Friction modifier question

many oil manufactures make gear oil that they say is specifically formulated for LSD's. Do I still need to use friction modifier If I use let's say Mobile 1 LS? Can I use LS product in my front dif and transfer case? I live in the mountains and our only auto zone has very limited selection,the only mobile one gear oil they have is the LS one. They also only had 5 quarts in stock in the entire store!!

 

I don't think you have limited slips in anything in your truck. You can use it without any problems if it has the modifier in it. The problem is if you have a limited slip differential and you don't use it.
You should be fine with that gear oil.

Others should chime in shortly.

 

I believe I do have LSD. My truck is 07 TRD Sport which I thought had them

 

05-08 trd sports and some higher model SR5 models had lsd diffs from factory.

Anything newer it was electronic lsd

So yea you do need to use oil with the additive to not have any problems

 

Is oil with additive (like Mobile 1 LS) good enough on its own or should I still add a bottle of friction modifier to it just to be safe?

 

That’s what I’ve always added to my truck (mobil 1 with the lsd additive) and it’s been fine.

 

Are you talking about Mobile 1 LS or regular Mobile 1 and separate additive?

 

It was the same way at Advance, which is why I had to use their CarQuest brand. I guess hardly anyone buys gear oil?

 

They didn't have enough to do a complete dif oil change on one vehicle lol

 

Or is Mobile 1 LS the only gear oil Mobile 1 makes??

 

Yes you should still add the little bottle of modifier in the rear end, when done find a parking lot and do 6 or 8 figure eights to work the modifier into the clutches.

Yes you can use ls oil in the front and t'case without a problem.

 

Exactly the answer I was looking for! Also I've been reading that I shouldn't use synthetic with lsd differential?

 

Prioritize, do rear first then front cause it's a bitch to do, then the t'case.
Remember to remove the fill plug before the drain plug, cause if you drain and can't fill your screwed.

 

Old school says dino is better, but it really doesn't matter.

 

I laughed and walked out without buying anything, gonna order it on Amazon, just have to make up my mind on the brand.

 

I was reading this article today where they tested about 10 different brands of gear oil and apparently Amsoil Severe Gear outperformed other brands by far while RP and Red Line didn't do that great, Mobile 1 LS took 2nd behind Amsoil. Perhaps bunch of bs sponsored by Amsoil?

 

http://goodsenseoil.com/G2457-GearOilWhitePaper.pdf

 

I also have an 07 with the LSD rear, currently at 82,500 miles. I've changed the gear oil in the rear diff several times, I have had good results with any 80w-90 gl4 or gl5 gear oil and a bottle of Champion LSD additive. I got the champion additive at my local O'reilly store, its pretty high on Amazon for whatever reason, I think I paid like $8. One time I used synthetic Lucas 75w90 which states on the bottle that it is for LSD rear ends...my rear diff chattered terrible with it, I drained it and went back to a cheap non synthetic 80w90 and a bottle of the aforementioned LSD additive, no issues with any non synthetic brand of gear oil i've used in the rear differential. For whatever its worth ECGS suggests that you should use non synthetic Lucas 85w140, or 80w90 for extreme cold, also see here.
I have just been using whatever synthetic 75w90 oil is available for the front diff and transfer case. Any LSD additive should work for the rear end. I have one more bottle of the champion additive and a tube of this sitting on the shelf for later, I haven't tried the Trans-x yet, but I think it should be fine. Ford also has a LSD additive that I wouldn't hesitate to run.

Keep in mind that ECGS is well known on this forum and others, they build, sell and warranty units for these trucks and many other applications every day... Lucas non synthetic is what they want you to run for their warranty purposes. With that said, any fresh, proper grade of gear oil is better than nasty worn out oil with loads of wear metals in it, in my opinion.
Lucas 85w140 gallon
Lucas 85w140 quart
Lucas 80w90 gallon
Lucas 80w90 quart

 

Found my receipt, I bought 3 of the Champion Lsd additive at O'reilly in February of 2012 for $7.19 each.