sounds easy enough

 

wouldn't you fill each diff/case till the oil runs out fo the fill bolt?

 

Sure. Isn't that the way it's supposed to be filled? It' also close to spec, however I didn't measure the exact amount.

 

I drained each carrier and then placed the drained fluid into a 1 quart bottle and noticed the rear was around 1.1 qt from the rear carrier and about 0.9 from the front carrier, case was around 0.8qt. I believe factory spec is 1.1 and 0.9 for transfer case. So i tried to stay close to factory spec.

 

A suggestion from lessons leaned on old Porsches

One may wish to remove the filler plug before draining the oil. Sometimes (particularly if one off-roads or drives in snow/salt zones) the filler plug refuses to budge. If one has already drained the diff oil, one is truly "up the creek".

Don't ask how I know this!

johnt

 

One may wish to remove the filler plug before draining the oil. Sometimes (particularly if one off-roads or drives in snow/salt zones) the filler plug refuses to budge. If one has already drained the diff oil, one is truly "up the creek".

Don't ask how I know this!

johnt

Great advice

 

Thanks for the picture writeup! Nice n easy thanks to you. This should save some of us some bucks and most importantly to get a head start on some preventive maintenance.

 

aaks38 thanks for the how to. A sensor in my stepper motor has gone bad, and therefore my entire stepper motor needs replaced. Will i need to drain the transfer case to perform this repair? Despite this being a common problem with Tregs, i haven't found any DYI's on the forums.

 

No simple job

 

Thanks for the write up! How often should this be done? My 2004 has 58k miles and just bought about a month ago. Was thinking of doing this to be safe.

 

.....I used Mobil 1 75w90 gear lube and Red line D4 synthetic ATF although the Mobile 1 synthetic ATF is also VW compliant..

Did you use one type for one diff and the other type for the other, or did you mix the Mobil 1 and Redline? I'm only curious.

 

I used the redline because i had 1 quart leftover and just wanted to use it up. There are many, mostly in the racing world, that swear by redline and prefer it over mobil, so its not a bad choice but usually only available at hi perf shops. The Mobil Synthetic is available at any auto store. You can not mix and match the transfer case and differential oils, they are different weights.

 

I find an 8mm metric hex bit a closer fit. If the o-ring goes bad I'd just replace the o-ring. I'm not sure the logic behind VW's new bolt each time while they use oil filter inserts for environmental reasons among others. A new bolt each time is a waste of natural resources.

9 Piece 3/8" and 1/2" Drive Metric Hex Bit Socket Set

I used VW fluids last time, but next time I'm thinking of using Valvoline synthetic gear oil and Mobil-1 synthetic ATF for the transfer case. The Valvoline gear oil met the latest, more stringent MIL-PRF-2105E which is folded with MT-1 into SAE J2360. Both are supposedly far above the plain GL-5. (see url below) Mobil-1, which I respect and will use for the transfer case (and engine oil 0W-40), met only GL-5 that I know of.

API GL-5 Clearing up the confusion - Automotive Gear Oil Additives - Driveline Additives - The Lubrizol Corporation

 

I switched my diffs and transfer to Amsoil. Amsoil ATF in the transfer case and 75/90 (GLI 5) Amsoil in the diffs. It has made a noticable difference as there is less parasitic drag, and is now more responsive from idle.

 

has anyone tried friction modifiers in the Xfer case? are there any slip clutches in there?

what about the diffs? any slip surfaces, or are they open?

the product I use will render any slip surfaces useless (like Limited Slip Diff).

thanks

 

Even though I mentioned Redline in post #15 last summer, I too elected to go with Amsoil just a few weeks ago. I'm now running 100% Amsoil on the T-Reg. Engine and all driveline including tranny. Curious to see how this pans out in the long term, as I plan to keep the beast a very long time. Well, at least as long as gas prices stay sane going into this new decade, and onto the next one.

 

......however they also only offered that exceptional performance for about 1000 miles and then it dropped off.

Not sure I understood that part. Say again?

 

Giving the benefit of the doubt to your friends claim, a 10mpg decrease would mean some serious FRICTION issues caused by an x brand of oil, which makes no sense at all when you add things up proportionally. That engine would be toast soon enough if mileage dropped by that much due to severe parasite drag caused by bad quality oil.

