Removing Center Joint and Torque Tube

[bosco]

I bought all the parts to finally re-do the center joint and torque tube rubber parts, bearing and differential seal. I've come across two different ways to remove the center joint, torque tube, etc. from the car and wondered which was easiest. The manual says to just put a jack under the center joint, unbolt it and let it down, where it can then be unbolted from the differential and removed. The other way involves undoing the shocks, removing each spring and reconnecting the shocks to hold the axle up, then unbolting from the differential. Both ways apparently relieve the downward force at the center joint. I'm thinking that the best of these ways would allow the bolts of the center joint to line up easiest as I am bolting it all back in the car.

Does anyone that is famiiliar with this proceedure have a preferred way of doing it? I've already put it off a few days thinking its probably going to be a "pain in the neck" kinda job.

Thanks.

[kwilford]

Originally Posted by bosco The other way involves undoing the shocks, removing each spring and reconnecting the shocks to hold the axle up, then unbolting from the differential.

That way sounds better to both remove and replace it. Replacing it is the hardest part. I have done it the other way, with the springs in place, and using a floor jack, a crow bar, a pointed bar, and a LOT of four letter words to get the central joint back in place. I would try this way, and lift the differential up to reduce the angle in the central joint as you position it. Where did you read that idea?

[opelbits]

I actually just did this last Wednesday. Disconnect the driveshaft and remove it. Disconnect the Panhard rod. Loosen the bolts at the center joint mount. Loosen and remove the torque tube to differential bolt that holds the brake line, and gently swing the brake line out of the way (just barely, the less movement the better). Put the jack under the center joint, remove the bolts and lower. The differential will rotate a little causing the car to shift. I did mine with the parking brake 'on'.

When reinstalling, attach the tube to the differential first. Then raise it into position using the jack.
To line up the center joint, you can do one of two things to make it much easier. One, use a fairly long (eight inches or so) phillips screwdriver/tapered punch to align the holes. Stick it through the bolt hole in the center joint then into the bolt hole in the chassis. The idea is to pump the jack and use the screwdriver/punch to guide the joint into position.
The second idea is to get two studs (50mm long bolts with heads cut off will work just fine) to install in the bolt holes in the chassis. Raise the joint and guide it onto the studs/headless bolts. Leave the jack in place while you swap the studs for the correct bolts.
The best idea may be a combination. One stud/headless bolt, and the screwdriver/punch in the other. This way you can guide it and the stud will keep it located while you switch to the bolts.

I have it on good authority (OGTS) that if you leave the Panhard rod attached, it will tend to pull things slightly out of alignemnt and can lead to a metallic clanking. A clunking under clutch engagement has been bothering me. It was recommended to remove and replace the torque tube/center joint and reinstall it with the Panhard rod disconnected.

Of course, it didn't solve my problem.

[bosco]

I heard the spring removal idea from Dennis at OGTS. When discussing it further he suggested not to remove the Panhard rod as it can sometimes be difficult to line up for re-attachment. Instead, as you said Keith, jack up the differential until everything rotates around into line. Never having removed the springs before the method "bits" described was the way I was leaning. Now I'm thinking I'll just bite the bullet and remove the springs (not sure about the Panhard rod) so it will be easier to bolt the center joint back up. I'm still not sure in my mind how the bearing, bearing shell (?) and 27mm nut all figure in but I'm sure it will be much clearer one I get it all out from under the car. Was hoping to do it this weekend but now I think I have successfully postponed it until next weekend.

Thanks for all the input.

[opelbits]

The hardest part about the Panhard rod was getting the bolt out, if it is seized in the sleeve, you will just waste time and not really achieve anything. I disconnected the bar at the body mount. Lining it up can be done the same as the center joint using the screwdriver/punch and, if need be, having someone push the car body side to side a little. If you do mess with the Panhard rod, it can only really be done with everything else bolted up. Otherwise, with the torque tube off or lowered, the differential will force the rod to rotate within the body mount, thereby wedging it.

The extra benefit of dropping that end of the rod is that it makes it so much easier to refill the diff with gear oil. All I had to do was hold the bottle up and stick the tip (you know the pointed cap that you cut the tip off) into the fill hole and squeeze.

You will need a small pointed punch, preferably round not a chisel, to 'undo' the locking tang/groove on that 27mm nut. There is a groove in the threaded end, when the nut is tightened you then use a punch or very dull chisel to to drive the lip of the nut into the groove, thus 'staking' it so it will never come loose until the next time. So, you need the little punch to open it up again.

[bosco]

Yesterday I finally got around to removing my torque tube/center joint and ....UNFORTUNATELY on one of the two bolts that holds up the center joint/rubber donut the welded-in nut (attached to the body) broke loose. I was able to pull down on the center joint enough to create enough tension to remove the bolt but I have NO idea how to re-install it. Has this happened to anyone???? Any ideas??????????????????

[Old Hippie]

I have a idea for you. If you can't weld a new nut in place (don't have my book at work to look at), try using a riv-nut. It may have a different name in civy life, but thats what we called it in the military. It's just a internally threaded collar with a collasping ring on it. It needs a special tool but it's a wonderfull way of replacing threaded holes (like licence plate attach points). You'd have to check the size of course, but if it works on jets, it should work fine on the GT.
Just my 2 C's

[namba209]

Bosco, I just checked my GT, only because it's still unassembled, and the nuts for the donut housing are located under the vertical wall that the package shelf behind the seats sits on. They can be seen through the holes in the back of the wall, but I think impossible to weld back in place without cutting the sheetmetal. It may be possible to position the nut in place and run the bolt back into the nut and "J-B Weld" the nut back in place. From what I saw on my car, the nuts were torqued in place then welded in. If you opt to use this method be sure the bolt threads are heavily coated in grease to prevent the J-B Weld from permanently attaching the bolt to the nut. Attached is a pic showing the 2 holes where you can see the nuts by looking inside toward the center of the car, taken from the rear of the car looking forward. HTH

[bosco]

Thanks for the tips, guys. Ron, thanks for looking for me and finding those holes....I think you might have just made my day. Now if I can just get that large nut off thats inside the center joint.....it seems to be on there pretty darned good.

