Driveline vibrations.

[dlundblad]

This is with my Chevy Blazer. 218k miles. I’ll get a driveline vibration immediately upon acceleration that will go away until 40 mph or so and then mostly go away after that. The low speed vibration IMO rules out an unbalanced wheel. I want to say a bad u joint, but I’m not seeing anything obvious there play wise. Revving in neutral doesn’t do anything either so I’m also ruling out motor mounts.

Thanks in advance.

 

[DuckRyder]

How's the slip yoke into the trans? Tail shaft bushing?

 

[dlundblad]

How's the slip yoke into the trans? Tail shaft bushing?

I will have to double check, but nothing was too obvious when I checked the transmission side u joint.

 

[Astro14]

Under acceleration means either it’s the transmission mount, or it’s in your driveshaft. Check U - joints, center bearing if you’ve got one…

What year is the Blazer?

 

[SwampSurvivor]

That's when you're putting the most torque on it. It is possible you have a tired u joint that just isn't doing enough under normal circumstances. But something else is worn (engine mount, leaf spring bushings) thats causing either the transmission or axle to move enough that it makes the u joint unhappy.

 

[gman2304]

I’ll get a driveline vibration immediately upon acceleration that will go away until 40 mph or so and then mostly go away after that

My Chevy truck had the exact symptoms and 2 new u joints fixed it.

 

[dlundblad]

Under acceleration means either it’s the transmission mount, or it’s in your driveshaft. Check U - joints, center bearing if you’ve got one…

What year is the Blazer?

1997. The S10 style. (Not the GMT400 2 door Tahoe.)

 

[Tman220]

U-Joints most likely. It's not lifted or lowered or anything anything is it? That can change angles enough to induce vibration. It's also surprising how much sagging engine mounts and transmissions mounts can change the angle of the tailshaft, so I would certainly look at all that stuff.

 

[dlundblad]

New u joint a fixed the issue. The culprit had started spitting a fine rusty dust when I replaced it. I replaced both just because.