ok so i have a 92 s10 blazer 4.3l... anyway a couple months ago my blazer would drive fine and when id hit fifty and it started making this weird winding noise untill u got to around 25mph and it would just could out like it finnaly enganged or something... anyway now at even 25mph it makes the weird winding noise again and doesnt cut out till like 10mph. what could this be?

wheel bearing?
transfer case?
transmition?

please help!

 

Highly doubt if it'll be a wheel bearing with something like that. Normally you feel them going out before you hear them. Do you notice a loss in power from the motor, or a loss in acceleration when you push on the accelerator? I see you mention a transfer case, is it a 4wd? Is it a standard or an automatic? Have you checked the level, color, and smell of the trans fluid / gear lube? Have you checked the rear differential, and front differential (if it's a 4wd) gear lubes?

The main thing that's holding up more of a pin point from me is what kind of trans, 2wd or 4wd, where you believe the sound is coming from (front, mid, or rear), if you can feel any changes in power or acceleration, and the fluids.

If I had to start checking for myself, I'd start with the fluids to make sure that everything is in order there. Then I'd start to find out if the noise is effecting the performance of the truck. If so, how and when. If there's a vibration with the noise or just a noise.

If it's a wourling type noise, I'd check the rear (and front for a 4wd) differential for proper lube level and wear. If it's a manual trans, I'd check the lube level in there as well. If it is a 4wd, check the transfer case level's as well. It might be a gear-to-gear sound from not having enough lube on it.

Check that stuff out and get back to us with more info. The more info that you can get to us, the more likely we'll be able to pinpoint what it might be before more damage is done.

 

ok it is 4wd automatic trans.. and i dont think it loses power but i think when u mentioned the front and rear diffs, that it might be the front diff because it sounds like its comming from the front.. it does make a wirling noise and as u slow down it starts to get louder untill u hit about 25-15 mph where it gets really lound and then it clunks and sounds like it engauges or something.. its really hard to explain lol but ya... what else do u think it could be??

 

You might want to go ahead and check the front diff fluid level and fill if, or change, if needed. The next time you hear it, and get down to around 35-40, put it in neutral and drop into 4 wheel high, then put it back in gear and keep going. If you still hear the sound, but doesn't get louder or quieter, it might be your front 3rd member wearing bad. If the noise changes, your hubs might be going out. The clunk is something that I remember from an old Ford pickup my grandpa had. Whenever the hubs would disengage, they would thunk.

If your hubs are wearing out, they are easily replaced. The 3rd member is another thing that's somewhat easy to replace, but a little costly. I'd surely be focusing on the front axle.