[b2ke]

My car is 2006 330xi, the front axle popped out and two bolts attached to the engine in the same area have snapped.

Driving from San Fransisco back to San Jose I hit a pretty bad bump on the freeway. Afterwards driving down the road a bit more I hit another dip in the road and I guess it popped out my front driveshaft axle.

It looks like I can replace the boot, relubricate the parts and pop it back in place, at least I hope so. Not sure if I need to replace the entire axle. I found these two DIY's https://www.youtube.com/watch?v=0RylDpbxnMI and https://www.youtube.com/watch?v=RwcQjSMeY-Q&t=100s

My main problem is that there are two bolts that connect to the engine that have completely snapped off. Any help would be appreciated. I don't know the exact names of all these parts so bare with me as I post pictures and hopefully you guys can help me out.


This is the front passenger side.



Picture of the snapped bolts. I am trying to figure out whether it is a good idea to remove that box the axle popped out of to have room to take out the snapped bolts.

[juld0zer]

What I'd do is go to www.etk.cc and punch in the last 7 characters of your VIN and have a look at the engine sump and front axle sections

https://www.etkbmw.com/bmw/EN/search/selectCar/E90/Lim/BMW+330xi+N52/ECE/22_0113

https://www.etkbmw.com/bmw/EN/search/selectCar/E90/Lim/BMW+330xi+N52/ECE/31_0718

It might help guide you in the right direction.
No insurance?

[Biginboca]

I’m going to take a wild guess that you have a bigger issue here. I would guess a bad engine mount (likely on that passenger side) which allowed all this to happen. Cars hit bumps all the time but don’t have major components separate like this so I would look deeper into it.

The passenger side engine mount is right in the midst of your trouble area where you had 3 things shift and separate when you hit those bumps.

Oh, and you apparently have an oil leak lol

[Efthreeoh]

My advice would be to contact your insurance company first and see if this is covered under your comprehensive coverage, which it should be IMO. Second, did you hit the bump with the right wheels of the car? If so then I'd check for wheel damage both front and back. Was it a bump up, or a bump down (i.e. a pothole)?

I think the axle is broken and needs replacement. The inner CV joint is a press fit between the two separated parts, which you'd never just push back together. Whatever force broke the engine mount bracket bolts was enough to break the press-fit between the two parts of the inner CV joint.

The engine mount bracket may also need replacement, I can't see how it is not broken if the lower two bolts snapped. The upper bolts must be snapped too, but if not, then the bracket had to break. The engine is just not meant to move that much beyond the limits of the engine mount and snap bolts, that takes a shitload of force.

Now, where is all the oil coming from and what oil is it, engine or transmission (i.e. the front drive unit)? Was the oil there prior to the incident, or came after the incident. If it came after, then you need to figure out where the source of the leak is.

I think you should have the car evaluated by a professional mechanic (after you contact your insurance company) for other damage and a safety inspection. Here's the parts for the mount:

[Efthreeoh]

I got to thinking about this more on my way into work. The lower bolts broke off at the head and not at the block as one would expect if the were to shear. So that tells me some ape over torqued the aluminum bolts and snapped the heads off at some point during the car's history.

I think what happened is the bolts where already broken and the force of the several bumps, allowed the engine to violently move, which pulled the CV joint apart. Maybe a machine shop can press the CV joint back together, and you can first try that, but the joint may be damaged now and not stay together. Maybe it will press back together and then they could tack weld it to keep it together.

It probably would be cheaper to just get a new halfshaft.

[racermp]

the cv joint just needs to slide back in, there's no pressing it or anything. but i'd recommend a rebuilt one. the bigger problem is gonna be that mount. you can do it your self or cheap shop for under 500 i'm guessing or pay deductible and let insurance fix it at dealer or something.

[Efthreeoh]

To get equal length halfshafts, which reduce torque steer, the right halfshaft has an extension between the spider-ball joint (the inner CV joint) and the splined shaft that attaches to the differential. The extension has separated from the CV joint, and is a press-fit assembly. The halfshaft in this case was extended far beyond the limits of design and broke. It is possible the CV joints were also damaged just prior the point the extension broke away from the inner CV joint.

