Rear end oil change

[Shimy87]

What should I refill rear with??

[Scoobum]

I grab posi additive and gear lube from my GM dealer here in town. I've been beating on that Auburn Pro Series unit for 7 seasons...and it's still hanging in there...so I must be doing something right.

[Scoobum]

Shimy, if the funds are there...grab a diff girdle. It's cheap insurance. I have the one from Jeremys yellow car on mine...along with his dual fan setup.

[1KWIKSIX]

X2 I'm with Brad .


Here's what Auburn say about oil for their differentials. ....this is also what I run in my Auburn Pro Series rear end.
Obviously you can substitute the Auburn Gear Friction Additive with the GM product.

Non-Synthetic 80w90 GL-5 oil treated with Auburn Gear friction additive, part #504102 (also known as a friction modifier). Three (3) ounces of additive will treat one quart of oil. GM or Ford limited-slip additive may be used. We do not recommend synthetic oil.

[earlbrown]

 If you have a stock posi I like synthetic gear dope.   Don't add the whale jizz additive unless you get chatter.

[good2win22]

Has anyone seen an aftermarket diff unit manufacturer that recommends a synthetic? I know eaton does not recommend synthetic

[earlbrown]

Do they not recommend it, or recommend against it?

[gusszgs]

Just redid the clutch packs in my T. Got them from Bruce Ponti. He's been doing rear ends for yrs and said Dino 75-80/90 with Posi Gm additive

[reality]

From what I gather synthetic will 'fall' off if the car sits any length of time.

[good2win22]

Do they not recommend it, or recommend against it?

I'm pretty certian eaton recommends against using synthetic

[Scoobum]

Shimy, while you're under there ya' may as well toss a set of Moser axles in it. Only a few more minutes work. If the wife starts complaining... give 'er the choice of axles or you pissing the cash away on peelers.

[Shimy87]

    

[earlbrown]

I wonder if that recommendation is because they would sell less additive?


My stock posi chatters with dino and doesn't with fully synthetic.


Since I've got over 1/4 million miles on my stock rear end on synthetic, I think I'll ignore the advice and stick with what I've got.

[good2win22]

I wonder if that recommendation is because they would sell less additive?


My stock posi chatters with dino and doesn't with fully synthetic.


Since I've got over 1/4 million miles on my stock rear end on synthetic, I think I'll ignore the advice and stick with what I've got.

Earl my question was about aftermarket diff manufacturers

[Forzfed]

Do they not recommend it, or recommend against it?

Good question.  All I know is my posi with the synthetic no longer works as good as it use to.  Sometimes I question if I even have a posi!  Sucks especially in the Truck with ice and deep snow.  It works but takes much longer to lock up.