[N55lif3]

I installed xDelete on my car and put my xDrive to "Off" for four days before taking it off because I missed my traction.

Two days later my bushings and bearings started to make noises when I was accelerating/decelerating. The next day under heavy acceleration, the back wheels would "lock up" as if they were losing traction.

Went into the shop for them to tell me that I needed new bearings and bushings badly, only for them to surprise me by telling me that THE REAR DIFFERENTIAL IS DONE. Makes a clunking noise when you put a stethoscope to it and spin the wheel.

Keep in mind I only have 60K MILES!!!! Theres no way my rear differential would go on its way out with such early mileage and my economical driving. As soon as I install xDelete everything starts to go to shit. Coincidence? I think not.

Im not going to bother asking this company for compensation of the big bill I am about to pay because I know they wont accept responsibility but I just want to warn people that it is not worth getting xDelete on your car. I'm even uninstalling xHP on my car because I've heard people have had their clutches gone the next week and that their "D" stopped working and thought nothing of it; but now I'm actually worried.

Its not worth it.

[Tambohamilton]

But the x drive rear diff is the same part as the rwd rear diff (as is the rest of the rear drivetrain), so there's no way that xdelete caused the failure of your rear diff.

You say you drive economically, but that you miss the traction of awd.....

[Biginboca]

First of all, take off Rear diffs are all over eBay for around $250 delivered. To swap it takes less than 2 hours in your driveway so it’s not really a huge deal. It’s actually a pretty cheap expense and easy install compared to many issues these cars have, so you are getting off easy as far as issues go.

Second, the guys above are right. The diff is the same for awd and rwd cars so your scenario doesn’t exactly add up. It has to be either coincidence or the result of the some event which happened during the 4 days.

If you drive conservative is there any chance you loaned your car to someone during that time it was in “Hoon” mode lol

[Efthreeoh]

If you have the diff off the car and rotate either axle flange, the diff will click very loudly. It's normal. On the car, with the diff loaded by the driveshaft, and axles, the sound is muted somewhat.

I assume xdelete is coding that tells the transaxle to fully disengage the front drive clutch, so essentially the front drive just freewheels? That should not hurt anything. The x-drive system constantly adjusts engine torque between the front and rear axles, and up to 100% at either end, so the hardware is designed to run open without torque applied to it.

I think you just have BMWitis.

[ppointer]

Valet at the airport “hoon’d“ my 335i and caused the charge pipe to blow. Whole dash was lit up when I picked up the car, so little question who did it. Point being I no longer assume a valet won’t abuse my car.

[Welcome to NBA Jam]

I think you need a second shop's opinion before making the conclusion that software destroyed your differential.

I also don't understand how you missed your AWD traction in the summer, yet you drive economically.

[N55lif3]

The days I was RWD I did do some pulls to see how it would feel, but if you're telling me I cant test quarter miles because my rear diff will be shot then I dont see any good either way with this app. No drifts, nothing like that.

[Welcome to NBA Jam]

Originally Posted by n55rei

The days I was RWD I did do some pulls to see how it would feel, but if you're telling me I cant test quarter miles because my rear diff will be shot...

What people have said is the differential hardware between an XDrive and a standard RWD 335i is the same, meaning yes, you can do that.

[e90yyc]

Originally Posted by Efthreeoh

If you have the diff off the car and rotate either axle flange, the diff will click very loudly. It's normal. On the car, with the diff loaded by the driveshaft, and axles, the sound is muted somewhat.

Sorry to sidetrack from the original thread, but you’re telling me that it’s normal for the diff to make noise and vibration when spinning either wheel with it still on the car?

Rats. I really should have checked before ordering a replacement diff off eBay. Mine has over 300k km’s and I thought it might be getting a bit noisy. I am a fool...

I will say the new one sounds much quieter off the car, but I could be mistaken.

/end threadjack

[Efthreeoh]

Originally Posted by e90yyc

Sorry to sidetrack from the original thread, but you’re telling me that it’s normal for the diff to make noise and vibration when spinning either wheel with it still on the car?

Rats. I really should have checked before ordering a replacement diff off eBay. Mine has over 300k km’s and I thought it might be getting a bit noisy. I am a fool...