[Maestro]

As it was pointed out, you need to figure out where all the oil came from. Most of the oil looks new, and some of it is old since there is road grim mixed in with the oil and that only happens over time.

I personally would be concern about the motor mount bolts shearing off like they did, there are 4 bolts two sheared off and the mount separated from the motor, that means the mount is bent or the other two bolts also shears off. It is going to be hard to pull out the broken bolts and there could be damage to the engine block.

At this point the drive shaft is the lease of your issues. You have lots of work in front of you even if the block is not damage as part of this.

I do not believe hitting a bump in the road caused this, I hit a pothole which split my front and rear rims since I hit the pothole going almost 60. I had no frame or suspension damage, I did not even knock the alignment all the much.

[Efthreeoh]

Originally Posted by Maestro

As it was pointed out, you need to figure out where all the oil came from. Most of the oil looks new, and some of it is old since there is road grim mixed in with the oil and that only happens over time.

I personally would be concern about the motor mount bolts shearing off like they did, there are 4 bolts two sheared off and the mount separated from the motor, that means the mount is bent or the other two bolts also shears off. It is going to be hard to pull out the broken bolts and there could be damage to the engine block.

At this point the drive shaft is the lease of your issues. You have lots of work in front of you even if the block is not damage as part of this.

I do not believe hitting a bump in the road caused this, I hit a pothole which split my front and rear rims since I hit the pothole going almost 60. I had no frame or suspension damage, I did not even knock the alignment all the much.

I agree. I think the engine mount bracket bolts were rung off by someone working on the engine in the past and just left them broken. Who would notice something like a broken mount bolt?

[PhaseP]

Here is what I think going on, based on my knowledge of my XI and a few others who posted popping out passenger side CV axles in the past:

The engine mount bracket (support) bolts on to the engine block with aluminum bolts. You can find the part number here, number 7:

http://www.realoem.com/bmw/enUS/show...diagId=22_0113

Being an N52 with magnesium block, anything bolts on to the block uses aluminum bolts not to cause galvanic corrosion, and itself is aluminum.

There are some engine mount replacement DIY's that instruct to remove the engine mount bracket (support) to aid in replacement of the engine mount, especially on the passenger side. But the engine mount replacement DOES not need the engine mount bracket to be unbolted from the engine! I have replaced my mounts without doing it and DIY from places like Pelican Parts, FCP Euro also show doing the engine mount replacement without removing that support bracket, rightfully so.

Because the bolts are aluminum, they are one time use. Reuse them, like removing them for aiding in engine mount replacement, you risk breakage like this case.

I would bet someone in the past removed those bolts and reused them without replacing with new ones.

Since the heads are broken off, there won't be any tension on those broken bolts and they will most probably come out easily, unless they are galled.

About the CV axle that came apart like that; that is not press fit that got broken. It is made of two separate pieces there, and the two pieces are held in place by the boot only when axle is not installed on the car. When axle is installed on the car, the geometry of the suspension components do not allow each part to move away far enough from each other such that the boot will tear out and two parts will come apart. In your case, because engine mount bracket bolts broke off, engine moved down and swung to side causing extreme enough movement inside that inner CV joint and the two pieces came apart. Whether you can put it back in and reuse would depend on if the bearings and the surfaces they ride on had sustained any damage or not. There are 3 small wheel like round bearings that ride on the 3 guides on the inner CV housing, these should have mirror finish on them still. Any nicks on them will cause the CV to not last long even if you put them back together. And then these small wheel like bearings inside them have needle bearings they should be fine too. Lastly the inside surface of the inner CV housing that these ride in and out has to be still smooth. Obviously if anything was bent, can't reuse.

