Final Drive Oil Leak

EZ_Fixes_Only

Active member
Joined
Sep 2, 2001
Location
Tuxedo, NY
TDI
Jetta, 2002, Silver
My wife told me her 2002 Jetta TDI temp. gauge was not working. So I got out my Bentley Service Manual and think its probably the sender. So I take a look and all of the wiring looks okay but I think I'll order one anyway and try replacing it because it looks easy to do. But then I look at the top on the final drive and its got oil pooled up in the casting re-enforcement grids near the area of the breather and the speedo sender. I cleaned it all up and drove the car around and think the source is the breather. Question: why would the breather be leaking oil?
 

EZ_Fixes_Only

Active member
Joined
Sep 2, 2001
Location
Tuxedo, NY
TDI
Jetta, 2002, Silver
Following up a few day later...no responses. Labor day weekend was probably not the best time to pose such a question as most people are not spending time in front of their computers. I any case, a spent a few hours searching and reading for "final drive" "differential" "oil leak" etc. and have not run across any useful information yet. Does anyone have any suggestions for search terms or remember any topics that included the final drive and related oil leaking possibilities? I'm going to read through Bentley's again and then try to get the speedo sender removed from the final drive to see what the oil level is. I'm thinking it could be transmission oil leaking into the final drive since the oil in the final drive is separate from the automatic transmission.
 

EZ_Fixes_Only

Active member
Joined
Sep 2, 2001
Location
Tuxedo, NY
TDI
Jetta, 2002, Silver
And that drives the nail in the coffin! I got the speedo gear drive assembly out and it 0.16" over-filled indicating about 10% too much oil in the unit. So oil is getting in there from somewhere. The Bentley Service Manual is very limited on this subject. Has anyone ever figured out a way to check the transmission oil when its cold based on the level? I don’t have the VW software needed to monitor the temperature so I can’t check the transmission fluid level without going to the dealer. I think I’m about to have the dealer extract some dollars from my bank account.
 

EZ_Fixes_Only

Active member
Joined
Sep 2, 2001
Location
Tuxedo, NY
TDI
Jetta, 2002, Silver
I'm just churning this thing to bring it to the top again hoping get some useful information or opinions about what's causing the oil level to rise. Hopefully, a final drive or transmission expert will see this during the weekend and comment. I've been watching it all week. Its a slow steady leak. Perhaps only a few ounces when driven 500 miles.
 

Harvieux

Vendor , w/Business number
Joined
Aug 15, 1998
Location
Whittier,CA-USA
TDI
06 A5 Pkg.2 w/navi & ASEP
EZ_Fixes_Only, Are you the original owner? If not, how long have you had the vehicle? The only time I have experienced FD overflow was when a tranny rebuild took place and the FD fluid was changed while they were at it. Of course, this overflow was due to overfill. Rather than waste the scratch at the dealer, why not spend a couple Franklins and get Vag-Com and see where you are levelwise between 38-42 degrees C on the tranny side. If low, add to spec and then monitor the FD level from there by sticking a Mity-Vac tube in the speedo sensor hole and suck up to correct level and see what transpires from then on. If the level rises, you have intrusion from the ATF side but, I don't have past experience of this possibility to set in it stone regarding positive diagnosis. In other words, I think we have to wing it with our common sense process of elimination
. Later!
 

EZ_Fixes_Only

Active member
Joined
Sep 2, 2001
Location
Tuxedo, NY
TDI
Jetta, 2002, Silver
Thanks Harvieux, I think your approach is logical.

Regarding your question, I have maintained the vehicle since it was new but have never checked the final drive level until I found it leaking out of the vent cap. The transmission was replaced at 3,500 miles by the dealer after it developed a problem where it would drop out of gear at idle and then clank back in after the RPM went of 1,000. Everything was so clean at that time I don't know if the final drive was replaced with the tranny or not. I must say that the dealer did a flawless swap as far as everything being put back the way it was...but maybe not. In any case, I agree the next step is to check the trans. fluid level. The vehicle is now at 60k miles. I looked the final drive today and the vent cap has not leaked anymore fluid during the last 200 miles of driving. So this may be an intermittent condition.

