AK 83

I just got a 83 pick-up and took it out this weekend and started getting kind of a ca-chunk ca chunk noise when I'm under power like going up a hill, in 4 lo. I didn't check to see if it did it in 4 hi. It sounds like its right under the floor boards but I cant tell if its the transfercase or the double cardan joint. What would be the best way to rule out the u-joints? Any ideas on what else it could be?

82blueyota

inside the double cardan joint is a collar like dust sheild and a ball on a spring mine made the klink klink noise so i rebuilt it and the dust sheild i just left out dosent seem to hurt it. found the ball kit at my local driveline guy(murls drivline in spokane) new u joints are always a good idea.you will need to find out what size the stud is inside the joint see pic.napa has the ball kit also.my joint werent bad but when the driveshaft would turn the dust colar would go klink klink klink.hope this helps
also try removing all the floor shifter boots and test drive might help locate the noise easier i drove around for two days without it to locate my problem.helped without the boots.

AK 83

thanks, I'll drop that drive shaft and check it out.

wentz912

you could just lock the hubs in and leave the t-case in two wheel, if it still makes the noise then it's the d-line.

g_cali

That doesn't make any sense. What difference would locking the hubs make if its in 2wd? That will have no effect on either drive shaft, how would that confirm that the noise is coming from the drive shaft?

To check your u-joints just crawl under the truck and grab your drive shaft at either end right next to the u-joints and try to push/pull them in every direction. If there is play there you have a bad u-joint.

wentz912

if you either lock the hubs in, put the case in 4wd, or both, the d-shaft WILL spin.

Think about it, engage the wheels to their respective axle shafts, when the wheels turn so will the axle shafts, which turns the differential carrier and ring gear, which will make the pinion turn, and that's bolted to....guess what, your front drive shaft. TA-DA!

Oh and just in case you don't believe me...

http://auto.howstuffworks.com/four-wheel-drive2.htm

Al's Chop Shop

actually you are both right, in some ways. yes, with the hubs locked the driveshaft will turn.

however..... the noise of bad u-joints usually only occurs under load, just as the original poster noted its only up hills when there is a load.

in this case, locking in the hubs probably won't do anything to pin down the noise.


i also vote for the double cardan, mine does the same thing.

Al

g_cali

Wentz you are right, the driveshaft will spin simply with the hubs locked. But like Al said, there is no power to the front driveshaft with the t-case in 2wd, which means not much stress on the joints.

wentz912

Still if he runs his hubs locked, with the case in 2wd, and he still gets the same noise, under the same conditions, that 99% eliminates the case immediately.

OR, if it's lifted, it might just be that the driveshaft doesn't have enough slip in it and is riding in the very end of it's splines, which I have heard make a chunking noise like he is saying.

OR, his front shaft could be out of phase, which I have also heard make loud chunking noises.

OR, since first gens have little baby driveline mount bolts, some might have sheared and the noise he is hearing could be the driveshaft flange slapping the case output or pinion flange.

AK 83

I got a new front driveshaft in and it fixed the problem so it was the double cardan.