About the oil there, some of it the can be due to the axle grease that came out, but looks too thin for grease. The other possibility which my guess would be, is the front differential oil leaked. The front differential oil right side seal is where that right side axle enters the oil pan. If the axle was hit that hard, the seal there could easily have been disturbed to leak the differential fluid. The front differential is bolted on the left side of the engine oil pan. There is a tube that goes through the oil pan where the straight section of the passenger side CV axle is inserted and how it reaches the differential. This tube has differential oil in it splashing around and wheels turn.

By the way there are two potential leak points for the differential oil, one is the axle seal, and the other is an o-ring that seals the "pedestal" that is bolted to the oil pan and the oil pan surface. The axle goes into this pedestal and the axle seal is on this pedestal. It is that box like thing that is coming out of the oil pan.

Search this forum for "popping" or "broken" "passenger CV axle" "half shaft" you will find similar stories.

One example:
https://www.e90post.com/forums/showt...nt+axle+broken

[Efthreeoh]

Originally Posted by PhaseP

Here is what I think going on, based on my knowledge of my XI and a few others who posted popping out passenger side CV axles in the past:

The engine mount bracket (support) bolts on to the engine block with aluminum bolts. You can find the part number here, number 7:

http://www.realoem.com/bmw/enUS/show...diagId=22_0113

Being an N52 with magnesium block, anything bolts on to the block uses aluminum bolts not to cause galvanic corrosion, and itself is aluminum.

There are some engine mount replacement DIY's that instruct to remove the engine mount bracket (support) to aid in replacement of the engine mount, especially on the passenger side. But the engine mount DOES not need the engine mount bracket to be unbolted from the engine! I have replaced my mounts without doing it and DIY from places like Pelican Parts, FCP Euro also show doing the engine mount replacement without removing that support bracket, rightfully so.

Because the bolts are aluminum, they are one time use. Reuse them, like removing them for aiding in engine mount replacement, you risk breakage like this case.

I would bet someone in the past removed those bolts and reused them without replacing with new ones.

Since the heads are broken off, there won't be any tension on those broken bolts and they will most probably come out easily, unless they are galled.

About the CV axle that came apart like that; that is not press fit that got broken. It is made of two separate pieces there, and the two pieces are held in place by the boot only when axle is not installed on the car. When axle is installed on the car, the geometry of the suspension components do not allow each part to move away far enough from each other such that the boot will tear out and two parts will come apart. In your case, because engine mount bracket bolts broke off, engine moved down and swung to side causing extreme enough movement inside that inner CV joint and the two pieces came apart. Whether you can put it back in and reuse would depend on if the bearings and the surfaces they ride on had sustained any damage or not. There are 3 small wheel like round bearings that ride on the 3 guides on the inner CV housing, these should have mirror finish on them still. Any nicks on them will cause the CV to not last long even if you put them back together. And then these small wheel like bearings inside them have needle bearings they should be fine too. Lastly the inside surface of the inner CV housing that these ride in and out has to be still smooth. Obviously if anything was bent, can't reuse.

About the oil there, some of it the can be due to the axle grease that came out, but looks too thin for grease. The other possibility which my guess would be, is the front differential oil leaked. The front differential oil right side seal is where that right side axle enters the oil pan. If the axle was hit that hard, the seal there could easily have been disturbed to leak the differential fluid. The front differential is bolted on the left side of the engine oil pan. There is a tube that goes through the oil pan where the straight section of the passenger side CV axle is inserted and how it reaches the differential. This tube has differential oil in it splashing around and wheels turn.

By the way there are two potential leak points for the differential oil, one is the axle seal, and the other is an o-ring that seals the "pedestal" that is bolted to the oil pan and the oil pan surface. The axle goes into this pedestal and the axle seal is on this pedestal. It is that box like thing that is coming out of the oil pan.

Search this forum for "popping" or "broken" "passenger CV axle" "half shaft" you will find similar stories.