For the record, I think the trans. oil checking procedure is the worst feature of this power plant and the problem I'm having is a perfect example of why a simple quick check method is vital for normal "field" trouble shooting. My choice is to either go to the dealer and spend at least $100.00 and hope they do it correctly or spend over $200.00 for a software tool (not to mention a lap top PC since I don't have one). In my opinion, its not a diesel engine problem as much as it is a VW engineering/cost tradeoff thing. At least the Vag-Com will provide a lot more value in the long run.

And another general comment on the economy of this car, I got my wife to agree to drive this car on the grounds of economy but when you factor in the cost of "VW’s" maintenance I'm not sure that's true. Think about it… at the 60,000 mile point, if the average cost of fuel was $2.50 per gallon (on average) there is only about a $1,700 savings over a gas car getting 30 miles per gallon over this TDI assuming it has averaged 45 miles per gallon. Now balance that against the cost factors of the pending timing belt change, this potential repair/troubleshooting cost and the amount of time it takes to keep up with all of the other little problems that need attention on this model. Sometimes this is a "hard to love" car.
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
>>Now balance that against the cost factors of the pending timing belt change<<

Well... your car needs a TB replacement at 80,000 miles... if you use the updated (2003) parts, you should be good for 100,000 miles after that... show me another car in its class that would not need some type of similar maintenance for that kind of milage??

Yuri.
 

EZ_Fixes_Only

Active member
Joined
Sep 2, 2001
Location
Tuxedo, NY
TDI
Jetta, 2002, Silver
My 94 Chevy truck with a 350 CID engine was in my mind when I said that...only fluids, filters and a few sets of ignition components (plugs, wires, Dist. cap etc. (all inexpensive)) and still going strong with over 150,000 miles on it and zero failures. But I can't offer that up in an economy argument because it only gets 17 miles per gallon. I think GM designed my truck to be inexpensive to maintained by the owner. I think VW designs it vehicles with a different mindset and the trans. fluid check procdure is a good example of that (so in the timing belt for that matter). However, you said "...show me another car in it class that can beat it..." and to tell you the truth I don't know of one so you made a good point.
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
>>I think GM designed my truck to be inexpensive to maintained by the owner.<<

I believe that was also the philosophy behind the Ford Model "T"...

Yuri.
 

frugality

Top Post Dawg
Joined
Sep 19, 2003
Location
Spring Lake, Michigan
TDI
none, 2016 GTI
And the original VW Beetle. I had a 1973 that I made into a Baja Bug. Anyone else who's worked on the old air-cooled VeeDubs has got to know the book, "How To Keep Your Volkswagen Alive: A Manual of Step by Step Procedures For The Compleat Idiot". Such a simple car to work on. No VAG-COM necessary. (heck, there was only one electrical wire going to the engine!) No fancy-schmancy timing belt tools. No intake clogging. No emissions requirements.
I miss that car......except for the 'no heat'....
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
That book was a lifesaver !!!!!! I still have many of the tools I bought back then... they were affordable at that time... (When I went to Wingnut's place a couple of months back, he was impressed that I had a Snap-On triple-square wrench for the CV joints... Back then I paid something like C$2.50 for it...)

Do you remember the part where John Muir told us how to adjust timing for those engines that required it to be set dynamically with a strobe? Go to the dealer and get it done, come home, get out a file and make another notch on the harmonic balancer pulley... then you could always set it to the same place with a 12 cent timing light... Priceless !!!!

Given the added complexity of the newer cars, this website is today's equivalent of that book - and it's interactive!!!

Cheers (from the distant past...)

Yuri.
 
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EZ_Fixes_Only

Active member
Joined
Sep 2, 2001
Location
Tuxedo, NY
TDI
Jetta, 2002, Silver
Back to the original point... The trans. oil was about 16 oz low but the leak seems to have stopped. Plan going forward is to check the final drive often and if the problem happens again and/or verify the source using UV dye. It was the hottest week of the year when the problem occured (100 degrees F). I wonder if that could have been a factor?
 
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