Write-Up: Filled Rear Motor/Transmission Mount

It's cheaper there but i needed it ASAP b/c i'll be moving soon and wont have a garage to work in for a little while.

Take notes when you do yours in case i missed something. i was doing a lot of trial-n-error removing bolts trying to find an easier way to get it out.

Boy, the mount sure doesn't look like the drawing in the manual...
I wonder if the expensive, OEM replacement comes as a complete, bolt-in unit.

driver side complete unit is available form AZ for $102

What does the manual look like? maybe the 96 is different than the rest of them?

Eldo wrote:

Boy, the mount sure doesn't look like the drawing in the manual...
I wonder if the expensive, OEM replacement comes as a complete, bolt-in unit.

Yes, the OEM replacement that was purchased for my car during the Trans rebuild for a million dollars comes complete with all the heavy steel ready to bolt in and looks like the complete one Matt posted above.
Don't know if it's the same as the one he posted, but sure looks like it from memory.
I have the remaining metal part that eventually I'll put one of those Rock Auto mounts in with some Black Urethane and see how that feels.
Just another thing to add to the list when I drop the cradle for other repairs. Not urgent since mine was replaced, but the OEM one is too soft and allows for a lot of fore and aft movement.
Need to fill the voids in the other new one that was installed in front also.

Mr.Riviera wrote:

driver side complete unit is available form AZ for $102

What does the manual look like? maybe the 96 is different than the rest of them?

Thanks for the extra photo, I'm sure it will help others along the way.

It was my mistake, I would have sworn that I read yours as 1998 last night... that's what I get for skipping my Vitamin V.
Yes, '95-'96 and '97-'98 are different because of the different trannies - '99 even uses a third one that is the cheapest! To add to the confusion, GMpartsdirect lists 3 different mounts ranging from $50 to $200, but they use the same diagrams for all years...
The only good thing I see in all of this is that the "Drive" mount, which takes most of the abuse, is the front one, which is the easiest to change.

So now I have another question: Do all years use the 4th mount on the drivers side?

my 96 has a 4th mount by the EBTCM.

Also note that rockauto lists the same rear mount for 95-98 rivieras; anchor part 3065 that Aaron posted earlier.
The 99's have this listed for the "rear left" :

I just received mine from Rockauto, looks just like the picture:



I'm going to fill it with epoxy before installing.

I also received mine! Hoping it helps some of the false knock I'm getting. Now if I could just get a chance to go to the shop and work on things.

If you don't mind me asking what symptoms were you experiencing to warrant the replacing of this mount?

Chris,
if you have a car that is 12 years old with 100k miles on it, chances are (at least) your rear trans mount is shot.
Both my front and rear were no good when I bought my car with about 76,000 miles on it.
I waited untill I had my trans rebuilt to have them replaced.
At that time, they weren't available aftermarket and I didn't know any better so i paid retail at $300.00 each. Figured while the trans was out for O/H it made sense to spend another $600.00. What a friggin dope i was.

My car showed signs of the worn mounts before the trans issues by the engine moving around the engine bay during acceleration and decelleration. Serious fore and aft movement and some banging when accelerating hard, but just the movement was enough to know that they were worn out.
Once the trans was out of the car and you could look closely at these mounts, it didn't take a second for me to tell the shop to go ahead and buy new ones, even at the price i was quoted. I was told they were not available other than through the dealer and i made a couple of phone calls to verify that.

You all are lucky that the internal parts, the rubber and center bushings are now available for what you would expect to pay for a rubber mount. Just replace them if there is a question. You will be glad you did.
And what I have found out from this site is to fill the gaps with the 3M window urethane that has been mentioned several places on here before.

The reason being is even the brand new mounts are made so flexible for a luxury car feel that they don't quite do it even when new.
Meaning they still allow the engine to rock back and forth too much.
This summer, while doing a bunch of other preventive maintenance to the car I'm going to fill the rear and front mounts with that 3M window seal, urethane, and let it cure overnight and hope i haven't waited too long to do it. Preferably the surfaces should be clean of all oil and dirt before applying.

If you buy new mounts, buy this stuff and fill the factory voids with it before installing the mounts and let sit overnight, you'll be glad you did for an extra $10.00 a tube.

That's good advice because mine have gotten sloppy since I bought the car and started doing modifications. I was gonna replace the rear and want to do the front solid with the hockey pucks. thanks Rick and good to hear from you.

crlombardi69 wrote:

That's good advice because mine have gotten sloppy since I bought the car and started doing modifications. I was gonna replace the rear and want to do the front solid with the hockey pucks. thanks Rick and good to hear from you.

If your thinking about doing the front with Hockey Pucks, have you seen the Pic's from Turtlemans car today.????
Glad to hear your still with us as well.
Look at the pics and think twice or 3 times before doing the hockey puck mod.

