I have a case of driveline slack, much more than most vehicles I've driven.

I can drive it pretty smoothly - but I know it would be a whole lot nicer to drive without the slack. If you don't know how to drive it, the slack can cause bucking quickly - which is absolutely terrible for the driveline.

I've got the NV4500 to the transfer case, and a Dana 80 in the rear.

Any ideas? I imagine the 5 spd and 80 are fine, so perhaps the transfer case? What loosens up to give slack?

 

Maybe what you are feeling is axle wrap? I know mine felt like it had a decent bit of slack in it and after my traction bars its much better. Just a thought

 

I would think that, except it doesn't have anything to do with power applied... it just feels sloppy at low output torques. You feel the slack if you coast from engine powering to engine braking. Or vice versa... I would imagine axle wrap would be occuring under higher torque loads (than basically nil).

 

I'm guessing the chain in the transfer case is worn out... though doesn't the chain not drive the rear driveshaft?

 

U-joints, spider gears.

What also typically happens is that everything, splines, gears, bearing surfaces, wears a little and the cumulative total can result in quite a bit of lash.

 

I should probably just dedicate an hour to crawling under the truck and trying to rotate the hell out of everything, and see what turns. I can't imagine the u-joints would be worn enough to cause that much slack, though there are 3 of them down the shaft, and everything does add up.

I hope it isn't in the differential - that would suck.

If I have the driveshaft off, I may as well put the transfercase saver in.

I'll probably stumble upon something that is ridiculously loose at some point, and shake my head for not finding it earlier.

 

the only obvious things will be the u-joint at the rear axle, other than that it could be slack in the transmission input/output, or the transfercase....

 

If I hold the output shaft on the 5spd, and rotate the input shaft theres some play between when it engages the output shaft, but I don't think thats gonna cause what ur talking about because the flywheel is always moving so it won't cause slack unless it's from a stop and u engage the clutch, but thats not ur problem, i'm pretty sure ur's has somthing loose between the transfercase and the axle...

 

Could possibly just be your rearend getting some play in it. Take out the back drive shaft and see how much play is in the rear end.

 

Check the engine and tranny mounting bolts.

 

If all of the above point to the rear end, take the cover off and check for backlash with a dial indicator.

 

Put the t case in neutral and grab the drive shaft see how much slop you have in the rear end and u joint then put t case back in gear check the front u joint if at this point you have not found the problem check bolts as Infidel said . Still did not find it drop the rear u joint and turn the shaft to check for slop in t case

 

Thanks for all the suggestions, guys!

I was hoping there was one thing that everyone had difficulties with (replace this $4 part, and it'll work great!), but I'll just mill around under the truck and go through everything suggested.

Certainly, it will be a buildup of slack in a a bunch of components, but if I can tighten up the worst offenders, I should be able to make it a whole lot better!

 

I have quite a bit of slack in my spider gears in my D80. I am just living with it for now. I replaced the spider gears in my Mom's 92 (D70) several years ago, and it had slack within 6mo, so I am not too concerned about it.

Daniel

 

Your truck is just old. As previously posted, a little wear here a little wear there and it all adds up. My 97 had the same problems. It just makes you drive a little smoother

lewis