M1031 pulls to the right in 4-high unlocked

[bshupe]

I have always had a difficult time getting my transfer case to shift between 4H, 4L etc. A buddy of mine gave me a tip that if you sort of give the shifter a good strike towards the floor it will shift more easily. I didnt know that so I was anxious to try it. The next time I was in the truck I tried it and I was shocked that the shifter moved from 2H to 4H easier than the transmission gear selector. (theres a free tip for you if you struggle with this as well)

A side effect of this was that I accidentally left the truck in 4H unknowingly. I was driving around a couple of days later and my heart sank as I started noticing that when I was accelerating the truck was pulling pretty heavy to the right as though I had a flat tire. I got out and checked everything and couldnt see any problems. I got back in to drive and started away. Same thing. I started pushing it a bit to see if I could flesh out any more details of the problem. As I went faster (30) it just got worse. Push the accelerator and it goes to the right making me turn the steering wheel about 1/4 turn to the left to compensate. Let off the pedal and it straightens right out. I started checking everything. Hub locks, tire pressure, steering stabilizer, ball joints, leaf springs etc. I was sitting in the truck just pouring over the systems trying to think of what in the world could cause this. Then I noticed the transfer case stick didnt look right. (Not sure why the 4x4 light wasnt on and Im still working on that) I remembered that I had been messing around with it the week before so I gave it a hit and moved it up one position to 2H. The truck drove perfectly after that.

Can anyone shed some light on why the truck would pull to the right like that when the T-case is in 4H and the hubs are unlocked? I havent been by any place where I would feel comfortable locking the hubs and seeing if it pulls like that. I have had the truck off-road before but never noticed this although I never was driving street speeds.

Thanks for any help you are able to provide.

 

[Keith_J]

Have you lifted the front wheels off the ground and checked for proper hub disengagement? How about the knuckle universal joints?

 

[trukhead]

Have you lifted the front wheels off the ground and checked for proper hub disengagement? How about the knuckle universal joints?

Ya, ditto with what Keith_J said.

 

[Skinny]

Sounds like a sticky hub or something adding drag/acceleration to a front wheel. Remember you have an LSD for a front diff. When I drive mine hubs locked in 2HI it does have lots of steering wheel feedback.

 

[bshupe]

I have not put it in the air to see how the fronts spin, free/dragging etc. but that sounds like an excellent idea.

Skinny - the status while Im seeing this problem is t-case in 4h and hubs unlocked. (if that makes a difference in what you are saying)

 

[Keith_J]

Part time transfer cases typically have no center differential action. They are locked 1:1 front and rear, a solid spool. So if you have one hub locked, there will be pull to one side. Sometimes the hubs fail in the locked position. The check is easy, with the engine off and all 4 tires on the ground, try to turn the front drive shaft out of the transfer case by hand. In the 1031 or any CUCV with LSD front differential, both axle shafts should turn. If not, jackstand the front tires off the ground and try again. Or jack up one wheel and turn the wheel while looking at the knuckle U-joint to see if the axle is turning.

The LSD in the front will allow slippage but there will be enough torque to cause pulling if one hub is locked.

 

[bshupe]

Part time transfer cases typically have no center differential action. They are locked 1:1 front and rear, a solid spool. So if you have one hub locked, there will be pull to one side. Sometimes the hubs fail in the locked position. The check is easy, with the engine off and all 4 tires on the ground, try to turn the front drive shaft out of the transfer case by hand. In the 1031 or any CUCV with LSD front differential, both axle shafts should turn. If not, jackstand the front tires off the ground and try again. Or jack up one wheel and turn the wheel while looking at the knuckle U-joint to see if the axle is turning.

The LSD in the front will allow slippage but there will be enough torque to cause pulling if one hub is locked.

I went out to the driveway and climbed under the truck and tried turning the front drive shaft. It only rocked back and forth a small amount. Slightly more than I would expect a rear drive shaft too. For kicks, I rotated both hubs to the locked position (more on that in a second) and climbed back under. The front shaft rotated slightly more than the first time and I heard the passenger side make decisive snap but nothing from the drivers side. The front drive shaft tightened back to only rocking slightly.

Back to the hubs; When I rotated the drivers side hub it felt very slippery like plastic on plastic with no real feel of anything happening behind it. The finger turn rotates past the lock position and then past the free position when rotating back the other way and in fact seems to pull in or push out on one side as though part of the finger turn has something on the back that is trying to go up over something pushing it out on one side.

When I rotate the hubs back to free the front shaft was as it was at the start of this test and when I put the hubs back to lock I again got the snap on the passenger side but not the drivers although with a little less rotation needed.

Im no expert on these things but I would imaging this means that the drivers side hub is stuck locked (better than unlocked I guess) and that would make perfect sense for pulling, pushing rather, to the right under torque. Am I on track here?

If this is the case, my understanding of the hub would be that it is only the operator interface that is non-op and if those parts can be replaced then it would be a simple fix. If someone thinks the problem is or may be deeper/more severe than this lets have that too.

If Im facing hub replacement I think I understand that there is nothing particularly special or fancy about the ones that are in there and the can be replaced pretty easily?

Thanks again for the helpful input.

 

[Skinny]

I would highly suggest after you fix your hubs to change your diff fluid and put in limited slip additive. More than likely you made that Trac Lok very upset.

 

[bshupe]

I would highly suggest after you fix your hubs to change your diff fluid and put in limited slip additive. More than likely you made that Trac Lok very upset.

Are we presuming that one axle has been locked and the other not so the diff has been spinning all the time Im driving?

 

[GHall]

Just keep it in 2wd till you get in the slick stuff.. Still make sure all drive systems are 100% though.

 

[bshupe]

Did anyone have any thoughts on getting parts for this or am I looking at a replacement hub assembly? Does anyone sell single hub assemblies? Does it make any sense to replace only one, should they both be replaced?

 

[Stonepicker1]

Just a thought, I had my M1031 pull to the right do to different size tires on rear. Left/Rear was new and the Right/Rear was at about 40%. Replaced the used tire with another new one and this fixed the pulling when giving it fuel going down the road.

 

[bshupe]

Just a thought, I had my M1031 pull to the right do to different size tires on rear. Left/Rear was new and the Right/Rear was at about 40%. Replaced the used tire with another new one and this fixed the pulling when giving it fuel going down the road.

Thanks Stonepicker. The problem goes away when in 2WD.

 

[bshupe]

OK, so I opened up both hubs to see if I could see anything obvious. On the passenger side the weather cap came of smoothly with a compressed spring and some plastic parts that thread in and out on a central threaded piece that is connected to the turn dial on the outside.

On the drivers side, when I got all the screws loose the thing popped off into my hand leaving the cap off and an (un-compressed) spring and the misc plastic parts in the truck side of the hub.

Im guessing this is the problem but it does look like I might be able to reassemble the weather cap side since there does not seem to be any broken parts, it just came apart.

Anyone ever try this? I would love to save $200

 

[porkysplace]

Save yourself a bunch of headaches down the road and buy a new pair of Warn hub locks . Yours will fail again when you really need them .