[LouisBennett01]

So I’ve got a 2007 335i n54, last two weeks car has been jolting when downshifting into 1st and 2nd with the occasional metal clunking. Yesterday whilst accelerating from 2nd the first there was a loud bang (sounded from the rear but can’t be 100%) followed by a complete loss of power and a yellow transmission light.

Got it towed home that night, car still starts and revs fine, also when put in m/s the car seems to be selecting gears fine. Also cannot for the life of me get the transmission code to pop back up on the dash and when a code reader is plugged in no codes are found as seems the code has gone away

Some info that might help:

• Car now rolls while in park

[*]Driveshaft does not spin in drive[*]Slight leakage from the diff but nothing major[*]No leakage from gearbox [*]Both rear wheels spin freely but don’t spin together when only spinning one[*]Other than the occasion metal clunk no other noises can be heard from either diff or gear box[/LIST]
I’m hoping it’s something up with the diff but I imagine it’s going to be more serious than that. Any info is appreciated

Cheers

[Podunk]

put car up on jack stands, in all 4 corners, make sure it is VERY secure, turn off TCS, put in gear, do the wheels spin? does the driveshaft spin? if the wheels spin in air but not on ground, it could be a trans issue, if the wheels don't spin but the driveshaft does, it's in diff, if nothing spins, your trans is bad. would also be a good time to look at your Guibo.

[LouisBennett01]

Appreciate the reply, just incase anyone has the same problem the wheels both spin with the car on the floor and in the air while the shaft does not, I dropped the diff and upon inspection the gears inside has come loose and wrecked itself and seized.

Upon speaking to a mate I’ve since found out if any strain is detected on the shaft the clutch disengages and locks the shaft to avoid possible damages to the rest of the transmission.

After taking off the diff (obviously releasing the seized diff, everything spins fine when putting the car in drive.

[Podunk]

Originally Posted by LouisBennett01

Appreciate the reply, just incase anyone has the same problem the wheels both spin with the car on the floor and in the air while the shaft does not, I dropped the diff and upon inspection the gears inside has come loose and wrecked itself and seized.

Upon speaking to a mate I’ve since found out if any strain is detected on the shaft the clutch disengages and locks the shaft to avoid possible damages to the rest of the transmission.

After taking off the diff (obviously releasing the seized diff, everything spins fine when putting the car in drive.

well most of these are an open diff, so tires will spin without shaft spinning. glad you got it figured out.