spec: W210 1999 E300TD turbodiesel 150k miles

question: does it have limited slip differential ?

it's a RWD rear wheel drive, did not have it in the winter, so I don't know.
my guess , no LSD

as such, like to replace , the black oil from the diff,
85-90 synthetic diff oil, some Moly grease to it, and some lucas oil stabilizer.

notes: Moly is slippery stuff, more then PTFE Teflon,
the engine stuff is to small/fine for a diff

reason: improve MPG, extend MTBF,
side benefits, quieter, more power to the rear wheel, lower oil temp
reduce HP loss in diff,...

probably should check diff temp with a infrared laser, before and after,...

as of now, don't think I have LSD (limited slip) differential,
so , should be ok, to add the moly gear lube to it.
what do you think?

 

update:

did change the oil on the diff, used 75W90 synthetic, lubro moly,
2 bottles, needed 1 1/2, they come with a pull out neck, what is nice,
otherwise you'd need a tube.
also put in the little tube, moly for gears.

the old oil was black, had a smell, but not rancid yet.

did notice, had some moist dirty oil on the cover, indicating,
a new seal be nice.

question: to take off the differential cover
how to do it, what's involved, how much time for a mechanic ?
definitly does not look like a DIY

thinking, maybe a cleaning, and adding some black heat silicone, to help

notes:
temp on the diff, is 60-63 C with laser infrared thermometer,
did not see a temp difference yet.

also noticed the axle seals, are possible worn, but to replace them,
need to pull the whole diff ?

appreciate any input

 

LSd was a special order option and not many came with it. Raise the rear tires clear of the pavement. If they counter rotate to eachother then you have open diff. Probably do anyway. Rear assembly must be pulled to change the seals. It is time intensive and better left to a specialist to do, dealer or indy, your choice.

 

thanks, no LSD,

found link https://mbworld.org/forums/e-class-w...pictorial.html
looks like a boat load of work, and $500 buck plus.

for right now, I'll take a look at using some black high temp silicone, to seal around the bottom half, do think, that they start leaking at the bolts, but don't want to goop those up, if I get a syringe, maybe around it.

the moly I put in, should be 2-5 microns, that should help with seals on the axel, at least a little bit, I mean hot oil, is 1-2 microns think under pressure
maybe tightening up the bolts a 1/4 turn be enough too.
just got the car, so I want to get 100k + out if it first, before doing major stuff.

wondered about the mechanical tail, to leave it alone,... since it's lifetime ,... yeah right,... but he said, it be noisy, and to put brass shavings in, that's what he does,
obviously not the dealer,... non the less some merit to it, anybody heard of it ?

well, the stuff I put in is like a fine paste, MOS2 withstands 200k+ psi pressure, do think
its fine, actually thinking, the varnish from the backed in old oil is probably thicker, and stickier.

note: I used 75W-90 synthetic , + moly for gears, + squirt of lucas synthetic stabilizer

did get some moly for engine,... but that was 0.5 microns, good for engines,
but figured, for those big gears in the diff be worthless, might as well use baby powder,....

another thought is, that the new oil and moly be lubricating the bearings, maybe even tightening them up a tiny bit, what would align the big gears under load, overall bring the most benefits.

last not least, on the next diff oil change, 30k,... consider a purge/flush,
but I am weary about doing damage to the side bearing seals, that be bad.
anybody ever did a seafoam purge on a diff ?

 

I just had the differential seal on my 99' E300 repaired. The dealer quoted me $800 on the job. My independent mechanic did the job for $450. Just find an honest indy and have them do it. Its just a black silicone seal.

 

what cleaner to use ? brake cleaner, might be to tough on a old seal ?

just want to clean it around, before putting silicon around, without changing the whole seal.

won't be able to get it all the way around, but bottom half, should ensure, that there is always oil in it.

down the road, once the diff is pulled, thinking the side axel seals, maybe the main bearing,..... what about , doing a purge/flush on a diff ? any benefits ?