Blazer is a '97,3 door, 4x4, 5 speed manual with 122k miles.

The front drive shaft U-joint area is hitting the very front of the bellhousing. Noticed a clanking noise every so often as I drove up and down the dirt road to get to the house I'm staying at, and I am NOT hard on my Blazer. The road is bumpy, snowy and icy; so every time I hit a bump the clanking was heard, and I'm only going 10-15mph on this road.

I get back to the house and parked in the level garage and that's how I found what's in the pictures. There's plenty of clearance as he's sitting there level, so I'm guessing as he's hitting the bumps in the road that it's pushing the trans/motor over that way or something. It was 9°F when I was checking, so I didn't do a full inspection, but all I noticed was the front shaft u-joint was hitting the bellhousing; scraping away material as shown in the pictures.

Any suggestions on WTF this is about? I'll do a more thorough examination come sun-up, but I didn't see anything else out of the ordinary other than where it was hitting. And I've taken this Blazer apart inside and out and know every nut and bolt on him. I didn't touch anything that would cause this or hit anything while driving.

I just replaced the blower motor and all the components to that system. It's always something huh? HAHA

Showing clearance and where it was striking...

Closer view of the strike mark...

 

Could you have a bad motor mount?

This is the front u-joint on the drive-shaft to the front axle right? If so, I'd think that the front axle would be unlikely to have shifted position as it is bolted to the frame whereas I could see how a damaged motor mount could allow the motor and the bell-housing attached to it to shift. There is also the mounts for the transmission to check too.

 

It's the front u-joint on the front drive shaft to the front differential just as the pictures show. I'm going to check motor and trans mounts later today. Replaced the trans mount a little over a year ago so I doubt it's that.

 

I'm with Christine, I think your motor mount may be damaged.

 

Oh joy. Gonna get under and confirm in a moment. Can't wait to do that job. This is what I get for not doing that when I changed the manifolds and had the trans out. Haha XD

 

Update...the driver side engine mount is broken. The passenger side wasn't too far behind. I managed to get the passenger mount off but called it a night due to it being almost 1 degree and I can't feel my hand and feet. Plus the driver side is going to be impossible to remove without taking more things out.

Anyway...broken engine mount...glad it wasn't worse.

 

Glad you got a solid diagnosis. Until I know what the cause is, I'm always a bit nervous. LOL

And yes, it pays to try to to anticipate what other parts are worth replacing when doing another job. Unfortunately, it is easy to forgot to do that. I know I've been guilty of that mistake myself!

 

In my case, the cause for the mount breaking was this bumpy dirt road leading up to the house I'm staying at temporarily, subzero temps and it being the original mounts from 1997. They had a good run!

 

The stock engine mounts are terrible. If yours are original, consider yourself lucky. Most of them don't make it this long.

 

They look original enough to me. Driver side one is bent TF up. At least it'll be easier next time they break since I cleaned everything.