Need some detailed help on 3.0 front engine mount after engine install and new gimbal

insttech1

Petty Officer 1st Class
Joined
Jun 26, 2011
Messages
340
OK, here's the basics:
I bought my '99 Regal in 2011; I know the PO had pulled the engine at least once.
Pulled my 3.0 engine for the first time ever (bad harmonic balancer).
Replaced my gimbal bearing for the first time ever (15 year old boat; don't know if it was ever done).
I've pulled the drive 3x; never had an issue getting it on or getting it off.
Never previously checked alignment (I know, not good, kicking myself).

So now for the good stuff:
Pulling the front motor mount w/ the engine took some small chunks of resin with it.
I filled those w/ epoxy when reinstalling, so slight chance of a tiny height difference.
So, I need to check alignment, and it needs to be done annually anyway.

Put new gimbal bearing in; checked that the OUTER ring of bearing is squarely in the housing w/ a micrometer.

I CAN get an alignment tool through the bearing, into the coupler, and spin freely w/ one hand.
HOWEVER--I can only do this if the gimbal is tweaked way off center and pointed nearly all the way down.
(I have taken a rod and pushed the gimbal to all four of its limits. I know about where "center" should be.)

This is confusing; I read ALL of the alignment posts I could find.
I looked up the alignment dimensions, and bought a 1.010 shaft to put in the coupler.
It goes through the gimbal, into the coupler, but points down at 6 o'clock as compared to the gimbal, after centering the gimbal w/ the alignment tool. (as in the shaft has 1/4" clearance to the top of the gimbal, and 1/8" to bottom).

So I'm thinking, OK, front mount needs to come down to "properly" center gimbal and coupler.

I pulled the rear mount bolts and washers; the square nuts are lined up, but one is about 1/8 higher than the other.
Rubber on both sides looked good.

I loosened the TOP bolt of the front mount. There are three more nuts on the mount.
The highest one is recessed under the top bolt, and holds a washer against the rubber mount.
I can actually get to this one and turn it, but I see ZERO change in how my 1.010 shaft goes thru the gimbal.
Is there ANY height adjustment when backing this nut down, or does it just hold the rubber mount in place?

Second, I attempted to get to the 2nd highest nut to adjust the whole threaded rod downward.
I even attached a come-along to take tension off the front of the engine. Not budging. Will get longer wrench.

the 3rd, and lowest nut, on the threaded rod at the base of mount, has virtually ZERO clearance to get to w/ a tool.
The mount only sits about 3/4" from the lateral "stringer" surrounding the gas tank.

So in a nutshell, I guess the real questions are:
1. How far can a gimbal be off-true from the bore (not the coupler) and still be "aligned"?.
2. Is there any vertical adjustment from the highest nut on the front mount?
3. Anyone have any tricks for the other two nuts?
4. Is there any adjustment on the REAR mounts? Looking at pic's, it looks as if tightening/loosening the bolt
from the bottom would provide some adjustment by compressing the rubber. As stated above, there is a 1/8 height difference side to side, but everything I read says "no adjustment".

Thanks for your time!!!!!!
 
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insttech1

Petty Officer 1st Class
Joined
Jun 26, 2011
Messages
340
Re: Need some detailed help on 3.0 front engine mount after engine install and new gi

OK....I have the up/down figured out.
I didn't have to get to the two lowest nuts; just lift the engine up a hair, and get to the nut embedded underneath the top of of the mount, with the bolt loosened, and lower it.

All previous posts that I read said 1/4 turn would make a major change on alignment.
I triple-checked the rear mounts. I was able to tighten one rear mount in place by lifting the engine slightly, and it's now 1/16 higher than the other side.

I did, however, have to turn down the inner nut by about 5/16" until my 1.010 rod was looking about centered in the gimbal.
The alignment tool goes in just as smoothly in this position as it did pointed way too far down.

So now I'm concerned that everyone says alignment is critical to part longevity, but I can get the bar in easily from both positions.

And no, the splines inside the coupler, or on the drive, aren't damaged, and have always been heavily lubed.

Any thoughts?
 
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insttech1

Petty Officer 1st Class
Joined
Jun 26, 2011
Messages
340
Re: Need some detailed help on 3.0 front engine mount after engine install and new gi

Made more progress.
I thought the upper bolt/nut were part of the adjustment.
I now assume they're NOT. I guess the nut underneath is only to compress/hold the upper rubber vibration mount.

All adjustment should be from the two bottom nuts, correct? I have the shop manual, but it is only for the newer
style that has adjustment nuts only; not a top bolt.

So I can get the 2nd highest nut loose and lower the drive. That leaves me w/ the issue of not being able to reach the
lowest nut so I can tighten everything back up.

Making progress, but still not quite there yet.

Feel free to chime in w/ any thoughts.
 
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