Front drive shaft spins. Cvs not spinning..

[jman11788]

So I posted earlier in the week about having issues engaging 4wd. I solved that (well partially). The vacuum hose had a hole in it. Sealed it up and BOOM everything engaged perfectly! I was so relieved.

Later I jacked the whole truck up on jacks, engaged 4wd and to find out my front tires won't spin... wth is it now...

Now when I'm in 4wd or 2wd the front driveshaft spins with gas but doesn't turn the cvs. Something in the diff is proabbly locked up correct? I really dread replacing that diff again. I do not have locking hubs. It's a 2000 limited auto 4x4 with locker.

I'm just hoping it could be something else other than the diff.

 

[JohnMc]

Is your 4WD light turning on and staying steady, or is it flashing?

The ADD needs to engage to make 4WD work (and for the front driveshaft to turn the wheels), but I think there's a limit switch that it has to hit to make the 4WD light go to steady on.

If it's able to get to that state and still not engage the front wheels, there's probably something wrong inside the front diff.

 

[rkntoy]

Is your 4WD light turning on and staying steady, or is it flashing?

The ADD needs to engage to make 4WD work (and for the front driveshaft to turn the wheels), but I think there's a limit switch that it has to hit to make the 4WD light go to steady on.

If it's able to get to that state and still not engage the front wheels, there's probably something wrong inside the front diff.

+1 on the 4WD light. What is it doing?

Not quite correct though on the ADD. The ADD is only on the passenger side axle tube. Regardless of whether 4wd is engaged or not if you spin the front driver tire it should turn the front driveline. Does it?

 

[jman11788]

The 4wd light stays solid as it should. If I spin the front tire it does not spin the driveline

 

[phattyduck]

If something is FUBAR in the front diff, you will probably find remnants in the fluid.

Maybe do a drain and refill on the front diff and look for chunks? (remove fill plug first...)

-Charlie

 

[jman11788]

If something is FUBAR in the front diff, you will probably find remnants in the fluid.

Maybe do a drain and refill on the front diff and look for chunks? (remove fill plug first...)

-Charlie

Did a drain a fill today. Didn't notice any chunks or debri

 

[HiluxSurf SSR-G]

for those with multi-mode 4WD, is it normal to have the front propeller shaft to keep turning even in 2WD?

 

[jman11788]

for those with multi-mode 4WD, is it normal to have the front propeller shaft to keep turning even in 2WD?

That's what I'm curious about too. Mine always seems to spin

 

[phattyduck]

for those with multi-mode 4WD, is it normal to have the front propeller shaft to keep turning even in 2WD?

It can and does spin, just not in any direct relation to wheel speed. It can get slightly back-fed via friction in the front diff. It won't be locked to anything, since the right axle is disconnected from the diff.

-Charlie

 

[HiluxSurf SSR-G]

What I meant was with the 4 corners jacked up, the engine running, the tranny in D, and the multi-mode TC in 2H, is it normal for the front propeller shaft to spin and being driven by the TC? But the front diff is not engaged.

 

[JohnMc]

+1 on the 4WD light. What is it doing?

Not quite correct though on the ADD. The ADD is only on the passenger side axle tube. Regardless of whether 4wd is engaged or not if you spin the front driver tire it should turn the front driveline. Does it?

It disconnects the pass side CV shaft from the diff. The driver side CV is still hooked to the diff, and all it turns *for sure* are the spider gears. Anything else that turns (ring and pinion and the front shaft) all just turns because it sort of feels like it. Due to the slight amount of friction the spider gears have as they spin in the diff carrier.

So it can turn somewhat, but it's certainly not geared in. And depending on the varying age and wear on the different sets of bearings, it could probably range from not turning at all to turning a fair amount.

If the driver side wheel was still solidly geared into the front driveshaft, there wouldn't be any reason for the ADD to exist. Its entire point is to slightly reduce friction in 2WD mode by not turning the front driveshaft u-joints and front diff ring and pinion gears/bearings. It's not much friction/drag, but it's some. It's a lot of complexity for a very small MPG increase.

 

[phattyduck]

What I meant was with the 4 corners jacked up, the engine running, the tranny in D, and the multi-mode TC in 2H, is it normal for the front propeller shaft to spin and being driven by the TC? But the front diff is not engaged.

Its conceivable to be driven from the TC side too... as long as in 2WD you can reach under the truck (not running) and turn the front driveshaft, everything is mechanically disconnected as it should be.

-Charlie

 

[jman11788]

Resolved the issue!

When I i replaced the actuator thinking that was bad, I installed the new one wrong.. I didn't place the pitch fork correctly on the lock ring in the diff causing the fork to move but no monevement of the lock ring. Really glad I have 4wd drive now! Thanks for all your help as always

 

[EdTru]

Resolved the issue!

When I i replaced the actuator thinking that was bad, I installed the new one wrong.. I didn't place the pitch fork correctly on the lock ring in the diff causing the fork to move but no monevement of the lock ring. Really glad I have 4wd drive now! Thanks for all your help as always

Glad you solved this! Having same issues here. Hopefully this does the trick for me when I put the new actuator in the front differential. I have an 02 limited and the hose nipple on the actuator broke off. Fingers crossed.

 

[Bad Luck]

Glad you solved this! Having same issues here. Hopefully this does the trick for me when I put the new actuator in the front differential. I have an 02 limited and the hose nipple on the actuator broke off. Fingers crossed.

That hose nipple is for a breather tube. 01-02 front diff actuators are electric operated not vacuum like 00 and earlier. Still with the nipple broke off its likely water got into the actuator. Hope replacement fixes your 4wd.

 

[EdTru]

That hose nipple is for a breather tube. 01-02 front diff actuators are electric operated not vacuum like 00 and earlier. Still with the nipple broke off its likely water got into the actuator. Hope replacement fixes your 4wd.

Yea after hours of reading through forums I figured that part out. I opened it up and sure enough it was filthy inside. It's a goner forsure. Should be getting the new actuator soon.