Mineral Oil? - PeachParts Mercedes-Benz Forum

rummur · #1 12-07-2008, 01:38 AM

Ive got a 71 220d, curious if 90w mineral oil would be apropriate for the rear diff? Also any body know where to find some higher gears?

Also another quick question.. I was searching through the posts for the recommended oils for the boxes, and I read that 80-90 was bad for synchros ? Is that just MB synchros or is that for all synchros?

dkveuro · #2 12-07-2008, 02:02 AM

Quote:

Originally Posted by rummur

Ive got a 71 220d, curious if 90w mineral oil would be apropriate for the rear diff? Also any body know where to find some higher gears?

Also another quick question.. I was searching through the posts for the recommended oils for the boxes, and I read that 80-90 was bad for synchros ? Is that just MB synchros or is that for all synchros?

No...unless you want to know how long plain Mineral oil will make a diff' last.
Manufactures do not arbitrarily list oils for different components.

Diff's come in different flavors...Hypoid and spiral-gear differentials mostly although there are over-shot bevel and worm types.

Each type requires the use of a compatible oil and most LSD types ( Limited Slip Differentials.) require special oil/s.

It is the result of compatibility with the components duty and operation that the oil or grease is recommended.

Syncro's ( Syncromesh.) cones rely on friction to allow gear matching .
Changing the friction characteristics of the cones will degrade the performance of the cones ability to match the gears clusters.

IIWY I would stick to the recommended oils. Changing the Viscosity is about the only latitude allowed apart from regular or synthetic.

For instance...the Alfa and Fiat Spider cars used a special gear oil for the transmissions whereas the 1959 up Mini used engine oil because the engine and tranny where one unit with the engine sitting above the gearbox..several BMC/BLMC vehicles used engine oil in the gearbox. An Automatic is another beast altogether.
.

rummur · #3 12-07-2008, 02:13 AM

I only ask because I have a 5 gallon bucket of the stuff and dont know what to do with it..

So any idea what the manufacturer recommended?

dkveuro · #4 12-07-2008, 02:30 AM

Quote:

Originally Posted by rummur

I only ask because I have a 5 gallon bucket of the stuff and dont know what to do with it..

So any idea what the manufacturer recommended?

The recommended oil for yours is : 5 1/4 pints of EP90. ( SAE90.)
Your '71 has a Hypoid differential.

Mercedes recommended change interval for that oil was as of August 1965, 12,000 miles.

CAUTION : Some models where fitted with an LSD and should have a plate on the axle housing stating "Achtung Spezial-Ol Sperrdifferential"

These require Veedol Multigen Limited Slip Special Lubricant...although you'd need to check with Mercedes to see what is recommended nowadays.
Perhaps someone here can shed some light on this.

vox_incognita · #5 12-07-2008, 07:47 AM

MB sells BP oil nowadays(for both open and LS diffs),MB 235.7:
http://www.oel-schlenker.de/datenblaetter/Energear%20MBE.pdf
...for a regular diff any aftermarket MB 235.0 ,SAE 85w-90,or straight 90 is allright(those would be API GL-5 level hypoid oils)...mineral usually.
The dealership MB 235.10 ,used in mechanical transmissions from the 80-ies (717.4.,#7340 241-on) is Esso Gear Oil 317.
For the earlier mechanical transmissions they still list the hard to find(obsolete) ATF TASA (Mb 236.2),and the majority of benz owners use the later Dexron IID,III oils..or MTL...some use engine oils..

http://www.lados.ru/lados/lados.nsf/ires/Service-inform/$File/BB0040-P-00231-01A.pdf

Anyway,if you`ve got a standard diff and the oil in the bucket is API hypoid GL-5 (EP) SAE 90,you`re ok.

Johnhef · #6 12-07-2008, 08:39 AM

If you're looking for a different ratio for yours, I believe any 107, 114, 115, 116, 123 and 126 to 8/85 will swap.

I tried to post the pdf- file size is limited apparently. Tell us what gear you're looking for and I'll try to list what models have it.