I'd be more than happy to sell you a Brand New Bonneville front engine mount to do the job, I have one that I was going to install with the GenV, but from what we have seen tonight, I would not do that to you. Unless you plan on reinforcing that area completely by welding a patch that goes all around the sub-frame.
After that is done you are ready for the mount and pucks.
Rick

Quote :

If you don't mind me asking what symptoms were you experiencing to warrant the replacing of this mount?

I started hearing a "clunk" sound during mild cornering. It sounded like there was a large socket rolling around under the hood. I took the car in for inspection and they pointed out a bad right side ball joint, and the failed rear mount. The tech took a crow bar and lifted the engine to show how loose it was - i'm not sure there's much rubber left insulating anything. Lots of movement.

I've since replaced both ball joints, but still have the clunk sound, so hopefully it's the mount.

I'm going to buy the new replacement motor mounts and do the 3M window sealant trick to them. I do expect deflection beyond my liking though and will be boxing in the subframe with plate steel and install the hockey picks or something similar to get the solid mount effect. I love doing things after the first pioneers do these mods. As most of us know is the second time doing mods and such you can do them better and with less work/time involved. This site is great for the Riviera owners and enthusiasts.

I am unable to find P/N 3065, from Rock Auto, which was listed in this thread for the replacement mount for the rear trans mount.

Not a listed number anymore from what I get for feedback.

If anyone knows different, please let me know. I really would like to buy one.

Maybe I should start looking at the local Auto Parts Stores as well and see if the aftermarket or at least the local stores list it.
I definitely broke mine. Cheap OEM crap with about 30K miles on it. For only $300.00 at the time.

Rick,
RockAuto's part number might be 3127 for the trans mount for 95-99 Rivs.

That is the one currently listed and I believe that is for the front.
The one for the rear seems to have disappeared from their listing already.

And I don't know who gave you a Red mark for trying to help but I hit it with a Positive to negate it. That was foolish of whomever thinks every little thing requires a score of negative.

Thanks for looking though Dave

No sooner did I hit "Enter" for this post, that the Red bar showed up. This is ridiculous. To say the least.

I was able to pick up mine from autozone. They had to order it but it was pretty cheap. As i said earlier in the thread i filled the voids with window weld and it has been holding up VERY well. i actually have a little more cabin vibration now that all my mounts are semi-poly. Not near as bad as my friends regal with all poly mounts but i do notice a vibration at certain rpms.

ok, i think the forum is messed up b/c mine went red instantly when i posted.

Mr.Riviera wrote:

I was able to pick up mine from autozone. They had to order it but it was pretty cheap. As i said earlier in the thread i filled the voids with window weld and it has been holding up VERY well. i actually have a little more cabin vibration now that all my mounts are semi-poly. Not near as bad as my friends regal with all poly mounts but i do notice a vibration at certain rpms.

ok, i think the forum is messed up b/c mine went red instantly when i posted.

I negated the Red with a positive.

Thanks for responding to my question on mounts.

I have a question for you, Did you use any kind of adhesion promoter on the mount before injecting with the 3M Urethane.?

Nope I actually had to cut the tube open because the nozzel was clogged from the last mount i filled.

I took gobs of it with my hand (gloves are a must) and packed it in the voids squishing out the air and then as it started to harden i smoothed the ends for aesthetics.

I just checked on-line with Advanced Auto Parts and they list the Anchor mount #3065 as in stock allong with the 3M Super Fast Urethane.
I have a $10.00 off coupon from them in the mail as they just opened a store a couple of miles from me.
So, I'll go and get the stuff there today and get the new one filled before lifting the car and wrestling with the old one in the rear.
Will be doing it on a lift while changing out my front sway bar, brackets, bushings and end links.

Can you take some pics Rick?

Rick,
Thanks for negating the red mark with a positive...appreciate it. BUT, at age 61 I don't care what games folks play...I try to give my best car advice to people who are asking...not always dead on accurate but I do offer a little something based on my experience with at least prior or current cars I have owned or now own. This is a great forum, but I don't take stock in the extremely subjective "Integrity" section. Folks like AA, Eldo, Derek, Randall, you (as examples) are ones I trust with sound advice.

Ship wrote:

Rick,
Thanks for negating the red mark with a positive...appreciate it. BUT, at age 61 I don't care what games folks play...I try to give my best car advice to people who are asking...not always dead on accurate but I do offer a little something based on my experience with at least prior or current cars I have owned or now own. This is a great forum, but I don't take stock in the extremely subjective "Integrity" section. Folks like AA, Eldo, Derek, Randall, you (as examples) are ones I trust with sound advice.

Thank you for the kind words, much appreciated,
Rick