2001 Chevrolet Blazer 4.3L 2wd 4 door has 105,000 miles & is making a whiney noise as the car accelerates and sound descends as car decelerates. I’m sure it’s coming from the differential and maybe it’s time to change differential fluid... along with gasket… what brand of gear oil is everyone using on this forum? I’m staying away from Lucas products since I have heard bad things about their oils.

 

Also not a bad idea:

 

Sounds good I've seen that gear oil in my local auto parts.

 

x2 on TBB's post. That is what I used the last time I serviced the rear diff on my old Bravada. Even made a how-to on it. Check the Tech Article (DIY) section and have a look at the 1st post stickied in there for a summary of all tech articles.

 

how often should u change the rear diff fluid not to thread jack but didnt feel the need 2 start a new post to ask that haha

 

TripleBlack those came out looking really sharp! Is that a larger diff cover in the first pic (dirty vs. clean = OEM vs. something different?) or are you just that good?

 

I don't understand what you're asking but it is the same size cover. Just one is brand new and hammer painted and the other was the old rusted/leaky stocker.

 

Ah. In the second pic the one on the left (old stock one) looks smaller than the one on the right (newer looking possibly bigger). Either way, my question was answered

 

I got the rear diff serviced last week on wednesday (June 10th) Noticed a big difference. I think i gained 500 horse power :P LOL but really i noticed a diference. A lot smoother

 

Glad to hear it!