I have a 1998 S10 Blazer that is having a problem shifting back into 2WD from 4HI. It takes about 30 to 45 seconds to engage back into 2WD, but when it does it makes a thud sound. The faster I'm traveling the louder the thud. At 30 miles an hour it sounds like I hit a pot hole or a speed bump. Any suggestions?

 

You have either different sized tires front to rear, or otherwise. Or a severely worn tire or low tire pressure...

 

I do have a different size tire on the drivers rear. A couple of months ago I had a flat and put the spare on which is 235/70R15. The rest of the tires are 235/75R15's. The blazer is in need of new tires anyway so tomorrow I will try this. This makes sense.Thank you for the input.

 

lastcoupe

I put some new tires on today and that's what the problem was. Thank you

 

No problem guy, glad to help!