grinding noise?

[lak2004]

Well I searched through as many threads as I could find and I didnt find anything that matched my problem. I have only had my blazer a few weeks and I noticed when I bounced it around in the snow this loud grinding noise would act up under acceleration, mostly just from a stand still. I checked the tranny mounts and t-case mounts and those seem fine. I was thinking maybe U-Joints? It happens a lot when I am going over really bumpy stuff. It seems to happen more in 4hi than 2hi but it has happened in both with the hubs locked and unlocked. It sounds like it is coming from under my feet too. It kind of sounds like the tranny and t-case are bouncing around and hitting the crossmember, but I checked the mounts. ANy hellp?

 

[chromewontgetyouhome]

It could be the double cardin joint in you front drive shaft.

 

[lak2004]

Would I have to get a whole new front driveshaft? How can I test for it?

 

[lak2004]

anyone?

 

[diesel4me]

shake it!..

The double U joint (constant velocity) is probably worn where the driveshaft rides on a stud and ball arrangement between the two U-joints..this will made a clunking or grinding sound you can feel thru the floor,sounds similar to a bulldozer with worn tracks and sprockets under acceleration..

You can grab the front shaft and push and pull up and down on it to see if there is excessive play there..it might just be the U-joints themselves,or the shaft might be toast--loose splines on the sliding yoke can cause similar noises too..if those areas are worn,your better off getting a rebuilt shaft,rather than attempting to repair it..its a somewhat difficult job putting those double U-joints in,and if the shaft and ball are worn,it requires machining to install the repair kit in most cases..you can buy a rebuilt shaft for under 100 bucks most likely...

 

[Brodie]

Look at your CV and make sure that it isn't hitting on the X-Member. Mine did that until I put in an adapter and it made the exact same noise.

 

[84 K5 4x4]

I dont know if it helps but a buddy of mine bought a blazer and he had a big clunking sound when he hit bumpy terrain. His problem was the yoke for the rear driveshaft was to big and it was hitting the driveshaft when the suspension flexed. Rare but it has happend. He had to put it on a rack and put it in gear to find it.

 

[lak2004]

Thanks for all of the quick replys! I think I found the problem, it looks like the driveshaft is hitting the crossmember, will a spacer help that or something else I should do? Thanks again for the help!

 

[lak2004]

Look at your CV and make sure that it isn't hitting on the X-Member. Mine did that until I put in an adapter and it made the exact same noise.

Where did you get the adapter?

 

[Brodie]

Superlift Driveshaft Spacer Pt #4310 $55.95 at Summit.
Or you could get it at any offroad shop.

 

[lak2004]

Thanks!