Rear Gear Lube - Synthetic Or Conventional?

Dragsinger · 05-19-2015, 10:35 AM

Lou, good question. I have some feedback and will work it up and post later.

Jon Sarrett · 05-19-2015, 10:57 AM

I think this is one of those ask 10 people and get 10 different answers kind of thing. I run Royal Purple synthetic in my Plymouth but run what Strange recommended (and sent) in my Camaro. The brand name escapes me but it was a non synthetic oil.

Myron Piatek · 05-19-2015, 04:08 PM

I'm an Amsoil user as well. When I can, I break in the gears and bearings with conventional fluid, just like an engine. I was also told that the OEM gear coatings are not good for the gears and bearings afterwards. So a flush to eliminate that as well as any initial metal wear seems like a good idea. Then I go to the Amsoil Severe Gear 75w-90 synthetic. I just checked my 8 3/4" gears after several years of running. They were much better than expected so I put them back in. Unfortunately, I have yet to count the # of runs I get on some of my parts.

If you have the gears REM surface finished, you won't have the coating to worry about. But it's best to set the gears up before REM because it can be difficult to get a pattern reading, according to my differential guy.

Shake & Bake · 05-19-2015, 09:39 PM

I use Amsoil Severe Gear Sae 75W-110 Synthetic Extreme Pressure Lubricant. It's a premium grade extreme pressure (EP) lubricant engineered specifically with "High Film Strength" for high load demands.

It's also compatible with conventional and synthetic gear lubes and most limited slip differentials.

Plus it's recommended for applications requiring 75W-110, 75W-90, or 80W-90 gear lube with any of the following specifications: API GL-5, MT-1, MIL PRF-2105E, Dana SHAES 234 (Eaton PS-037), Mack GO-J, or the differential gear lube specifications from GM, DaimlerChrysler or Ford.

Ed Carpenter · 05-20-2015, 10:24 PM

Redline heavy duty shockproof in my Dana no problems.

Rory McNeil · 05-21-2015, 02:30 AM

Quote:

Originally Posted by deuces wild

Redline heavy duty shockproof in my Dana no problems.

Same here, (and light shockproof in the Jerico)

Brett C · 05-21-2015, 08:02 AM

We run all Strange products with Royal Purple. Never had an issue. (Knock on wood)

ATI Performance Products · 05-22-2015, 09:59 AM

Quote:

Originally Posted by Brett C

We run all Strange products with Royal Purple. Never had an issue. (Knock on wood)

We have run Qualifying Driven oil in the Challenger Rear with no issues and a 4.88 until I went to 3470+ lbs. At 3250 no issues for 2 season. At 3470 we hurt gears. They are not Pro Gears and its only an 8 3/4.....so keep that in mind.

Switch to the Driven's Speedway Synthetic oil in Challenger and have always ran in COPO with no issues. Its VERY light.....

I do break in for 3-4 passes with No Synthetic Driven Break in or Torco oil from Mark Williams.

As far as an A to B to A test - never done - doesn't matter since I won't run a light weight non synthetic in the rear or trans anyway - we have enough other **** to test when we go out!

Jeff Niceswanger · 08-02-2015, 05:32 PM

Quote:

Originally Posted by deuces wild

Redline heavy duty shockproof in my Dana no problems.

Ed , You have a PM ... Jeff

1320racer · 08-05-2015, 08:24 PM

Been using Mobil 1 75W-90 Synthetic gear lube for over 2 decades in my bracket cars that see more passes each season than 95% of stock/super stock cars.

My 3144 lb. Firebird that is restricted to run 9.0 every week, 60 foots low 1.20s to high 1 teens with a best to date of 1.17 and has gone 700+ passes without a R&P failure, running out of the box Richmond gears.

