Vibration / Resonation from rear end. - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

cArSiK · 10-15-2003, 01:35

Hey guys/galz
Ever since installing king spring lows and new shockers in the ED ive had quite a bad vibration / resonation from BOTH sides of the rear suspension at 1200-1300rpm under load. (I have a manual so that happens quite often). Its quite loud and its getting to the point that its just pi$$ing me off. All the trailing arm bushes are new so im stumped as to what it may be.Anyone else had this problem?

Cheers
James

Rollin · 10-15-2003, 02:23

make sure that the exhaust isnt touching the diff at any point when the car is at its normal ride height, and allow a bit of space for when the engine torques over.

other than that...i dunno. you will have to just look under and try and find anything thats rubbing where it shouldnt. silly question but you did do up the bottom shock bolts tightly?

cArSiK · 10-15-2003, 02:36

exhaust isnt touching anywhere - exhaust actually was just replaced the other week and its still doing it. As for the shock bolts , EVERYTHING is tight as......

cArSiK · 10-16-2003, 04:32

so no one has heard of or had this problem before? what am i doing wrong?!?!?!?!!?!??!?!?!

james

Rollin · 10-18-2003, 19:53

are you in brisbane?

cArSiK · 10-18-2003, 20:57

no mate syd , why?

Cheers
James

'92BigBronco · 10-18-2003, 22:12

I'm not up on all the Aussie lingo so excuse me for sounding ignorant....but if I understand you correctly you lowered the rearend by installing aftermarket springs? If that's the case, your problem is probably driveshaft/u-joint related. A worn u-joint or out-of-balance driveshaft will cause the vibration you're describing.

cArSiK · 10-19-2003, 16:24

interesting - thanks for the idea mate . Yes i did install aftermarket springs ....can anyone else elaborate on this theory?

thanks
james

C0V3R · 10-20-2003, 01:05

Also if youve lowered the rear too much you can get vibrations due to the excessive angle in the u joints from the /diff

'92BigBronco · 10-20-2003, 15:55

Yes, you may have a slight binding in the u-joints after changing the geometry back there but the fact that you say it only does it at a certain RPM makes me think it's a bad u-joint or a driveshaft balance issue. Whenever you remove the driveshaft, you need to mark both ends to be sure you install it back in the same position it was before you took it out to ensure you don't get any funky vibrations. I'd bet on a u-joint/joints........