OK I am going to be putting in some Amsoil gear lube in the diffs, my dad sells the stuff so I get it at a good price VS the royal purple. So now the questions.
1 where can I get the friction additive for the rear? Is the dealer the only place?
2 will the limited slip ability be reduced with the slicker lube or will the additive make it the same?
3 have you guys stayed with the Ford recomended weights of gone to some thing different? If you changed what are you running now?

Thanks

 

Some synth diff oils have the friction stuff in them RP I think...
Get the closest weight..or what they recomend..
Dealer or good parts place for the modifier.
I use fords synthetic for the rear...$$$$

 

If there is a local Jiffy-lube around their prices are very cheap for the equaltorque required for the rear diff of your truck. GL-5 90W-75 is what I believe is recommend. A local lube store should have it in their data base. Ford dealerships would for sure know. All you need for your truck thought is one equaltorque for the limited slip diff. Synthetic oil is best over conventual just make sure you either match the recommend weight or get as close as you can otherwise you risk jacking up your rear diff.

Hunter

 

daimon1054

Don't remember what forum but this year there have been very good discussions on this. I think SmokeyWren over on the dieselsite had a good thread on how to add friction modifier and test then repeat untill you had the right amount.

Every TorkLock clutch setup is a little different and has worn differently. Not possible with a used diff to just add and go. You could add too little or too much.

Just my opinion, the Ford synthetic is as good as ANY other brand and I never pay thier inflated $18 per quart. Unless you just want to be cool and use Amsoil or Royal Purple (and thats ok) there is nothing to be gained by switching. Won't be cooler, won't gain one ounce of HP, or any increased milage. Ford synty is spected for life of the diff unless towing heavy and fast, or water submersion.

On the other hand getting another brand for significant savings won't hurt either.

You get the rear end good and warmed up with no modifier, then make a series of slow speed hard turns, left and right full lock to lock... You are trying to get the TorkLock to engage and see if you get binding and chatter. Do some backing with turns also. You want the forward motion to be you guide on how severe the chattering is (in reverse it will always be a heavier torque chatter because the LS has mostly worn in forward use)

If the LS clutches are TOO thight you WILL know it. The idea is to add about 2 oz and test again, sneeking up on the point where there is very little chatter but just enough to let you know the clutches are holding.

Doesn't do much good to have Llimited Slip diff if there is too much additive and the diff is now Maximum Slip!

 

1. Friction Additive you can get at AutoZone, Kragan, or similar retail auto supplier.

2. Use the recommended grade/weight oil. Period.

The only minor hassle we had when putting in the synth gear oil in my rear diff was that it was cold (winter), and that makes it hard to squirt out of the bottle and into the diff. But since it's summer now, you s/b ok... and besides, if your Dad sells the stuff, he probably has or has access to one of those nice, handy-dandy pump squirters! Good luck with the project; s/b an easy job...

Daryl

 

Well Daryl he sells the 2 stroke and motorcycle oil but because he is a dealer he can get all their products so I will be crawling under doing it the old fassion was

Fredvon04 thanks for the tip!

 

Go to ford for the additive it works the best.And yes you will need it .