Oil that is too thick in weight for a given application on the other hand, will in fact reduce fuel consumption. Even then, a 10mpg decrease would be unheard of.

 

Giving the benefit of the doubt to your friends claim, a 10mpg decrease would mean some serious FRICTION issues caused by an x brand of oil, which makes no sense at all when you add things up proportionally. That engine would be toast soon enough if mileage dropped by that much due to severe parasite drag caused by bad quality oil.

Oil that is too thick in weight for a given application on the other hand, will in fact reduce fuel consumption. Even then, a 10mpg decrease would be unheard of.

Agreed...something else went wrong.

 

I need to get this done on my 05 V8 with 78K miles. I suspect it may not have ever been done.

I am however confused on what oils to use for the diffs and transfer case. I went to amsoil.com, punched in my treg details and it listed the following:

Differential, Rear W/O Locking Diff......GLS [3]
All TEMPS......
No AMSOIL Product Recommendation
Differential, Front......GL-4
All TEMPS......75W-90 [4] [5]
Synthetic Manual Transmission and Transaxle Gear Lube (75W-90) API GL-4 (MTGQT)
Differential, Rear W/ Locking Diff......GLS [6]
All TEMPS......
No AMSOIL Product Recommendation
Transfer Case,......AE [7]
Synthetic Multi-Vehicle Automatic Transmission Fluid (ATFQT)

So as you can see above, there is no recommended Amsoil oil for the rear diff.

I am looking for Synthetic oil types I can use for both diffs and transfer case that meets or exceeds VW specs that I can pick up and a regular parts store.

Any help with this info would be appreciated.

 

Look it up under a 2004, which is what I did for my 06 V10. Amsoil is kinda spotty on product recommendations for the touareg. 2004 is the most complete

I used the 75/90 GLI 5 for the diffs, and ATF for the transfer case

I need to get this done on my 05 V8 with 78K miles. I suspect it may not have ever been done.

I am however confused on what oils to use for the diffs and transfer case. I went to amsoil.com, punched in my treg details and it listed the following:

Differential, Rear W/O Locking Diff......GLS [3]
All TEMPS......
No AMSOIL Product Recommendation
Differential, Front......GL-4
All TEMPS......75W-90 [4] [5]
Synthetic Manual Transmission and Transaxle Gear Lube (75W-90) API GL-4 (MTGQT)
Differential, Rear W/ Locking Diff......GLS [6]
All TEMPS......
No AMSOIL Product Recommendation
Transfer Case,......AE [7]
Synthetic Multi-Vehicle Automatic Transmission Fluid (ATFQT)

So as you can see above, there is no recommended Amsoil oil for the rear diff.

I am looking for Synthetic oil types I can use for both diffs and transfer case that meets or exceeds VW specs that I can pick up and a regular parts store.

Any help with this info would be appreciated.

 

I should have read this post more carefully. I just changed the fluid in my front diff and used the GL-4 spec Amsoil fluid. Hopefully no damage will be done and I'll change it out this weekend.

On another note the factory fill fluid was pretty dark. I sent out a sample to Blackstone labs for analysis. I would have sent a sample of the transfer case fluid also but I somehow managed to knock over the full sample bottle creating quite a mess. It would have been a pretty neat job had I not done that.

FYI the drain plugs on the front and rear diffs are the same for those interested in changing them. The part number is 0AA-409-057. The plugs on the transfer case are of a different design and do not have an O ring like the diff plugs.

 

Did my front & rear diff oil change today. Piece of cake. I used a 8mm allen key instead .
Refiled the diffs with synthetic 75W90 royal purple at $18 / quart.

 

Am I reading this thread correctly to understand that people are putting ATF into the center differential/ transfer case - and gear oil into the front/rear diffs?

I thought the transfer case (A.K.A. "ceneter differential") is to be filled with gear oil - the same oil in the front and rear diff's. ATF goes into the Transmission?!?

Any thoughts?

 

I thought the transfer case (A.K.A. "ceneter differential") is to be filled with gear oil - the same oil in the front and rear diff's. ATF goes into the Transmission?!?

