Front and rear differential lube recommendations please. - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

Welcome Enthusiast! If you already own a Chevy TrailBlazer or GMC Envoy or perhaps thinking of purchasing such a vehicle, then you have come to the best TrailBlazer and Envoy site on the net! Rainier, Bravada, Ascender, and 9-7x owners welcome too!

You are currently viewing our site as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to search and post topics, communicate privately with other members, respond to polls, upload content, and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
Join Today!
Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2002 - 2009 TrailBlazer/Envoy Tech > 02-09 Vortec 4.2L I-6 Engine and Drivetrain > 4x4 Drivetrain

4x4 Drivetrain 4x4 Repairs & Problems is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
Thread Tools
Old 08-22-2009, 01:16 PM
c good c good is offline
Senior Member
2002 GMC Envoy SLT
Indigo Blue Metallic 4.2L I6 4X4
Join Date: Feb 2009
Location: San Diego, CA
Posts: 539
Front and rear differential lube recommendations please.

Even though they were checked at a quickie lube place before I bought this vehicle, I'm going to change them out. What would you all recommend for these two differentials front and rear? Brand, weight, specs, etc. I'll also be doing the transfer case but found out the Autotrac II is recommended. Thanks for any input. c good
Reply With Quote Quick reply to this message
Sponsored Links
Old 08-22-2009, 04:45 PM
Chickenhawk's Avatar
Chickenhawk Chickenhawk is offline
Senior Member
2004 Chevy TrailBlazer LT
Medium Red Metallic 4.2L I6 4X4
Join Date: Apr 2008
Location: Canada
Posts: 996
Any good quality 75W-90 is fine. Many of us have gone to full synthetic 75W-90 front and rear. Mobil 1 and Amsoil make two of the most popular choices in here.

If you have the G80 locker rear, you should get one made for limited-slip differentials. This is not critical because:
#1 - You can always add a limited slip additive in whatever you choose, plus;
#2 - There is some debate as to whether the G80 needs an additive anyway, because it is more mechanical in its operation than ones that use the more traditional clutch packs.

Be careful adding an additive to a lubricant that already has it because you can actually make it TOO slippery and it won't lock up properly. For example, Amsoil has it already but Mobil 1 only has it in the 75W-90LS version. (My friend roadie can explain this a million times better than me ... and no matter what we recommend in here we always defer to "WWRD.")

Stick with the AutoTrak II for the transfer case. It is inexpensive, and the transfer case NEEDS changing every 50,000 miles without fail or you risk majour problems.
Reply With Quote Quick reply to this message
Old 08-22-2009, 04:58 PM
91RS 91RS is offline
TrailVoy Alumni
2007 Chevy TrailBlazer SS (1SS)
Imperial Blue Metallic 6.0L LS2 V8 2WD
Join Date: May 2008
Location: GA
Posts: 1,852
You have to use a full synthetic gear oil, that is what all modern GM diffs call for. If you want to go ahead and change the transfer case too (easy, it has a drain and fill plug), it ONLY takes Auto Trak II which you can get at the dealer. You can also ask for the LS gear oil at the dealer, which is full synthetic and has a limited slip additive already in it. They may try and tell you the LS gear oil is only for a Corvette, but that's fine because it works just the same. I believe it's only about $8 a quart, unlike the regular GM gear oil which is $30 a qt. Typically you'll need 2 quarts exactly for the rear diff and a little under 2 qts. for the front. The TC also takes 2 qts.
Reply With Quote Quick reply to this message
Old 08-22-2009, 05:12 PM
the roadie's Avatar
the roadie the roadie is offline
No longer with us
2004 GMC Envoy SLT "Roadiemobile"
Extreme Offroad Pewter 4.2L I6 4X4
Join Date: Apr 2005
Posts: 26,181
I use Mobil1 75W-90LS from Kragen. But then I'm not a fan of the more expensive purple alternatives. If my axle breaks, I just swap it out.

As always, read the Owner's Manual first before even consulting trailvoy. It's not 100% full of lies like folks think. And the fluid requirements are listed.
Reply With Quote Quick reply to this message
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum forums, you must first register.

Please enter your desired user name, your email address and other required details in the form below.
(Only letters, numbers, dashes and underscores are permitted for user names)
The user name that you choose is permanent and can never be changed.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Where you live (ex: Philadephia, PA)
Vehicle Year
Choose your year
Or enter your choice here:
Vehicle Color
Choose your factory color (Custom, Not Listed & Two-Tones; Use Text Field Below)
Or enter your choice here:
Vehicle Make
Choose your make
Or enter your choice here:
Vehicle Model
Choose your model
Or enter your choice here:
Vehicle Engine
Choose your engine
Vehicle Drivetrain
Choose your vehicle drivetrain
Security Question
Fill in the blanks: Tra___oy
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

» Sponsors

Advertising Info

All times are GMT -4. The time now is 09:57 PM.

Chevy TrailBlazer and GMC Envoy Enthusiasts - Copyright 2004 - 2009 All Rights Reserved.
All trademarks referenced herein are property of their respective owners.
RSS Feed