Urethane torque axis mount

[BillBoost37]

After seeing 99 ssei's plan to use hockey pucks and having thought about pucks or urethane myself, it was time to try it. 99 ssei and I are both S2's with enough power to tear these up, and they fail frequently once you have enough power and drive it for enjoyment.

Took some work and failures that can be found here Full post with ugly details etc but the basics are a new mount that should be much stronger than the stock one. I am hoping 99 ssei finishs his soon so that we can put them in and compare results. The cost of the urethane is ~$30 a mount.

[sandrock]

Is this a full-on urethane mold, or is it urethane-encased factory rubber?

[harofreak00]

full-on urethane mold, check out his post on BPro, its hilarious

[superchargedSSEi]

I've had a half done poly TA mount sitting around for several months now. By half done, I mean the rubber is cleaned out of the TA mount and I have a container of urethane sitting next to it...got sidetracked and never finished it.

My planned mount is identical to yours...full poly mount...though I chose urethane with a 60A hardness instead of the 80A used in yours. I'll be sure to finish it up while the car is down for this *dang* motor swap so we can have a comparison between two poly mounts of different stiffness, and Ken's hockey puck mount.

[BillBoost37]

If you are planning to do one of these, read the full write up. You should laugh and learn at the same time. Overdo your sealing and template and you should have success on the first time.

If not, drink before you start to have a excuse as to why you failed.

[95naSTA]

Sweet.
So, there will be 3 actual experiments with results.
Good to see an aftermarket approach wasn't poopcanned.

[willwren]

The other approach wasn't poop-canned as you put it. Problems with the design were pointed out and the topic author was told what to expect from a practical sense.

This is a far better approach. Purely the correct approach in all aspects.

[PDXGTP]

Looks good Bill,

What is the durometer of the poly once it sets up?

[BillBoost37]

The hardness shore rating is 80A with a tensile strength of 1725 psi.

McMaster also carries a 60A mentioned by Aaron with strength of 1250psi and a 95A with strength of 3120psi. There are also putties etc with varying strengths/durometers.

[PDXGTP]

So have you bolted it on yet and givin it a go?
I'm just wondering how she feels? - meaning .. do you feel any vibration?

I have the MSP dogbone poly mounts on my GTP and I don't feel any vibration. Other people have installed the Intense & ZZP dogbone poly and they feel tons of vibration.

So the reason I ask is...
The Grand Prix's have a different version of the TA motor mounts. I have gone threw 3 of them. I have been considering making one from poly because my last one only lasted 3 weeks & 200 miles. Seems like every time I step on the gas I break something. Naturally this is to be expected but it gets tiring.

I want to go to the track in efforts to break into the 11's in the next few weeks and prerty much expect that I'll break my last newly installed mount.

Later,

[willwren]

Thomas, you're talking about the one under the harmonic balancer?
The one we replaced on Celin's car at WCBF?

Crappy design. In comparison to the H-body TA mount anyway. I have one of those GP mounts at home, I may just have to look at that sucker. The trick is getting all 4 fasteners/studs properly located before the poly pour.

[PDXGTP]

Thomas, you're talking about the one under the harmonic balancer?
The one we replaced on Celin's car at WCBF?

Crappy design. In comparison to the H-body TA mount anyway. I have one of those GP mounts at home, I may just have to look at that sucker. The trick is getting all 4 fasteners/studs properly located before the poly pour.

Yes, yes and yes...

The other thing is I'd like it 3/8" shorter because I have an IC and the engine sits so high with the new mounts that the SC touches the hood and its rubbing a hole in my hood.
I also need to make one for the other side.. the "trans Mount" ZZP sells them for $79.00 and advertise that you will feel much more vibration.
I also have a few spares on the trans mount too.

Bill.. Wren, I can make a jig to hold the position of the mount during pour and setup of the poly.

I was wondering how easy or difficult it will be to get all the old rubber off the mount? I was thinking to just burn it off with a torch..

[BillBoost37]

Having a fleet of W bodies in my stable (and never repeating a color so far) I know the mount you are speaking of a little too well. I believe it is a couple pieces of metal that are only seperated by the rubber and potentiall filled with oil. I would make up a mold that has the ability to hold top and bottom sets of studs in the correct location and at the height you are looking to achieve. Coat with a release agent and pour away. Instructions say it takes 1-2 days at 77F to cure at 70-80% strength and 7 days at 77F to cure to 100%.

This should be easy to do and make, pick up two 1lb containers though, you will most likely need the second one.

I am pretty busy (W bodies do it to a guy ) and will try to get the mount on the car soon with some testing that proves if the mount is better than a stock one with 10K miles on it. Butt dyno doesn't cut it if you are trying to prove things and gain those last few tenths.

[willwren]

The two solid front trans mounts I made, I simply used a few scraps of 2x4 for the jig. Worked like a champ.

With an oil-filled mount, I'd hold off on the torch until after you've drilled and drained it.




(or do it in the kitchen)

[BillBoost37]

The two solid front trans mounts I made, I simply used a few scraps of 2x4 for the jig. Worked like a champ.

Wrong mount Bill.

Additionally this is an exposed rubber mount meaning it has nothing containing it, and the urethane is pretty thin when working with it. A method of containing the urethane would be needed. Check out the Thomas Edison version on www.BonnevillePro.com if you haven't. I had a bit of fun with learning how thin of a viscosity this urethane has.

[willwren]

Bill, my jig idea was to represent a JIG OPTION. I'm very well aware we're talking about a different mount, but material selection in making a jig would work for either just as well. In both cases, you have two critical attachment points that have to be held in the proper positional relationship to each other.

When I work with polyurethane, I simply make rigid tape dams for containment. Two different types of tape. Foil for the rigid portion lined on the inside with teflon release tape. It won't stick to polyurethane. In the case of the W-body mount, you can pour through a hole in the jig if necessary.

[PDXGTP]

Bill, the other Bill is talking about the other correct mount.
I'd like to re-manufacturer both mounts, the W body TA mount and the trans mount basically looks like the same thing but its on the other side.
The trans mount is about 30% smaller but has the same basic configuration.

[willwren]

The primary mount under the HB would be very easy to jig, dam with tape, and pour. I did some playing tonight. (Talking W body here)

The basic principles and techniques would apply to all mounts like this regardless of location. The exception (more difficult) would be the front H body trans mount from 92-99. Because of it's construction and the need for the poly (or other dampening material) to bind to flat plates would make it a little less practical for this type of rework, but two or three other methods have proven good for that mount.

[BillBoost37]

Tman.. the hardest part will be prep. Make up a mold or jig that includes the 1/4" drop and then figure out how to clear the old mount off. Personally..I thought about a bonfire myself.

[sandrock]

Do poly inserts exist for the dogbone mount? I know they exist for Fiero dogbones, but what I don't know is if the bushing size is the same between the two.

In any case, it seems that the dogbone mount would be the easiest one of our mounts to poly...very little damming to do.