rear diff fluid
That's where mine is,it's faded but still readable....I put my VIN in compnine
and got a buildsheet full of info on my truck.Not sure if it's all accurate but it seems to be...
A question guys....a couple of the gear oil brands like Mobile1 have LS on the bottle.
We still have to add the friction modifier right?? Also, what's up with the 4 oz bottles of it? The book says 5oz, you guys say 7oz(which I'm going with) so 2 bottles have to be purchased? I gonna look in other stores and see if there's bigger bottles....What brand of that do you guys like best?
and got a buildsheet full of info on my truck.Not sure if it's all accurate but it seems to be...
A question guys....a couple of the gear oil brands like Mobile1 have LS on the bottle.
We still have to add the friction modifier right?? Also, what's up with the 4 oz bottles of it? The book says 5oz, you guys say 7oz(which I'm going with) so 2 bottles have to be purchased? I gonna look in other stores and see if there's bigger bottles....What brand of that do you guys like best?
Veteran
Joined: Sep 2011
Posts: 351
Likes: 0
From: Gloucester, Mass
Ty,I thought so....I was at a CAP Auto,they ONLY have the 4oz bottles(@$7.99)
2 of those and the Mobile1 seemed excessive....I asked about bigger bottles but the guy was being a Richard...(long for dick)......
Heading to A/Z in the morn,I can do both my diffs and the transfer case buying there...
Anyone like the Lucas or stay with Mobile1??
2 of those and the Mobile1 seemed excessive....I asked about bigger bottles but the guy was being a Richard...(long for dick)......
Heading to A/Z in the morn,I can do both my diffs and the transfer case buying there...
Anyone like the Lucas or stay with Mobile1??
Hall Of Fame
Joined: Jun 2005
Posts: 14,228
Likes: 19
From: Riverton, UT
Yes you need to use the friction modifier even though you are using Mobil One LS 75W-90 gear oil. Yes the friction modifier is supposed to be already in the Mobil One lubricant, however different differentials use different amounts, therefore what Mobil One puts in might not be enough. Are you going to lay the $1200 dollar wager down that it's enough, or are you going to add what you need and know that your not going to spend the $1200 dollars down when you have to rebuild the differential? Well the answer is clear to me, what about you?
The fact of the matter is, if you use a litte too much friction modifier it wont hurt, but don't add enough, well there is a $1200 dollar price tag to have it rebuilt. So that being said;
Go to Auto Zone and for $5.99 you can buy a 8oz bottle next to the 2 cycle engine oil area. You put the whole bottle in then top the differential off to about 1/4 inch under the fill hole on the differential cover with the proper lubricant, even if it is Mobil One LS Fully Synthetic. I know people at the dealers that put in 2 bottles for a total of 8oz just to make sure. Trust me, do it right and you will be happy.
Mobil One is a Poly oil base, whereas Valvoline is a hydra-cracked fully synthetic. There is a difference if you read the MSDS sheets and know basic oil foundations. A blend is a waste of time, because the synthetic oil base is contaminated with conventional oil base. Don't waste you money, do Fully Synthetic or conventional, but if you do decide on Fully Synthetic, then know the difference between them.
I missed this, what exact lubricant did you use?
The fact of the matter is, if you use a litte too much friction modifier it wont hurt, but don't add enough, well there is a $1200 dollar price tag to have it rebuilt. So that being said;
Go to Auto Zone and for $5.99 you can buy a 8oz bottle next to the 2 cycle engine oil area. You put the whole bottle in then top the differential off to about 1/4 inch under the fill hole on the differential cover with the proper lubricant, even if it is Mobil One LS Fully Synthetic. I know people at the dealers that put in 2 bottles for a total of 8oz just to make sure. Trust me, do it right and you will be happy.
Mobil One is a Poly oil base, whereas Valvoline is a hydra-cracked fully synthetic. There is a difference if you read the MSDS sheets and know basic oil foundations. A blend is a waste of time, because the synthetic oil base is contaminated with conventional oil base. Don't waste you money, do Fully Synthetic or conventional, but if you do decide on Fully Synthetic, then know the difference between them.
I used some konklin synthetic, after putting it in I noticed that it was for a Mack semi, oh well
Veteran
Joined: Sep 2011
Posts: 351
Likes: 0
From: Gloucester, Mass
Yes you need to use the friction modifier even though you are using Mobil One LS 75W-90 gear oil. Yes the friction modifier is supposed to be already in the Mobil One lubricant, however different differentials use different amounts, therefore what Mobil One puts in might not be enough. Are you going to lay the $1200 dollar wager down that it's enough, or are you going to add what you need and know that your not going to spend the $1200 dollars down when you have to rebuild the differential? Well the answer is clear to me, what about you?
I got enough for both diff's in the D, and the rear in my van....I'm never going to CAP again,tiny 4oz bottle is more than an 8oz at Autozone,huge difference in the gear oil prices too,it's worth the drive out of town ...besides the difference in prices pays for the gas....
Mobil One is a Poly oil base, whereas Valvoline is a hydra-cracked fully synthetic
Last edited by laz45; Oct 7, 2011 at 11:42 PM.
hydra... you mind explaining for me... and for the rest of us who dont know the chemical side of oils...
No, as you still have the same gears and parts as us with LSD's, you just do not actually have the LSD.
But it is for the clutch plates in the LSD's, so really no need to add it if you do not have an LSD.
But it is for the clutch plates in the LSD's, so really no need to add it if you do not have an LSD.
Record Breaker
Joined: Jun 2011
Posts: 2,387
Likes: 41
From: Bismarck, ND
Konklin, it is a severe service 75W-140 full synthetic. I looked on the back and saw it was the factory for a Mack semi.