I could use a little rear suspension advice.
 

I recently purchased a 2004 2.5 w/76,000 mi. on the clock. Saturday I replaced the upper rear control arms with the Volvo arms as described in another post. They certainly fixed the camber issue but now the rear end is bouncing up and down like a basketball. On the concrete/expansion joint streets in Savannah it's almost un-driveable. Any suggestions? The car wasn't behaving this way before the control arm swap. Any ideas would be greatly appreciated. Thank you in advance.

CJagB, if the rear end is bouncing to beat the band, then I would start looking at the rear shocks to make sure that they are good. It is possible that if you let the shocks stop the lower suspension travel (normally happens when jacking up the rear end), with the age of the car, that may have been enough to cause them to fail internally. The other thing that I would ask is whether you got a new alignment. If the rear alignment is off, that can cause the rear end to be squirly and cause what you are seeing. It wasn't an issue before because the upper arms where allowing enough slop that the rear end was able to move and suck up the movement you are seeing now.

Thanks for the reply. Your assessment is pretty much the same as what I was thinking. Always nice to get a more informed opinion. It really blows when you try to do something nice for your car and it makes everything worse. I'll get it sorted out. Once again, thanks for your expertise and your reply.

I just put new shocks on my 06 with 90,000 and i believe original shocks

I went with the bilstien comforts from rock auto $76 each

I had 1 lower shock bolt that was a nightmare to get out but otherwise all the other bolts came out easy.and they had thier fair share of rust. Of course i sprayed it a day earlier with pb blaster

Upper shock mounts are a 13 mm i think and a couple sizes of extensions are helpfull

New shocks bolt right up, i could tell a difference after my 6 mile test run

Have a link to that volvo control arm thread? How could you tell your car needed them. My mechanic buddy went under mine and was prying and flexing mine and said they seem fine. But he is not a jag mechanic.

Slownlo,

Here's Thermo's original thread on replacing the rear upper control arm:

https://www.jaguarforums.com/forum/x...rol-arm-88530/

slownlo, part of it is simply looking at the rear wheels and seeing if they are leaning in at the top. They should normally be leaning in slightly. But there is the correct amount and then there is too much. You will also see that the rear tires will start to wear on the inside edge. But this can be caused by 2 things. So, before you just start replacing parts, try this: Find a long sweeping turn (say a long clover leaf exit/entrance) and take it about 25 mph, in the middle of the turn, step on the gas like you were going to overtake someone, if the rear end steps out on you, then you have a bad lower/forward arm, otherwise you have a bad upper arm.

Hope this helps.

My rear driver's side tire was leaning in at the top and it was eating up the inner shoulder of the tire. It's a fairly straight forward job but a couple of the bolts were an absolute nightmare.

Punched it going around a turn last night and it was solid as a rock

So only problem now is some inner tire wear. I just put a set of stuuded pirellis on so i will watch it closely

slowlo: It's good to have rock solid handling when you punch it thru a turn. That means your lower, front control arms have good bushings to keep the rear tires pointing forward thru the turn.

However, Thermo's adjustable upper control arms are not for stability thru tight turns. They're for fixing negative camber in the rear suspension, which is when the tops of the tires lean in, causing the inner tread to wear prematurely.

If your old tires wore the inner tread quickly, then your new Pirellis will do the same and soon become old Pirellis. Install Thermo's adjustable upper control arms and fix the camber from negative 2-3 degrees back to factory spec of negative ~0.7 degrees, and you'll ~double the life of your new Pirellis.

Just my 2 cents.

I had same issue, replaced upper with Volvo as well. Started to sway and then I replaced springs and shocks 100k miles it was time anyways. Still didn't help, told me it was my frame. 2 Pirellis inner wore out :-( . 3rd time back at the shop and finally someone else has a symptom trailing arm which is connected towards the front to the frame and the lower control arm was shot. After installing everything the top now sticks out so it was those bushing all along not the upper control arm. I will post it on forums when I get my pictures and part video together and when I go back and get the final results. ;-)