I'm getting a clunking noise when shifting from 2nd to 3rd on my '89 Formula 700R4. I was checking my trans mount and found that when I try to tighten the nut on the tranny mount stud, the stud is turning. Never having worked on one of these before and not being able to see the top of the stud I can't figure out how to keep the stud from turning.

Is the fact that the stud is turning an indicator of a specific problem or am I just not looking in the right place. Any input would be appreciated.

Thanks

 

Best thing to do is going to be, support the trans with a floor jack or the like, and remove the crossmember. Should be pretty easy to get at the remains of the stud that way.

 

Get a replacement tranny mount in advance. Even if the mount is still semi-intact, the fact that the stud spins freely means it should be replaced. Buy a replacement and have it ready for installation before attempting to remove the old one. Can't say if this is causing your 2-3 "clunk" - but it should be fixed.

Just trying to remove the crossmemebr might not to help. Let's say you remove all 4 bolts for it - it's still going to be held tight to the tranny mount due to the bad stud. I can't recall if you will have room to access the tranny-to-tranny mount bolts on each side. Even if you can; you'll be dealing with the crossmember that's just hanging there in the way.

My advise is to use a cut-off wheel to cut the tranny mount to crossmember nut/stud flush with the crossmemeber. The mount is junk anyway so cut the stud off and be done with it. Then support the tailshaft with a jack and remove the crossmember completely. Then you will have good access ( and can use penetrating fluid or HEAT ) to the tranny case around the tranny mount bolts. I'd highly recomend fluid and heating up the case 'cause you DON'T want a bolt to snap in the tranny case ! Once the old one is off, reinstall everything and take it for a test drive.

 

Thanks for the responses guys. I planned to get a new mount before I started. Cutting the nut and stud off is a good idea. Should make it easier. I will update the thread as soon as I get it replaced.

 

Are there supposed to be spacers between the transmission and the mount?

 

No. Energy suspension poly mounts come with a spacer but they are know to cause vibrations and usually they are left off for that reason

 

Thanks for the quick reply 86TA. That's what I thought. Now just to figure out what size nut goes on the stud that goes thru the crossmember and a road test.

 

Nut should be 10mm x whatever the "std" (not "fine") pitch is for that size; 1.5mm if I'm not mistaken.

 

Thanks Sofa. Had to cut the old nut off. Bought some the size you suggested tonight. Will try them tomorrow.

 

10mm x 1.5 was the right size. Thanks Sofa