Hey folks, I need some help. I drive a 1993 idi, manual, 4x4 and the other day I was cruising along in 5th gear and out of nowhere it started making a loud grinding noise and wouldn't respond to the throttle (as if it had popped out of gear, but it was still in gear). While still rolling, I put in the clutch, took it out of gear, put it back into 5th and it drove normal for about 100 yards. I kept putting in the clutch, taking it out of gear, putting it into the next lower gear, releasing the clutch and each time it would drive a short way and make the noise and stop going. By the time I pulled into a parking lot, letting out the clutch in any gear would make the noise and it would not respond at all.

I was assuming the clutch must have failed somehow until I had someone let out the clutch while I layed under the truck and it was immediately apparent that the noise wasn't coming from the clutch area, it was coming from further back. Seemed like it was coming from the rear of the transfer case. The speed of the noise corresponds with how far the clutch has been released (if you barely let off the clutch it is slow) and sounds like something with teeth is hitting something else.

I removed the front end of the drive shaft and released the clutch and the shafting coming out of the transfer case spins and there is no noise.

I'm not sure what to do next, except drain the transfer case and see how it looks. Anybody got any ideas?

 

I guess that I should mention that I was driving in 2wd when this happened. I haven't used 4wd in two months probably.
Also, when the clutch is released and it is making the terrible grinding/clanking noise, the driveshaft twitches just a little bit with every 'clank' that happens. Thanks ya'll.

 

I'm no expert on 4wd but a friend of mine had a similar problem. The timing style chain between the main shaft and the front drive shaft broke. Good luck.

 

sounds like the rear differential died.

 

The rear differential dying would cause that noise in the transfer case? Should I drain the diff. and look for bad stuff in the fluid? Would that confirm a dead differential?

 

Driveline on = noise. Driveline off = no noise. Are you sure the noise is coming from the transfer case? Or is it traveling up the driveline from a blown rear diff? Easy way to tell is remove the back inspection plate from the rear diff and look for damage.

 

One thing might be to pull the rear drive line and then cycle through the various positions on the transfer case. Make sure that the front driveshaft spins in 4x4 when rotating the transfer case output shaft, it doesn't when in 2x4.
If the transmission is in gear, you should not be able to rotate the output shaft, if it is in neutral you should be able to.

 

I the rear dif went out. The drive shaft would spin. OP says it just twitches. Pull the drain plug on the TC and see how much trash is in the TC oil.

 

Thanks for the thoughts. Tomorrow I will play around with it in 4wd and see what happens. Am I correct in thinking that if it goes and doesn't make the clanking noise in 4wd, then the transfer case is suspect? I will also take a look at the fluid in the transfer case. If I'm still stumped I'll take the back off the differential. What would I see in there if it is dead?

 

If you pull the driveline, try to rotate the differential yoke(where the driveline connects to) with the wheels on the ground. If it rotates, you've got a big problem. It should move back and forth a little, but not rotate.

If you lift a wheel off the ground and release the parking brake, rotating that wheel should rotate the yoke.

 

Ok, I stopped by the truck today (it's been stranded about five miles away) ready to try it in 4wd and drain some fluid. But when I got in it just to give it a try in 2wd, there was no noise and it seemed totally normal. I drove it around the parking lot for a while, then headed home. And it did fine, no problems! When I got home I drained the transfer case fluid and it was very black and ther was not much of it. Hard to say how much because it's hard to catch all of it after it runs off that skid plate. I peeked inside the drain hole and there was some loose debris so I pulled it out and found a white plastic thing, a chewed up rubber hose and what looks like a bunch of gasket maker squeeze out. I'll try to post the picture. Anybody know what the white plastic thing is? Or if there is supposed to be any rubber hose in the transfer case? And would just being low on fluid cause the above problems?I'm very glad to have it home to be able to work on it. Thanks for all the help.

 

I can't seem to put the pictures on here.

 

hmmmm. that sounds like a BW 1356 t-case with pump failure.
you can try refilling it with automatic trans fluid, but if it was mine i would be looking for a new t-case.

 

^^^^^ +1; that plastic thing is the "your t-case is shot" indicator. Shoot, if you were closer, I have a 1356 with good innards and a cracked case in my basement. I'd be checking CL, local yards, etc.

What model is your truck? The 1356s that went in the F350s had a PTO plate, but I don't know if they're built any beefier inside. They're interchangeable, though. Year-to-year, I know there were differences between the output shafts; I just don't remember offhand what was what.

 

+1 trans case pump failure. The planetary gears get eat up along with the hub that slides in and out of the gear set when they no longer get oil. I could mash on the go pedal and it would quit and grind when coasting. The rubber hose i believe is from the pump when it spun on the shaft. part 135 is hose and 132 is what wears through case ridges. Raised aluminum ridges on case holds pump body from spinning but over time it rocks back and forth and wears through aluminum. White plastic may be the shifter fork pad.[***************]Save[/COLOR]