Hello all. I just got my Blazer about a month ago and ever since, I've been noticing some problems, and I'm hoping someone has ideas on what it might be.

First, while driving I hear a grind coming from the back, which sounds like wheel bearings are going. The sound gets louder the faster I go. Back brakes and tires are brand new as of 3 weeks ago. The sound has been that way since day one. Rear bearings? If so, what do I need to replace the bearings (Autozone made it kinda confusing)?

Second, shifting from park to drive, there is usually a hesitation until it actually shifts into gear. I'm wondering if I need to get a tune up on the transmission, or if there is something else I can do to fix that.

Lastly, my speedometer is off after 60. On the highway, I have the cruise set to 75, but the GPS is showing that I'm going 70. I wouldn't be worried if it was only 1mph difference, but 5 is a little much. It's accurate at 60 and under. Another thing a transmission tune up would fix?

Any input would be greatly appreciated. Thanks.

 

#1 - You have to remove the axle to replace the bearing. It is a bit different if you have the G80 rear diff, but it starts with the removal of the axle cover.

#2 - How long is the delay? Sometimes this is normal and every transmission is different.

#3 - What size tires do you have on the truck and what size tire is noted on the label affixed to your driver side door? Having larger or smaller tires will throw off the speed reading by a certain percentage. 75MPH speedo to 70MPH actual ground speed is roughly 7% difference. And most speedometers will over state the speed by a bit stock.

 

#2 The delay isn't terrible, maybe 1-2 seconds, but it's enough for me to worry.

#3 The tires are the proper size. I guess i'll have to deal with the variance.