I will say the new one sounds much quieter off the car, but I could be mistaken.

/end threadjack

If I get time, I'll make a vid of my old diff from the E90. When chasing my driveline vibration, I started on the outside and went inwards (you know the story...). Keep in mind this was at 325,000 miles... So I replaced the rear wheel bearings first. Nope. So I said well maybe the diff finally lost a bearing or the pinion gear set was worn beyond spec. Up on the lift as I spun the wheels, I could hear the diff clicking/clumping as it rotated. I found a 40,000-mile diff out of a 138i on-line from a reputable dismantler for $250. I pulled the old diff. Spun it on the bench and it just clacked around like mad. Then I did the same for the new (used) diff, same exact noise! Well, I just happen to have two other BMWs sitting around (lucky me ), a 1997 Z3 and my 2008 Z4. I put them on the rack and sure enough they made the same noise as my 325i's (old) diff did when installed. So based on that evidence, I'm positive that the open diff design BMW uses is noisy. Bottomline is, all 4 BMW diffs I have make the same exact noises. The mileages range from 40,000 to 325,000 miles.

In my defense, the original driveline parts in my 325i started to get the "tink" sound in the driveline when loading and unloading it at slow speeds. That sound appeared around 150,000 miles. I opened up the driveshaft and replaced (added really) the splined bushings that go in the splined part of the shaft. That helped for a while. So maybe the tink sound was the well-noted drive flange noise at the diff, where you pull the yoke and add some special, magic Lock-Tite compound. That seemed like a lot of work for something that just seemed impossible to be cause of the noise I had. So I took the route of I'll let it really break. The "let-it-really-break" point came at 325,000 when I replaced the diff (still had the tink sound too). As I discovered eventually, it was the center bearing on the driveshaft. I just replaced the entire driveshaft with a new one since I figured after 325,000 miles, the runout spec on the u-joints (.004 in) could be suspect as well. I had previously replaced the center bearing about 100,000 miles before the new driveshaft went in, so I didn't think it could be the bearing, but it was. The rebuilt driveshaft has a slightly different design and has a set-screw (bolt) at the splined section of the shaft. No tink sound since the shaft went in...

Like I've said before, chasing noises and vibrations in the driveline, is tedious, especially at very high mileages.

[N55lif3]

Originally Posted by Welcome to NBA Jam

What people have said is the differential hardware between an XDrive and a standard RWD 335i is the same, meaning yes, you can do that.

Well obviously I can't. I did a few pulls on the highway and noticed the differences in traction and overall feeling. Did a pull on a street and I had no traction whatsoever. I figured I wanted more stability in my driving. It's really not rocket science; summer or not.

[Tambohamilton]

The bottom line is that xdelete is not responsible for your diff failing, if that is what's broken. Sure, it would see more load without the FWD, but nothing it couldn't handle.

If it has failed, it would have been near failure anyhow.

Whatever in the back end has broken has just given up due to the extra stress of running rwd only, but every component in the back end should be fully capable of handling the load if it was in good condition.

I hope you get it fixed easily and inexpensively, but I don't think you can assign any direct blame to xdelete. I certainly can't dispute your preference for awd and more grip

[Efthreeoh]

Originally Posted by n55rei

Well obviously I can't. I did a few pulls on the highway and noticed the differences in traction and overall feeling. Did a pull on a street and I had no traction whatsoever. I figured I wanted more stability in my driving. It's really not rocket science; summer or not.

OP, I seriously doubt your rear diff is shot; especially after a few thousand miles without the front drive operating. Doing pulls when the front drive is artificially disconnected probably is activating the Xdrive-programmed DSC, which probably is programmed to compensate for the front drive engaging. I'd bet the programming of the RWD DSC system is different than the Xdrive DSC system. You are messing with the car's engineering, so you should expect some misbehavior. And bushings are shot when (a) the alignment can't be put into spec and there is abnormal tire wear, or (b) there is banging noise as the suspension moves against road bumps. These cars use sealed straight ball bearings (vs. tapered). Bearing noises are difficult to troubleshoot and most wheel bearing problems show up with vibration more than noise.

