AWD driveline bind

[MickeySpiers]

Patient is a '97 Limited with a V8. Long story short, replacing the front axle and half shafts (CVs, whatever you want to call them) alleviated the issue of dragging the front wheels across concrete when trying to reverse. Replacing the rear axle alleviated the issue of the truck sounding like it would tear itself apart when a turn was made (never seen a diff lock solid before, but this one did). However, when I finally installed a front driveshaft & turning the truck back into AWD, I was rewarded with a major driveline bind. I can grind the truck to a halt by initiating a tight turn, and half throttle in a well running V8 is required to move the thing at full lock. Straight lines are OK but you can still feel a little pull. Pull the front driveshaft, no problems, it drifts through turns like it should. Front diff is OK, wheels off the ground will spin freely like they are supposed to. I've read all the threads talking about an AWD truck drifting if the front shaft is pulled, trans is in park and no Ebrake, but mine doesn't do that. My driveway is very steep, there is no e-brake as I haven't adjusted them after replacing the rear end yet, and with no front driveshaft the thing doesn't move an inch when in park. I've read that when the t-case in an QWD goes, the viscous coupling burns up, but is it possible this one has frozen? Anything else I should look at?

 

[IZwack]

I think the problem all along is the transfer case -- so you did not need to replace the CV or rear axle. So check the transfer case's fluid level, and if its still good, then have it looked at or replace it. That should get rid of your binding problems

 

[410Fortune]

AWD t case is shot, if you are fed up with the AWD system you may consider the 4406 conversion.......
I converted my 96 5.0L in my signature and so have others on this site before me

I have a complete 96 AWD t case, (83K miles) and front d shaft for sale if you want it, $400 I am also in Littleton if you can believe that

 

[MickeySpiers]

The front diff was completely shot, the driveshaft was disconnected (actually missing completely when I bought it) and the front pinion flopped around about a half inch. Front wheels wouldn't spin with the front end lifted off the ground. Rear end was similarly toast, it had the limited slip which had apparently frozen as it groaned uncontrollably in a turn but was pretty happy straight. CVs, well they didn't need replaced, but it seemed a good time to do it... The truck is completely original, probably down to the engine oil, so most things need replacing...

I think the problem all along is the transfer case -- so you did not need to replace the CV or rear axle. So check the transfer case's fluid level, and if its still good, then have it looked at or replace it. That should get rid of your binding problems

 

[MickeySpiers]

Thanks Jamie. I've read your posts, along with all the others, and actually have all the electronics I need for the 4406 swap. Just need the case, shafts ($500 for all up at Stadium) & a sport tank, but haven't been able to convince my wife to give up the fancy message center telling her when she's out of gas... If I can figure how to hack that thing, or how to dent my current tank enough to clear the shift motor, the 4406 would have been in by now.

AWD t case is shot, if you are fed up with the AWD system you may consider the 4406 conversion.......
I converted my 96 5.0L in my signature and so have others on this site before me

I have a complete 96 AWD t case, (83K miles) and front d shaft for sale if you want it, $400 I am also in Littleton if you can believe that

 

[CDW6212R]

The message center should not be affected by changing to the BW4406, where did that thought come from?

I agree that likely the TC is bad, it sounds like the wrong tires or gearing were in the truck, for a long time. If that happened, the TC would easily be damaged. How sure are you that both differentials have the same gearing now? Check that first if you haven't yet. Regards,

 

[MickeySpiers]

The message center should not be affected by changing to the BW4406, where did that thought come from?

I agree that likely the TC is bad, it sounds like the wrong tires or gearing were in the truck, for a long time. If that happened, the TC would easily be damaged. How sure are you that both differentials have the same gearing now? Check that first if you haven't yet. Regards,

The message center will be affected by the changing of the size of the fuel tank, a reduction of capacity which will throw off most calculations of the thing, including the distance 'till empty calculation to which she pays more attention than the fuel gauge (yes, I know, I've tried, trust me).

When I bought the truck, the front tires were 225s and the rears were 235s, all four were bald and dry rotted; had to tow it home. Obviously been on there for some time, but the previous (second) owners only put 4k miles on the truck in the 4.5 years they owned it, and they were pretty much clueless about the thing. The front axle, which was shot, had been replaced in the past as it had junkyard markings on it.

I have only gone by what the junkyard told me on the new axles, I haven't tried to validate number of rotations yet. A good idea tho, I'll test that soon, thanks.

 

[gijoecam]

Indeed, the case is locked-up. This may have been caused by running without the front driveshaft, or may have been masked by the bad rear axle prior to removing the driveshaft. At any rate, a viscous coupling should never be locked up solid like yours obviously is.

-Joe

 

[CDW6212R]

The message center will still work, I thought you were suggesting it would cease to.

If you hadn't discovered yet, the message center is very inaccurate, do not rely on it for DTE etc. There is no way to recalibrate it, and I do not think that they have a learning ability. Likely the tank size is set in the system to calculate DTE based on a percentage. That means that the error will be proportional, not great, but not really much worse than what you have now. he DTE is the main calculation for all predicted distances, fuel, and time. That comes entirely from the fuel level sensor. Thus for a sport tank if it thinks that 10% remains, the error will be an additional 22/17 of that fuel. That amounts to maybe a half of a gallon, which is in the normal realm of error. I am sure that just like now you will be able to be comfortable with how it works, and use it equally well.

I am swapping in the sport tank with my BW4406 as well, I expect no more or less from my message center. I like it for its fuel mileage readings, though I wish they could be tricked into being more accurate. Regards,

 

[MickeySpiers]

Thanks Don. I've been watching the other threads, have seen you threatening for some time now to install that electric 4406, and knew you had the message center to contend with as well. This MC has actually proven to be maddeningly accurate; all information it's shown has actually been dead on, on the nose with gallons left & used, and mileage within a half mile over the full range of the truck. I didn't realize the MC calculated off the fuel sensor; I was afraid it would calculate based off knowing that "full tank" = 22 gallons, so when the sport tank was empty, it would still think there was 5 gallons in there & display a 100 mile DTE. Anyhow, I've also seen that PGDSM managed to whack the snot out of his big tank & fit it with the electric shift, so I may try that route before I replace it with the sport. It would take one heck of a dent to reduce fuel capacity by five gallons... Of course I've also read that the front mount needs serious modification as well, to the point of maybe not being stable, and I sure don't want that so I guess we'll see what this truck has in store for me. I'm already hoping that I'm one of the lucky few that can retain my stock secondary cats in their current stock location...