*Solved* Pulls from side to side in 4WD?

[dualsport]

So here's my scenario:

I'm driving in 2wd, hit some slick stuff and push the 4wd button. After the 4wd engages, the steering begins to pull from one side to the other as I go down the road. Sometimes it hits a bit hard with a major pucker-factor, and other times it just rides against the edge of a good pull- feels like I'm in a groove in the pavement, ya know? But it's definately the 4wd causing it, because the second I go into 2wd, it stops.

Some history:

-I recently replaced the passenger side CV axle
-Before this change, this 'pulling' never happened
-Therefore, it's related to the new CV
-I've heard a few metallic sounding 'pops!' near the front region area direction... One right after the install... (don't say it... don't... say... it...)



-Could it be a bad CV that I installed?
-Could the other have immediately gone bad with the other 'good' installed?
-Anyone have a good check procedure for these CV's?
-Might the install have affected the diff?
-Might the install have affected the engagement mechanism?

I appreciate your help and advice!!!

Thanks...

[HenryJ]

Sounds like the shift fork is not on the collar? If so you are going to need to pull the axle and the front axle actuator to get things right. I had the same thing happen to me on one of the Tahoes.
Anything worth doing is worth doing at least twice

[dualsport]

That shift collar can come off when I just pull the CV? I'm gonna hafta poke around and find a front diff schematic... This one just got stranger.

Thanks HJ, but for the record, it would NOT be the second time... try fourth. Darn it. I just told on myself! It took me a couple tries b/c I shot myself in the foot the first go around. I forgot the shield on the back of the rotor... then put it on backwards (didn't catch that until it came time for the caliper. What can I say- It was dark, I was on gravel, my stomach was empty and it was the end of a long day, plus the BBQ was full of fillets from Valdez- I wanted DONE!


Thanks for the shift fork advice. I'll check it out...

[HenryJ]

If the axle shaft gets pulled out the shift collar can fall down and the shift fork gets displaced. That shouldn't really give you the feeling of a pull , as the front is not locked. More likely it would feel like the front was not working. The 4x4 indicator would show engaged, but the right shaft would not be locked.
It would probably make some gnarly sounds?

It is kinda tough to guess this one long distance. Go back over everything a fifth time and see if you can find something out of place.

[dualsport]

5th time... I'll git er done. Thanks.

I'm on a 4/10 schedule but I'll be back at work 'off the clock' tomorrow morning with the rig pulled in the bay. I just got the drivers side CV axle and I'm gonna put that one in too (boots been opened up all summer- maybe longer).

I know the 4WD is working though, because I'd never make it up my driveway pulling 2000 lbs of water! No crazy/gnarly sounds either. We've already been in the slick stuff for over a month now and I use it often... Makes me really miss the longer fall season of Wallowa County too- especially opening morning bull season (my Dad's already made that phone call, rubbing it it...)

[HenryJ]

If the 4x4 is working then it is not the shift collar. Gonna need more clues to something else going on. Maybe a seizing wheel bearing? Stuck slide pin dragging a brake? E-brake cable stuck? Differential side gears buggered?

[dualsport]

HJ-
How would you suggest checking those 'buggered' side gears? Remove the axle and peak in with a flashlight? That sounds like a real pain to replace/fix/access, eh?

[HenryJ]

It is probably easier to drop the axle assembly. Pull the whole thing out and set it up on the bench?

If the side gears or spiders are chewed up the oil should show metal. That would be time to pull the assembly. There would be lots of slack too.

I am no expert on the 7.25" diff assembly. Miles is the expert on those. I'd PM him and point out this thread. Drop over to TXZR2.com and ask some questions.

Hows the rear axle?

[dualsport]

Just replaced the driver's side CV this morning, then did a test run down to NAPA to get the core refund. 4WD works just fine- I verified it. Ducked into a big hard pack parking lot with my boss ridin' shotgun and both our heads hangin out the windows watching for the front wheels to spin while I spun a series of 'perfect 10' donuts Must have been a sight for anyone to see... Two grown men laughing and half hangin out the pickup. Heh heh... breaks the monotony.

