I have a 99 Jimmy that I have diagnosed as having the front differential shift engagement mechanism to be bad. Rather than replacing the fork, collar, and gears, i’m just going to get a known working unit with a warranty. My question is, will a front differential from a manual transmission blazer/ jimmy bolt right up in my automatic transmission jimmy? The only difference I can find through my research is that the MT differential is steel and not aluminum. Thank you

 

The front diff is interchangeable between the manual and automatic transmission. Generally, the iron front diff is stronger than the aluminum one, so if you off-road that may be a good option/upgrade.

 

And match up gear ratios ......

 

Thank you for the information, I figured the two would be interchangeable, but wanted to check with folks that were more familiar and knowledgeable with these vehicles than I am. I’ve already looked up my RPO code and it is GU6, so i’ll find one with the same gear ratio as the rear end.