bad motor mounts?

**Poppn** · 10-29-2008, 12:44 PM

It's a 99 SS with 55,000 miles.

Sometimes when I get on it good and shift to 2nd gear, the shifter shakes violently as the car grabs for traction. Other times, it stays put.

I installed a prothane tranny mount in the spring, but I checked it the other day and everything is torqued and mounted right.

Also, as the RPMs climb is seems to vibrate the car more and more.

What could be the problem?

**sunsetorangess** · 10-29-2008, 02:19 PM

Wheel hop? Do you have traction when the shifter is jumping?
J

**Poppn** · 10-29-2008, 02:59 PM

No traction when the shifter is hopping. Would wheel hop shake it violently side to side? Sometimes it does it and sometimes it stays put

**Wesman** · 10-29-2008, 03:10 PM

Originally Posted by Poppn

No traction when the shifter is hopping. Would wheel hop shake it violently side to side? Sometimes it does it and sometimes it stays put

Wheel hop can definitely make it hop side to side if its bad enough. Sounds like thats your issue.

Upgrade to some tubular trailing arms, a tubular panhard rod, bilstein shocks, and a polyurethane torque arm mount. Then your wheel hop problem should be resolved.

**Poppn** · 10-29-2008, 05:19 PM

Good game......I already have lakewood LCAs, and a whole new torque arm is planned in the spring.

I'm confused as to why the tranny would move side to side during wheelhop?

Shouldn't it bounce up and down?

**Snakes4** · 10-29-2008, 06:16 PM

Jack your car up again and double check your trans mount. If you really get on your car and the transmission is bouncing all around underneath then the mount is either broke or the nut that holds the mount to the crossmember is missing or loose.

**Poppn** · 10-29-2008, 06:22 PM

Ill triple check again friday, but it only happens sometimes when the tires break traction, so it's gotta be wheelhop or something

also, its a prothane mount with only a couple thousand miles on it

is there anything else that could be broken?

**sunsetorangess** · 10-30-2008, 01:14 AM

I would lean towards wheel hop, and if thats the case you have to be careful, you can destroy alot of parts. If you have checked your mount twice then im sure its good. The poly mounts are a little stiffer than stock mounts and will have a bit more vibration through the shifter but not enough to call it "violent" shake..
J

**Spaz** · 10-30-2008, 10:50 AM

Originally Posted by Poppn

It's a 99 SS with 55,000 miles.

Sometimes when I get on it good and shift to 2nd gear, the shifter shakes violently as the car grabs for traction. Other times, it stays put.

I installed a prothane tranny mount in the spring, but I checked it the other day and everything is torqued and mounted right.

Also, as the RPMs climb is seems to vibrate the car more and more.

What could be the problem?

sounds like wheel hop... but if the shifter is moving then it is probably you motor mounts... i had pretty much the same problem till i put in prothane motor mounts... but i still get wheel hop on wet roads...

**Snakes4** · 10-30-2008, 11:17 AM

hey man, if your car didn't have any wheel hop until after you installed the trans mount and your shifter only occassionally moves around here and there, then it is more than likely your trans mount. Unless you really modified the shit out of your car, then the issue is probably your trans mount. Why did you replace your trans mount? Was it because you wanted a poly mount or because you tore the stock mount? I modified my TA and it didn't tear until I modified it. The transmission would occassionally move around when I got on it but not every time. Do you feel like the noise is under you when your shifter moves? If your whole trans is moving because of the trans mount either tearing or the nut is missing or your trans crossmember is missing bolts or something to that effect then you might have some wheel hop here and there when it occurs. Im not saying that your motor mounts are not tore or that your car is putting out so much power to the wheels that you aren't having wheel hop but more than likely if everything was ok before you put the poly mount on and then within a short time frame after you install it the wheel hop and shifter movement is occuring and nothing else has been changed, then it is probably your trans mount or something around there that you took off in order to install the trans mount. Just installing a trans mount if nothing else has been changed is going to cause your rear end to start hoping unless you really modified the shit out of your car. True putting a poly mount will make a slight difference in how your TA performs but not to the extent that your rear end starts hopping. Trust me on this. You need to take into account what you did before, during and after the poly trans mount. Like I said before, if this is the only thing you changed and then all of a sudden you start having this issue it is more than likely because of the work you did on it. Im not saying you did a bad job or that you didn't know what you were doing but sometimes we forget to do something or bolts and nuts are not tightened properly or who knows what else. Just jack your car up again and really look at all the parts around your trans mount, including the crossmember. If you have put another jack under your trans and take off the crossmember to look at your poly mount again then thats what I would do. Whos to say that you didn't receive a defective poly mount?

The other thing is, like I mentioned before you didn't really tell us what else if anything has been done to the car? If it is basically stock then I highly doubt that just changing the stock trans mount to a poly trans mount is going to create so much more torque that your wheels start hopping. Check your trans area again and take off the crossmember and really look at the mount. Thats what I would do before I sank a bunch of money into my TA which might not even fix your current problem.

**menardst** · 02-16-2009, 06:37 PM

What about motor mounts... would that explain the left to right shift?

**Poppn** · 02-16-2009, 08:34 PM

I'm glad this thread got revived, I forgot about it. I got the Camaro back on the road this weekend, and I took out the poly mount and installed the stock rubber mount. Tonight, the hopping still occured. I KNOW I installed the mount right....but I was beginning to think, would not having the lower trailing arms greased correctly cause wheel hop??? I have Lakewood LCAs, and I need to put more grease in them but haven't yet. That's the only other thing done to the car when the hopping started up.

I'm gonna grease the LCA bushings within the next few days and see if that improves anything. I'll also check the nuts and bolts on them as well.

**carmelo** · 03-30-2009, 11:20 PM

hey everyone im new to ls1.com but i have a question about my 2000 z28, recently after i stomped on my car a lil bit, it started bouncing when i let off the clutch, what could cause this? could it be the transmision mount?

**side2000** · 03-31-2009, 05:22 AM

Originally Posted by Poppn

No traction when the shifter is hopping. Would wheel hop shake it violently side to side? Sometimes it does it and sometimes it stays put

side to side is motor mounts. wheel hop exposes the issue of dead motor mounts. pop your hood, start car, pop the clutch a few times and watch the motor. that tells you how your motor mounts are doing without using the shifter as a judge. if your shifter is moving noticably, even under wheel hop, your motor mounts are prob bad.

**driftpin** · 03-31-2009, 06:04 AM

Originally Posted by Poppn

I'm glad this thread got revived, I forgot about it. I got the Camaro back on the road this weekend, and I took out the poly mount and installed the stock rubber mount. Tonight, the hopping still occured. I KNOW I installed the mount right....but I was beginning to think, would not having the lower trailing arms greased correctly cause wheel hop??? I have Lakewood LCAs, and I need to put more grease in them but haven't yet. That's the only other thing done to the car when the hopping started up.

I'm gonna grease the LCA bushings within the next few days and see if that improves anything. I'll also check the nuts and bolts on them as well.

You mentioned the Lakewood LCA, those arent the Lakewood Traction Action LCA's are they? If so without some other suspension mods they can cause wheel hop, kind of crazy since they are used to help the car hook hard. I would do what snake4 said and remove the x member and just inspect the prothane mount, if good, look at the motor mounts.

**side2000** · 03-31-2009, 06:58 AM

why remove the x member? if the stick isnt moving up and down the tranny mount is fine. you can see if its cracked and even stick a prybar in there if you dont trust your eyes. stick will ALWAYS move up and down under load if the tranny mount is bad.