rear diff and TC oil - repost of info
 

seems the other board that I visit has total amnesia so I am reposting here. It is a good time of year to get your oils changed. before winter sets in.Wheelspin on snow is hard on the gears, and they get hot...

HERE IS WHAT I KNOW.

Jag spec is the M2C 192A synthetic oil This is a 75W140 synthetic gear oil WITHOUT friction modifiers needed for limited slip differentials. I never went to a ford dealer but they probably have it there.
when I went to my local Jag dealer they went to get a bottle of oil and showed up with a Castrol oil called SAF XJ 75W140. The bottle had huge letters "made for BMW differentials" on it. The crooks wanted 91 dollars for a litre! The BMW dealer was half that price. I did not buy it. This stuff is a synthetic 75w140 gear oil WITH limited slip additives.
I called Castrol USA and they told me that it is a european oil and not imported into north america by Castrol. They have no compatible product in their line. They told me that it is up to the individual car companies/dealer to get the oil they need. They choked when I told them the price I was quoted.
From all that I have heard, and asked, adding limited slip additives will not be a problem in an open diff (which we have rear and TC) - (note TC has viscous coupling, which in itself is sealed and there are no friction plates in the centre diff that will come in contact with the TC oil) The fact that the Ford product does not have the additives makes it somewhat rare. It is easier to find compatible oil with the additive since it does not matter either way once you have the additives in there.
I ended up buying REDLINE 75w140 gear oil, the one with the additive, even though they sell it without. They were very confident saying they exceed the specs of the Castrol SAF-XJ, but no data on the Ford part number.
I suspect that a royal purple or Amsoil product will be fine also.
Finally.. any oil in the diff is going to be better than what most of us have found when we changed it. Seems that by 100k miles the oild is at least half missing and very sludgy.
Dont be too fussed by the oil spec... Nobody is going to give you written guarantees.
YOu can buy dealer oil for $91 a litre, or get some technically better oil for $15 or less....

RE: rear diff and TC oil - repost of info
 

Good info Bo, thanks!

RE: rear diff and TC oil - repost of info
 

In the Ford world that spec# is for 75w140 synthetic axle lube. XY75W140QL is the Ford p/n. I sell it for MSRP of $21.04/qt.

RE: rear diff and TC oil - repost of info
 

Actually I would be a little cautious with the oil you use.

STA-LUBE SYN-GO, FULL SYNTHETIC GEAR OIL (SAE 75W-140)(SL2496)

meets Jag/Ford spec M2C192A for a synthetic SAE 75W140 lubricant.

You can get it at NAPA for $44.79 for a 2 quart bottle.

Doing a chemistry experiment in your transfer case is a very expensive risk in my opinion. Since the 2 qt bottle will do the transfer case better than three times, it's only as expensive as the $15.00 stuff that might work. Why use stuff that doesn't specifically meet the spec to save no money?

Just my $.02 worth.

RE: rear diff and TC oil - repost of info
 

Diff oil is very important, or for that matter the correct oil for the job is always important. Using the wrong kid/viscosity will fry whatever it wasn't intended for! Case in point, years ago, I was working on a 69 GTO, we just put in 4.11 posi multi clutch and i left for the day with instruction to the owner to add the posi lubricant, which was only a little 5 or 12 oz bottle of fluid. The case took 4 qts of 90wt (plus the little bottle of posi oil).

Anyway, the next day the car was all done and he took it away...happy as a pig in some kids house crapping under the bed......4 months later the posi was destroyed...clutches burnt to hell......

We figured it was defective....so in goes another one, brand new. I leave again, since he doesn't need me to add oil.......

Another 4 months later and you guessed it...fried his second rear.....we were both like WTF....

So we oder a third one.....install it and as i go looking for some rags in the bottom of his tool box, i find two bottles of posi lubricant! I was like, dude, why didn't you add this to the first case??? he was like, it's just oil...doesn't matter.....Yikes!

Anyway, long story short, we added the little bottle of oil to the posi and the freaking thing never came back for a 4th! lol

OIL IS IMPORTANT

RE: rear diff and TC oil - repost of info
 

A GM 12 bolt takes more like 5.25 PINTS, not quarts.
The limited slip additive is 4 ounces. (I think it is whale oil???)
That makes up the 0.25 part of the case capacity.
That rearend should have been chattering and grabbing
all over the place long B4 it burned up the clutches. Did
ya find any stupid pills in his tool box too?

Red Line gear oil isa full synthetic gear oil and as Bo
pointed out, will be fine in the rear end.

RE: rear diff and TC oil - repost of info
 

lol...na, we were young back then and it was fun (from what i remember) pints, qts, what's the diff?? (get it diff...as in differentail....) hahahahaha....all i really remember is that thing smokin the tires all to hell!!

RE: rear diff and TC oil - repost of info
 

To the best of my knowledge, Red Line does not claim that their synthetic gear lube meets the Jag/Ford spec. I believe that if you write to them they will extol its virtues, but they will not say it meets the spec for the transfer case.

As I said, since there is no reason not to use the lube specified, I'd stick to what is called for. Of course, you are free to do to your car what you want.

RE: rear diff and TC oil - repost of info
 

Red line did claim to meet the SAF-XJ spec, which is an improvement on the ford stuff... the dealer was using it, and was selling it for 91 bucks a litres.

I think it is a low risk decision to use redline oil, their reputation is good. Keep in mind the Jag has no LS clutches..

RE: rear diff and TC oil - repost of info
 

Are we talking about Red line beer?

RE: rear diff and TC oil - repost of info
 

NOOOOO nonono!!! Don't drink red beer!!!
[:'(][sm=smiley11.gif]

RE: rear diff and TC oil - repost of info
 

Ah..now that's the best tip ever! thanks!

RE: rear diff and TC oil - repost of info
 

Does anybody know if amsoil makes a tcase and diff oil that meets jag specs?

RE: rear diff and TC oil - repost of info
 

AMSOIL tech sheet. Look on page two... they reference the ford spec

Bump