Differential Swap - Full Size Blazer

[Blazer_Lover]

I have a 1993 2 door full size Blazer. I also have a 1999 Escalade donor vehicle. QUESTION: Will the rear diff of the Escalade fit on my Blazer? Both are 10 bolt, 3.73 ratio. The Escalade diff is posi-traction.

Thanks

 

[jerryjoe28]

yes it will bolt right up

 

[Blazer_Lover]

Great! Now the fun begins........

 

[Nak]

You didn't mention 4WD or 2WD. The rears are different from one to the other.

 

[ccapehartusarmyINF.(ret)]

yes because if the blazer is 4wd chances are the rear diff is also limited slip ive never seen a 4x4 open rear axle ive also never seen a 2wd blazer for that matter

 

[Blazer_Lover]

My 93 Blazer is 4x4. I would like to use the Esky rear diff and suspension because it is slightly newer and has larger drum brakes. I will probably use the front diff also just to be sure the ratios match. Based on what I read elsewhere on this site, my manual New Process 241 transfer case should be okay. Is this correct?

 

[Nak]

Assuming the Esky is a 400 body style and both vehicles are 4WD, it will be a bolt in. The NP241 Transfer case won't be affected. You'll need a conversion U-Joint and a brake combination valve for JB6 brakes. You are correct in that the bigger 11" drum brakes are far superior to the 10" drum brakes on your Blazer. Both feel and performance will improve dramatically. However, if you don't replace the combination valve your brakes will be biased way too much to the rear. The bad news is you can't buy the valve new anymore; you'll have to find one in a wrecking yard. Look for a 1992-1994 Suburban with JB6 brakes.

 

[Blazer_Lover]

NAK, I'm not versed in body style but I'm pretty sure the Blazer and the Esky are the same. The only obvious difference is the front sheetmetal - hood, grille, bumper and fenders. In fact, my project is to create a one-of-a-kind 2-dr Esky. Thanks for the info on the combination valve. Any info/explanation you could provide on the "conversion U-joint" would be appreciated. Thanks Again....

 

[Nak]

Sure. The yoke on the 14 bolt uses a bigger U-joint. A conversion U-joint has two different size spindles; one size for the driveshaft, another size for the rear axle yoke. The only downside to the conversion u-joints is that they aren't available in a permanently lubricated version; you have to lube them through a zirc fitting occasionally.

Also, I forgot to mention you'll need the plates that go under the axle as well, the ones the U-bolts clamp to. They aren't interchangeable with the 10 bolt version. While you're changing them, consider drilling a drain hole in the plates. When you look at them you'll see water can pool in the plate, causing corrosion on both the axle tube and plate.

 

[Blazer_Lover]

NAK, Thanks for the info on the U-joint. As for the plates, my intent is to swap the rear in its entirety - diff and springs. Just returned from the local pick-n-pay. Pulled the combination valve from a 94 GMC Suburban. Verified it was JB6 from the RPO code sticker in the glovebox. Again, thanks for sage advice.