Okay, this is for my near stock auto 195k 94, but the drivetrain is so very similar, and the 4th gen boards haven't been much help.

I read why I was going through trans mounts was because the motor mounts were shot. So I replaced them, and 3 days go by and the brand new trans mount breaks.

Does the torque arm mount have anything to do with this? I bet the torque arm mount is original, and there is some spacing between the mount and the arm, it doesn't look snug. BUUuuuuut, can the torque arm cause this much carnage to the trans mounts?

I've had a poly trans mount that held up for months, but removed it because I can't stand the vibes/buzz that it does to the interior.

I've read the LS1 mount is stronger, but if something is breaking the mounts this quickly, I doubt the $72 LS1 mount will only last twice as long.

how is the trans mount breaking? is it just ripping the stud out? rubber breaking apart? Does the motor vibrate severely when you rev it? that just seems crazy with a stock motor that youd be breaking mounts like that.

Get the torque arm mounted to the crossmember like it should be.

Its ripping the rubber in half. The motor stays nice and smooth with the new mounts. I swear it feels like a car with 30k miles now. But its still ripping trans mounts like it is its job.

Jmd, thats not in the cards. But I will buy a poly tq arm mount.

My 96 trans-am done the same thing, (ripping) the rubber trans mount in half, never figured out why (sold)

Why'd you make the thread if you didn't want to solve the problem.

Even if you get it done quick and dirty w/ the torque arm mount welded to steel bracket off the stock crossmember, it's better than breaking mounts and...

adding vibration to the tailhousing cracks a small number of them.

Just saying.

are you buying the same brand mount? If everything is stock and its ripping the mount in half try a different supplier.... maybe the design is defective. otherwise check for a rear suspension problem, frozen bushings or something else. Unless you are running serious power with slicks the stock torque arm should not put that much strain on your trans... JMD has the right idea with a divorced mount, that will take all the strain off the tranny and put it to a structual member instead.

Understood about the new torque arm, but is that the issue of the tearing mounts? Im not buying a torque arm just because you say so. A stock fbody does not need one, nor did it need it for many years from the factory. Not being a Dick just trying to figure it out not throw unneeded parts at it.

My question was what else could cause the mount to tear, not should I buy a torque arm. Ive tried 3 different brands. Im waiting in the stronger ls1 style mount to come in.

I was just saying that having your torque arm mounted to the crossmember is a better idea, you don't need a new torque arm. Just need to figure out a way to mount the torque arm mount to the crossmember itself. I understand where you are coming from i wouldn't go out and buy a 300$ part because someone online said to either, just so you know. From everything ive learned about forces, the engine puts a twisting force on the mount putting a sideways load on it. The torque arm puts an up and down force on the mount. That is the only thing that i can think of that would put enough force on the mount to rip it in half. but stock the torque arm shouldn't be putting that much force on it, thats why id check the rear suspension to see if something else is contributing to that force on the mount. On my camaro a couple of the bolts were/are frozen in the bushings, something like that might be putting an extra amount of force through the torque arm. Try laying on the ground next to the car, have a friend put a foot on the brake and the gas, see how much movement your car has in the rear suspension. on my car i was gonna try and flip my torque arm mount upside down and use some steel brackets to mount the torque arm mount to the crossmember.

Just get this http://www.jegs.com/p/Energy-Suspens...43960/10002/-1

Apparently, you didn't read all of the first post?

Agreed completely. Find the problem, don't band aid it. When I first bought my car, I went through rubber mounts at least once a month. Soon after, my 700r4 bit the dust. It was shifting rough before it died. Rebuilt the trans and haven't torn a mount yet. How does your trans shift?

Another possibility is crappy parts store mounts vs GM. Have you tried a GM mount?

