whats the best NON-synthetic gear oil?

[jmaster]

i have looked into it before. i was warded off using lucas, and told that delo is the best. it must not have limited slip additive in it.

the application is a 500hp(450 at the wheels) 2001 mustang bullitt 8.8 rear end with an auburn pro differential. its daily driven during warm months in se michigan, it is beat on and occasionlly goes to the strip.

auburn recommends a non snthetic 80-90 with gm or for ls additive or their proprietary additive. i just add enough of the auburn additive to stop it from chattering which it doesn't take much(1-2 ounces for 2 3/4qts)

 

[dparm]

Why do they recommend dino?

 

[Oil Changer]

DELO

 

[salv]

castrol hypoy-c 80w90 according to amsoil testing is the only dino tested that met or surpassed all gl-5 specs. it even beat out some synthetics.
i have it in the rear of my XJ with bg ls additive for the trac-loc limited slip.

 

[mechtech2]

I have to ask why they would not like a full synth in that unit?
And what is wrong with having a LS type?

Just seems strange...

 

[salv]

even with LS type gear oil you need a friction modifier. LS type is good enough by itself in a gear style LS rear, but a clutch type LS rear needs the additive for proper operation of the clutches.

 

[dparm]

There are plenty of good 80w90 GL5 gear oils. Unless they can give you a more firm answer, I would run a syn.

 

[Y_K]

Chevron Delo ESI

 

[dailydriver]

Originally Posted By: Y_K
Chevron Delo ESI


^^^This, the Torco RGO, some of the Schaeffers products, and Lube Engineers products.

 

[dailydriver]

Originally Posted By: dparm
Why do they recommend dino?


More likely than not because they just NEVER, EVER tested with synthetics, just like Eaton, which says the same thing for their diffs.

 

[Garak]

Yep, either because they never tested it, or they simply specify a viscosity that is generally dino only. Most 80w-90 lubes I've seen are conventional, with the synthetics being a 75w-90.

 

[WMSmotorhead]

I've always had great success with Mag1... 80w-90's are very plentiful, and most are quite good.

 

[jmaster]

Originally Posted By: dailydriver
Originally Posted By: dparm
Why do they recommend dino?


More likely than not because they just NEVER, EVER tested with synthetics, just like Eaton, which says the same thing for their diffs.

thats exactly it! heres what they have to say about lubrication for their diffs.

-IMPORTANT LUBRICANT NOTEThe
Auburn Gear limited-slip differential design has been
extensively tested with high quality non-synthetic 80W90
hypoid oils treated with GM or Ford friction additives (3
oz. of additive will treat 1 quart of oil). To avoid differential
clutch chatter (noise) and for optimum performance, use the
oil and additive described above. Use of other additive and
oil types may cause differential clutch chatter.
Ford Part Number: C8A219B546A
GM Part Number: 1052358

so do you think i would be fine using a synthetic like amsoil or redline? i guess i will stay with non-synth if they make a point to not test with it.

i do like the delo, torco and schaeffers, mag1 looks good, wish i could have bought it on amazon when it was $2 a quart. so if the gear oil says "for limited slip diffs" it doesn't have a friction modifier? whats different about them?

 

[jmaster]

also i dug up this email from a while back, pretty definite no from this rep:
Our recommendation is to use a NON-synthetic oil with either our additive or an OEM additive (Ford or GM). Do not use synthetic oils as they polish the gearing and will reduce the strength of the unit, also do not use K & W brand (or TRANSX) additive, both of these with also cause much chatter that can get severe. Use an 80/90 weight, petroleum based, oil from a Ford or GM dealer with our additive or their additive. We recommend 3 ozs. of additive per quart of oil. Hope this helps.

and a different rep:
Thank you for using our product. Our recommendation is a non-synthetic, 80/90 wt. gear oil, preferrably an OEM (Ford/GM) with either our limited-slip additive or a GM or Ford additive. This is what we have found to work best.


Nancy Lapp
Inside Sales Representative

 

[dailydriver]

IF you are worried about it, and they threaten to not honor the warranty if you use synthetic (and you want to follow their advice to the letter); I would use a Motorcraft gear oil (if they still even make a mineral based, NON-synthetic, NON-blend gear oil with the excellent Motorcraft XL-3 additive.

 

[mechtech2]

Originally Posted By: dailydriver
Originally Posted By: dparm
Why do they recommend dino?


More likely than not because they just NEVER, EVER tested with synthetics, just like Eaton, which says the same thing for their diffs.

Insert slap on head smiley!

Yes - of course this must be the answer!

 

[Loobed]

Swepco makes a good gear oil, but I think it is a synthetic blend, and it costs about as much as synthetic.

http://www.swepcolube.com/gear-lubricants

 

[dailydriver]

Originally Posted By: Loobed


Swepco makes a good gear oil, but I think it is a synthetic blend, and it costs about as much as synthetic.

http://www.swepcolube.com/gear-lubricants



Yes, one of the Porschephiles' faves.

 

[Bgallagher]

Originally Posted By: WMSmotorhead
I've always had great success with Mag1... 80w-90's are very plentiful, and most are quite good.


+1