Does SynPower have LSD additive?

[exranger06]

Does the Valvoline SynPower already have a LSD additive in it for my Trac-Lock? It says on the bottle that it can be used in conventional and LS diffs but it doesn't mention if it actually has an additive. Also, should I go with 75w-90 or 75w-140 for rear diff? My Ranger is usually either empty or has a light load in it, and the very occasional 1300 lb load of top soil in the bed. I don't think the 140 is really necessary, especially since it's spec'ed for a 90 and I would like the increase in MPG, even if it's a negligible amount. But I would like to hear other's opinions. I'll definitely be going with the 90 in the front since I hardly use 4wd.

 

[Chris71]

I would go with the 75w-90 and add the additive. All the G-5 gear oils say that you don't need the additive but trust me you usually do. I have an Auburn unit in my Dakota and I have to run 80w-90 mineral-based oil and GM or Ford additive.

 

[Colt45ws]

Originally Posted By: Chris71
I would go with the 75w-90 and add the additive. All the G-5 gear oils say that you don't need the additive but trust me you usually do. I have an Auburn unit in my Dakota and I have to run 80w-90 mineral-based oil and GM or Ford additive.

I installed Amsoil Severe Gear 75W140 in a '04 Dodge Ram 1500 with factory t-lok. I bought the Amsoil additive, but didnt install it to see if it was needed. Never heard a peep from it.
You could also look for a 75w110 for your Ranger. The 110 spec is the top half of the old 90 spec.

 

[anti-chatter1]

I would stay with the FORD LSD additive for chatter prevention if needed after a gear oil drain and refill.

 

[wgtoys]

Some time ago I helped a friend change out the axle fluid on his Grand Marquis (and fix a leak at the same time). We refilled with Royal Purple which said it had the LSD additive built in and the car runs as quietly as you could hope for.

 

[Colt45ws]

Did it have an LSD?

 

[Ken2]

If the label says that the gear oil is suitable for limited slip differentials, then it already contains the LS friction modifying additive.

Refill with this gear oil and drive slow figure-8s for several turns. This works the new gear oil into the differential clutches. If the differential remains smooth, great. If not, add a half-tube of additive at a time and drive more slow figure-8s until it is smooth. More additive is not better. Just enough is just right.

Of course, limited slip without clutches and locking differentials do not need the LS additive...it is only for the clutches.