. This past Sat night the track was very rough the car was getting airborne going through the ruts probably broke off then.