Hi
I just bought a 1999 chevy blazer 4wd with 170000 kms(about 100k miles)
The guy I bought it from told me that the right hand side wheel bearing is done for. The symptoms are as follows:
1. Pulsing sound from the passenger side, starting at around 50kph till around 80kph where it becomes more continuous
2. No steering wheel vibration
3. At low speed, no issues at all

It does look like that the wheel bearing needs to be replaced on the front passenger side, but if I am wrong I would be ever so grateful if you let me know
I also have couple of questions:
If I am to replace the wheel bearings, should I replace both front ones? Only the passenger side? or all four?
Also, are the wheel bearings different between the 2wd and 4wd models?

Thank you very much

 

Do you have any funny wear on the front passenger side tire? I started to have some when my second one went out.

I replaced my front bearings/hubs on my 1999 a couple years apart with the second one (on the driver's side) a year ago at 125,000 miles. So it is not unreasonable that yours could be bad too. As for doing both, if one is shot, it is not unreasonable to expect the other to be at the end of its life too. However, unless it is worn past spec, there is no reason to change it out.

I noticed the second one was bad when I was doing some front end work that had me take the front tire off leaving the bearing/hub exposed. If you can feel it move by hand, other than rotate, you should replace it. The hand test is crude and it still might be bad if it feels snug.

I remember my manual giving instructions on how to test if a front bearing is bad by use of a displacement micrometer tool and looking for some really small amount of displacement as being bad. I didn't need that as I could easily feel it was bad with motion of a couple millimeters!

Ultimately, you should do a thorough check of your front end components on your own or have an alignment shop do it for you. The previous owner might be right or he could be wrong.

As for the parts interchange, a quick look at the part numbers at an online parts dealer (like Rockauto) should answer that question. However, the drive shaft for 4wd's goes though the middle of the hub on the front wheels whereas for 2wd trucks, the wheels run on spindles; a fundamentally different arrangement.

I don't see any reason to replace the rear axle bearings unless there is evidence that it is needed.

 

Welcome to the forum.

It does sound like it could be a wheel bearing.

It's not necessary to change all at the same time, back and front wheel bearings tend to wear at a different rate.

If I do rear wheel bearings I'll do both sides at the same time because the diff cover is off, and fluid is already drained, so there's no sense in not doing the other side at the same time.... besides, rear wheel bearings(despite being harder to do) are relatively inexpensive.


Usually if one front wheel bearing goes the other isn't too far behind- however normally I will just change the problem one and wait for the other to go bad... mainly because they are more costly , and it doesn't save any time to do them both together.


Also, 2wd and 4wd front wheel bearings are different.

Edit: it looks like Christine beat me to answering your question.. I must type too slow lol

 

LOL, and I thought I typed slow!

But, it is always good to get a second, and third, etc. opinion!

 

Thank you both very much
After driving it for a bit, I am more convinced that it is the wheel bearings, I tried sweeping left and right at a bit higher speed, and when the weight shifts, I can clearly hear it, and it starts fading when going the other direction. I think I am going to replace both since I can also hear the left side going bad, it is just hard to hear over the other side's noise.

Now I googled wheel bearings for blazer, and I got a lot of results, which brand is the best? I've been mostly a Japanese car kinda guy lol
I bought this car at a very good price for the mileage(900CAD) and I am kinda using it to slowly build an off road vehicle, and to learn

I found these very informative videos online, I am mechanically inclined, so I think I am going to attempt it myself, what do you guys think?

 

I like the 1A Auto videos. I just wish their prices were lower.

One bit of advice. That hub nut can be a bear to get off. I broke a 18" breaker bar on one. I was just barely able to get it off with an air wrench and lots of penetrating fluid.

I think I used Timken brand hubs on mine. I can't tell you why they might be good but I know I would have tried to look around for peoples' thoughts on hubs before I purchased mine.

 

I have always known timken bearings to be good quality- they have a wide variety of bearings available as well...I've even been able to get bearings for early 1950's MG's thru them.

 

That is awesome, I guess I am going to buy Timken bearings
I am burrowing a gear removal tool to remove the bearing