That condition is what psycologists called having aShort Attention Span. Meaning, somepeople get tired of readingafterone or twosentences.

My old high school friendwho quit school in the 9th grade is a good example of the comdition.

 

I just must be stupid. I never said I had a G80.

 

It doesnt matter if you have the G80 or not. It's the same fluid.

 

My statement holds true regardless of whether you have the G80 or not. No means NO! I added the bit about the G80 in case you had it to settle any questions in that regard prior to it being asked.

Must have a very short attention span to miss NO in my post... Yours, well...

 

You can worry about something else.

No GM differential from 1973 to thepresent requires a "friction modifier" to be added to the differential lube. GM started using a Gov-Loc(G80) passive locking differential(also known as a "Time Bomb")in 1973. That unique unit has clutches that uses"governor actuated" ramp system for engagement. They were designed to eliminate the use of organic lubricants such aswhale oil friction additives andpetroleum based lubricants.The 1957 - early 1964GM Dana (belleville spring loaded) and late 1964 - 1972 Eaton (coil spring loaded) clutch type limited slip differentials must use afriction modifier. The clutches in a modern Gov-loc differential areNOT spring loaded and do not require a friction modifier. They evenrespond well usingsynthetic lubricant, for which they weredesigned.

 

I use Royal Purple in my awesomely annoying open diff...Once I snag that locker for a few dollars...I'll keep using Royal Purple

 

If you replace your open carrier with aGM Gov-Loc differential, you will STILL have a open rear end over 20 MPH. To do that, you must remove the carrier and ring gear, install the Gov-Loc differential assembly attach the ring gear andreset the ring/pinion gear backlash. That is too much trouble for a part timer like me.

Install a drop-in Richmond PowerTrax No-Slip differential. That unit is specifically designed to replace a Gov-Loc or open differentialassembly in theexisting carrier. It is a 1-hour drop-in, locking differential.Your existing open differentialcarrier does not need to be removed and the ring/pinion gear backlash does not require resetting.

You should "snag" a Powertrax No-Slip locking differential for $465.00 for an open differential. The PowerTrax No-slip differentiallocks both axles at all speeds and differentiates wheel speed around corners and curves, without anynoise.

You can useany rear end lube you want as long as it is API Service GL-5 hypoid gear lubricant.All GL-5 service lubes are thesame except for the brand andcolor. No friction modifier additive is required because the PowerTrax No Slip differential does not have any clutches. It usessteel syncronizer rings to lock and unlockthe axles.

 

I also have the GU6 code but I have a limited slip or posi rear end. When my drive tire looses traction the other tire engages on loose ground or at the boat ramp. This kind of had me puzzled. Any input?

 

You only have a the posi rear end if you have the G80 code. Or someone put alot of money into your blazer and didn't tell you

 

You know it is strange, I took it to the chevy dealer and he told me I had a zr2 package but not the lift, based on the VIN. I have no idea. I have ran the rpo codes and nothing tends to show this. I guess I need to drop the diff cover and find out for sure sometime!