Front Disconnect Problems

[Bay Wolf]

I don't want to clog up the lurker thread any more with my disconnect problem, so I'll continue here, instead. I've been lurking here almost as long as I have at trailvoy.com. I thought I had registered here, but when I tried to log in, it failed. Sure enough, a day after doing so, I discover my front disconnect is toast. Good timing, I suppose.

What I've done so far to one of my TrailBlazers, a 2003 LT w/4WD:

--Bilstein HDs
--Moog Shock Mounts
--Moog End Links
--NAPA Polyurethane Sway Bar Bushings (front, anyway; rears look like the rubber OEM ones)

So, not much!

I also changed the front diff seal on the driver's side a couple weeks ago.

I regret not shelling out for the G80 way back in 2002 now, and for not getting a more aggressive tread last January when I needed tires. Oh, well. Maybe next time. It does what I need it to do right now and it does it well.

[Bay Wolf]

I want to, but I don't know if I'd be able to get it apart, figure out what parts I need, get them all, and put it back to together before a trip on Sunday (one where I'd like to have 4WD capabilities).

Jack up truck.
Remove right front tire.
Unclip ABS wire and remove brake line bracket (2 10mm bolts).
Unbolt swaybar endlink. (Use impact gun or 7mm allen inside stud)
Remove bolt/nut from upper control arm pinch joint. (15mm)
Tap UCA upwards with hammer to disconnect from hub assembly. Let hub assembly hang.
Whack backside of CV axle tripod joint with drift and hammer to pop axle out of disconnect. A 2lb sledge gets it done in 2-3 whacks.
Disconnect harness from splined disconnect.
Unbolt 4 bolts holding disconnect to oil pan (leave the other 4).
Lightly tap disconnect with hammer/drift to rotate it in the pan (to free it up if yours is stuck).

20 minutes to get it out if yours isn't stuck. If it is, unbolt the other 4 bolts on the disconnect, pull the guts out and replace parts as needed. The inner bearing/seal almost never sees much wear.

If I read this right, I don't need to mess with the CV shaft at the hub, at all. That's good to see, because that's what we did on the other side when changing the seal. I was a little concerned at flexing the CV shaft as much as we had to to move it around.

I assume you've read through the how-to?

http://www.offroadtb.com/articles/tech- ... disconnect

The longest lead time is acquiring the parts you need... you'll probably have to take it apart to determine that. At a mimimum, 2 bearings and a seal are needed. But depending on the amount of wear and what broke, you may need more parts.

Skimmed all of it; read the first part of it closely, so far. Excellent resource.

I want the 4WD working properly, as we're going to CO for a couple of weeks on Sunday. The biggest problem I see is acquiring all the needed parts in time to do a rebuild. As a backup plan, I've ordered the full disconnect assembly by ATP from Amazon. It'll probably be a little costlier ordeal, but seeing one of your past threads and the amount of damage inside, the cost may not be much different, after all. I've had some vibrations in the steering shaft for some time now. I suspect this and the bad front diff seal are all related.

I think I have some experience with the rest of the process from the seal change. I'll deal with rebuilding the busted one after vacation.

[bgwolfpack]

BTW Hello and Welcome

[fishsticks]

If I read this right, I don't need to mess with the CV shaft at the hub, at all. That's good to see, because that's what we did on the other side when changing the seal. I was a little concerned at flexing the CV shaft as much as we had to to move it around.

Correct, if you disconnect the swaybar endlink and UCA pinch joint, it will allow the LCA/hub to hang down/out enough that you can pull the axle clear of the disconnect without having to touch the hub. I had enough room to change an axle out at camp by doing this. Woke up at sun-up, drank coffee, changed CV axle, ate breakfast, wheeled.

If you need a little more room, disconnect the tie rod end from the hub. Just watch the brake/ABS lines if you do.

Once the axle is out of the disconnect, you can move that end around as you get the disconnect bolts.

[Trail X]

Correct, if you disconnect the swaybar endlink and UCA pinch joint, it will allow the LCA/hub to hang down/out enough that you can pull the axle clear of the disconnect without having to touch the hub. I had enough room to change an axle out at camp by doing this. Woke up at sun-up, drank coffee, changed CV axle, ate breakfast, wheeled.

If you need a little more room, disconnect the tie rod end from the hub. Just watch the brake/ABS lines if you do.

Once the axle is out of the disconnect, you can move that end around as you get the disconnect bolts.

That seems like you're just making more work... removing the axle from the hub is so easy and I think it makes the removal easier. It seems like trying to remove the Tripod side with the hub side still attached would be a PITA. But I haven't tried it, so I could be wrong.

[Diacom]

Welcome to the Site.

[fishsticks]

Correct, if you disconnect the swaybar endlink and UCA pinch joint, it will allow the LCA/hub to hang down/out enough that you can pull the axle clear of the disconnect without having to touch the hub. I had enough room to change an axle out at camp by doing this. Woke up at sun-up, drank coffee, changed CV axle, ate breakfast, wheeled.