Back to the issue at hand. The rig still pulls from side to side, but mostly to the right as I go down the road in 4WD.

Got back to the shop and pulled the passenger side (this would be pull #5) and checked the splines- they all look good. Oil looks good too. One thing was the snap ring was a real bear to get popped free.

Thats all for now. Gotta run. I'll be back in an hour for more 'fun.'

Thanks HJ...

[HenryJ]

What you may be feeling is binding in the transfercase when operating 4wd on dry pavement?

The front differential allows the two front wheels to travel at different speeds in a turn. The rear differential works in the same way. There is no differential in the transfercase to allow the front axle to turn at a different speed from the rear axle. When you turn on dry pavement or accelerate hard both axles will turn at the same speed. This will cause you to feel a pull in the steering as it tries to equalize the speed and maintain a straight line forward.

[dualsport]

i have a theory:

could it be an idler arm? I've got some play back and forth on the passenger side (this is the side of the pull). I looked back at a different post i made a month ago (?) and i was looking for steering slop. *bingo. just found the source. idler.

maybe that's working the front 4WD back and forth with the slop/play?

hmmm...

anyway... it's back together and i'm off for the weekend. finishing a lift on my wife's astro van 4" in an awd with some bfg's... sure makes a world of difference!!!

[HenryJ]

...finishing a lift on my wife's astro van 4" in an awd with some bfg's... sure makes a world of difference!!!

Sweet
That will make one fine expo rig! Start a thread on it in NOS. We want to see more

[dualsport]

Done... Just posted pics of the lifted Astro. Overall I'm very pleased with the outcome. We've got a growing family and I just bypassed the 'soccer mom minivan' phase for my wife and still have an 'eight passenger strong' for her! And she's very excited, which, at the end of the day is the best part of it all...

[F9K9]

Good deal!

[dualsport]

Ah junk...

Just got out from underneath the pickup and noticed that the rubber boot on the front driveline was toast! Looks like the grease went all over too. The driveline rattles around pretty good too... I did a search but came up with nothin. You guys know if they sell a kit for changing out that boot? Whole driveline time? Anything I should be worried about?

I don't think this would contribute to the 4wd pulling though... Seems to be before the differential 'choosing' sides...

Headed home... Happy Thanksgiving folks...

[dualsport]

Well it's been over a month since my last post on this and I'm slackin so bad the snow's gonna be gone before I fix my 4WD! But I'm headed out to stand in line for a winter moose hunt and really should have something more 4WD dependable for the trip...

I did just replace all four ball joints (with some fine help from this forum I might add) and now the front end is a LOT tighter. I still have pulling going on up front, but I think I'm getting more positive feedback from what's going on up there...

I think I need to just pull the front out and take it in for repair. It's starting to whine going down the road a bit (but the oil level is good) and shake a bit when I engage the 4WD under acceleration. Not good.

Any ideas on how to eliminate the transfer case vs. the front diff? Drop the driveline?


Thanks guys! And Happy New Year...

[dualsport]

*Solved*

OK guys...

1st: Thanks for all your time and input.
2nd: Ever have one of those fixes where you're like, "Duuhhh!!"

I just took the pickup in for another alignment, because things just weren't making sense and I 'thought things were better' after replacing the idler arm... Well, turns out they probably were, and I was headed toward to right direction (especially because I also replaced all four ball joints) but the final solution was not to repair/replace the front diff, but just to have a 'reputable' shop do another alignment.

Now it's driving in a straight line with no jerking when I hit the ice. We're just about in break-up and the roads are constant ice/pavement patches. It's been a complete pucker factor for weeks!

Thanks again for your time and input. I'm stoked it's not a new front diff!

[F9K9]

Wow! Sorry you didn't get more help. You slipped under my radar but, amd glad you have it worked out.