Jump to content
TEAM SHELBY FORUM

Lowered rear end bottoming out - Resolved


darksnake

Recommended Posts

Lowered car rear end bottoming out, clunking, at high speed interstate driving (70-80 mph) when hitting a large dip, bump, or bridge transision.

 

A 2008 GT500 with FRPP lowering springs, -1.25" to -1.5", with BMR adjustable upper arm, lower arms, lower arms relocation brackets, sway bar, adjustable pan hard bar w/ "offset bracket" (larger axle cover). Everything was professional installed & 4 wheel aligned. Normal & spirited driving car handles & rides great/smooth. No issues until the big bump at higher speeds.

 

Examined clearances & for wear marks on upper control arm, tires, wheels, axle, drive shaft...all ok. Did notice, the two axle bump stops are only 3/8" from car frame with wear marks.

 

Other ideas?

Link to comment
Share on other sites

Mine started to scrape the exhaust while backing out of driveways transitioning over a curb when I installed a full-size spare tire; I assume the extra weight in the trunk contributed to this. So I removed the Shaker 1000 subwoofer assembly, which I don't use anyways to remove 37 pounds. This seemed to cure the problem. I still have the OEM shocks/struts, but I believe better shocks, geared towards lower vehicles with some adjustment, would help too.

Link to comment
Share on other sites

Rear end bottoming out, clunking, rubbing sound, at high speed interstate driving (70-80 mph) when hitting a large dip, bump, or bridge transision.

 

 

I had the same problem. I just fixed it 24 hours ago. My assumption was that it was happening when the suspension compressed. I was wrong. At full extension the BMR Panhard relo bracket was hitting the sway bar (FRPP). It's easy to check. Just jack both sides from the rear jack points so the axle is hanging and take a look. If the bracket is any where near close to the bar you've found the problem.

 

Steve

Link to comment
Share on other sites

I had the same problem. I just fixed it 24 hours ago. My assumption was that it was happening when the suspension compressed. I was wrong. At full extension the BMR Panhard relo bracket was hitting the sway bar (FRPP). It's easy to check. Just jack both sides from the rear jack points so the axle is hanging and take a look. If the bracket is any where near close to the bar you've found the problem.

 

Steve

 

 

Found it....resolved! Steve, many thx on where to look.

 

Actually, my relocated pan hard bar is hitting the oem "upper panhard bar support", now right above it. Not bracket hitting sway bar. Plenty of clearance there.

 

When using the BMR panhard bar relocation bracket on "lowered" cars, you need to also install BMR's flatter upper support bar. The two bars are now directly under/over each other, with only 1" clearance to stock upper bar. The BMR upper bar will give you 2" clearance.

 

https://securec20.ezhostingserver.com/bmrsuspension-com/index.cfm?page=products&vehicleid=20&maincatid=96&catid=290&productid=776

Link to comment
Share on other sites

Glad to help.

I forgot about the upper brace. I had that problem too, but it was three years ago.

Also, Zporta suggested cutting the bump stops. I've been running that way for the same three years until the other day. I put in a set that FRPP recently brought out for lowered cars. They're the same height as stock, so they must be a different density or something. It's too soon to have an opinion.

 

Steve

Link to comment
Share on other sites

Glad to help.

I forgot about the upper brace. I had that problem too, but it was three years ago.

Also, Zporta suggested cutting the bump stops. I've been running that way for the same three years until the other day. I put in a set that FRPP recently brought out for lowered cars. They're the same height as stock, so they must be a different density or something. It's too soon to have an opinion.

 

Steve

 

 

Thx for the FRPP bump stop info, I'll look into that also.

Link to comment
Share on other sites

Where did you order these from? I can't seem to find them listed as a seperate part on the Roush website.

 

Thanks,

 

GT

 

sorry I can't remember the part number just for the ( bump stops ) but you can get them by themself ,,just call Roush and ask them for just that number ,you might have to go to a Roush mustang Ford dealership to order them thoe,,thats what I had to do ,but you can get them ,,there like $ 40.00 for both plus shipping ,,and they work great ,,no more banging out the bottom on bumps ,nice and soft feel ,,one of the best mods I've done after lowwering my car all around 1.5 inch . :shift:323470-R1-23-22A.jpg

323470-R1-23-22A.jpg

Link to comment
Share on other sites

  • 4 weeks later...

sorry I can't remember the part number just for the ( bump stops ) but you can get them by themself ,,just call Roush and ask them for just that number ,you might have to go to a Roush mustang Ford dealership to order them thoe,,thats what I had to do ,but you can get them ,,there like $ 40.00 for both plus shipping ,,and they work great ,,no more banging out the bottom on bumps ,nice and soft feel ,,one of the best mods I've done after lowwering my car all around 1.5 inch . :shift:323470-R1-23-22A.jpg

 

 

Thanks for the info............ happy%20feet.gif

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...
...