Got a 83 pickup and I think.. THINK THE U JOINTS ARE GOING OUT. MAKES A LOUD CLUNKING NOISE WHEN ACCELERATING. BUT ONLY WHEN ACCELERATING. IT'LL STOP WHEN I PRESS THE CLUTCH IN BUT IT ALMOST SEEMS NON STOP. AND NOW THIS MORNING WHILE I WAS DRIVING TO WORK I NOTICED IT WOULD POP WHEN DOWN SHIFTING FEELING LIKE IT WOULD ALOMST POP OUT EVEN THO I CAN'T. PLEASE HELP I AM LOST ANY IDEAS WOULD BE GREATLY APPRECIATED THANKS!

 

Is the "pop" the same as the "clunk"? Popping when down shifting, even though it might not seem like it, is often the carb/exhaust, not driveline.

Have you checked the ujoints? Get under your truck and see what kind of play there is in them.

Does the clunking noise speed up as your truck speeds up? Or is it a constant speed, regardless of vehicle speed?

Does it clunk if you just rev the engine, but aren't moving, or do you have to be moving?

I'd be move inclined to think transmission or rear differential/axle than u-joints.

Any vibration, or just noise?

 

Might try blocking the wheels, leave the truck out of gear and climb underneath and grab the drive shaft and give it a good going over, feel for any play up/down or side/side. And if that is all tight, you could unbolt the shaft and feel the joints moving by hand, see if the joints are binding or feel gritty or too loose when the move. Also check both flanges for play at the t-case and differential.

 

The driveline has a little play to it. It'll spin bout 25 degrees both right and left while the truck is parked. It is loose where it connects to the diff. The clunking does speed up if I accelerate. It doesn't make any noise while parked sounds normal. It only makes the noise while its moving

 

I would almost think it sounds like there binding cause it would bind then pop free driving down the road.

 

Pinion flange should not be loose, see if the retaining nut has loosened up on you:
- http://www.4crawler.com/4x4/CheapTri...eal/index.html

 

25 degrees is a LOT of movement. Mine essentially has no movement. I think...and someone will correct me if I'm wrong, that much back & forth movement might be the t-case output or rear differential, and not the u-joints.

It's been a little while since I worked on that stuff with my truck, though...

You're quickly getting toward catastrophic failure. Depending on where it breaks, it could really be pretty dangerous.

 

Could that possibly be the culprit of noise? And would Id have to drop the driveshaft in order to do that correct?

 

I could be wrong cause I'm am not exact with the degrees but it does spin a bit left and right

 

x2 on the loose yoke!!!

 

Yes, mark the position of the u-joints to how they connect to the rear differential flange and the t-case output, then take it out. There'll be a staked nut on either end (not driveshaft, but what it was bolted to). That nut having loosened could be your problem.

Get yourself a manual if you haven't done this stuff before, or take it to a shop.

https://www.yotatech.com/forums/f114...wnload-261385/

 

Well I pulled the driveshaft down to check out the loose flange. I tightened it up and then I did notice the yoke was a little bit more free then the other. But other then the loose flange I found nothikn g. I am stumped

 

Nothing to be stumped about. If the flange is loose (is it?), and it's not the nut, then it's an interior issue (either t-case or differential, depending on which end is loose).

So you re-staked the nut?

If you bolted the d-shaft back up, would there still be movement? Or was it just the one end?

 

Nut was loose as well, it was the diff side. Now that its sunny out I think ill throw the dshaft back on to see if I'm still getting play or not

 

Found out it was a blown rear end. Swapped rear ends an now no more noiise

 

Great!