1960s '61 DeVille transmission alignment

[ZGJim]

Today I noticed that the engine/transmission in my '61 DeVille coupe is not aligned with the center of the frame.  The tailshaft of trans is offset to the passenger side of the frame.  The crossmember had two extra holes in it that are offset to allow the trans to be bolted in.  This is causing the drive shaft to also be offset where it passes through the frame.  I am sure the engine has been rebuilt, and all of the engine/trans mounts appear to be newer than original.  Is it possible to install the engine mounts in a way that would cause this misalignment?  Anything else that would cause the engine/trans to be misaligned?
Thanks.

[Clewisiii]

Yes. but you would also notice an issue at the crank pully.  There are ears on the front of the block that the motor mounts mount to. The motor mounts attach to the engine block ears on different sides from right to left. If you put them on the same way from right to left they will actually be crooked.  The motor and trans mount in just the three locations.



Old one.

[ZGJim]

Thanks for the pics.  Does the motor mount on the passenger side also mount on the rear side of the lugs?  My Crossmemeber is different too.  It doesn't have slotted mounting holes for the trans.

[ZGJim]

Just checked the engine mounts.  Both sides, the mount is on the front side of the lugs.

[Clewisiii]

Driver side motor mount goes to the rear of the engine flange.


The passenger side motor mount goes in front of the engine flange.


Balanced nicely in the tunnel.

[Clewisiii]

Both on front would twist to passenger side.

Fixing your driver side mount should turn it back to center.

[Clewisiii]

If you can get in there you should see an issue with the crank pulley to. That is how I knew I had an issue and had to fix it. I did not have the Trans in yet to see it was also off.

[The Tassie Devil(le)]

Looks like someone prior had drilled the second pair of holes in the crossmember because they couldn't get the trans to line up because of the front mounts being installed incorrectly.

I found that out when I was installing the 390 into my '60 CDV.   Caused me to use my brain again to figure out what was wrong.

Bruce.

[ZGJim]

Thanks for the great information.  Now, is it possible to correct the installation of the ds motor mount without completely removing the engine?  I have the car on a lift, so I have pretty good access to the engine from above and below.  If I unbolt both of the mounts, will the engine lift up enough to be able to reposition the ds mount?
Thanks again for all the great support.

[The Tassie Devil(le)]

Should be but take care of the clearance between the fan shroud and the fan.

Plus, you might have to loosen the exhaust pipe flanges as when the engine returns to its correct position, it might just need the movement in this area.

Bruce.

[Clewisiii]

FYI you might be looking at replacing the carrier bearing as well. Do you know how long it has been driven like that.

[ZGJim]

I think I will loosen the bolts on the exhaust pipes, just hope the bolts aren't seized in the manifold.  That would be a whole new can of worms.
I do not know how many miles it has been driven the way it is.  It has been in collections for at least the past 12 years and driven very little.  The condition of the engine suggests only a few thousand miles at most since the rebuild.
I only noticed this because I was checking the propeller shaft alignment.  The car developed a shudder under acceleration after I replace a leaking output seal on the trans.  I think that I will loosen the mounting bolts for the carrier bearing while the engine/trans is being realigned.
Thanks again for all the support.  I will let you know how it turns out.

[ZGJim]

It turns out that it is possible to reposition the motor mount on the engine with the engine in the car.  The engineers who designed the car did not allow for that, but it is possible.  It is not however, a job for the faint of heart.  After loosening both mounts from the frame, loosening the exhaust pipes and the carrier bearing mount, I used a jack to raise the driver's side of the engine.  It went just high enough to remove the engine mount.  Reinstalling the mount is not easy.  The bolts for the mount are installed from the inside of the frame lugs and that is a problem because access is very limited.  I spent way too much time trying to get the two upper bolts installed from under the car.  I finally admitted that the only way to install those two bolts was to remove the exhaust manifold.  Removing the manifold with the engine in the car is another job the engineers did not allow for.  Fortunately all of the bolts came out cleanly and with the right amount of twisting and turning the manifold came out.  Mount bolts now easily installed.  With mount installed in the correct position, the engine/trans are now centered in the frame.  Reinstalled everything that had been removed.  The driveshaft is now centered in the opening in the frame, the trans mount now, with a little persuasion, fits in the original holes in the crossmember. 
I would never have attempted this job without a lift. (That thing gets me into all sorts of trouble.)  The car went up and down several times during the course of the work.  I had/needed assistance many times.  I have an extensive tool collection and used a lot of it to reach some nearly inaccessible nuts/bolts.
Now that the car is driveable again, the shudder that was annoying me is gone.  It has been replaced by a loud banging.  It bangs 3-5 times when starting from a full stop.  After that it is as smooth as you please.  Will have to get it back in the air and check the condition of the carrier bearing.
Thanks again for your knowledge and support.

[Clewisiii]

Good job. And it sucks accessing that lower mount bolt in the frame. I had almost complete access when I installed mine and it still took half a day.

[The Tassie Devil(le)]

Congratulations on getting the job done.

As for the banging, check the length of the exhaust system to see that it clears everything.   It could have been installed with the engine offset, and now requires some action further back.

Bruce.

[ZGJim]

Thanks for the reminder on the exhaust.  Hadn't thought about that.  It is not original, but still might need some adjustment.
I spent about six hours on the disassembly, because I didn't want to remove the exhaust manifold.  About another 3 hours on the reassembly, spread out over 2 days.

[Clewisiii]

The closest possible issue in the area you were working in would be the Emergency brake bracket that mounts to the frame. The exhaust pipe passes right in front of it.

It is a very tight gap and somewhat adjustable on the cable ends. Other then that you should look at how tge exhaust hangers are set up.

[Clewisiii]

E brake area to check out.