One example:
https://www.e90post.com/forums/showt...nt+axle+broken

I stand corrected. I see now that the CV joint just has a really deep bearing race (they are usually not that deep). From the picture it at first looked like to me the detents indicated a press fit onto the back of a (shorter) CV joint. I was thinking the elongated bearing race was just an extension. But still, the bearing races on the OP's CV joint looked torn up at the edges anyway and if he reassembles the CV joint assuming he can get it clean, it doubt it will last very long. I'd get a new axle.

[Maestro]

Originally Posted by PhaseP

Here is what I think going on, based on my knowledge of my XI and a few others who posted popping out passenger side CV axles in the past:

The engine mount bracket (support) bolts on to the engine block with aluminum bolts. You can find the part number here, number 7:

http://www.realoem.com/bmw/enUS/show...diagId=22_0113

Being an N52 with magnesium block, anything bolts on to the block uses aluminum bolts not to cause galvanic corrosion, and itself is aluminum.

There are some engine mount replacement DIY's that instruct to remove the engine mount bracket (support) to aid in replacement of the engine mount, especially on the passenger side. But the engine mount DOES not need the engine mount bracket to be unbolted from the engine! I have replaced my mounts without doing it and DIY from places like Pelican Parts, FCP Euro also show doing the engine mount replacement without removing that support bracket, rightfully so.

Because the bolts are aluminum, they are one time use. Reuse them, like removing them for aiding in engine mount replacement, you risk breakage like this case.

I would bet someone in the past removed those bolts and reused them without replacing with new ones.

Since the heads are broken off, there won't be any tension on those broken bolts and they will most probably come out easily, unless they are galled.

About the CV axle that came apart like that; that is not press fit that got broken. It is made of two separate pieces there, and the two pieces are held in place by the boot only when axle is not installed on the car. When axle is installed on the car, the geometry of the suspension components do not allow each part to move away far enough from each other such that the boot will tear out and two parts will come apart. In your case, because engine mount bracket bolts broke off, engine moved down and swung to side causing extreme enough movement inside that inner CV joint and the two pieces came apart. Whether you can put it back in and reuse would depend on if the bearings and the surfaces they ride on had sustained any damage or not. There are 3 small wheel like round bearings that ride on the 3 guides on the inner CV housing, these should have mirror finish on them still. Any nicks on them will cause the CV to not last long even if you put them back together. And then these small wheel like bearings inside them have needle bearings they should be fine too. Lastly the inside surface of the inner CV housing that these ride in and out has to be still smooth. Obviously if anything was bent, can't reuse.

About the oil there, some of it the can be due to the axle grease that came out, but looks too thin for grease. The other possibility which my guess would be, is the front differential oil leaked. The front differential oil right side seal is where that right side axle enters the oil pan. If the axle was hit that hard, the seal there could easily have been disturbed to leak the differential fluid. The front differential is bolted on the left side of the engine oil pan. There is a tube that goes through the oil pan where the straight section of the passenger side CV axle is inserted and how it reaches the differential. This tube has differential oil in it splashing around and wheels turn.

By the way there are two potential leak points for the differential oil, one is the axle seal, and the other is an o-ring that seals the "pedestal" that is bolted to the oil pan and the oil pan surface. The axle goes into this pedestal and the axle seal is on this pedestal. It is that box like thing that is coming out of the oil pan.

Search this forum for "popping" or "broken" "passenger CV axle" "half shaft" you will find similar stories.

One example:
https://www.e90post.com/forums/showt...nt+axle+broken

I did not know if those bolts were single use, I know not all the bolts on the engine are single use, it is not always clear to me why some are and some are not. I was told if the bolt head has blue paint on them they are single use.

You are correct if they were reused then the toque strength is gone, I was told the way the AL bolts work, they stretch under torque which provides the holding strength, once stretched they no longer have the holding strength once loosened and will come loose if reused. In this case the person may have reused and over torqued which over stretched the head causing it to pop off.

[PhaseP]

Originally Posted by Maestro

I did not know if those bolts were single use, I know not all the bolts on the engine are single use, it is not always clear to me why some are and some are not. I was told if the bolt head has blue paint on them they are single use.