Any thoughts?

Transfer case calls for Synthetic ATF according to Amsoil website. I have a Dodge truck that also runs ATF in the transfer case. My understanding as to why they do this is so that if the seal between the transmission and transfer case breaks you don't have gear oil in the transmission which can ruin it. Both run ATF so if a seal breaks no cross contamination. I've been running Amsoil ATF in the transfer case of my Touareg for around 5K miles with no problems.

AMSOIL Product Recommendations - 2004%7cVOLKSWAGEN%7cTOUAREG%7cU

 

Just came from the dealer... tried to sell me atf for the center diff - instead I gave him my vin and had him pull up the screenshot of the transfet case. It listed "Oil"!

It was not ATF nor was it the 75w90 listed for the front and rear diff's. It seems its a special "ATF" of sorts formulated to work with the haldex clutch found in our transfer case. I mentioned the cross contamination/ same fluid and it turns out it is not the same fluid.

I will check amsoils recommendation for both the atf and transfer case. Also, I am unable to find amsoil in my area - big box stores stopped carrying it and specialty stores dont have it either

I will put in RP 75w90 front and rear and stealership oil in the center diff - $30/.85L!

BTW: RP gear oil bottle says NOT FOR USE IN WET CLUTCH SYSTEMS, this is why transfer case requires ATF.

 

So far so good with the Amsoil in the transfer case - $8.29.

 

$30 from the stealership. The quality of this fluid vs. Others is for another discussion. Dealer lists different fluid for both tranny and transfer case. IMO not the place to save $10.

 

Did this job earlier today, and the instructions from p. 1 of the thread were pretty spot-on.

Chalk it up to good insurance on a vehicle I plan to keep for a few 100k mi. Mine has about 52k now, and I wasn't expecting the fluid to be spent. But I also didn't want to push it upwards of 100k mi...

The transfer case fluid was brownish, but the plugs were clean. On my T2, the threads are coated with a nylon-like substance, presumably to keep them from vibrating loose. (That may explain why VW expects them to be replaced during a fluid change.) Mine weren't too hard to get out with little/no loss of the thread coating.

The rear diff. fluid was darker, and I found a very thin film of metal 'powder' on the lower plug. A medium-sized breaker bar was needed to loosen both plugs, but the o-rings on them looked very pliable and relatively undeformed. So I felt OK not replacing them this time around. But they probably should get replaced (along with the TC plugs) when I plan to do this again at 100 k mi.

The front diff. went pretty much the same, except that access was a little tougher. I used a wrench on my 8 mm hex driver for the fill plug, with a deep-dish socket and extension slid over the end as a MacGyver'ed breaker bar. Both plugs had a dark film on them, but none of the metal powder that lightly coated the rear diff.'s drain plug.

Oh, and I used the OEM fluid from the dealer. As others have said, this isn't the best place to save a few bucks. And I still walked away from the job saving about $400 in labor. :mrgreen:

Chris

PS--If anyone's interested, I did take some cell-phone pics during the job. Mainly this was to document it for myself (and any downstream claims). But if anyone wants to see some, just let me know.

 

I'd like to see the pics. I'm going to change differentials and transfer fluid in the next month. Thanks for the offer.

 

+1. I would stick with the OEM fluids for the transfer case and differential. The more I read the more I agree these are not the places to save a few dollars. I stuck with OEM brake pads (but use aftermarket rotors) and now I will too these fluids.

The front differential looks typical and has a small case, therefore a non-LS gear oil may suffice. However, the rear differential is probably not. I believe the VW gear oil has 4% friction modifier, but aftermarket gear oils will not have that much. I wonder if for the long haul aftermrket gear oils may result in excessive wear in the rear differential.

 

I am going to change these fluids in the next month. Your recommendation from the above quote is to purchase the fluids for the differentials and the transfer case from VW correct? I do have an AMSOIL dealer in my area.

 

SamT, I sent you a question in this thread about drivetrain fluids discussion here: http://www.clubtouareg.com/forums/f92/the-gas-engine-and-drivetrain-fluids-discussion-73900.html