best diff lube?

Replacing rear diff oil on Tuesday, best one to use? Dino or synth? I hear synthetic will cause leaks. Any experience?

 

you have the LSD right???

 

lucas is the best way to go

 

No its a base prerunner.

 

I use lucas upper cylinder lubricant. Love that stuff. Ill check it out.

 

I'd be looking at Amsoil Severe Gear 75W90.

$30 Mobil 1 75W90 Mobil 1 104361 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

Mobil 1 75W90 is easy to find and reasonably priced, as is Valvoline SynGear. Royal Purple got too big for their britches(man, my mom used to say that when I was a kid) in the last 5 years and their pricing is out of control, esp. their gear oil.

 

Thanks. I think I'll try the ams.

 

Jut sayin...I sell amsoil and use lucas

 

*update* I ended up using Royal Purple. Manual called for 1.6 in the rear and 2.7 in the gear box. Little did i know it would take 3 in the rear, and 3 and a half in the gearbox. i had to use a quart of a different brand of high performance synthetic cause i ran out of RP. Hope they are compatible.

 

I'm guessing you mis-read the manual... The 8.4" rear diff should take about 3 quarts. The 1.6 quart number I believe is for the transfer case amount for the 4wd models.

Out of all the brands, you do realize you paid a premium for purple oil, right? Royal Purple is decent enough oil but it isn't anything special other than the color.

 

Truff

 

I am moving to the extreme cold and needed to switch to a synthetic. I wanted to use Redline, because my gearbox was getting a little crunchy and i hear good things. but the part wholesaler my dads buddies shop used didn't carry it. they had castrol, mobil or purple. Chose purple. I figured i would give it a go. I will change it again soon to Redline after about ten thousand miles. I wanted to see if royal purples claim to "Smoother Shifting" was true. and i did notice a difference. But i still wanna use redline.

 

What are you considering 'extreme cold' and why does that warrant a 'need' to switch to synthetic?? Dino oils have been around for a long time and there have been vehicles in those 'extreme cold' environments running on dino oils for a long time also. If you truely are going to put the truck into an extreme cold environment, a change in oil weight would help more than the switch from dino to synthetic.

If things are messed up in your gear box and you are getting 'crunchy' sounds, no oil is going to magically fix your gear box. Did you have metal shavings in the oil when you drained the transmission?

Redline makes some good stuff. Out of the options at your dad's buddy's shop, I would have gone with the Mobil.

 

No metal shavings. the synchro's just don't like 1st thorough 3rd for some reason. when i said crunchy i didn't mean sound wise. i meant feel. Since i changed the fluid it feels easier to slip into gears. I use synthetic everything. where i am going is only very cold a few months of the year. Not sure how cold it will get because ive never been there. (going to school) 8,500 Elevation.

 

I buy my lubricants on API spec...and a non-lsd rear end should be a API GL-5...and should be available in the five gallon bucket at your local FLAP for under $75.

I keep a bucket on hand and go through about two a year.

I maintain three trucks, a jeep and 8 motorcycles...


Howard

 

I heard lucas does the job quite well.

 

Damn, you're lucky everything takes the same oil. I maintain 2 vehicles and a motorcycle and the oils don't overlap at all

 

Mobil 1 ftw.... This is a completely subjective topic though, honestly, the fact that you are changing it is probably the most important part!

 

Amsoil or Redline for me

 

Valvoline, Mobil, Shell, Castrol GL5 spec for the diffs, GL4 in the trans

Syn is at your discretion, I stopped using synthetics and just doing more frequent intervals myself. Napa has 80w90 made by Ashland (valvoline) that I use. Redline MT90 in the trans.