Loud banging when engaging/disengaging clutch?

[Suzukibking08]

Hi guys. I have a 95 regular cab nv4500 that makes a horrible banging/clanging noise when engaging the clutch. It doesn’t do it all the time but when you push in the clutch after letting off the throttle at low speed (1-2mph) it shakes the entire truck.

It seems to also do it if your driving down the road and let off the throttle abruptly (not touching the clutch) it shakes pretty bad. I was able to get a few videos below, any ideas? I noticed the rear differential and leaf springs move around in sync with the banging sound. It’s been doing it for a few thousand miles now and I can’t figure it out. Thanks.

 

[Joe Mc]

Yikes! I'd "think" that's in the t-case? What's it do in 4 high? Be interested in what you find out. Subscribed

 

[Tuesdak]

Rotate this by hand and what do you feel? A broken gear tooth or other binding? IMO you may have more than one problem.

From the top video it looks like a locked up U - Joint, frozen slip joint, or a bent driveshaft. It, the yoke, should not be walking in and out of the transfer case like that ... unless you hit a bump and the suspension moves on a 1 piece driveshaft. (I am used to two piece driveshafts that absolutely don't move in and out of the transfercase.)

Now what is by the truck frame that's moving and shaking? Upper left in first video. Center bearing support? Spring? It looks like something broke off and shouldn't be moving like that.

 

[NIsaacs]

Start draining gearboxes, take your pick which one first until you find a mess. transmission, t-case and rear axle cover. I think I would start with the rear axle.

 

[Suzukibking08]

Thanks for all the responses, I was able to test the truck in 4 high, it makes the same banging noise.

Tuesdak- What are you asking to rotate by hand, the driveshaft? It is a one piece also. I just replaced the u joints on the drive shaft. What is a slip joint is that only on a 2 piece?

Also the piece that is moving by the frame is an old support for side step rails I believe, unrelated to the banging noise. Nice observations! I would really like to get this figured out.

 

[BigPapa]

The yoke at the TC is the slip joint on a one piece drive shaft. You can see it moving in and out quite a bit in the first video.

 

[Tuesdak]

What are you asking to rotate by hand, the driveshaft? It is a one piece also.

Yes rotate driveshaft by hand. Did you spin the diff and transfer case by hand when the driveshaft was out? I assume the first video is on jack stands? If so the amount of in and out movement is not normal. Regardless X2 on @NIsaacs advice to look for a broken gear in something.

At least it is giving you a warning to stop driving it till it's fixed: unlike the bolt that fell out of my buddy's Mazda transmission into the gears. That was a quick stop, with the rear tires locked up, and I had to drag him out of the intersection in 4 Low.

You can put the T-Case in Neutral and maybe help isolate it to transmission or rear end.

 

[Suzukibking08]

Yes rotate driveshaft by hand. Did you spin the diff and transfer case by hand when the driveshaft was out? I assume the first video is on jack stands? If so the amount of in and out movement is not normal. Regardless X2 on @NIsaacs advice to look for a broken gear in something.

At least it is giving you a warning to stop driving it till it's fixed: unlike the bolt that fell out of my buddy's Mazda transmission into the gears. That was a quick stop, with the rear tires locked up, and I had to drag him out of the intersection in 4 Low.

You can put the T-Case in Neutral and maybe help isolate it to transmission or rear end.

Unfortunately I didn’t spin them while they were off. I got the video driving, I was able to mount my phone under there to get the clips. Looks like I’ll start taking a look at the gear boxes.