B4 Blown Differential?

[MikeB4]

Hi all,

It's been a while since I've posted, as I've had years of trouble-free service from my B4 sedan until yesterday. It appears that my differential is shot. I get no power to the wheels, just a horrible gear-skipping clunking sound when I attempt to apply power regardless of gear. The sound happens in neutral as well, when pushing the car. Changing a transmission or differential is way over my head, and my mechanic (a trusted TDI shop) is trying to source another transmission. (I'm sure decent ones are hard to find). I presume he is not interested in or capable of doing a tranny or diff rebuild, so that's why he is looking at a swap.

I was wondering, is the differential oil separate from the regular transmission gear oil? The reason I ask is that I've had a light-brown oil leak on the right side of the car for a long while now, and I thought it was from my steering rack with the torn boot over there. However, maybe it was the diff leaking all along . . . . I knew it wasn't the tranny oil since I've got redline MT-90 in there, which is red in color.

Thanks!
Michael
97 Passat TDI
Orange County, CA

 

[garciapiano]

Are you sure it’s not a broken CV joint? I had this issue when I had a ball joint come loose on me once, the spindle moved out of its normal travel path. I thought I had blown the trans but the inner CV joint had just come undone.

I have a known good CTN in my garage in the San Bernardino area, ready to go. PM me if interested.

 

[Steve Addy]

Sorry to hear of your dilemma. There are known cases where 02A transmission differential housings blow out, I saw one on a 96 VR6, here's a rather crappy photograph of what happened.

Steve

 

[MikeB4]

Are you sure it’s not a broken CV joint? I had this issue when I had a ball joint come loose on me once, the spindle moved out of its normal travel path. I thought I had blown the trans but the inner CV joint had just come undone.

I have a known good CTN in my garage in the San Bernardino area, ready to go. PM me if interested.

Hi,

Thanks for the reply. Well, I'll look again at the CV joint and see if I see signs of damage. I would have thought that even if the right-side

Are you sure it’s not a broken CV joint? I had this issue when I had a ball joint come loose on me once, the spindle moved out of its normal travel path. I thought I had blown the trans but the inner CV joint had just come undone.

I have a known good CTN in my garage in the San Bernardino area, ready to go. PM me if interested.

Hi,

Well, I didn't see anything obvious on the CV joint, but I'll look again. I would have thought that even if the CV failed on the right side, I would have gotten at least a little power on the left. But, maybe with the stock differential, you get absolutely no limited-slip functionality. I'll look again. There may be a chance I will be contacting you about that CTN. At least it's within driving distance and I can come pick it up. What is your email address?

Thanks,
Michael

 

[garciapiano]

PM’d you.

 

[IndigoBlueWagon]

If one joint is broken the car will be immobilized. No power to any wheel.

 

[MikeB4]

Hi all,

Once again, you smart people on tdiclub called it right. I crawled under the car today, and was showered with a few large steel bearings and a piece of a broken bolt when I removed the belly pan. Sure enough it was just a blown inner CV joint. I've never had one fall apart like this before, especially since it was an inner one and I had no warning that doom was impending! It was a generic aftermarket half-shaft that was probably about 15 years old, so I can't be too sorry. I'm thrilled it's not the whole transmission or the differential. Thank you all for your advice, and thank you garciapiano for offering to sell me a used CTN transmission just in case.

Michael

 

[Steve Addy]

Good news then!

Steve

 

[Abacus]

I've seen a few of them over the years, not fun. I think the remanufactured stuff can be hit or miss.

And as others have mentioned, when a transmission lets go, it's epic.