Mustang Forums at StangNet

Whose fault is it? Rear control arms or springs?

This is a discussion on Whose fault is it? Rear control arms or springs? within the 5.0 Tech forums, part of the 5.0 Mustang category; I have a problem with my car where my driveshaft scrapes up against the top of the undercarriage whenever I ...

Go Back   Mustang Forums at StangNet > Mustang Forums > 5.0 Mustang > 5.0 Tech

Over 151,000 Members!!

Register Vendors Garage FAQ Calendar Search Today's Posts Mark Forums Read



Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 11-02-09, 08:04 PM
Member
 
Join Date: October 2009
Location: Los Angeles
Posts: 26
Garage
Whose fault is it? Rear control arms or springs?

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?

Last edited by No.11; 11-03-09 at 02:11 PM.
Reply With Quote
  #2 (permalink)  
Old 11-02-09, 10:09 PM
89Fox351's Avatar
Member
 
Join Date: September 2009
Location: NY
Posts: 3
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
Reply With Quote
  #3 (permalink)  
Old 11-03-09, 12:04 AM
Member
 
Join Date: October 2009
Location: Los Angeles
Posts: 26
Garage
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?
Reply With Quote
  #4 (permalink)  
Old 11-03-09, 02:41 AM
StangGT1995's Avatar
have car, will race....wait, it doesn't run
 
Join Date: October 2004
Location: New Lenox, IL
Posts: 4,298
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.
Reply With Quote
  #5 (permalink)  
Old 11-03-09, 07:02 AM
Mustang5L5's Avatar  
Join Date: February 2001
Location: Earth
Posts: 14,094
Garage
+1 on engine/trans mounts


what scrapes? The driveshaft?
Reply With Quote
  #6 (permalink)  
Old 11-03-09, 08:44 AM
90lxcoupe's Avatar
Official Member
 
Join Date: October 2003
Location: Springfield, MA
Posts: 751
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
Reply With Quote
  #7 (permalink)  
Old 11-03-09, 09:04 AM
89Fox351's Avatar
Member
 
Join Date: September 2009
Location: NY
Posts: 3
ahh yes i was assuming we were talking about the rear end of the car!! oops!
Reply With Quote
  #8 (permalink)  
Old 11-03-09, 09:20 AM
Official Member
 
Join Date: January 2009
Location: Nashville, TN
Posts: 114
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
Reply With Quote
  #9 (permalink)  
Old 11-03-09, 02:11 PM
Member
 
Join Date: October 2009
Location: Los Angeles
Posts: 26
Garage
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.
Reply With Quote
  #10 (permalink)  
Old 11-03-09, 03:48 PM
90lxcoupe's Avatar
Official Member
 
Join Date: October 2003
Location: Springfield, MA
Posts: 751
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
Reply With Quote
  #11 (permalink)  
Old 11-03-09, 04:07 PM
Mustang5L5's Avatar  
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?
Reply With Quote
  #12 (permalink)  
Old 11-03-09, 09:52 PM
rd rd is offline
Founding Member
 
Join Date: January 2000
Location: Burton, SC
Posts: 2,902
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.
Reply With Quote
  #13 (permalink)  
Old 11-03-09, 10:46 PM
Member
 
Join Date: October 2009
Location: Los Angeles
Posts: 26
Garage
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.
Reply With Quote
  #14 (permalink)  
Old 11-03-09, 10:47 PM
Member
 
Join Date: October 2009
Location: Los Angeles
Posts: 26
Garage
I'll try to take some pictures tomorrow.
Reply With Quote
  #15 (permalink)  
Old 11-08-09, 12:31 AM
Member
 
Join Date: October 2009
Location: Los Angeles
Posts: 26
Garage
Click the image to open in full size.
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.
Reply With Quote
  #16 (permalink)  
Old 11-08-09, 06:05 AM
Maryland Stang's Avatar
Official Member
 
Join Date: August 2002
Location: Swift Creek, NC
Posts: 1,306
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.
Reply With Quote
  #17 (permalink)  
Old 11-08-09, 10:40 AM
2000xp8's Avatar
Official Member
 
Join Date: August 2003
Location: NJ
Posts: 3,053
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.
Reply With Quote
  #18 (permalink)  
Old 11-08-09, 12:59 PM
Member
 
Join Date: October 2009
Location: Los Angeles
Posts: 26
Garage
Here is the pic from the side of the car:
Click the image to open in full size.


And here is the transmission:
Click the image to open in full size.

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.
Reply With Quote
  #19 (permalink)  
Old 11-08-09, 01:05 PM
Member
 
Join Date: October 2009
Location: Los Angeles
Posts: 26
Garage
Quote:
Originally Posted by 2000xp8 View Post
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?
Reply With Quote
  #20 (permalink)  
Old 11-08-09, 01:09 PM
I_AM_CANADIAN's Avatar
Official Member
 
Join Date: March 2005
Location: B.C.
Posts: 196
If your transmission is sitting crooked, have you checked your motor mounts?
Reply With Quote
  #21 (permalink)  
Old 11-08-09, 01:13 PM
Member
 
Join Date: October 2009
Location: Los Angeles
Posts: 26
Garage
Quote:
Originally Posted by I_AM_CANADIAN View Post
If your transmission is sitting crooked, have you checked your motor mounts?
I will check that.
Reply With Quote
  #23 (permalink)  
Old 11-08-09, 02:33 PM
tannerc91gt's Avatar
Official Member
 
Join Date: March 2009
Posts: 175
I'd definitly look into the motor mounts like everyone is saying and as for trans mount bolt not lining up. Try jacking up one half of the trans a little bit to help rotate it into place and then put the bolt in, it worked for me yesterday
Reply With Quote
  #24 (permalink)  
Old 11-08-09, 02:41 PM
Mustang5L5's Avatar  
My guess, the engine mounts are blown causing the engine to sit low and raising the end of the trans. As a result, the driveshaft is now higher in the tunnel and rubs.

If you change the engine mounts, might as well change the trans mount too
Reply With Quote
Reply




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


 




All times are GMT -6. The time now is 10:14 AM.