The E90 does not break as easily as everyone on the internet thinks. I've been driving BMWs for 30 years. All four of the cars I've had and still have, have been driven very hard for literally hundreds of thousands of miles. The lowest mile car I have is my 2008 Z4 at 97,000 miles; I didn't buy it to drive to church on Sundays...

[e90yyc]

Originally Posted by Efthreeoh

If I get time, I'll make a vid of my old diff from the E90. When chasing my driveline vibration, I started on the outside and went inwards (you know the story...). Keep in mind this was at 325,000 miles... So I replaced the rear wheel bearings first. Nope. So I said well maybe the diff finally lost a bearing or the pinion gear set was worn beyond spec. Up on the lift as I spun the wheels, I could hear the diff clicking/clumping as it rotated. I found a 40,000-mile diff out of a 138i on-line from a reputable dismantler for $250. I pulled the old diff. Spun it on the bench and it just clacked around like mad. Then I did the same for the new (used) diff, same exact noise! Well, I just happen to have two other BMWs sitting around (lucky me ), a 1997 Z3 and my 2008 Z4. I put them on the rack and sure enough they made the same noise as my 325i's (old) diff did when installed. So based on that evidence, I'm positive that the open diff design BMW uses is noisy. Bottomline is, all 4 BMW diffs I have make the same exact noises. The mileages range from 40,000 to 325,000 miles.

In my defense, the original driveline parts in my 325i started to get the "tink" sound in the driveline when loading and unloading it at slow speeds. That sound appeared around 150,000 miles. I opened up the driveshaft and replaced (added really) the splined bushings that go in the splined part of the shaft. That helped for a while. So maybe the tink sound was the well-noted drive flange noise at the diff, where you pull the yoke and add some special, magic Lock-Tite compound. That seemed like a lot of work for something that just seemed impossible to be cause of the noise I had. So I took the route of I'll let it really break. The "let-it-really-break" point came at 325,000 when I replaced the diff (still had the tink sound too). As I discovered eventually, it was the center bearing on the driveshaft. I just replaced the entire driveshaft with a new one since I figured after 325,000 miles, the runout spec on the u-joints (.004 in) could be suspect as well. I had previously replaced the center bearing about 100,000 miles before the new driveshaft went in, so I didn't think it could be the bearing, but it was. The rebuilt driveshaft has a slightly different design and has a set-screw (bolt) at the splined section of the shaft. No tink sound since the shaft went in...

Like I've said before, chasing noises and vibrations in the driveline, is tedious, especially at very high mileages.

Thanks for the detailed reply!

Yeah... I suspect this isn’t going to make a difference sadly. I have it now though so I figure I might as well replace it. I thought maybe, you know, all that sweet NA N52 power has finally had its way with the diff, but alas...

I don’t think it’s wheel bearings either. There is a slight noise when I weave side-to-side at speed, but I feel like it might just be my tires.

I’ve got the characteristic noise so I know my front diff pinion bearing is on its way out for sure. Best case it ends up being my rear diff pinion bearing and the problem is solved, but I’m positive that won’t be the case.

I’ll watch for a video if you post one. Thanks again!

[Welcome to NBA Jam]

Originally Posted by n55rei

Well obviously I can't. I did a few pulls on the highway and noticed the differences in traction and overall feeling. Did a pull on a street and I had no traction whatsoever. I figured I wanted more stability in my driving. It's really not rocket science; summer or not.

If you floor it from a standstill in a RWD car with 300HP/Torque, your rear wheels are going to spin. This is expected behavior.

[N55lif3]

Originally Posted by Efthreeoh

OP, I seriously doubt your rear diff is shot; especially after a few thousand miles without the front drive operating. ...

When I fully accelerate (AWD) my back wheels lock up and make a rough clunking noise and stop me from going forward. Could these still be symptoms of a bushing or bearing? This is the only reason why I'm choosing to believe my mechanic in getting a new diff.

[N55lif3]

Originally Posted by Welcome to NBA Jam

If you floor it from a standstill in a RWD car with 300HP/Torque, your rear wheels are going to spin. This is expected behavior.

I take it you're from the south. AWD is all you can get for a daily in Canada and is all I've driven; from 4matic to quattro to now xdrive. Thought to try out RWD for a change with this easy looking app.