05-19-2015, 10:35 AM	#1
Dragsinger VIP Member Join Date: Jul 2008 Location: Liberty City [East Texas] Posts: 1,760 Likes: 5 Liked 99 Times in 60 Posts	Re: Rear Gear Lube - Synthetic Or Conventional? Lou, good question. I have some feedback and will work it up and post later. __________________ Larry Woodfin 471W

05-19-2015, 10:57 AM	#2
Jon Sarrett Member Join Date: Mar 2002 Location: Sullivan, OH Posts: 311 Likes: 827 Liked 140 Times in 46 Posts	Re: Rear Gear Lube - Synthetic Or Conventional? I think this is one of those ask 10 people and get 10 different answers kind of thing. I run Royal Purple synthetic in my Plymouth but run what Strange recommended (and sent) in my Camaro. The brand name escapes me but it was a non synthetic oil.

05-19-2015, 04:08 PM	#3
Myron Piatek VIP Member Join Date: Nov 2001 Location: Florida Posts: 1,542 Likes: 34 Liked 138 Times in 51 Posts	Re: Rear Gear Lube - Synthetic Or Conventional? I'm an Amsoil user as well. When I can, I break in the gears and bearings with conventional fluid, just like an engine. I was also told that the OEM gear coatings are not good for the gears and bearings afterwards. So a flush to eliminate that as well as any initial metal wear seems like a good idea. Then I go to the Amsoil Severe Gear 75w-90 synthetic. I just checked my 8 3/4" gears after several years of running. They were much better than expected so I put them back in. Unfortunately, I have yet to count the # of runs I get on some of my parts. If you have the gears REM surface finished, you won't have the coating to worry about. But it's best to set the gears up before REM because it can be difficult to get a pattern reading, according to my differential guy. __________________ LOCOMOTION Racing Last edited by Myron Piatek; 05-19-2015 at 04:15 PM.

05-19-2015, 09:39 PM	#4
Shake & Bake Member Join Date: Mar 2010 Posts: 312 Likes: 40 Liked 37 Times in 33 Posts	Re: Rear Gear Lube - Synthetic Or Conventional? I use Amsoil Severe Gear Sae 75W-110 Synthetic Extreme Pressure Lubricant. It's a premium grade extreme pressure (EP) lubricant engineered specifically with "High Film Strength" for high load demands. It's also compatible with conventional and synthetic gear lubes and most limited slip differentials. Plus it's recommended for applications requiring 75W-110, 75W-90, or 80W-90 gear lube with any of the following specifications: API GL-5, MT-1, MIL PRF-2105E, Dana SHAES 234 (Eaton PS-037), Mack GO-J, or the differential gear lube specifications from GM, DaimlerChrysler or Ford.

05-20-2015, 10:24 PM	#5
Ed Carpenter Live Reporter Join Date: May 2006 Location: Dripping Springs, Tx Posts: 2,709 Likes: 186 Liked 520 Times in 132 Posts	Re: Rear Gear Lube - Synthetic Or Conventional? Redline heavy duty shockproof in my Dana no problems. __________________ Ed Carpenter 2005 Chevy Cobalt A/SM Race Engine Development

05-21-2015, 08:02 AM	#7
Brett C VIP Member Join Date: Oct 2011 Location: Thibodaux, LA Posts: 1,195 Likes: 327 Liked 1,018 Times in 217 Posts	Re: Rear Gear Lube - Synthetic Or Conventional? We run all Strange products with Royal Purple. Never had an issue. (Knock on wood) __________________ Brett Candies 4192 Stock/SS God Bless America

08-05-2015, 08:24 PM	#10
1320racer VIP Member Join Date: Nov 2007 Location: New Jersey Posts: 2,628 Likes: 160 Liked 759 Times in 379 Posts	Re: Rear Gear Lube - Synthetic Or Conventional? Been using Mobil 1 75W-90 Synthetic gear lube for over 2 decades in my bracket cars that see more passes each season than 95% of stock/super stock cars. My 3144 lb. Firebird that is restricted to run 9.0 every week, 60 foots low 1.20s to high 1 teens with a best to date of 1.17 and has gone 700+ passes without a R&P failure, running out of the box Richmond gears.