Rear suspension problem?

[Deimos]

I am not sure how to describe this but here goes...

Recently I have noticed that I can feel bumps through my stickshift. The movement is pronounced enough that I can see the stick shifter move out of the corner of my eye. The shifter will move in all gears as well as neutral position. The shifter only moves when the rear axle hits the bump.

I have made no recent changes to the stang.

Anyone have any ideas?

 

[dysan]

Are you still running stock motor mounts? I would suspect it's just the hydro motor mounts flexing, twisting your trans and thus going through the shifter.

You could either switch to prothane or equivalent motor mounts or get a CHE k-member brace with torque limiters to brace your trans. I would recommend the motor mounts first.

 

[Deimos]

I already have the K-member brace.

Arent the motor mounts in the front of the car? I only get the motion when my rear axle hits the bump. I suspect the LCAs may need to be regreased. They are squeaking like crazy right now.

 

[rojizostang]

could there be a problem with the tranny mount?

 

[Royski]

Any update on this?

Driving home tonight, I noticed that my shifter (pro 5.0) handle was moving with the bumps/ride of the car (basically vibrating/moving front to back).

I'm getting the k member brace installed tues along with LCA's, but was wondering if maybe the motor mounts need to be replaced as well or if something is just loose/broken with the shifter assembly...

 

[JeremyH]

If your lowered, and its only when the rear hits bumps, sounds like the axle is hitting the stops and deflecting causing the excess movement/vibration. Trim down your bump stops on top of the axles to account for the lowering.

Im lowered on frpp k springs and mine were hitting, trimmed the first notch and its much better.

 

[JeremyH]

Stock axle bump stop

 

[JeremyH]

Trimmed down

 

[FastOrange]

When i changed to a 1 piece DS, and still had the factory engine mounts in the car, mine would do the same. DO you think that could be your problem? The 1 pieces are lighter, but in reality place more load there at the trans as I come to find out because of their lack of support half way down the shaft.

 

[Tom]

When i changed to a 1 piece DS, and still had the factory engine mounts in the car, mine would do the same. DO you think that could be your problem? The 1 pieces are lighter, but in reality place more load there at the trans as I come to find out because of their lack of support half way down the shaft.

This is very true!

As for the shifter moving, there are a number of variables. The O.P said it's happening in nuetral as well so my question to him is how do you drive the car( hard, easy etc,etc) and how many miles and what clutch is in the car.

 

[Royski]

Found out my issue today was that one of the bolts holding the assembly in had loosed out a decent amount. Had my shop snug it up again and use some locktight.

 

[blackstallion06]

Check this out guys. My whole rear end feels like it moves around a bit. I really notice it on roads that have the groves in road for wet weather. ( dont know what they are called so cal has them in highways) It really doesnt do it when I am on the gas just when I am cruising or i let off ect. It feels as if the rear end moves around a bit or floats. I do run my tires air down a bit but nothing serious. I am going to air them all the way up and change my bushings in my control arms and see if that helps with the floating. My shifter also moves around a bit just vibrates back and forth. I really notice it though when Im off the gas going down hill at highway speeds. I just assumed it was from my ram air hood forcing air into the CAI and me not being on the gas.

 

[Deimos]

This is very true!

As for the shifter moving, there are a number of variables. The O.P said it's happening in nuetral as well so my question to him is how do you drive the car( hard, easy etc,etc) and how many miles and what clutch is in the car.

Sorry for the extreme delay on this thread. I put the car away for several weeks as I had other things to take care of.

To answer your question. I drive the car easy on the street and beat it at the track. The car has 40k miles on it and I am on the oem clutch, never replaced.

I had a chance to get on a lift and check out the underside a few days ago but I saw nothing obvious. That having been said, It would have to be pretty fucking glaringly obvious for my dumb-ass to find it. I checked the bolts which seemed to be tight and the shifter is not loose against the car.

EDIT: I have trimmed the bump stops which did not fix the issue.

 

[19COBRA93]

My car is doing this as well. I noticed it the most after hitting the track last weekend. I never noticed it before, now it's done it ever since. I've crawled all over under the car and found nothing loose, broken, or unusual.

If I just rest my hand on the shifter I can feel something in the shifter everytime I hit a bump. It really feels like the transmission is bouncing around when I hit a bump.

 

[Deimos]

Thank god I am not the only one!!!

Doing some research, I have noticed that others have complained of drivetrain noise like there was something loose under the car. Particularily when they push the clutch in at low speeds. In general it just seems like something is loose down there and I would really like to know what to look for.

It has been postulated that my clutch is going, and I am sure it is as i really beat it like a red headed step child at the track. If this is the first signs of the clutch going then I can prepare to have it replaced.

 

[19COBRA93]

The issue you describe shouldn't have anything to do with the clutch itself.

 

[Deimos]

UPDATE:

I have replaced the transmission mount with a brand new unit from the dealership. I think it's a little better but that could be placebo. I will need to put some miles on it to be sure.

 

[Deimos]

after driving around for a while it seems that the problem is no better after the mount replacement.
My car is lowered on Pro Kit springs but stock shocks for the last 35k miles. I think this could be a contributing factor but some disagree.
It has also been postulated that the problem could be in the transmission itself.
Anyone have any thoughts on this?

 

[IronStomach]

Err... why wouldn't the shifter move when the rear wheels move? I'd be worried if the front wheels had any effect.

Your rear wheels are pretty much connected directly to the driveshaft through the differential. The shifter is more or less leveraged between the transmission and the body, any movement of the transmission should effect the shifter slightly.

It could be that your stock shocks aren't damping anything any more causing you to notice it more... after 39k miles on mine, the stock shocks have definitely given up the ghost.

 

[Rubrignitz]

I'm guessing motor mounts. The stock ones are hydra-mounts and could have blown out or something. I used to see my shifter move as well before the steeda HD motor mounts. It's BMW-tight now with the motor mounts, one-piece driveshaft and watts link. All of those items made a huge difference in feel and control.

As for the rear end wandering issue I had problems with that too which the watts link corrected. Drives straight as an arrow now over all roads. I can take my hands off the wheel for about a mile. The car nearly drives itself.