[l8nit3]

Year: 2007
Model: 328XI
VIN: KX61536
KM: 294,000

I bought this vehicle not running , as a project car for 1000$.

I have changed front struts, both outer tie rod ends, passenger side output shaft (drive axel), injectors and spark plugs, rad, etc. These were all needed to be changed, not thrown at this particular problem.

Since I first had it running and driving, Ive noticed a shudder/binding in the front right wheel. This occurs mostly between 65-75kmph and occurs whether cornering or driving straight. There is no noticeable noise at the time, but IS a noticeable shudder where a passenger can also feel it (not in the steering wheel).

Steps so far :
-Changed axel with hole in boot - still shudders
-new struts in front ( were blown out)
-all injectors and spark plugs changed
-2x fresh oil changes, only 1000km apart to 'flush' any potential old oil or contaminants - came out clean.
-re-torqued all suspension to spec to ensure it wasn't loose.

When I saw a hole in my axel boot, I changed that immediately assuming it was the issue and was just binding. To no avail. The only thing that has helped, I pulled my front driveshaft last night after some forum research, and have driven 40km this morning with no issue in RWD only.

Many forums state that fluids may need to be changed for a first step, does this mean front dif, TC, or rear dif?

Before pulling the drive shaft, I also thought: sticky caliper, broken motor mounts, wheel bearing, old suspension bushings, or bad lower control arm. However, after some forum research here it sounds more and more like the xdrive shudder many have experienced before.

Any other suggestions for diagnostics, or a first place to start would be highly appreciated.

[Peter Morrin]

I had to replace the front drive shaft under similar symptoms. Also check the front motor mounts at that milage. Do you have any warning lights and if so, have you run a scan? Vehicle speed sensors are frequently a problem source for the x-drive system. If it is just one wheel, you might want to switch the VSS from one side to the other. Rock Auto has good pricing on Hella sensors.

[l8nit3]

Originally Posted by Peter Morrin

I had to replace the front drive shaft under similar symptoms. Also check the front motor mounts at that milage. Do you have any warning lights and if so, have you run a scan? Vehicle speed sensors are frequently a problem source for the x-drive system. If it is just one wheel, you might want to switch the VSS from one side to the other. Rock Auto has good pricing on Hella sensors.

Thank you for the reply and the ideas.
No, there are no lights on the dash, or misfires detected or errors that would lead me to a more precise diagnosis.

Im in the process of doing a front suspension refresh to replace a badly worn ball joint and control arm bushings and hoping that's the issue, or that ill find something loose along the way. ( https://www.amazon.ca/ALADICHE-Contr...dp/B0D2B8H996/).

Motor mounts are a great idea, and ill add it to the list to check.

<UPDATE>
After having changed the suspension refresh kit, (issue got much better, but didnt dissapear)I had a close look at my motor and strut mounts.
It would seem some of the rubber on my strut mount (hat) is cracked quite a bit when turning the wheel. Could this be the cause of my vibration/stuttering issue?

[Peter Morrin]

I don't think the torn strut bearing is the source of your problems, but I would certainly change them. Get the OEM xdrive stut tops for about $50 USD each. I would not try aftermarket for these. Do you have a a US postal address to get parts from FCP or others? Getting things shipped to Canada can be really expensive for shipping and brokerage charges. If you have to get them sent to Canada from the US, United States Postal Service is typically the best way.

Find yourself a friend over the border and make a periodic trip to pick stuff up. Customs agents will typically let you bring stuff in under $500 without paying anything, but if you have to pay, it is just HST (which you would have to pay anyway).

[l8nit3]

Originally Posted by Peter Morrin

I don't think the torn strut bearing is the source of your problems, but I would certainly change them. Get the OEM xdrive stut tops for about $50 USD each. I would not try aftermarket for these. Do you have a a US postal address to get parts from FCP or others? Getting things shipped to Canada can be really expensive for shipping and brokerage charges. If you have to get them sent to Canada from the US, United States Postal Service is typically the best way.

Find yourself a friend over the border and make a periodic trip to pick stuff up. Customs agents will typically let you bring stuff in under $500 without paying anything, but if you have to pay, it is just HST (which you would have to pay anyway).

You are absolutely correct, both about the issue and about the shipping.
The strut mounts/bearing were not the source of my main issue, although have been changed regardless.

I believe I have narrowed the issue down to one of 3 things, and am hoping to find out if ISTA, INPA< or the Bimmergeeks protool app (full license) could help me in further diagnosing the issue.

Given that when putting the front driveshaft back in, the issue is immediately noticeably worse, I've come to the conclusion the most likely culprit is either the transfer case actuator, transfer case itself, or potentially the front differential. It seems to be during acceleration or tighter cornering, but is absolutely a 'shudder" and not just wheel vibrations.

Do you , (or anyone else reading this) know of a method of further isolating which of the 3 of these may be my issue?

What's making it so weird, is there is really no noise when this occurs, no rattle or clank or clicking that most report having. Just the rather unhealthy shudder.

<Update>
Without the front driveshaft being installed I still have the same shudder, and am beginning to believe it is either the transfer case actuator or old and cracked guibos and center bearing for the prop shaft

<Update #2>
Disabled the TC fully with xdelete as a method of eliminating one potential cause. Still have the same shuddering/vibration, although it's seemed to minimize the frequency.

Leaning more and more towards the guibos and center hanger bearing on the driveshaft, or the driveshaft itself. There are no engine, or misfire codes, except one I have been dealing with since I purchased the vehicle (code comes and goes): loose gas cap/small leak. However, I dont believe the issues to be related.