4x4 help

[1972CST]

The last few times I have tried to use my 4wheel drive it seems theres some binding going on. On dry pavement in 4-low it idles along slowly but the back tires act like they are being drug (breaks tracton and tire slides). Its almost like the front and rear axles are two different ratio's... trying to turn at two different speeds! Any ideas or clues? No major changes to drivetrain...350/350/205, D44 &12bolt geared 3.08 w/ 33's.
Thanks in advance, Ben

[72lb4x4]

You aren't supposed to drive the truck in 4wd with the hubs locked on dry pavement because it will do what you describe.

[1972CST]

Originally Posted by 72lb4x4

You aren't supposed to drive the truck in 4wd with the hubs locked on dry pavement because it will do what you describe.

I understand what you are saying and I dont use 4x4 on dry pavement... this was a quick test to see if anything changed. It acts the same way on and off road.

[truckster]

Because there's no differential between front and rear axles, they will turn at exactly the same rate when in 4WD. If your tires are at all uneven, due to different sizes or just from wear, the tires can't turn at the same rate.

[SeventyOne]

You sure you have the same R&P Ratio front and rear? Have you actually counted the driveshaft rotations or the gear teeth?

[1972CST]

This problem has just started in the last 3 months or so. In early winter I used the 4x4 a couple of times w/ no issues. Yes the ratios are correct.

[SeventyOne]

Check all fluids (diff and tcase)?

[Cap'n Hook]

Mine does the same thing off road, the front tires drag the rear tires when locked in 4x4. I've never checked the insides of the front and rear diffs, but I'm guessing somebody has swapped out gears at some point either in the front or rear without doing both at the same time.

On a side note, it will go anywhere you point it, so far, even with the different gears (if that's the problem).

[SeventyOne]

You guys both have 4 matching tires of equal wear?

[1972CST]

Originally Posted by SeventyOne

You guys both have 4 matching tires of equal wear?

My tires dont even have one oil change on them I hope they are the same diameter still. All my fluids levels are good.
Yea there is definitley something binding up..... its very,very difficult to shift from 4L to 2H w/ the trans in N.

This thing doesnt do well off road... cant get out of its own way. I did swap the front axle a while back but its got the correct ratio and had no problems after the swap... until now.

[SeventyOne]

I'd pull the diff covers to make sure everything is the way it should be and if so then recount the teeth to get the ratios. Also check the tcase fluid level. No leaks?

How are the ujoints in the front axle and the drivelines?

It drives well in 2wd? No dragging brakes in the front?

[dubds10]

How are you're u-joints? My rear u-joint was sloppy and needed replacing and that alone caused my 4x4 to not engage properly. It couldn't get out of a few inches of mud it was so bad lol Now that I've got new u-joints and everything it tight again, even with bald fronts I can get in and out of deep mud.

Just a thought, if it was fine before and just started to happen.

[old man jimmy]

From what you a say in your first post. That sounds pretty normal. You front & rear will turn at a slight different ration, even with the same gear ratio, 3.07's. That's the reason you can't use 4X4 on dry pavement with your hubs locked in, they bind. As far as going from 4 lo to 2 hi in n. Try pulling it back into 2 hi when in drive at a crawl at the same time you let up on the gas pedal. Other than that all I can think of is if you have posi. Find an empty parking lot(paved) or something, and go around in tight circles(slow) a couple time both directions, In 2 hi of course. That will help take the glaze off the clutches.

[1972CST]

I have been pondering my problem and considering all the comments. I get home the other day and wanna mess w/ the K5 some more. I lock the hubs, fire it up and head up the road to a place I can tinker more with the 4wd. While driving in 2Hi (acording to the shifter pattern) and the front hubs in the locked position I made it about 100yds before things started binding up and the rear wheels sliding. I pull over and get out to unlock the hubs and they will NOT unlock. I get back in and try to move the 4wd shifter and it wont budge. I start it up and alternate going forward and rev a few times before the drivetrain frees up enough to unlock the hubs and go home. Correct me if I am wronge but I should be able to drive all the time on highway w/ the hubs locked and the case in 2hi... after all some trucks had drive slugs in place of the locking hubs. I think I am gonna dig into my t-case linkage and make sure the shifter rails are in the correct positions to make up 2Hi. Could there be something broke in the t-case allowing incorrect 4Hi engagment when it should be 2Hi??? I know this seems like a longshot but in 2wd it shouldnt matter if the hubs are locked or not. I can unlock the hubs and have no binding problems what so ever in 2wd. Thanks again guys for all your input. I have checked all that has been recomended and found nothing yet.

[72lb4x4]

That sounds strange. Have you crawled under to see what TC it is? Maybe someone swapped it and the shift pattern is not as it seems?

[dubds10]

U-joints if worn down cause binding and 4x4 wont engage as well.

[old man jimmy]

You didn't say. But the road you were on was dirt or gravel, right? It's a big no no to use 4 wheel drive on hard surfaces. You have to have some slippage at the wheels. And yes you can drive in 2 hi with hubs locked in. Matter of fact that's how we always recomended everyone do it when they were new. Run them locked for the first 1 or 2 hundred miles. You might try using 4hi and 4lo with the hubs UNLOCKED. See what happens. That you can do on hard pavement. Sounds like you have something binding you up. You are sure you heve 307's front & rear, right? Also you don't want to unlock your hubs till after you get back in 2hi.