Jeff 98XJ WI
NAXJA Forum User
- Location
- Butternut, WI
Hey guys. When in 4wd I've been getting a growling noise with a
constant clicking that increases frequency with speed. Also, when
shifting back into two wheel drive, the case would remain in 4wd for
what seems like a bit too long. It takes actually backing up as
shifting to neutral isn't enough nor is sawing the steering wheel back
and forth. I thought it was in the t-case, so I took it all apart the
other night in my dad's heated garage, and upon testing, it STILL makes
the noise and won't drop out of 4wd easily!
Background: 231 case with 6 pinion planetary, wide chain and sprockets,
AA HD SYE, synchro setup inside, D44 front end with lockouts, 7" of
lift, Tom Woods CV shafts front and rear, D44 Rear end, 4.88 gears and ARB's, wore out 33x10.5 BFG AT's. This case worked noiselessly
for quite some time, but recently has developed this noise. Also, the
rear driveshaft was apparently suffering from a siezed slip joint for some undetermined period of time. When I first
removed it a couple weeks ago, the rear T-case output flange was a tiny
bit loose! I tightened up the nut a turn or so and put the lubed shaft
back in with no change in the noise. After disassembling the case this
past Friday, I swapped out the synchro parts for non synchro parts
thinking the synchro might be part of the not wanting to drop out of 4wd
problem and it's not needed anyway, but this didn't help. I did find
that the u-joint at the front pinion was kind of dry, but I just added
grease and reinstalled the shaft.
Testing: With the front hubs engaged and the t-case in 2wd, the noise
isn't there other than a bit of vibes from the spinning front shaft
which runs at an offset (in other words, this feels normal.) With the
hubs unlocked and the t-case in 4wd, the noise isn't there other than
the same basic spinning front shaft noise. At speed, if I shift back to
2wd, it drops out imediately. However, with the hubs locked and the
case in 4wd, I get terrible noises!!! I've checked the shift fork
linkage and all seems good there. I found no debris in the case, it had
fluid and now has new fluid. The bearings were all replaced when I put
this case together about a year ago. It feels smooth in 2wd at any
speed.
What the heck is causing this noise?!
On a slightly different front, how can the case remain in 4wd when the
lever is moved to 2wd? The shift fork HAS to move since the linkage is
connected directly to the shift sector. Actually, the mode fork rides
on the top of the shift sector, so I guess if the shift sector moves in
a way that would cause the shift fork to drop back to the 2wd position
utilizing the force of the mode spring, but there is some binding
between the shift collar, the chain sprocket, and the mode hub, the mode
spring might not be able to push the shift fork over and disengage the
mode hub from the chain sprocket. I guess I understand it now. Jeff
constant clicking that increases frequency with speed. Also, when
shifting back into two wheel drive, the case would remain in 4wd for
what seems like a bit too long. It takes actually backing up as
shifting to neutral isn't enough nor is sawing the steering wheel back
and forth. I thought it was in the t-case, so I took it all apart the
other night in my dad's heated garage, and upon testing, it STILL makes
the noise and won't drop out of 4wd easily!
Background: 231 case with 6 pinion planetary, wide chain and sprockets,
AA HD SYE, synchro setup inside, D44 front end with lockouts, 7" of
lift, Tom Woods CV shafts front and rear, D44 Rear end, 4.88 gears and ARB's, wore out 33x10.5 BFG AT's. This case worked noiselessly
for quite some time, but recently has developed this noise. Also, the
rear driveshaft was apparently suffering from a siezed slip joint for some undetermined period of time. When I first
removed it a couple weeks ago, the rear T-case output flange was a tiny
bit loose! I tightened up the nut a turn or so and put the lubed shaft
back in with no change in the noise. After disassembling the case this
past Friday, I swapped out the synchro parts for non synchro parts
thinking the synchro might be part of the not wanting to drop out of 4wd
problem and it's not needed anyway, but this didn't help. I did find
that the u-joint at the front pinion was kind of dry, but I just added
grease and reinstalled the shaft.
Testing: With the front hubs engaged and the t-case in 2wd, the noise
isn't there other than a bit of vibes from the spinning front shaft
which runs at an offset (in other words, this feels normal.) With the
hubs unlocked and the t-case in 4wd, the noise isn't there other than
the same basic spinning front shaft noise. At speed, if I shift back to
2wd, it drops out imediately. However, with the hubs locked and the
case in 4wd, I get terrible noises!!! I've checked the shift fork
linkage and all seems good there. I found no debris in the case, it had
fluid and now has new fluid. The bearings were all replaced when I put
this case together about a year ago. It feels smooth in 2wd at any
speed.
What the heck is causing this noise?!
On a slightly different front, how can the case remain in 4wd when the
lever is moved to 2wd? The shift fork HAS to move since the linkage is
connected directly to the shift sector. Actually, the mode fork rides
on the top of the shift sector, so I guess if the shift sector moves in
a way that would cause the shift fork to drop back to the 2wd position
utilizing the force of the mode spring, but there is some binding
between the shift collar, the chain sprocket, and the mode hub, the mode
spring might not be able to push the shift fork over and disengage the
mode hub from the chain sprocket. I guess I understand it now. Jeff
As an update,I tried locking one hub, locking the front ARB, and driving in 2wd and 4wd. Then doing the same with the other hub. Wasn't able to really get any good inf. from these tests. Seems like the noise is loudest when both hubs are locked and in 4wd, but somewhat noisy with only one hub locked and in 4wd (neither one made that much of a difference.) It seems like the noise is at a much higher rate than the axles turn indicating that it is probably emanating from the driveshaft or the t-case as it turns 4.88 times for each revolution of the axle shaft. I plan to swap to an old stock front shaft when I have time and see if that changes things. Jeff