Can Mobil shc 634 be used as 4x4 diff lube? Torsen

Status
Not open for further replies.
F

Fraser

Joined
Jan 10, 2014
Messages
6
Location
Canada
Hello everyone,
I ended up with 5gal of Mobil shc 634, im wondering what the gear lube gurus have to say about running this pretty much straight 140wt synthetic gear lube in a Dana straight axle?
I know it CAN be done because its currently driving around in a friends stock jeep axles (clutch LSD rear, open front) with no problems.
Just don't know if it should be done.

I have installed 4.11 gears and a pair of Torsen differentials (truetrac) in my axles and would like some feedback before/if I try this free stuff out.

One thing to mention is that my gear lube gets changed at least once a month, every time I'm underwater so I go through the stuff pretty quick, only reason I'm asking about a big pail of expensive but free to me not quite right oil

Thanks!
 
There may be seal compatibility issues, according to the MSDS.

I wouldn't use it. What axle, 30, 44, 60?

I typically use Supertech 80W90 or 75W90 in the axles I build.
 
Have not noticed any seal problems yet, in anything that gets beat on the track I have had great luck with swepco gear lubes..mostly in vw's. The Jeep (xj) gets usually whatever 80w90 Dino is on sale, actually every lube in the Jeep is on sale special but I change the fluids so frequently that it's really the only way to afford it..the 634 is currently in a 30 and a 44, I have a pair of 30's one 8.25 and a 35 I could dump it into as well
 
The stuff is pretty thick, can anyone comment on what problems if any you could have from running a straight 140wt? other than some mpg loss or possible torque bias changes in the Torsen diff? Thanks
 
The spec sheet actually looks pretty good for cold performance (it's used in ski lift lubrication, according to the data sheet) but is still somewhat thick.

I don't foresee any issues with a Trutrac, but you may feel the parasitic drag. I think in Canada in winter, you'd be better off with another lubricant.
 
Originally Posted By: Zaedock
I think in Canada in winter, you'd be better off with another lubricant.

Within reason, it depends where. If he's right on the west coast, the viscosity issue won't be nearly the deal it would be just about anywhere else. Don't tell the Vancouverites I said that, though. They like to delude themselves into thinking they have a winter.
wink.gif
 
I'm about as close as your going to get to Vancouver, and yes many ppl here think an inch of slush and 0* is winter, I spent a few years living in the okanagan And that was a little different story but I would not worry 2 much about cold weather performance around my current neck of the woods.

I really opened up a can of worms with this oil research business, so much to read, something new to keep me up thinking all night lol..

ANYHOW one thing I did want to clear up is the EP additive end of things..
I can't find anything to let me know if this oil can be used in a hypoid Setup, it looks like even the synthetic gear lubes are not all ep rated.. Or if ep is even really required?


It looks like the oil would work ok just so long as it does not kill ring and pinions.
[censored] for all this time I could have bought a lot of the right oil but I just need to know now!

Thanks again
 
Quote:
ANYHOW one thing I did want to clear up is the EP additive end of things..
I can't find anything to let me know if this oil can be used in a hypoid Setup, it looks like even the synthetic gear lubes are not all ep rated.. Or if ep is even really required?


In any hypoid differential you need an oil with high film strength supported by EP additives.

No where in the SHC literature did I find that it contained an Extreme Pressure (EP) additive. It undoubtedly contains an Anti-Wear (AW) additive, but until I had a written statement from Mobil that it supports hypoid differentials, I would not use it in any differential.
 
Last edited:
Hi,
Fraser - I've used GL5 EP rated synthetic gear lubricants (75W-90) from Mobil & Castrol for many millions of kms. All trouble free I may add, and they lowered the operating temperatures by about >20C and offered unsurpassed operation when too
 
Status
Not open for further replies.

Similar threads

N
  • Locked
2013 F150 Transfer Case and Front Axle Lube
Replies
15
Views
45K
cb_13
F
  • Locked
Lube Recommendations for 2002 Tacoma 4x4
Replies
5
Views
3K
Fred4
K
  • Locked
Mobil SHC 632 / ISO VG 320 Use Question
Replies
1
Views
9K
tom slick
C
  • Locked
Need advice on which lubes to use 69 Chevy 4X4
Replies
1
Views
2K
Chris142
S
  • Locked
mobil gear lube
Replies
8
Views
5K
heyjay
Back
Top Bottom