2002 (RPO) G80 axle what gear lube???

[tomtk]

2002 G80 Axle what gear lube will work ????

What yall runnin????

[F9K9]

Anything! No additives. Check out walllywords synthetic techlline. Meets are exceeds tests that Mobil 1, Royal Purple, or Amsoil can't pass but, spend your money how you please. I believe it is 75-140W. I won't hang around for the controversy that will follow. Just my own research and the belief of many others.

[HenryJ]

Sticky: GM Fluid and Lubricant Recommendations
I say no to synthetics where clutches are used. That includes the G80 and transmission.

Gm GL-4 Ouch!
How to change rear differential fluid.

[tomtk]

Is there any commercial ones thats safe to use????

[HenryJ]

Is there any commercial ones thats safe to use????

Those that are GL-4 meet the requirements.
GL-5 contains additives that could be detremental. It is not an upgrade.

[killian96ss]

Royal Purple 75W/90 synthetic or Redline 75W/90NS synthetic.

Synthetics are perfectly fine to use with the G80 not to mention they will protect everything much better than standard gear oil, plus you will get slightly better gas mileage with synthetics.

BTW, GM uses synthetic gear oil in all of their newer G80 equipped vehicles.

Steve

[HenryJ]

GM uses synthetic gear oil in all of their newer G80 equipped vehicles.

Not through at least 2004 and that is what we are dealing with here.

[tomtk]

Synthetic or Mineral???

Whats it say on the bottle???

Royal Purples Techline said theirs would work...but who knows the knowledge level of their techs??

Interrestingly their GL-5 is also backward compatable with GL-4 and will not harm copper alloys like most GL-5s...per them

I have the rear end open now and darn sure has the EP additives from factory has that sulfur smell.

dam all this cause the backplates for the rear disks rotted away....my GM factory manual has the spec for the 10.9 grade 10MM bolts at 100 lbft....thats gotta be wrong my SAE handbook chart says 60 lbft dry 47ftlb wet

If thats the accuracy of GM service data maybe I should just put in the Mobil 1

I can chew on it over night as I want a new lock bolt for the pinion shaft I do not like the amount of wear on this one

[killian96ss]

Mobil 1 gear oil will also work just fine with the G80 Gov-Loc!

I have used Royal Purple & Redline gear oils in 3 different G80 equipped S10's with a combined mileage well over 300,000 miles with absoluetly no problems!

Just don't add any "limited slip additive" which is usually sold separately in small bottles.

Steve

[tomtk]

1. Do the clutches need the additives?
2. does the GM PN 1052271 and its replacement have them blended in ?


he said Delvac Syn 75W90 is basically the same as the Mobil 1 75w90NS but without the any friction modifiers additives

I had a 1984 2.8L V6 that I dragged all over the world while in the military even had it buried in ash by MT Pinatubo and found 1/2 of an inch of ash in the oil pan and axle when I opened it back in the US I ran all Mobil 1 juices in it and that trans 700R4 lasted Another 80K before a rebuild.... so I think Syn juices work well...

This is clear as mudd

[killian96ss]

Just don't add any "limited slip additive" which is usually sold separately in small bottles.

As long as you don't add "additional" friction modifier you will be ok even though most gear oils have some friction modifier already blended in.

The clutches in the Eaton Gov-Loc do not need friction modifier like the clutches in a limited slip "posi" rear end.

Steve

[tomtk]

the Delvac 75w90 would be idea.....Am I interpeting this correctly or will it chatter absolutely none of them additives???

[F9K9]

I am as guilty as you both but, I have stopped paying for advertising or pyramid products!

[tomtk]

went thru this before on the great harley versus syn oil debates about ten years ago.

Harley condemed syn oils as unsuitable...I selected Castrol Syntec 20W50...recently I noticed that Castrol touts their 20W50 Syntec as having the higher levels of ZDDP that they recommend it for classic muscle cars...lack of ZDDP was one of he reasons Harley stated that syn oils were not suitable.

Funny syn is all the Harley has at the dealer for sale now.

[caltman]

nobody saying anything about lucas?got my cover off now cause im replacing dust shields,is lucas okay to use?

[F9K9]

.........is lucas okay to use?

Dunno, sorry.

[HenryJ]

I'd pass on anything other than recommended lubricant for the sake of the G80 clutch materials.

[caltman]

well it says its okay for the gl-5,i got a zr2 so it got the g-80

[killian96ss]

nobody saying anything about lucas?got my cover off now cause im replacing dust shields,is lucas okay to use?

As long as it has a GL4 or GL5 rating and is the correct weight, 80W90, you will be ok. Lucas Oil products are high quality just like Royal Purple or Redline.

Steve

[HenryJ]

Look closely and make sure it does not contain additives that will corrupt the metallic in the clutch linings on the early 2000 Eaton GovLocs.
I had a tough time finding anything compatible with those specifications , other than the GM fluid. I finally did find some cheap StaLube that did not contain the "bad stuff". Pretty hard to find simple lubricants anymore.
There is a very good thread around here somewhere that gets into the specifics of which additives can be harmful.

[HenryJ]

Do not add additive to the Eaton GovLoc (RPO G80) differential. They do not use or require friction modifiers. That will ruin your day.

Check your owners manual or our sticky on lubricants.

Rear Axle (Locking, Differential) - Axle Lubricant, use only GM Part No. 89021671 (in Canada use Part No. 10953482). Do Not add friction modifier...

With RPO G80 1052271 only

Without RPO G80 (open diff) 1052271 or SAE 80W-90 GL5

GM Vehicle care Axle Lubricant SAE 80W-90
*excellent axle durability

1#1052271
Gr.8.800
23 fl.oz.

"Gm axle lubricant exceeds API GL-4 requirements and has been formulated specifically for use in certian GM axles as specified. Not all products labeled GL-4 will provide satisfactory service.

*excellent axle durability
*Compatible with limited slip fiction modifiers
*Compatable with seals/elastomers"

Contains : Petroleum oil (gear oil) - CAS 64742-65-0

The difficulty that I had was finding one to meet the GL4 requirements only. GL5 includes additive detrimental to the clutch material and can lead to problems. Most have gone on to the GL5 rating and boast compatability. The problem is that they do include and additive that is not compatible.

This is a good discussion on the topic

[caltman]

okay bottle says"excellent for use in limited slip differentials.no special additive needed"sooo does this it has additives in it already or just that it is good enough as is?

[HenryJ]

okay bottle says"excellent for use in limited slip differentials.no special additive needed"sooo does this it has additives in it already or just that it is good enough as is?

What bottle?

Use no additives or limited slip friction modifiers. Add nothing.

[caltman]

the lucas bottle

[HenryJ]

the lucas bottle

Personally, I'd pass.
Do your research and if you determine that it does indeed match the recommended lubricant, feel free to give it a try.
In the open front differential, I would have no worries about using it.

[caltman]

well i put it in so we'll see how it goes

[killian96ss]

All of the gear lubes that are GL4 or GT5 rated will work just fine with any year G80 Gov-lock. Almost all gear oils contain a small amount of friction modifier which will not harm the G80 Gov-lock in any way. You do not want to add additional friction modifier which is sold in smaller bottles. This stuff is for fine tuning limited slip differentials, aka positraction. I have used GL5 oil in 3 different G80 Gov-lock's from 1988 to 2005 with absolutely no problems at all!

Steve

[caltman]

alright thanks man i appreciate a clear answer