You are correct if they were reused then the toque strength is gone, I was told the way the AL bolts work, they stretch under torque which provides the holding strength, once stretched they no longer have the holding strength once loosened and will come loose if reused. In this case the person may have reused and over torqued which over stretched the head causing it to pop off.

The aluminum bolts are for N52 magnesium block not to corrode. OP has N52. 2006 N52 valve cover is also magnesium so valve cover bolts on those are also aluminum. Later year N52 valve covers are plastic and their valve cover bolts are steel. The head is aluminum and so if something bolts on to the head without touching the magnesium valve cover they are steel bolts, like the oil filter housing.

The factory put blue paint on the aluminum bolts. Any replacement aluminum bolts I had bought and used didn't have blue paint on them. So if it doesn't have blue paint on it, doesn't mean it is not aluminum. The aluminum bolts are very light weight and won't be attracted to magnet, easy to test that way.

All aluminum bolts I had seen on my car ('06 325xi) were torque to stretch and so one time use. There are some steel bolts that are in stalled torque to yield (stretch), those are also supposed to be one time use. If it is up to the BMW service manuals, almost all bolts are one time use

I wouldn't reuse an aluminum bolt especially on engine mount bracket though.

It is hard to tell for sure if the OP's bolts had been reused or not. It is definitely a possibility.

[Efthreeoh]

Originally Posted by Maestro

I did not know if those bolts were single use, I know not all the bolts on the engine are single use, it is not always clear to me why some are and some are not. I was told if the bolt head has blue paint on them they are single use.

You are correct if they were reused then the toque strength is gone, I was told the way the AL bolts work, they stretch under torque which provides the holding strength, once stretched they no longer have the holding strength once loosened and will come loose if reused. In this case the person may have reused and over torqued which over stretched the head causing it to pop off.

For the N52, it is easy to tell when aluminum bolts are needed. The TIS (or realOEM.com) always includes the part number for the set of aluminum bolts that are needed when repairing or replacing an N52 engine component. The TIS will usually state "set of aluminum bolts used in conjunction with" or make note of the need to replace the aluminum bolts, and then provide the part number for the set of bolts.

For example:

[Maestro]

Originally Posted by PhaseP

The aluminum bolts are for N52 magnesium block not to corrode. OP has N52. 2006 N52 valve cover is also magnesium so valve cover bolts on those are also aluminum. Later year N52 valve covers are plastic and their valve cover bolts are steel. The head is aluminum and so if something bolts on to the head without touching the magnesium valve cover they are steel bolts, like the oil filter housing.

The factory put blue paint on the aluminum bolts. Any replacement aluminum bolts I had bought and used didn't have blue paint on them. So if it doesn't have blue paint on it, doesn't mean it is not aluminum. The aluminum bolts are very light weight and won't be attracted to magnet, easy to test that way.

All aluminum bolts I had seen on my car ('06 325xi) were torque to stretch and so one time use. There are some steel bolts that are in stalled torque to yield (stretch), those are also supposed to be one time use. If it is up to the BMW service manuals, almost all bolts are one time use

I wouldn't reuse an aluminum bolt especially on engine mount bracket though.

It is hard to tell for sure if the OP's bolts had been reused or not. It is definitely a possibility.

All the replacement bolts I got when I have done work on my car has the blue paint on them, whether I got the parts directly from BMW or through ECS Tuning which I use for most of my replacement part. I guess there are less reputable places. I was told never try and go cheap on a BMW, if you can not afford the maintenance do not buy it.

[Efthreeoh]

Originally Posted by Maestro

All the replacement bolts I got when I have done work on my car has the blue paint on them, whether I got the parts directly from BMW or through ECS Tuning which I use for most of my replacement part. I guess there are less reputable places. I was told never try and go cheap on a BMW, if you can not afford the maintenance do not buy it.

I just replaced my alternator last year. The new bolts were not painted. All OE parts from a dealership, picked up at the parts counter.

