FAQ: Engine/Transmission Motor Mounts

I've heard a lot of guys on other forums use the JB Weld method so it must work fine. If it's going to be down a week you just as well should do the poly cast. I think the individual 1lb kit runs $28 which is easy enough to do a single mount. I think JB Weld (very hard) against old mount rubber (very soft) might cause a few problems...

ewolfe0050 wrote:

Good luck- it's a bear but pretty straight forward. I had my cradle dropped so it made it a little easier. There is very limited room to move around. If your trans is removed for repair it will be much easier.

BTW- if you go with the poly mounts, I think you will be happy. Mine settled after a couple weeks of driving and I love them. Keep in mind I went hard 80A for performance but I think you will be happy with 60A.

Damn you weren't kidding. I am still working on it. Got 4 bolts off .

At least you have some down time to work on it... good luck!

I wouldn't go JB Weld. It's a hard material that could crack quicker than the poly.

I've got my front mount in my truck. I should have reviewed this and redone the rear mount. Darn it.

Update?? What did you decide to go with OEM, poly, or JB weld?

Most likely going with JB Weld, because it was made by God! J/K

Because of time constraints and the ease of availability.

I found this trans mount on autozone and it's only 100.99 . Unfortunately that was after I paid to put on used ones
Link

wow, thanks andrzejsze< I've been looking everywhere for this, I will bring this part number in to autozone first thing tomorrow, thanks again

I see my link has changed but the part number is A5236 (97 riviera transmission mount) on the autozone web page

Enrique, you're gonna hate me for not thinking of this sooner...

Everyone knows by now about the hockey-puck mount that is so great for the 00+ Bonneville, and the later PAs. Well, us platform-mates from prior to 2000 have a little problem, as Oldsman can tell you. Our mounts aren't hydraulic. They have a square bushing, set up-right, and the trans side of the mount is a bracket that has a bolt that goes through the bushing. So we don't even have the hole to install the puck mount.

Well, after the frustrating experience yesterday of trying to get my front header off so I could get a drill in there to MAKE a hole, only to fail because the sleeve fit at the crossover pipe had WELDED itself together, I had a minor brainstorm. I hopped in, headed to Lowe's and grabbed 3' of 3/8" coated steel cable, and a couple cable-clamps. Came back, crawled under the car, and shoved one end of the cable up between the subframe and splash tray right by the motor mount. Then from above, I passed it over the bushing bolt and back down, crossed it under to the other side of the mount, and then back down again. Then I crawled under with the clamps and a ratchet and pulled the cables as tight as I could, and clamped it. Two clamps,for a little extra security. I passed the extra cable back up through the splash tray. So, now my motor mount is restricted to about 1/2" of movement back, which means no THUDding when I force a downshift. It even smoothed out the upshifts alot. And, unlike the puck-mount, it doesn't transfer any more vibration to the frame than an unaltered mount, unless your standing on it.

Old drag-racing trick.

Pretty simple, really, run it over either side on the mount, and cross it underneath. I need to clean up the extra, but you want to leave the tails so you can snug it down if it loosens at some point. I'll tuck the tails down today.

thats what they call in school, brainstorming

Nice!!!

I dont understand what you did....sorry....

i'm a little confused myself. so you just strapped the center bushing bolt to the sub frame? or are you filling space between rubber/housing with the cord?

Mr.Riviera wrote:

i'm a little confused myself. so you just strapped the center bushing bolt to the sub frame?

Bingo!

maybe this should be new thread - but -

I want to get a set of polyurethane-filled motor/transmission mounts. Do any of you knwo who I can send an old set of mounts to for gutting and refilling with PU? Please advise, thanks.

Albertj

TTT
Anyone have any input and/or experience doing this. I'm interested also.

there is a thread about doing exactly this. Search is your friend. I'm pretty sure it's written by ewolfe, and subject is something like 'polyurethane engine mounts' or something.

https://rivperformance.editboard.com/series-ii-engine-transmission-f4/write-up-rubber-trans-mounts-version-2-t2843.htm#32321

This should get you started... On the P mount I found the round tube I used augered out the hole after time. I replaced with factory new today (30min!) and will try a slightly different approach. I am going with a square bar with the middle drilled out to prevent alot of movement. Make sure the flat top and bottom are in line with up and down movement and you should be fine. eg...

this doesn't work too well after a while....


this should offer more support...


I think I am going to be a graphics designer when I grow up

By the way the two trans mounts have held up great. They are just up and down movement not the rocking that the P mount goes though....

Also, some people have adapted the Bonneville's lower front trans mount to replace our front mount. It seems to be a direct swap if you have all the Bonneville bracketry, and offers better support. Plus you can then remove the rubber all together and put some hockey pucks in their place...

Eric,
Where do I get the materials to make some myself and also is there any reading material you can recommend on the different grades of polyurethanes.
I would like to talk to someone about this and be able to speak somewhat intelligently about the subject.

Read the posted thread and it has all the info in it. Rickw.

For anyone who wants to do the hockey mount with Bonnie bracket, I have a bracket (OEM new) that will do the job... I figured while I did the others in poly might as well do them all but I have heard good things about the hockey mount way too.

I didn't recognize the number references you were giving for the different grades of urethane. Now I realize its the Rockwell Hardness Shore A, found under Rockwell R hardness charts for polymers. Makers more sense to me now.
I re-read your thread and am not completely sure which one chose for the trans mounts that you said are holding up real good. Is it the 60A or the 80A and would you recommend the 80A for a daily driver or the 60A.?

I use 80A hardness on all of my mounts (except for the driver's side which I haven't found out how to do yet), and suggest it for a performance car. If you are worried about vibration go with the 60A. Although wthout a inner ballance shaft, REALLY lopey cam, and 80A mounts, I don't think it is too bad on my car...

Thanks for the pointer to the mount fabrication instructions.

Albertj