[N55lif3]

Originally Posted by Efthreeoh

If I get time, I'll make a vid of my old diff from the E90. When chasing my driveline vibration, I started on the outside and went inwards (you know the story...). Keep in mind this was at 325,000 miles... So I replaced the rear wheel bearings first. Nope. So I said well maybe the diff finally lost a bearing or the pinion gear set was worn beyond spec. Up on the lift as I spun the wheels, I could hear the diff clicking/clumping as it rotated. I found a 40,000-mile diff out of a 138i on-line from a reputable dismantler for $250. I pulled the old diff. Spun it on the bench and it just clacked around like mad. Then I did the same for the new (used) diff, same exact noise! Well, I just happen to have two other BMWs sitting around (lucky me ), a 1997 Z3 and my 2008 Z4. I put them on the rack and sure enough they made the same noise as my 325i's (old) diff did when installed. So based on that evidence, I'm positive that the open diff design BMW uses is noisy. Bottomline is, all 4 BMW diffs I have make the same exact noises. The mileages range from 40,000 to 325,000 miles.

In my defense, the original driveline parts in my 325i started to get the "tink" sound in the driveline when loading and unloading it at slow speeds. That sound appeared around 150,000 miles. I opened up the driveshaft and replaced (added really) the splined bushings that go in the splined part of the shaft. That helped for a while. So maybe the tink sound was the well-noted drive flange noise at the diff, where you pull the yoke and add some special, magic Lock-Tite compound. That seemed like a lot of work for something that just seemed impossible to be cause of the noise I had. So I took the route of I'll let it really break. The "let-it-really-break" point came at 325,000 when I replaced the diff (still had the tink sound too). As I discovered eventually, it was the center bearing on the driveshaft. I just replaced the entire driveshaft with a new one since I figured after 325,000 miles, the runout spec on the u-joints (.004 in) could be suspect as well. I had previously replaced the center bearing about 100,000 miles before the new driveshaft went in, so I didn't think it could be the bearing, but it was. The rebuilt driveshaft has a slightly different design and has a set-screw (bolt) at the splined section of the shaft. No tink sound since the shaft went in...

Like I've said before, chasing noises and vibrations in the driveline, is tedious, especially at very high mileages.

Thanks for the info ! Going to approach the situation with this in mind

[e90yyc]

Originally Posted by Welcome to NBA Jam

If you floor it from a standstill in a RWD car with 300HP/Torque, your rear wheels are going to spin. This is expected behavior.

^

[Welcome to NBA Jam]

Originally Posted by n55rei

When I fully accelerate (AWD) my back wheels lock up and make a rough clunking noise and stop me from going forward. Could these still be symptoms of a bushing or bearing? This is the only reason why I'm choosing to believe my mechanic in getting a new diff.

When you say they are locking up, you mean the rear wheels are not moving at all? Your gas pedal is to the floor but the car is not moving?

Couple of questions:
Does this occur with DSC off as well?
Does this occur under all driving conditions, such as normal acceleration?
Is it as if the brakes are applied to the rear wheels only?

If you could make a video of this occurring, it could help.

[N55lif3]

Originally Posted by Welcome to NBA Jam

When you say they are locking up, you mean the rear wheels are not moving at all? Your gas pedal is to the floor but the car is not moving?

Couple of questions:
Does this occur with DSC off as well?
Does this occur under all driving conditions, such as normal acceleration?
Is it as if the brakes are applied to the rear wheels only?

If you could make a video of this occurring, it could help.

I will try to take a video. This occurs with DSC off, and only occurs under heavy acceleration, not regular getting-to-the-speed-limit acceleration. It sounds as if something is clunking and its nasty noise makes me let go of the throttle.

An update though: the humming grinding noise happens when the car is in D or neutral; but goes away completely when I turn off the engine while it is rolling in neutral.

Now the question for me to solve is: is it the rear diff. itself or is there a lack of fluid? Does diff fluid dry up? I just bought the car 3 months ago so I hadnt taken into consideration differential fluid yet. Ill let you guys know Monday!

[ptpending]

if you bought this car only 3 months ago, this mean that you gearbox dying. Previous owner probably made too much aggressive starts.