[russ93spirit]

Im working on a friend's 2006 PT Cruiser. Car has a slight shudder condition, which he described as a vibration between 50 and 55 mph. Pretty minor, but it is bothering him.

55k miles on the car, very well kept. In an attempt to solve the problem, he had a shop replace both CV axles and both upper and lower torque struts on passenger side, which were broken.

I know of nothing else to do, except consider the pass side engine mount itself. However, vibration at idle in gear is not abnormal to me.

I do notice the shudder at the speeds mentioned above, whether the trans in gear or not.

Thanks for any ideas!

 

[chuzz]

Could it be a busted belt in a tire, Russ? I'd try rotating them first.

 

[bguy]

Wash the mud out of the rims.

 

[russ93spirit]

Sorry...forgot to mention the tires are one week old, and the insides of the rims are clean. the entire underside and all very clean. Garage kept, super clean car.

 

[ImperialCrown]

New tires shouldn't shimmy, but can. Was the shimmy present before the new tires? You can balance an egg. Try a rotate anyways?
I have installed remanufactured axles before where the inner joints may have been repacked and rebooted, but the joint had wear pockets where the tripode joint rode. A different set (and brand) of axles fixed the shimmy. The parts store had no problem exchanging the axles.
The right, inner joint is a common failure due to its close proximity to the hot cat. The grease tends to cook down into wax after a few years.
Loose or worn suspension/steering bushings/components may not generate a shimmy, but won't dampen it as it should either.

 

[russ93spirit]

Thanks, Imperial...the condition was present before the new tires. The owner noticed the problem, took car to a shop he trusted, and they determined that worn "motor mounts" (actually upper and lower torque struts) caused the CV axles to fail. The tires were worn as well, so the owner replaced them. He sees no difference in the shudder condition at all.

I definitely would not describe this as a shimmy. The wheel action seems smooth as silk, and alignment seems perfect.

I am starting to suspect a worn transmission mount, on driver's side. Will inspect it asap.



FWIW, I notice the same condition in my Neon at 61 mph.

 

[ImperialCrown]

The motor mounts are also slotted for adjustment. Engine/transaxle positioning is important.
Inner joints probably aren't bottomed, but have to be centered and floating for the correct adjustment.
Does the 'shudder' feel 'up/down' or left/right'? It is felt in the floor and not the steering wheel?
Has it been returned to the shop for this (1 year warranty)? Maybe they could duplicate the problem on a lift in order to find it?
(The only problem is that by being on a lift, the suspension/axles are hanging down and not where they would be if the car was driving on the road with the weight of the car on them).

 

[russ93spirit]

No shudder or vibration in the steering wheel at any speed. Very smooth. Owner hasn't brought it to the shop since picking it up. The shudder seems to be present on left and right.

 

[djsamuel]

Just a thought, but do the new CV shafts have the damper on the shafts? I noticed when I replaced the shafts with the cheap ones from Advance Auto, I experience a similar vibration. I needed to change the passenger side shaft several months ago, and when I opened the box from Advance Auto, I was at first annoyed to see I was given a previously sold shaft (not used, but the wrapping was off, and had greasy fingerprints on it). However, I soon noticed that this shaft had the damper on it, and then realized this was a Chrysler OEM shaft. Near as I can figure, someone must have purchased two shafts, one from Chrysler and one from Advance Auto, and returned the one to Advance Auto. However, they put the wrong shaft back in the box. In any case, having one shaft with the damper on it has reduced the vibration considerably.

Another thought. A couple of weeks ago, I had to replace a very worn outer tie rod (passenger side). I was also notcing a vibration at around 65 - 70 MPH. After replacing that tie rod, the vibration was gone.

Just some thoughts, may be totally unrelated, but you never know.

Doug

 

[russ93spirit]

I pulled and checked the transmission mount today, and it looks fine.

Doug, those are good ideas to check for, and I'll do that and update. i suspect the shop used aftermarket axles, as evidenced by the Made in China sticker I saw on the torqure struts they used.