Following on from my thread last night i have found the reason i could not get up the hill, i have no drive to the front wheels, i assume i jack the back up stick it in drive & if the front prop turns then i have a broken drive shaft.
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Made a mistake thread update
- Thread starter joinerman
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Or a blown diff...
Mark Whiteside
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i would not check it that wayjoinerman said:
because if you have drive to the front you will drive of the jack
if it was me i would remove the rear prop and then see if the front prop turns
no drive to the front wheels should mean you have to have CDL engaged to make it move?
Not sure what you mean John, being an import i don't have front & rear difflocks just the high & low lever next to the normal auto selector, this is the cdl i assume, when i say i have no drive at the front my sympton the other night was when i got stuck the rear wheels were spinning not the front, selected low & no difference, the road on the estate where i work on is still thick with snow so this morning a mate stood & watched the front wheels while i gave it the beans & just the rears spin.
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whereisgibson
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Doesn't it mean that without any diffs, any power will go a spinning wheel / wheel with the least resistance to accepting more power, potentially robbing the other wheels of power. So unless the centre diff lock is on, there's nothing forcing some of that power to the front.
edit: but in low your cdl should be on, at least it is in my manual 80
edit: but in low your cdl should be on, at least it is in my manual 80
sorry cdl = centre diff lock. As Martin said above really - with the cdl unlocked you're only one wheel drive on a slippy surface so yes a spinning rear will take all the torque and waste it. In theory the viscous coupling in the transfer box should wind up and provide enough resistance for a bit of torque to go to the front but you might not have a VC or it might not be working. If you lock the cdl then you're 2 wheel drive on a slippy surface so a front wheel has to spin as well as a rear wheel to lose drive.
when you put it in low does the orange/yellow centre diff lock light come on? If not then you're not locked.
ok, when in low with the CDL light on solid a front and rear wheel has to spin to lose drive if everything is working ok, try it like that 
How do you know if you were in the truck? Not being funny, just trying to be thorough and avoid assumptionsjoinerman said:
ok, I think you should check it out with someone else watching again with it in low because sound can do funny things. If something were broken in the front drive train it would be equivelent to a wheel slipping so you wouldn't have any drive normally unless the CDL was locked. It doesn't sound like that's the case so either your CDL light is fibbing or a wheel on each axle was spinning or something has gone wrong with my logic map
Yes and no. You only have as much drive as the wheel with the least traction can support ... on a firm surface you're 4 wheel drive but put one wheel on something slippy and you're 1 wheel drive24Seven said:Without a center diff locked a "permanent" 4wd is really one wheel drive
On an 80 the viscous coupling in the transfer box is supposed to provide some torque transfer to the other axle but it's not a lot. I'm not sure what the arrangement is on a 90. 100's are the same as an 80 without the VC.
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Hi
I removed my viscous coupling last year and now find that in the slippery conditions wev'e had it is more like driving a rear wheel drive vehicle than a 4x4. Eg if you accelerate round a bend the back steps out and you have to correct. This never happened before VC removal. in fact in same circumstances it used to understeer slightly and just letting off the throttle would correct it. Although equal drive still goes through all 4 wheels without the VC and the the 80 being very light on the back the VC is needed. My early Range Rover had no VC but weight was distributed fairly evenly with a very light engine up front. I could throw it into a roundabout , accelerate and lose all drive because both inside wheels were off the ground. I used to keep the throttle fully open and there was a nice squeel from both tyres when they landed.
Frank
I removed my viscous coupling last year and now find that in the slippery conditions wev'e had it is more like driving a rear wheel drive vehicle than a 4x4. Eg if you accelerate round a bend the back steps out and you have to correct. This never happened before VC removal. in fact in same circumstances it used to understeer slightly and just letting off the throttle would correct it. Although equal drive still goes through all 4 wheels without the VC and the the 80 being very light on the back the VC is needed. My early Range Rover had no VC but weight was distributed fairly evenly with a very light engine up front. I could throw it into a roundabout , accelerate and lose all drive because both inside wheels were off the ground. I used to keep the throttle fully open and there was a nice squeel from both tyres when they landed.
Frank
