We'll guys, the noise in the front went away, however now I see that the majority of the noise came from the back. I now know that there will be a new DIY for the rear diff in the works in the not so distant future. Today I drained the rear diff oil and it was very deterriorated and looked like brown metallic paint which means that the bearings are toast. Definatelly don't wait 60,000 miles to change that especially that it only fits 1.2L of oil.

 

adam the rear diff is inside the transmission so your talking about the tranny fluid?

or are they seperated inside the case for oil?

 

When you get under the car to look at it, you will realize that the rear diff is piggybacked onto the TIP trans. That's probably why it's hard to source parts for it as the diff is probably a Porsche specific part, where's the TIP is full of benz goodies. So the differential has a big magnetic drainplug on the bottom and a fillplug by the passanger axle. I definatelly reccomend changing the oil in the diff as mine looked horribly unhealthy.

 

Boxster/996 tip has separate transmission and diff chambers (and thus ATF and 75-W-something fluids). I presume a tt tip is the same way.

 

Hi guys, Im getting that tell tale whine you speak about an Im going to bring to dealer. What do you estimate the cost to be to change the bearing...I saw the $3k price for the whole unit above, but why would anyone change the whole thing if its just the bearing that causing the whine anyway. Thx

Marc

 

The problem is that the dealer doesn't service the differential other than changing the clutch. They usually do the whole "unit" . Same with the Tiptronic trans. If you search for my posts you will see what I'm going through to chase down some of these bearings.

If your diagnosis leads to the front diff. These are easy to replace and readily available. You just have to make sure to get the same manufacturers to keep the tolerances as close as possible.

My next project is to change the pinion shaft bearings for the rear differential.

 

so the question is, how did they go, and maybe I missed it in another thread, but what is the tell tale noise? Im getting a whining sound from up front in my car. Im running stock GT-2 rims and factory tire sizes on my car and have it chipped and Miltek exhaust, so the car is putting out about 85 more ponies. I have read that the rim/tire combo may cause premature wear as the rotation cycles are different from the stock 996tt rim/tires? I brought it to dealer and they said I need to a new front diff. ($5k all in). I read this article and it seems like it fixes the problem with out shelling out big bux for the whole unit. (and what shd this nice little diff bearing project cost by just replacing the bearings so I have a benchmark) Any input would be much appreciated.

Marc

 

Awesome write up. i have a question about the seals for the driveshafts and how the driveshafts seal. I had to pull the front shocks out and the axles popped out of the differential in the process (made it much easier!). But now I notice that I have oil leaking from the front diff (a decent amount). I'm thinking either the axles aren't in all the way or I damaged the seals pulling the axles out and putting them back in. Do you recall how difficult it was to pop the axles back into the housing? I'm not sure if I should go down there and whack it a few times to try to get them to seat better or If I should just order the axle seals and try to pull the whole thing apart myself (not something I want to do). Any suggestions?

 

Fantastic write up. Great job!

 

Thanks for getting back to me!

Pardon the stupid questions, but should I just POP it out with a flat head? Or use something like a dental tool? It sounds easy enough to do this way, I might just do it to be safe.

 

There was a discussion on this on Rennlist a while back--hope this helps.

DIY front diff:
http://forums.rennlist.com/rennforum...and-flush.html

 

well, turns out that the noise that my local Porsche dealer told me was a bad diff (for only $5k to fix) was in fact wheel bearings....only $500 bucks to replace both and car is like new again. Humming in completely gone. Thx Craig over at RPM in Long Island for taking the time to trouble shoot the noise.

Marc

 

So, I've got a mild noise from the rear bearing of the tailshaft. This is in addition to a wheel bearing noise - hence the car being apart and the diff being in my hand.

If you remove the dustshield and boot at the tailshaft, you can see the bearing part number. The bearing itself is held in place by a circlip and is obviously pressed in.

Tailshaft rear support bearing: 6007-2RSR-C3 ***
- 6007 C3 is the bearing
- I think the 2 is a revision (not sure)
- RSR stands for rubber seal. The bearing is sealed
- *** is the mfg.

I'll post pics if I decide to tear into the tailshaft. I do have a spare used diff that I might just use incase my teardown doesnt go well.

 

Dear all,

my seal from the input shaft (behind the bearing) from the differential leaked. Oil comes thru the hole out the diff. cover.

Somebody had changed the seal and know which part number is it?

Thanks kiely

 

Hey Guys. Since I've been getting a ton of inquiries throught PM, here's a link to where I have the pics from this thread.
https://www.facebook.com/media/set/?...1&l=ac217bc0e1