What is this HORRIBLE noise?

[K5thatShmobs]

The noise started when I would give it a decent amount of gas in reverse. Its kind of like a loud "chink!" Its coming from the T-case/bellhousing area. It started getting easier and easier to simulate. I have to go forward first, then put it in reverse and go backwards. But if I go backwards, then stop and do it again, it wont do it. I have to go forward once again, and then reverse to make the sound again. Now its getting to the point where I go forward, stop, and all I have to do is shift into reverse for it to make the noise.

I had a buddy get in the truck, go forward, stop, and shift into reverse. The "chink!" sound seemed to be coming from the area where the tranny hooks up with the t-case. The sound almost sounds like someone hitting a piece of aluminum with a hammer.

Anyone ever seen this before?

 

[milspecjimmy]

u joint is my guess
/forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif

 

[K5thatShmobs]

The rear driveline was just made two days ago with fresh everything. The noise really does seem like its coming from the where the t-case and the tranny meet. It sounds also like it may be internal. Argh...

 

[milspecjimmy]

i am lost, hows the tranny mount on it?
/forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif

 

[K5thatShmobs]

Tranny mount looks good... no parts are hitting the body or any crossmembers from what I can see... once again... it sounds like its coming from inside the casing somewhere. Man, I hope this isnt an overhaul thing.

 

[tRustyK5]

I'd still bet on a roached U-joint. Check the tranny to t-case adaptor bolts on both sides of the equation though...who know's maybe some loose bolts?

Running 9" of lift on a K5 can make U-joint angles and longevity a challenge.

Rene

 

[MA87K5]

Have you put the rear up on jackstands or just listened while inside? That would be the easiest way pin point where the noise is coming from. Also check the fluid in X-fer case. That could cause a noise. Hope I helped a little.

 

[K5thatShmobs]

Well, I can pretty much rule out any U-joint problems or any issues with the driveshaft... it made this noise under the same conditions before I even lifted it at all, with an entirely different driveshaft, and the stock 10 bolt (now its got a 14). The noise however has got a lot worse since the lift. I only had the truck for a couple weeks before I lifted it, so I only encountered the noise once or twice when it was stock. Im noticing it a lot more now with all the extra rubber. So, yeah basically I can rule out anything involving the rear diff or driveshaft. Anyone else have a suggestion?

 

[Thumper]

Hmm, wierd... but I bet you are going to have to humor everybody and drop one end of the rear driveshaft and check the u-joints. The way you describe the sound, it sure sounds to me like one is going bad.
Thats what you get for diagnosing a sound from 2000 miles away! /forums/images/graemlins/smile.gif

Mike

 

[K5thatShmobs]

Tommorow I'll look thoroughly at the whole shaft... Ill follow up. Happy Thanksgiving everyone.

 

[tRustyK5]

Well there is a known weak design issue with the 241 T-case. The range collar does not take any abuse at all. If someone has done any shifting between hi and low range somewhat carelessly the teeth on the collar may be worn. Maybe the PO wasn't very careful???

Rene

 

[milspecjimmy]

the only thing other than a u joint and tranny mount are the motor mounts, some thing has to flex in reverse in order to make a noise like that. have you checked the motor mounts?
/forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif

 

[Grim-Reaper]

Hmmmm maybe it the famous slip yoke 208/241 clunk that gets worse when you lift a truck.

 

[K5thatShmobs]

Grim-
What if it was that... what exactly would it entail to fix that problem? Today Im going to hopefully figure out exactly where this sound is coming from... or just get more stumped. /forums/images/graemlins/confused.gif

 

[Grim-Reaper]

Special blue grease the dealer has.

 

[K5thatShmobs]

Problem solved. It was the tranny mount. The crossmember bolts were torn out of the rubber on the mount, and the metal casing around the rubber was cracked from stress. The sound is gone, and Im happy. Thanks all for the help.

 

[chevyfumes]

I still say it's the U joints... /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif