'02 4 Matic Transfer Case Leak...
 

Please help with an '02 E320 wagon (72K miles); the trasfer case is dripping fluid.

Dealer says case needs to be replaced as an assembly (mega $). Some of these cases were apparently replaced under warranty for "sweating?" Not on this car, though.

Leak is coming from rear face of case; I would guess from rear prop shaft seal, but not sure. Dealer says case is "sealed", and cannot be drained or filled.

So, is it possible to replace seal(s?), refill, and be OK?

The output shaft seal is apparently available from MB (according to a parts supplier).

Is the fluid ATF? Does the transfer case have to be removed from the trans to resaeal/refill?

Many thanks,

john

The case is easily resealed. The input and output seals are available and the case can be split in two and resealed. I do not remember but one of the seals requires the case to be split and the other can be done like a standard pinion seal. This is not rocket science by any means and requires no real special tools.

Good luck.

Thanks!
 

Is there a fill port or fluid capacity spec?

Is the fluid ATF?

To start with the transfer case is NOT sealed & fluid should be changed! uses synthetic ATF.

Second, almost any part of the transfer case can be purchased from MB including the $5 seal at the rear driveshaft.

IF they can't OR won't make a that repair....run from them!

Homework Results...
 

Thank you, MB Doc

I searched the forum, found EPC net, and looked up the transfer case diagram. I found the output seal (and companion flange lock nut):

A2109970646 seal ring

A2109900151 nut

I also see that there is what looks like a fill plug (believe upper LHS of front case half). Wish I could figure out how to cut and paste the diagram here.

Could not find a drain plug or an input seal.

Assuming no input seal on the E320, can the output seal be serviced without removing the transfer case from the trans? Assume siphon out existing lube (MB syn ATF, per your note), and refill - all via fill plug. Assume correct level is fill plug opening?

(Believe there might be a seal on on the ML as there seems to be an intermediate case between trans and transfer case on those models).

I am pretty familiar with porsche, audi, and BMW, but have no experience with mercedes. The EPC is pretty cool, and parts prices (via this forum site) seem reasonable, based upon what I've looked up so far.

I also saw work shop manual sticky on forum, and will order shop manuals. Assume this is the best way to go for shop manual access? I ask because the EPC link seem like it has workshop manuals online (for a subscription fee?), but I can't figure out how to sign up.

See you're in GA; wish you were closer. I'm in coastal NC.

john

Thanks Whipple, and Why was this post moved?
 

Whipple - thank you also!

Why was this post moved to ML et al, when the 4Matic I'm working on is an E320 wagon?

And people wonder why dealers have such a bad name... what a disgrace.

hisport- there should be two identical plugs- one up higher then the other for filling, while the other one is for draining.

wow dealer cant replace some seals.....

guess the techs is too lazy or the dealer wants to take you for a ride

Great!! Drain plug question.
 

Many, many thanks, everyone.

I found the fill plug, but can't find the drain, either physically, or in parts schematic. Is it tough to find?

Next one I'm under I'll take a look and see if I cant locate it for you. Is there a counterweight on it anywhere? Remove it and check behind it if there is.

Thanks, Johnhef
 

No counterweight that I can see.

I will clean and carefully examine.

Appreciate your help.

The W210 transfer case is different from the one on the M class, although they both use ATF.

There is NO drain lug on the W210 transfer case but a filler plug that is hidden behind a vibration damper (the counter weight referenced here). The damper is hard to remove (top nut).

The most probable cause of leak is between the transfer case and the transmission. There is no gasket in between.

Dealer will only do two things

1) gladly replace the whole transfer case at over $6k.
2) reluctantly reseal the transfer case for about $1k.

I bet the leak is very small. So just add some ATF once a yer or every two years.

The capacity is about 1 liter but Mercedes quote different capacity in Owners Manual, WIS, etc. You fill until fluid comes out of the filler plug (allen).

There should be a thread on benzworld by me and OliverK on this.

Your vibration absorber (counter weight) is missing. It is most probably that someone has done some work in that area and decided not to put it back on (the top nut is tough). The part number is 210 281 00 47. The filler plug is behind this.

Thanks, Bo
 

Appreciate the specfic advice.

Assume resealing the t'case split means disassembly and using something like the M-B black sealant between the case halves.

- I found the output seal; is there an input seal as well?

- I will look in the EPC parts list for the vibration damper. Assume this is a counterweight of some sort

bests

john

John:

The sealant listed is Omnifit FD 3041 sealant (50 ml), part number 002 989 47 20 10.

This might be terminologies but here is how I understand it.

The "input" is really the mating between the transmission and the transfer case. The T case in installed dry onto the transmission. ATF is then filed until it runs out from the filler plug.

Then there are two "outputs", one to the front and one to the rear. There should be seals for both.

From what I have communicated with other 4Matic members, you leak is most likely NOT from any of these seals but from where the T case mates with the transmission. If you examine really carefully, you should see wetness only below any of theses output shafts or seals.

The bad news is that you have to remove the T case for any work on it.

That would be my guess (might be an uneducated one).