Suitable gear lube for Trailblazer front diff?

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5,651
Location
Iowa
I'm servicing my friend's 07 Trailblazer (4wd, 4.2I6) and would like to know what lubes are suitable for the front diff (rear for that matter too). I know the spec is the stupidly expensive GM oil, but will a 80w-90 (on a shorter service interval) suffice, or even a synthetic 75w-90? I realize the grape juice is a 75w-90 by the way. My main concern with the front diff is the fact that it's capacity is so small and I have seen several fail. If push comes to shove, I'll use the big $$$ juice, but would like to avoid it- especially if it can be circumvented by a shorter drain interval. Also, I read of several people having issues with the non GM lube in the G80 w/locker. If this doesn't have a locker/limited slip, then would an 80w-90 suffice?
 
Messages
693
Location
PA
I'm sure AMSOIL has a GM equivalent, The only fluid my diff's see is AMSOIL. Go to an AMSOIL website and enter in your vehicle and it will list all fluids for your SUV.
 
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24,480
Location
Dallas,Tx USA
Originally Posted By: wsar10
I'm sure AMSOIL has a GM equivalent, The only fluid my diff's see is AMSOIL. Go to an AMSOIL website and enter in your vehicle and it will list all fluids for your SUV.
^^This.
 
Messages
689
Location
Chicago, IL
I can confirm that Mobil 1 75w-90 works in the front diff. I've been running that for the past 80K (40K intervals). Oil always comes out only slightly browner than the original but does not contain any noticeable glitter or large pieces of metal. Think I'll push it to 60 or 70K next.
 

The_Eric

Thread starter
Messages
5,651
Location
Iowa
I should have stipulated in my first post that I'm pretty much limited to locally available products. None of our local stores carry Amsoil gear lubes. I can get Mobil 1 and Valvoline in both conventional and synthetic, as well as parts store branded lubes.
 

MolaKule

Staff member
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21,914
Location
Iowegia - USA
I have an '08 TrailBlazer with 5.3L V8 and use synthetic 75W90. The only problems I have had was the leaking of the front differential drive pinion seal and the side seal due to bad seals. Luckily, they were covered by warranty. Any synthetic 75W90 should be sufficient.
 
Messages
693
Location
PA
AMSOIL is not something a store will stock, you can order it or put in your zip on there site to find a local dealer. The link I posted will also tell you what to use on your rear diff.
 

MolaKule

Staff member
Messages
21,914
Location
Iowegia - USA
Originally Posted By: The_Eric
Thanks for the input guys! What is the general consensus on the rear diff?
I'll express my opinion: I prefer the 75W110's as a good all around diffy gear lube for the rear differentials. You get a good thick oil film and a nice EP package.
 

MolaKule

Staff member
Messages
21,914
Location
Iowegia - USA
Originally Posted By: wsar10
AMSOIL is not something a store will stock, you can order it or put in your zip on there site to find a local dealer. The link I posted will also tell you what to use on your rear diff.
Pablo, BITOG member and sponsor can probably set you up with the 75W110 SVG.
 

The_Eric

Thread starter
Messages
5,651
Location
Iowa
Originally Posted By: MolaKule
Pablo, BITOG member and sponsor can probably set you up with the 75W110 SVG.
I agree- and if the circumstances were different, then I would definitely consider going that route. In fact, if I needed most anything Amsoil, Pablo would be my first stop. Unfortunately time is not on my side.
 

The_Eric

Thread starter
Messages
5,651
Location
Iowa
Originally Posted By: wsar10
AMSOIL is not something a store will stock, you can order it or put in your zip on there site to find a local dealer. The link I posted will also tell you what to use on your rear diff.
Yes and no. Our local stores do stock a very limited amount of Amsoil products- some Interceptor 2 cycle oil and I think, maybe some V-Twin oil. For a while, there was some Severe Gear too, but I haven't seen it lately.
 
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1,848
Location
FEMA Region 4
I just changed out my rear differential gear oil with Royal Purple Max Gear. It seems to be working just fine and I was able to pick it up for $20/quart at Autozone. I also hear good things about Amsoil Severe gear, but I have no first hand experience with this product, just heard good things.
 
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22,491
Location
Apple Valley, California
many stores here carry amsoil.napa has it as do the motorhome\rv places ,4x4 specialty shops and we even have 2 brick stores that only sell amsoil. im sure you could find it locally if you looked harder
 

The_Eric

Thread starter
Messages
5,651
Location
Iowa
Originally Posted By: Warstud
No special Fluid in the Diffs. But the Transfer Case requires the GM Auto Trak II.
Yes it does- and I have already done the drain and fill with it. Looked it up on the O'Reilly jobber site- 18.00 per quart and not in stock. I ended up using Mobil 1 75w-90 in the front and will probably use conventional 80w-90 in the rear, provided there is no locker/limited slip.
 

mjk

Messages
1,482
Location
Wishin' I was in Wi
You can get Amsoil Gear Oil for 12.99 at Fleet Farms here in MN/WI. 18.00 is quite the mark up. /
Originally Posted By: The_Eric
Originally Posted By: Warstud
No special Fluid in the Diffs. But the Transfer Case requires the GM Auto Trak II.
Yes it does- and I have already done the drain and fill with it. Looked it up on the O'Reilly jobber site- 18.00 per quart and not in stock. I ended up using Mobil 1 75w-90 in the front and will probably use conventional 80w-90 in the rear, provided there is no locker/limited slip.
 
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