I eat through them on real hard launches. No real baring to the situation just my two cents.

find an "interlocking" mount- one that has a steel tab inside it that keeps the rubber from pulling apart under load.. i don't know if any rubber mounts have this feature, but i do know that every poly mount does. i doubt if any of the Indian or Pakistani mounts you get for $10 at the local PepZone are going to have this feature.
regarding vibration- it's an F body, which is one of the worst unibody designs ever mass produced for isolating the driver from the car. actually, it's more like a design feature since these cars weren't designed with things like driver and passenger comfort in mind.. i guess what i'm saying is that there's gonna be some vibrations. if you want a car that is smooth and quiet like a Cadillac, then get a Cadillac...

The following is from Spohn. Perhaps something there will he helpful:


Normally, if you get a driveline vibration it is one of four things:

1. You have an Energy Suspension polyurethane transmission mount. This transmission mount is well known for causing driveline vibrations due to its taller than stock height. To fix this you should remove the "shim plate" that they send along and tell you to put between their mount and the transmission tailshaft. You may also consider going back to a stock or rubber transmission mount, or running the Prothane polyurethane (click here) transmission mount that is the proper height.

2. Your pinion angle is not set correctly. See our setting pinion angle article for instructions on setting your pinion angle properly.

3. You have a vibration from another part of your driveline such as from the rear end, clutch, flywheel, torque converter, etc. and it is now much more noticeable because of the chassis mounted torque arm transmitting it in to the chassis.

4. Your driveshaft is out of balance.

JamesC

As someone who has ate through a few trans mounts with stock power LG4s Its been so much easier to pop the poly mount in and be done with it. I've never really noticed any more or less driveline vibration because of it... I just hate replacing stupid rubber transmission mounts every year.

The T5 is a different beast. If you are dropping the clutch on launches, I am not surprised you are tearing up mounts. A well functioning 700r4 car with stock power level, should not be tearing up the mounts on a regular basis.

I'm starting to think this too.

I've killed a few rubber trans mounts in third-gens, always switched to ES interlocking polygraphite, never made the car feel noticeably unpleasant in any way. Same deal in my '95 Z28. When I tried a 200-4R in my '88 IROC-Z, when I first got it, I had to fab up a solid steel trans mount. That was noticeably unpleasant. These cars aren't about comfort, but the solid mount was intolerable! If you manage to break an ES interlocking poly trans mount, I want to see proof, otherwise it didn't happen.

It is the Prothane Poly one and yesterday I put it back in and it's better than before I replaced the mounts. But 70mph+ is buzzy cyclically; I bet the steel driveshaft is out of balance. So in the future I might be looking for a 3rd gen aluminum DS.

Also, the mount tears on the 35mph 3-1 downshift. It seems fine on launches and WOT upshifts, but that one downshift is where it kills them. But that is a fun downshift let me tell you!!!

I have a pic of the T/A mount, the general consensus is that it needs to be replaced.

If your driveshaft is out of balance bring it to a driveshaft shop and have them balance it,I had to bring in one from a work truck,the guy said alot driveshafts that have had u-joints replaced are out of balance,made a huge difference in how the truck drove and never,never ate another u-joint,in over 100,000 miles.

You have 3 solutions:

1. Install a polyurethane mount.

2. Remove the torque arm from the tailshaft.

3. Create a custom 2 piece transmission crossmember with secondary transmission mounts, like our early 3rd gens had.

@bigwhitegtp if you have a steel shaft and it vibrates at 70+ i think that is pretty common with those shafts if everything ive read is right. Mine does the same thing, at higher speeds its more of a feel than a noise, but buzzy sounds about right. Ive heard switching to an aluminum DS will fix that. and gotta say 3 - 1 downshift, damn with an auto? thats putting some strain on parts lol hope everything works out for you!

I've looked into the secondary trans mount, I would love to do that. But I don't have a fab shop. Again, this didn't happen to stock LT1s off the showroom floor, so there is something that is worn and causing it, so I'm determined to find it, not band aid it.

And that 3-1 downshift, I wish the 700r4 could do that. Would've been great in my old GTA.