GM OD Transmission to Stude engine-- bolts too short for flexplate/flywheel!

[wfhenderson]

OK-- I am definitely going to ask the community before pulling out my hair on this one. See photo below.

I am converting my Studebaker 289 Avanti over to a GM 4 speed overdrive AOD transmission. I purchased the whole kit from Myers. Problem: to mount adapter ring and flexplate to the crank snout on the back, the original bolts that are present are now about 1/4 inch too short. The nuts thread on about five turns and this is surely not enough.

How exactly does one address THIS? The bolts are mounted from the back of the crank snout, and there appears no room to remove them to slip new, longer bolts in place. Am I missing something obvious? Or does one need to disassemble the engine to remove these bolts and put longer ones in? Or am I doing something stupid and I shouldn't need longer bolts.

Just thought I would ask.

[DEEPNHOCK]

Make triple sure your bolts are rotated so the flat side of the bolt head has slipped all the way back toward the transmission.
Otherwise the bolts will be too far forward and the threads won't engage....and worse, they will loosen up when running.
Those bolts should be plenty long enough for that flex plate...
Try this...
Remove the flex plate.
Spin each bolt with your finger tips.
There should be one spot where the bolt head indexes with the crankshaft hub and the bolt can be pulled back a good 1/4"+....
Do that with each bolt, then put the flex plate back on.
Once the bolt indexes, you won't be able to rotate it.
Rotate and pull the bolts out again....
Also...
There are two lengths of bolts used on Studebaker crankshafts.
The manual trans bolts are slightly longer than the a/t bolts.
But you would have to pull the pan and pull the oil pump and rear main cap to change those bolts.
Some people remove those bolts and drill and tap the crankshaft flange for bolts that go in from the rear.
HTIH
Jeff

OK-- I am definitely going to ask the community before pulling out my hair on this one. See photo below.

I am converting my Studebaker 289 Avanti over to a GM 4 speed overdrive AOD transmission. I purchased the whole kit from Myers. Problem: to mount adapter ring and flexplate to the crank snout on the back, the original bolts that are present are now about 1/4 inch too short. The nuts thread on about five turns and this is surely not enough.

How exactly does one address THIS? The bolts are mounted from the back of the crank snout, and there appears no room to remove them to slip new, longer bolts in place. Am I missing something obvious? Or does one need to disassemble the engine to remove these bolts and put longer ones in? Or am I doing something stupid and I shouldn't need longer bolts.

Just thought I would ask.

[studer35]

I tapped threads into the flange and attached the flexplate with grade 8 Allen head screws. Hex head bolts did not leave room between snout and bolt head for a socket wrench. I have been well satisfied with this fix. Grant

[wfhenderson]

Gents- Thank you SO MUCH for taking the time to reply. Turns out that my problem was that the retainer ring that is supplied to adapt the Chevy flexplate to the Studebaker crankshaft snout needed to be pressed into place in the flexplate's center hole before assembly. Probably, tightening the nuts would have snugged it in, but doing it on a press beforehand made easy work of it. Mission accomplished.

Thank you again!

[sbca96]

I ditched the lock washers and went with self locking nuts on the Levesque adapter
I used almost 20 years ago.

Tom