Whole Car Shake
 

Hey Guys,
Fairly new to actually leaving a post so sorry if this goes on a while.... sorry, i have a few questions. First, MY car is a 01 4.4 with 105k miles. the whole car shakes like crazy when im maintaining a low idle driving speed but will go away if i give it more gas. This happened to me before on my 00' 323ci and it was the u-joints. But been reading here that it might be transfer case. any thoughts would help. Also I also have the front end pop on turning or backing up or hitting potholes (not that i am for them). So i have concluded that it must be the front end suspension that needs to be changed (Thanks to all the previous posters on here). Now the question, On ebay there is a complete front end replacement ,http://cgi.ebay.com/ebaymotors/BMW-X...Q5fAccessories
Damn thats long, anyways.... is that a good deal or is there something better? i figured i might as well replace everything to be on the safe side. Thanks in advanced

i had a similar problem before. It is highly likely an coil issue.
read the code with a ODB scanner and see whether there is any misfire.

I'm no expert, but that sounds like Constant Velocity (CV) half shafts are bad. They aren't too expensive and the labor isn't something you can't do yourself with some good tools and a jack. Good luck.

ScubaSteve,

I think you are on the right track. This is the same problem that I am trying to solve. The shaking is more obvious in overdrive when attempting to go just a few MPH's faster. I think I have linked the problem to several culprits. Keep in mind this is specific to my 2001 4.4 Sport with 90K miles but I'll bet there are many that are experiencing something similar.

Suspension: You are right about the front end suspension. The torsion strut bushings (large diameter attached to the forward most point of the suspension) and the control arm bushings wear out and create some slop in the suspension. Under load, they will allow the wheels to shimmy forward and aft at a high frequency. The $314 price tag is probably reasonable and will help correct this problem and part of the overall problem. I have only replaced the torsion strut bushing and it helped a bit. Cost was $130 for both plus $20 to press them in.

Drivetrain: The transfercase uses a chain to drive the front driveline. My front driveline rotates about 10 degrees before the rear driveline begins to turn. It should have some play but a tcase expert told me this was a bit much and believes the chain has relaxed and the gears might have some wear. He also suggested I change the guibo/flex discs that attach the front and rear drivelines to the differentials.

The front cv/half shafts might also be a bit sloppy which further contributes to the overall "slop" in the entire drivetrain. In theory, the front and rear wheels should be powered with the same amount of force at the same time. This works great when all the mechanical tolerances of the drivetrain components are in spec. With older high mileage vehicles such as ours the tolerances relax and perhaps exceed the allowed deviation. Sloppy drivetrain coupled with a sloppy suspension leads to what we are experiencing. We cannot expect the machined components to be perfect but the amount of wheel slip should be mainly controlled inside the t-case and inside the differential third member (backlash, clutches, etc.).

My order of events will probably be:

1. Replace entire front suspension (ebay kit). Simple DIY.
2. Replace both front half shafts (indie shop can source for about $300 with 1 year warranty). Labor - Indie shop $350 - $400.
3. Replace Guibo/Flex plates. DIY but I'm going to buy from stealer. driveline balancing is critical so I don't want to risk with aftermarket just to save a few bucks.
4. If the above doesn't sufficiently correct the problem I will probably drop the t-case and get a rebuilt unit from transfercases.com ($875 plus shipping).
An indie shop quoted me 12hrs for labor but that was dropping both tranny and t-case. I looked under the truck and the t-case can be dropped separately. This is probably a 6 hr job and relatively straight forward. The t-case only weighs about 45lbs.

Sorry for the long winded response but I have been researching this for about 6 months and I wanted to share this with everyone.

Hope this helps.