[PhaseP]

Originally Posted by Maestro

All the replacement bolts I got when I have done work on my car has the blue paint on them, whether I got the parts directly from BMW or through ECS Tuning which I use for most of my replacement part. I guess there are less reputable places. I was told never try and go cheap on a BMW, if you can not afford the maintenance do not buy it.

Can you give an example of bolts you bought from ECS ?

Tsk tsk tsk, look at this! ECS must be "ripping" people of selling cheap non BMW parts because they don't have no blue paint on them! Or I am color blind, my doctor have been ripping me off too, how come I didn't get diagnosed with color blindness with all those eye exams I had

The link to ECS site and in case anyone can't understand; I am being sarcastic. ECS is not ripping people off, those are genuine BMW branded bolts.)
https://www.ecstuning.com/b-genuine-...t/11132210959/

[PhaseP]

Originally Posted by Efthreeoh

I just replaced my alternator last year. The new bolts were not painted. All OE parts from a dealership, picked up at the parts counter.

My magnesium valve cover had been removed during warranty period by the dealership, of course under warranty for lifter ticking, they replaced the lifters. Three things came out of it:

- I still don't have valve cover gasket leak after 9 years, they must have torqued them good.
- None of my valve cover bolts have blue paint on them. Dealership must have used cheap knockoff bolts for warranty work LOL!!!! (Well I myself put blue paint on two of them when I was working on exhaust manifold leak this fall)
- I still have the lifter tick all these 9 years if I run the engine cold a few minutes and then shut off and restart after a few hours or next day.

[Efthreeoh]

Originally Posted by PhaseP

My magnesium valve cover had been removed during warranty period by the dealership, of course under warranty for lifter ticking, they replaced the lifters. Three things came out of it:

- I still don't have valve cover gasket leak after 9 years, they must have torqued them good.
- None of my valve cover bolts have blue paint on them. Dealership must have used cheap knockoff bolts for warranty work LOL!!!! (Well I myself put blue paint on two of them when I was working on exhaust manifold leak this fall)
- I still have the lifter tick all these 9 years if I run the engine cold a few minutes and then shut off and restart after a few hours or next day.

If my E90 N52 ever had a lifter tick, I never realized it. Being my E30 had mechanical lifters and noisy-ass fuel injectors, the N52 was damned quite sounding to me when I took delivery in May 2006. My '08 Z4 3.0si was built prior to the revised N52 head, if it has a lifter tick, I never realized it.

In 2009 I dropped in a new WP, the bolt set, again from the dealership, did not have blue bolts.

IMO, the 2.5L M20 "is" engine is the best sounding straight 6 BMW made in the modern era.

[PhaseP]

Originally Posted by Efthreeoh

If my E90 N52 ever had a lifter tick, I never realized it. Being my E30 had mechanical lifters and noisy-ass fuel injectors, the N52 was damned quite sounding to me when I took delivery in May 2006. My '08 Z4 3.0si was built prior to the revised N52 head, if it has a lifter tick, I never realized it.

In 2009 I dropped in a new WP, the bolt set, again from the dealership, did not have blue bolts.

IMO, the 2.5L M20 "is" engine is the best sounding straight 6 BMW made in the modern era.

Not to hijack the thread will mention here quickly, the lifter tick is very drive pattern related. Your driving pattern must not have been matching to the one that results in lifter tick noise.To have the lift you must start with a cold engine, run it for a few minutes but not long enough for it to fully warm up. Then shut it off. Wait enough for the engine to fully cool down, at least a few hours. Then start the engine, wait a few minutes on low RPM, then if you hadn't had the updated cylinder head you will most likely start to hear a distinct tapping sound, like a small hammer hitting on the exhaust side of the engine. If it doesn't happen that time, repeat this pattern one or two times, it will start the tapping/ticking. Very short commutes fall into this pattern and those with short commutes will usually have lifter tick. That is has been my experience. This lifter tick noise had been beaten to death anyway so I stop here.