Rear Spring Isolators on a '99

Hey all-

About a year ago I had a Bilstein BTS kit installed, which included all 4 shock/struts and springs... it made a good ride except im still close to 1/4" lower in the rear than the front. It's especially annoying when there's anything additional in the trunk.

Are there any spring isolators recommended that are thicker than usual? Late Model Resto's Prothane vs MM's Urethane one's? Again, just want to trim up just less than 1/4".

How hard is it to swap these things? I've got only the basic tools at home, so I hope this is do-able in the garage over a 6-pack and fewer than 3 busted knuckles... :rolleyes:

Pics and/or a step-by-step are really appreciated...


It's a little worse now, this was just after install... :nonono:
  • Sponsors (?)

Nice ride, I have a Rio Red 99 myself:nice: So the kit made your car lower in the rear? I actually had this problem awhile ago but it was because a friend of mine cut the springs too much in the rear. I ended buying springs online for cheap and I'm thinking you may have to do the same. I haven't heard of any larger isolators but if you do find some the rear springs will have to come back out. I find that renting a spring compressor helps out alot. You can search Stangnets site for spring removal or a google search can help
Dang... not totally the answer I was hoping for but will look into it. I almost wonder if the installer even put both isolaters back in after the spring swap. Will tear into it asap.

In the mean time SVT32VDOHC are you following this? I read in the search pages you found poly-isolaters to help?

Go to the Ford dealer and ask for struts and shocks for a 2003-2004 Mach 1.

Then order some Lower control arms from Mustang Parts & Accessories - 50resto They have different ones priced for everyones budget.

Then check and see what springs are in it, and see if it has spring isolators in it. If they don't...then buy some new poly isolators as they will raise the car about 1/4" all the way around. This may be all you need to stop scraping on the ground.

Are these the ones that have worked in the past..?
99-04 Mustang Cobra Rear Spring Isolators by Prothane at LRS - Same Day Shipping!
Thanks again everyone.
could you remove the front isolators?

GOOD idea I hadn't thought about that... although id prefer to level it out by raising the rear only. IMHO the ride height in the front is good as is.

As for the old iso's they were thrown out by the installer, my loss there. Anyone need to be talked out of doing business with this tuner in the Concord NC area, shoot me an IM. :nonono:

Otw, going to dig into the rear this weekend and see what's lacking.
Okay with wheel off and on jack stand I can see that the bottom of the rear "A" arm doesn't have anything in between it and the spring... not even a little noise limiting tape. SO I could go ahead and add an isolator to make up the lacking 1/4".

Still though, anyone have a reasonable idea what brand isolator will lift the rear about 1/4"? Does it even matter? Are there a total of two iso's per spring... one top and one bottom? That way if one doesnt do enough I could add the second?

I've also searched and found some randomness that the rear springs need to be "clocked-in" meaning that the ENDS of BOTH L&R lower springs need to be at the rear-est point / pointing towards the driver's side. Can anyone shed some light on this??
could you remove the front isolaters?

thats what I did to mine. rear sat lower than the front so I removed the front lower Isolaters. If I were to do it again, I would remove both upper & lower isolaters in the front.
if you remove them, wrap the bottom & top of the springs with a couple layers of black electricle tape to prevent sqeaking, works great:nice:
going this route would only cost you your time & no cash out of pocket.
Poly isos are harder than stock rubber isos. Using poly isos will raise the car up a hair. IF you have no isos out back which I think ou said you don't then add them.

You could take the front bottom isos out as well. Be prepared that front springs are much harder to R&R than rear springs. You need an internal spring compressor if the springs are stock. I did NOT need an internal spring compressor when I installed the Steeda Sport Springs. They fell right in place.