10 bolt rear diff oil and gasket change

[Dennis Wilkie]

I'm about to change the oil and gasket to fix a leak on my 1992 Chevy k1500 extended cab 4x4. Since the motor was swapped, it has me wondering if maybe the genius tweakers I bought it from didn't do the same with the rear end, considering it has absolutely nothing left of the rear brake system. Can anyone ID this rear end? I couldn't find a tag on it, but I did get the measurements, and I kinda need to figure it out before I go filling it with 80W-90. Any help would be greatly appreciated

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[CRF450R]

Looks to me like a run of the mill 10bolt rear end guys with big tires or that bag drive there truck's diss them but I've seen them go well past 500 +km . Just drop the oil refill it and carry on. I only run John Deere synthetic oil in my front and rear differential John Deere makes dam good oils in my opinion best money can buy. I go to a John Deere operator's course every year and I've seen the rigorous tests that JD oils and coolants have just blown everyone else outa the water these tests were also outa house non JD testing lab facts and results. I would also consider using premixed John Deere coolant in your truck both my truck and my 07 CRF 450R dirtbike run John Deere coolant ( bike has 200+ hours all original never bin rebuilt and still runs strong I run it hard every chance I get). John Deere only uses the cleanest most perified water possible to mix with there coolant and they are very very fussy on the base oil they purchase before they refine it to there specs. Out of 100 rail cars of oil John Deere rejects typically 20+ of them at a time. Food for thought

 

[Dennis Wilkie]

I just said f"k it and dove right in, lol. I just came to the conclusion that it's definitely not factory looking like this, especially with the odometer at +259k miles on it. Can't quite make out the numbers though, but i'm sure I can narrow it down by looking at the list

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[b454rat]

Looks like a typical rear, with grenade lock. If they hammered in it then it maybe have been replaced, those diffs dont like abuse. Look on end of gear for ratio. Prolly 3.42s.

 

[df2x4]

If it is a factory G80 carrier, don't use anything with friction modifier or posi additive. GL5 80W-90 with no additive is the factory recommended fluid. I use this stuff, ACDelco part number 10-4051.

https://www.amazon.com/gp/product/B007Q10F3S

 

[ullwn]

....[SNIP}. I would also consider using premixed John Deere coolant in your truck both my truck and my 07 CRF 450R dirtbike run John Deere coolant ( bike has 200+ hours all original never bin rebuilt and still runs strong I run it hard every chance I get). John Deere only uses the cleanest most perified water possible to mix with there coolant .... {SNIP]

Review the following

Cool-Guard II Educational Video

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Regards

Joseph

 

[Dennis Wilkie]

I can't quite make out the numbers on it. But to me, it looks like 3.15 and GM-D, and i've only found 1 differential with that ratio online, and nothing matching the GM-D.

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[evilunclegrimace]

look at the side of the ring gear and find the number set

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[evilunclegrimace]

the numbers in the blue circle are the tooth counts for the ring and pinion. Divide the small into the large and you have you ratio

 

[Dennis Wilkie]

I already sealed it back up after I took those pictures. It's sealed so i'm satisfied. I'll save the rest for another day. I've got soooo much other bs to do on this truck, it doesn't make any sense. Like an entire rear brake and header back exhaust system, gotta drop the oil pan that's above the front diff...again, figure out why the tbi started surging again all of a sudden, even though i've replaced every sensor and just about everything under the hood besides the engine itself. This truck has become a f'n nightmare, but for some reason I can't bring myself to stop working on it. It's about a 70% brand new antique truck at this point, lol. This is an old pic from early July, and i've got about $1000 in it since then, and about $3800 before that. It's killin me, lol

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[DerekTheGreat]

I dig the wire nuts on the taillight/trailer wiring. Top notch!

You can figure out the approximate gear ratio by marking the pinion and tire with something, then spinning the tire 2 or 3 times (I forget which) and count how many times the pinion hits your mark that you made. So say it crosses ~3.5 times, you have a 3.42 gear set.