Taking the EXpd in next week for 4.10 gears. Going to have East Coast Gear Supply, supply parts and do the job, lots of great reviews. One thing I am a little concerned about is they use Lucas non synthetic 85-140 lube in all axles. I may switch back to synthetic and 75-90 front after break in.
Does anyone use lucas gear lubes, and any reviews good or bad?

 

I've heard good things about lucas oil products but our axles are made for 75-140 synthetic in the 9.75 rear and i wouldent use anything else, paticulary for break in. I just did my gears and i went with mobil 1 for break in and the change after the first 500 miles. It is expensive but there is a reason ford recomends that specific oil. (with the cost of gears i wouldnt chance it) Just buy your own oil and leave it in the truck for them to use when they do the install.

 

I used it before I changed my rear end to trac loc. The different I took out looked brand new so I think it works good 75w140 synthetic. I'm using Valvoline synthetic next.

 

Differential*

 

u used the synthetic 75w140 before you track lock or the lucas?

 

I used the synthetic Lucas.

 

I would prefer going synthetic from the get go, currently running Red Line, but they are doing teh install and warranty. Warranty is 5 years on parts and labor, so they must know their stuff. I will probably go to Red Line at 500 mile change.

 

Use the gear lube recommended by the gear manufacturer.

 

I just bought 75w140 full synthetic Valvoline and equal torque modifier from Napa for my limited slip.