retrospect

Hey guys I think there is a problem with my 4x4. When i bought the truck it had brand new rear tires and the front were VERY worn and when I put it into 4wd on pavement (just to test it) it felt like something was binding but as soon as the wheels were on a slushy/snowy surface, everything worked fine. I assumed that the difference in tire diameter between the worn and the new rear tires were the reason for this. So today i replaced the 2 worn tires and tried again on dry pavement to find the same thing. when on the slippery surface, everything seems to work great but the second a wheel hits pavement the truck wants to slow right down and makes some drivetrain clicking noises and I am scared something is about to bust. The u-joints are fine. the specs of my truck are in my signature. Any ideas?

camo31_10.50

well for starters it's not recommended to drive your truck in 4wd on dry pavement....

with that being said...mine works fine on the dry pavement lmao

do ya got a locker??

retrospect

i know its not good to drive in 4x4 on dry pavement but that being said, it should still drive fine and only really bind when your cornering. Also when the road is half slippery sections (snow) and half pavement and your on the highway, you should be able to engage 4wd... I cannot lol. I really dont think it has a locker.... the PO didnt say it did and he was by no means the "wheeling type." Is there anyway to tell other than ripping apart the diffs?

toyotabull

this might shed some light. Have you checked the gears in the front and read to make sure they match? I bought a 2002 wrangler last year and put it in 4wd on the test drive only to have the tires start barking and jumping. Took it back and was told the front axle was replaced with a grand cherokee axle. We checked and the gears were different. Hope it helps

CappyKD

Different gears is exactly what I was thinking. Sounds like a third was swapped out.

Blue_petersen77

Same problem here. When I put it in 4 hi or low. As soon as I get offroad the 4wd works like a champ. Not really worried about it too much though since I never lock it in unless I get stuck or know there's gonna be a good chance of it lol

Junkers88

That sounds like the gear ratio in the front and rear are different, like folks here have already stated. In a low traction situation (mud, slush, etc) it doesn't manifest. On a high traction surface (pavement) the jumping and binding is a result of one axle turning lower (more torque) than the other.

Check the ratios. You could shatter something if you are not sure.

retrospect

ok, so now how to I go about troubleshooting this? I know my VIN code says I should have 4.88's, but it seems as though I dont (in both ends at least). Would there be an equal chance its the front or real diff causing the problem? Would my best bet be to mark the driveshaft and spin the tire 2 revolutions to check the rear ratio? How do I check the ratio of the front diff? Thanks a lot guys for the replys.

CappyKD

the 3rd member may have the axle code stamped into it. Crawl under there and take a look. yes equal chance as to which is the different one. I would guess the back as these Diffs seem to take out pinion bearing after a bunch of miles.

retrospect

what a piss off... sure wish i hadnt tested the 4wd on the snowy street when I bought it!! oh well, I guess its what happens when you buy an old vehicle!! still love the yotas....

JollyGreen

I think if you had different gear ratio's, it would jump and hop going down the road in 4wd
Does it just have resistance? If so, I think it's just the tire diameter difference, mine does that barely. like a very light braking action.
If it is hopping and skiding when going straight, like when you make a tight turn on the street in 4wd, you have different ratios.

CappyKD

Jolly,

He said he replaced the tires already. It's not that. The jumping would depend on which diff has the lower ratio.

Matt16

sounds like different ratio diffs to me. Not sure why the 4wd light is blinking... maybe the 4wd sensors got more complicated in late models, but i can bind mine up all i want doing circles on dry pavement with no liights

Stuwy123

iTrader: (1)

Easy way to check if you have different gear ratios front and back.

Put it in 4wd (lock the hubs if you gotten to).
Jack up and put some blocks under your rear axle so the tires are off the ground.
Jack up the front end so the tires are off the ground.
Use a couple ratchet straps to hold the two tires on one side. Either through the spokes or band it around the tires.
Mark the tires at the same spot.
Turn the wheels with your tire iron. Do two complete rotations.
If the marks don't line up (and the locked up tires didn't move at all), then it means your diffs are different.

I don't recommend running the truck with tires off the ground, your ratchet straps could come loose and shred your fenders.

retrospect

I will try this but when you say "use ratchet straps to hold two tires" do you man strap them so they are connected to one another or so they are tied so they do not move? im guessing the later....

Sorry, Im just not exactly sure how you mean, obviously the diffs are open ( I know they dont have a locker) so the passenger and driver side wheels should be able to rotate at different speads. I see your reason for jacking the truck up and spinning the wheels 2 rotations but what is the reason for tying/locking one side down? Please explain. Thanks!!!

retrospect

Oh, I emailed the PO to see if he had done any work on the diffs. He said "the front diff had the sealed axle bearing repressed." Would this maybe be a cause of the problem if it was done unproperly? Dont think it would but thought id ask... thanks again guys.

CappyKD

Did you look for codes stamped on the third members?

retrospect

quickly crawled under there last night. It was dark obviously and i only could get at the rear third... Im going to check again today but the only marking I saw on the rear was "4 x U" not sure what that means but.... Like I said i wanna try and have another look in the daylight after I get out of class...

Stuwy123

iTrader: (1)

The point of using the ratchet straps on the one side is to make only the two wheels on the one side spin.
If you don't bind up the other side, all four tires will spin at different speeds, unless you have a locker. If you do, my advise won't work.

Stuwy123

iTrader: (1)

I've also never seen any sort of marking out the outside of a diff.
The only markings I've seen are the pinion nut/flange paint and the stampings on the ring gear itself.