Possible Transmission / Front Driveshaft Failure *edit* Rear Axle popped out

[SRacin]

thanks for the translate.

If thats the case, could wheel speed be missing due to driveshaft failure?

Tow truck delivered home last night, so will have a poke around myself and try get the front drive shaft out as a first guess.

[SlickGT1]

Wait is that noise when going reverse? Yea could be. I’m honestly not an expert in transmission errors by any measurement.

You need to have someone else engage gear for you while you are under it. Just please take a lot of precaution. Don’t get run over by the wife. Or put the car on 4 jackstands. But still be carefulll.

[andrewwynn]

The error said that it's an impossible combination of output of transmission vs wheel speed. That hints at transfer case.

Put all wheels off the ground so you can try to get some motion with no real force.

Watch real-time input and output speeds of transmission.

If you get an output on the transmission that's matched to the gear ratio of R and 1, that suggests the transmission is ok and the problem is downstream. It should be very obvious where that sound source is!

We are all very curious. It could be a blown dif. or transfer case. It doesn't seem like it's the transmission or clutch at this point to me based on the transmission having in and out values from the snapshot

[SRacin]

The grinding is when going into park. From research one theory is that this is caused as the output shafts are still spinning and the parking locking mechanism fails to engage. On an e39 there was one forum post where this occurred due to an axle popping out of the diff. Could be similar to a failed front driveshaft perhaps?

Will get a few hours to debug tomorrow, then its on blocks for a week as I am out of town. Thanks for all the comments so far, will keep posted, really appreciate this community!

Thanks

[andrewwynn]

You didn't say the sound was when done I thought that was when trying to move.

Quite recent thread was the case of CV coming out of the differential. It will be quite obvious under the car if a CV is detached (or broken etc).

lift one end of the cat at a time, turn the wheel by hand, if the diff is working and the drive shaft is held by the park prawl, the opposite wheel will turn the opposite direction.

If you get a freewheeling wheel you have a defect in the CV or dif usually. You can look for drive shaft motion also, You should not be able to turn either drive shaft when In park.

You can put the car up off the ground then put the car in N and see if you can turn each drive shaft by hand to see if any wheel fails to turn. Better to do these tests power off.

Usually if the CV pops out, you'll get a grinding sound of the spline trying to engage when in gear (the rubber boots will usually add just enough pressure).

I have a good feeling that you are looking at a relatively inexpensive fix now that I know the sound was likely from parking prawl. A broken or detached CV or dif will give you all the symptoms save this: park will not work properly: you can push the car if a CV is broken, though it's possible one axle might lock if the other doesn't

[SRacin]

Originally Posted by andrewwynn

lift one end of the cat at a time, turn the wheel by hand, if the diff is working and the drive shaft is held by the park prawl, the opposite wheel will turn the opposite direction.

So I just jacked up the front right of the car, and the wheel turns in unison with the front driveshaft. Front CV's look ok.

Car is turned off and in park. Am I correct in saying the the parking pawl is not holding the front driveshaft, when it is supposed to? i.e. breakage between the parking pawl and the output shaft?

Stripped driveshaft?

[andrewwynn]

You should not be able to turn the front drive shaft when In park.

It's not too uncommon for the drive shaft to come out of the spline in the transfer case but the sound is usually unmistakeable when it happens (repeated bang as the spline will skip one tooth to the next).

Caveat: didn't you pull the fuse to disconnect the front axle? It would be normal for the front drive shaft to be free if the transfer case has disconnected the front.

My cars are pre facelift can't disable front axle.

[SlickGT1]

So from experience, a popped out cv will make zero noise. Your car will continue to drive, while spilling its fluids all over the metal bastard plate.

I also don’t get why car won’t move if front drive shaft is gone. You can fully remove front drive shaft and cause zero errors to the car. It will be full rear wheel drive with no error codes.

It’s either the guts in the transfer case, or output shaft in the trans.

[andrewwynn]

Only If the front axle is disabled will front CV out be silent. If power is applied and one corner has no load that corner will spin like the wind. Usually the spine will try to grab you'll get a gnashing of teeth not friendly sound.

If the TC has the front disabled then front is not part of the equation anymore.

The people that have had any front axle disabling issues usually report the 4x4 icon on the dash so I'm quite curious about the no errors claim.

[SRacin]

Ok. Daylight. Fresh Brain. Digested all the good advise. Start at the back and work forward. Right rear axle shaft has popped out. Why would this happen?



For reference the easiest way to pop it back in is to unload the axle by dumping the air in the system.
1. Jacked up right rear and secured an axle stand.
2. Using INPA dumped air from right rear and reservoir
3. Have a lovely assistance rotating the wheel slightly while prying against the chassis (did not like using the exhaust to pry).
4. Popped right in. Try a reverse pry to see if you can pop it back out easily or not.
5. Using INPA raise right rear.
6. Lowered car and tested.
7. Order new spring clip and seals to replace just to be sure.

So in hindsight...

1. As @andrewwynn suspected the key information is the grinding noise was when going from Neutral into Park. The pawl was likely unable to engage due to insufficient parasitic drag to slow the shaft down (what the shaft is called I am unsure).
2. First step should be to carry out a visual inspection in the day light starting at the wheels and working towards the transmission.
3. The parking pawl does not seem to lock the front driveshaft (a comment asked if the fuse was in or out, to confirm the fuse was only removed briefly).
4. There was rear suspension work carried out within the last 3 months. If you are having your commonly failed rear ball joints replaced (I had a whole kit done in the back end in Jan) make sure the mechanic checks the diff output shafts are engaged fully!
5. Check error codes. In my case it created error codes 51AD and 51AF in the transmission controller GS19A
6. The xoutpost community is awesome!
7. X5's are a love / hate relationship.

I will also edit the first post title message for future reference, hopefully to help someone else out.

I think we have dodged an expensive missile...

Thanks everyone for the help!
@SlickGT1
@andrewwynn
@wpoll