M12 Transmission estimate

Getting very close to maiden voyage in my 68 AMX. Bought the AMX from deceased owner's family. Had not been driven since 1981. I'm 2nd owner. Orig owner kept daily detailed log on car. The engine was frozen and  block was not usable. Bought another bare block from Galvin's. The M12 was totally rebuilt 44 years ago and has 48,726 miles since rebuild. The new tq converter is 39 years old and has 12,000 miles on it. Want to have the M12 serviced before bolting it to the rebuilt engine and installing from under the car.  Went to an established transmission/rear end shop that does a lot of classic car transmissions. Explained the history of the M12 and asked what he would charge to freshen up the M12. He knew the M12 has FMX components. He said because the car has not been driven in 37 years the seals are probably bad and the tq converter needs looking at. I asked best case scenario what is it going to cost. He quickly said $750.00. I mentioned I could get a master overall kit from APD and he said he'd rather provide his own parts. During this time, there was a transmission vendor listening who had made a few comments. The shop owner said he couldn't get to it until next week and I could drop the M12 off at anytime between now and then. I walked away feeling a little uneasy and wonder if this shop is playing me. What do you think.  

I'd put it in and drive it. I put in a used one about 35 years ago, so probably an original 60's era, and it is still doing well. As for the estimate, reasonable enough. If it needs T/C work or bands they will probably charge you more.

Edited by vinny - Aug/01/2018 at 8:37pm

I would risk it.  I would drop the pan, clean the screen/filter and inspect the fluid. If you have only a little gray sludge, that's good.  You can remove the driveshaft and replace the rear seal and you might want to replace the shift shaft seal while the pan is off.  You would have to drop the tranny to do the front seal.  but if the torque converter didn't hang on the front pump at all, (or for very long) the front seal might be OK.  Replace the pan gasket and the fluid and drive it.  Joe

Pacerman, I'm becoming interested in replacing the front & rear main seal, gaskets and cleaning the screen/filter. The tq converter has been on a bench since I removed it. The M12 is sitting on a 2x10's since I removed it. Where can I get a front seal puller or can a dent puller get it out? Can a a socket and mallet  install the  seal? Guess the same would apply to the rear seal? I already drained most of the fluid out of the pan.  I thought some disassembly had to be done to replace the shift shaft seal. 

Thanks for all the suggestions and advice. Got a second quote from R Performance a transmission/rearend shop. He came in at $450.00 if I supply the Master Rebuild kit from APD ($129.00). The owner has worked for several established transmission shops in the past twenty years. He remembers seeing me at car shows and and at the GM dealership I worked for. He is very familiar with the M12. Now I believe the M12 is in Good Hands. R Perf came highly recommended by the front end shop that is presently installing bushings in the control arms. Beginning to look like the 68 AMX will be on the road soon.