Weird grinding/ scraping sound 73 Chevy blazer

[Amber Foster]

So I've have a 73 Chevy blazer 350 small block with np205 transfer case, turbo 350 transmission on 3/4 ton front & rear end, drum breaks, apart trying to figure out where this sound is coming from. So when I hit 45-55mph and I let off the gas it makes a weird grinding/scraping noise, once it starts making the noise I can push the gas pedal a little bit and hold it and it stops the noise. I have checked my breaks, my axles, bearings and my gears in my rear end, everything has the correct fluid/oil and correct amount of fuild/oil. I don't have my front driveline either. 

[Jsdirt]

Could be a dry u-joint, transfer case problem, or an incorrectly preloaded pinion bearing in the rear differential. Usually the pinion preload will make the rear end sing (howl), rather than grind/scrape.

 

It's definitely something in the driveline, no question - just a matter of narrowing down exactly where. First thing I'd do is remove the driveshaft and see if any of the u-joints bind up when you try to move them around. I've had universal joints make all kinds of strange noises when they start failing. If that checks out ok, you're going to have to get it up on a jack + jack stands with a friend or two, and see if you can pinpoint the noise that way. Just be careful.

[Swimmer8366]

Sounds jlike transfer to me.

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[Amber Foster]

1 hour ago, Jsdirt said:

Could be a dry u-joint, transfer case problem, or an incorrectly preloaded pinion bearing in the rear differential. Usually the pinion preload will make the rear end sing (howl), rather than grind/scrape.

 

It's definitely something in the driveline, no question - just a matter of narrowing down exactly where. First thing I'd do is remove the driveshaft and see if any of the u-joints bind up when you try to move them around. I've had universal joints make all kinds of strange noises when they start failing. If that checks out ok, you're going to have to get it up on a jack + jack stands with a friend or two, and see if you can pinpoint the noise that way. Just be careful.

It's definitely not my rear end I pulled the inspection plate checked everything in there my slip yoke was kind of dry so put more grease in it. So hopefully that was the problem. 

[Amber Foster]

15 hours ago, Swimmer8366 said:

Sounds jlike transfer to me.

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What would be making that noise inside the transfer case?

[Swimmer8366]

Gears not merging together

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[Swimmer8366]

Does git change noises in 4wd?

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