Whose fault is it? Rear control arms or springs?

[No.11]

I have a problem with my car where my driveshaft scrapes up against the top of the undercarriage whenever I have weight on the car (passengers or groceries). I'm thinking it may be the springs, which sit kind of leaned over in a curve as opposed to straight. My grandfather says maybe there is something wrong with the aftermarket rear control arms. I'm not too sure about that one since I don't really know how control arms work. Can anyone give any input?

 

[89Fox351]

it is definitely not your control arms.. control arms only act as an axis point.. the problem is either your struts or your springs..

yes it is ok for your springs to be at an angle. my guess: sounds like you need new struts

 

[No.11]

Awww damn, that's another hundred or so bucks X_x... I just replaced my rear shocks since those bastards at PepBoys said that was the problem. The good thing is at least I replaced them and the brakes myself so they didn't rape me with $600 worth of labor. I still have to install a tie rod end but I'm gonna have to read up on that first or get some help.

I'm thinking of just getting some new springs anyway. I was thinking either Ford Racing C-springs or Eibach Pro-kits. What do you think, for street use?

 

[BlownFiveLiter]

What exactly is scraping? If your engine is rubbing the firewall, or transmission rubbing the undercarriage, I'd be looking at engine/trans mounts long before springs, or control arms.

 

[Mustang5L5]

+1 on engine/trans mounts


what scrapes? The driveshaft?

 

[90lxcoupe]

im confused as to what the hell the problem is... drivetrain is pretty vague, the drivetrain starts at the motor and ends at the rearend

 

[89Fox351]

ahh yes i was assuming we were talking about the rear end of the car!! oops!

 

[GDTrumbo]

Car info please? How old? '79 thru '98 Mustang has very little rear suspension travel to start with. (improved somewhat in '99)

*Rear springs may be weak.
*Pinion snubber may have deteriorated/fallen off causing metal-to-metal contact there.
*Make sure the emergency brake bracket/cables & such are not hanging & making contact with the driveshaft.
*Like stated before, check the engine/trans mounts too.

GT

 

[No.11]

Sorry yes I meant the driveshaft is scraping against the top of the undercarriage.

The car is a 90 LX 5.0 Hatchback. As far as suspension it has subframe connectors and rear control arms, and I just replaced the rear shocks with sensa tracs.

 

[90lxcoupe]

Springs dont normally go bad, unless they were heated with a torch cause someone cut them. Look at the rubber bushing on the UCA's. Also look at your upper torque boxes, they could be torn up. Is it the front or rear of the DS hitting

 

[Mustang5L5]

I have MM adjustable LCA's...and even at full lowered, it doesn't scrape the tunnel with a larger AL driveshaft.

Are you sure the driveshaft is scraping the actual trans tunnel? Or is it scraping the e-brake cables?

 

[rd]

Need to jack up at least the rear, and set the axle on jackstands, and check where it is rubbing.

Could be several things. If the car was lowered in the rear, and something got loose, like the exhaust, it could be rubbing.

 

[No.11]

It's definitely rubbing along pretty much the whole length of the tunnel. I saw the scrape marks on both the tunnel and the driveshaft. The tunnel has little grooves and ghats where it's rubbing. So it'll rub in one spot and then about two feet or so there's another spot where it rubs.

 

[No.11]

I'll try to take some pictures tomorrow.

 

[No.11]

You can see the rubbing on the driveshaft. Has anyone else ever had this?

We tried putting that bolt into the transmission mount, but we couldn't get it to align. My transmission seems to be crookedly aligned and gets in the way of the trans mount. I pretty much hate the previous owner right now for such sloppy maintenance on this car. Worn out bolts, missing bolts, oil ALL OVER the underside...

That damn bolt was being a pain to find...and it just so happened that my grandfather picked up a random bolt at the pick your part and it fit... although it's longer than the OEM one.

Oh well, we'll try again tomorrow with some more time.

 

[Maryland Stang]

Can we get a pic of the car from the side? So we can see how it sits. I'd also like to see one of the tranny looking at it from the rearend.

 

[2000xp8]

This is a first for me, i've seen it hit the ebrake cables but not in the tunnel.

I think your pinion angle is way off, could be a few things, like the motor mounts sit too high, the trans mount is too high, or for some reason your rear has the pinion side angled upwards.

 

[No.11]

Here is the pic from the side of the car:

And here is the transmission:

We were using that jack to try and tilt the transmission up from the right side and see if we could slide the mount into place.

 

[No.11]

This is a first for me, i've seen it hit the ebrake cables but not in the tunnel.

Speaking of ebrake cables, mine doesn't hold at all. Could this problem be related?

 

[I_AM_CANADIAN]

If your transmission is sitting crooked, have you checked your motor mounts?