If you need a little more room, disconnect the tie rod end from the hub. Just watch the brake/ABS lines if you do.

Once the axle is out of the disconnect, you can move that end around as you get the disconnect bolts.

That seems like you're just making more work... removing the axle from the hub is so easy and I think it makes the removal easier. It seems like trying to remove the Tripod side with the hub side still attached would be a PITA. But I haven't tried it, so I could be wrong.

Letting the hub hang puts outward force on the axle, which helps the tripod break loose.

[Bay Wolf]

When we changed the driver's side seal, we couldn't get the axle out of the hub assembly. What's the trick? I didn't want to pound inward on the end of the axle shaft (too much).

[bgwolfpack]

When we changed the driver's side seal, we couldn't get the axle out of the hub assembly. What's the trick? I didn't want to pound inward on the end of the axle shaft (too much).

You don't have a big enough hammer to hurt it. Give it a real whack with a steel hammer.

[Trail X]

Then grease the splines real good prior to reentry.

[fishsticks]

:Iagree:

Then grease the splines real good prior to reentry.

I will shut my mouth... I will shut my mouth... I will shut my mouth...

[Trail X]

Your plan is good, I just worry about hanging the weight of the knuckle off the rubber boot.

[Bay Wolf]

After 3+ hours under dark of night, illuminated with only a 75W light bulb and the spillover from the flourescent tubes in the open garage, a new front disconnect from ATP Inc. is hanging off my oil pan now. The old one is a mess, at first glance. Both inner and outer seals are wasted. When I flip it over, the inner gears slide and clank around. I haven't torn it apart yet to see the rest of the carnage.

I'm sure this will help. There is a lot less play in the CV shaft now where it enters the disconnect assembly. Surely that will squelch some of the vibrations I've had lately, right? I'm not sure this fixes the entire problem, though. With the passenger tire still in the air and the switch in 4WD, the passenger tire will rotate, but not as freely as in 2WD. I didn't go to the next step; it's dark and I'm tired.

I did test the actuator after I had the old disconnect off. It still works properly, and the transfer case motor sounds like its working, too. Looks like I have more reading to do...

Back at it in the morning.

[fishsticks]

3+ hours? Ouch. Rusty bolts? Lack of tools? Fatigue? Dark never helps either.

Removing some of that play in the axles should help with vibrations.

Which mode were you in? A4WD only puts the front clutch at the ready position inside the TC. That would explain why it was more difficult to turn, but could still turn. With the switch in 4HI and one front wheel on the ground, you should not be able to turn the other wheel.

[Bay Wolf]

With the switch in 4HI and one front wheel on the ground, you should not be able to turn the other wheel.

This is what concerned me the most, afterwards. It was a little deflating that the wheel still turned a bit in 4HI.

I took my time, and piddled around taking some pictures of the 2 units side by side for comparisons, as well as some during the job. I could probably do it in half the time now that I know what I doing. As with the other things I've done myself on this truck now, it was much easier than I anticipated.

No stuck bolts, no stuck housing, and the axle came free from the disconnect with just a few whacks on the tripot. I had a little trouble clearing the end of the axle from the old disconnect. I had the most trouble, probably, trying to bolt the actuator onto the new assembly. That bottom screw was tough to get lined up properly with the disconnect mounted on the oil pan.

[Gordinho80]

Moved thread into Troubleshooting Section.... carry on.

[Bay Wolf]

^Thanks.

Good news: the front end vibrations are gone. The ride is almost like new.

Bad news: still no 4WD. I suspect its at the transfer case, now. I don't know what I was thinking when I read "prop shaft" on the flowchart, either. Chalk it up to inexperience...

But, my goodness, does it feel nice to drive without the steering wheel vibrating in your hands all of the time. It makes me angry that I didn't do this sooner.

[fishsticks]

The thing to check now is whether, with one wheel off the ground and being spun, the driveshaft turns.

That will narrow your problem down further.

[Bay Wolf]

Let's go through the flowchart, with the new disconnect installed...

(1) In 4HI and with passenger tire in the air, will it rotate?

--Yes, but with resistance, sometimes to the point of not rotating.

(2) Does the prop shaft rotate?

--No; it only moves a slight bit (less than 1/8th of a turn) when the direction of the tire rotation is changed.

(3) With both tires raised and in 4HI, does the driver side tire rotate when the passenger tire is rotated?

--Sometimes, but not very often; more time than not, the driver tire was not rotating. If I spin the driver side tire, the passenger tire would spin with it in the opposite direction a lot more often; maybe half the time.

[fishsticks]

Make sure the disconnect bolts are tight in the oil pan.

It sounds to me like the splines on your intermediate shaft may be stripped. Did you take a look at them when the disconnect was off? Is there kind of a ratcheting feeling when you spin the passenger side wheel?