[namba209]

Bosco, if you are just changing out the rubber in the donut attaching piece, there's no need to remove the nut on the drive shaft, or to take the torque tube apart from the differential. There are 6 tangs that hold the donut in place and are visible through the rectangular slots in the donut holder, (for want of a better word). I just replaced all the rubber in that piece last week, easy to do, kinda. The front donut tangs will need to be unbent or straightened and the donut will slide out the front with some assistance of a screwdriver. The inside diameter of the donut holds the drive shaft bearing in place or vice versa, the bearing is at a fixed location on the shaft and the donut will have to be removed from the bearing. The cylinderical supports are held in by bolts through the donut holder and are threaded into the torque tube, water pump pliers needed here. The upper stop is pressed into the slot in the donut holder. When you pull the donut holder off the torque tube, the drive shaft will pull out of the torque tube. To put the donut back in, slide it over the rear end of the drive shaft, up to the bearing and orientate the tangs of the rubber donut over the reliefs in the bearing and slip the donut over the bearing. install the two cylinderical supports on the torque tube and then slip the donut holder over the donut to the point where the rear lip fits in to the rear tangs of the holder. Then slide the drive shaft into the torque tube until the donut holder can be bolted to the rubber support. I used a lot of "petrolatum, technical" to do all the slipping and sliding of the rubber parts, it's a commercial grade of "Vaseline". For the panhard rod, I left it attached to the body and disconnected it from the differential, left the trailing arms attached to the diff also along with the shocks. Actually except for the panhard rod, everything was disconnect from the body and the whole assembly was rolled out from under the car to make things easier. Don't forget to disconnect the U-joints, but leave it slid inside the tranny to prevent leakage. Oh yeh, the emergency brake able was disconnected too. A long post but HTH.

[bosco]

Thanks for the post, Ron. I'm pretty sure I see what you're talking about while I sit here and looking at this thing. I also bought a bearing but I guess if the original looks ok I'll just leave it in. It appears somebody has tried to change this all before as one of the torque tube to differential bolt heads was stripped out and this big nut was chewed on by a wrench that didn't fit right. So far its been a pain so I appreciate your help.

[namba209]

From the instruction sheet I got from OGTS if the bearing is free and not gritty feeling, it should be o.k. But it can be changed if necessary after the shaft is pulled out of the torque tube. HTH.

[bosco]

so Ron......

It appears somebody has been into this thing before. Basically i was able to pull everything out of the "donut holder" without unbending tangs because the rubber donut was basically shot. However...the tangs are at all different angles......as if the PO had done this but didn't bend them all back to the correct angle. Besides being somewhat leery of bending them again and having them break off I'm wondering what angle they need to be bent back to??? perpendicular to the inside of the donut holder .........or at some sort of angle other than that??

Other than getting the big nut off I can't figure out how to get to the bearing.......and I can't get the nut to budge. But .....the bearing seems to move freely and fairly smoothly, so probably I'm ok there.

Thanks for help.

[namba209]

Bosco, the tangs should bend easily, I hope, of course it all depends on how many times they were previously bent. The front tangs go towards the front and the rear ones bend to the rear, kinda like a U shape. The lips of the donut are held in place by the tangs and the bearing where the donut rides on the outer diameter. If the bearing is operating smoothly, there should be no reason to replace it. It's when it grabs or feels gritty that the problems begin. HTH.

[kwilford]

Originally Posted by namba209 If the bearing is operating smoothly, there should be no reason to replace it. It's when it grabs or feels gritty that the problems begin. HTH.

Even if the bearing feels "gritty", it might just be a bit of sand and dirt inside the shell. The bearing sits in a four piece "clam shell" (descriptive, if not accurate) housing, that can get a bit of dirt inside. On mine, the bearing sounded TERRIBLE, but when I removed the outer shell and cleaned it up, the bearing itself was perfect. Here are some photos of what I mean. The rear shell is welded to the shaft, but the front shell is held in place by the yoke. The bearing is then encased in another pair of shells.

To get at the bearing, you remove the nut on the yoke (I needed to use my impact gun to remove mine), and then pull the yoke off the shaft. I just rested the yoke vertically on a bench vise, and used a large centre punch and hammer to hit the shaft (in the recess) down-wards. The yoke came off clean. Watch your toes! Then you can remove the front clam shell, and the bearing and clam shells then press off. Then remove the outer clam shells from around the bearing, and inspect the bearing. Reverse the procedure to re-assemble.

HTH

[GTJIM]

The nut that holds the yoke on is a nyloc one and the FSM advises replacing it - if youhave no replacement then at least use a small amount of Loctite (TM). The volume inside the sheilds around the bearing should be packed with grease (wheel bearing grease should be OK) and the nut torqued to 87 lbs/ft.

If it was me I would replace the bearing with a quality (SKF or Fafner!) new one just because I hate doing jobs twice ............

[bosco]

Ok, I finally got the torque tube all back togther with new donut and other rubber (urethane) parts. All in all it was more a pain than I expected........but it sure is nice not hearing all the thumping.

The one thing that was much easier than I expected was bolting back up the center joint and lining up the holes. I went the route of removing the rear springs but not either end of the panhard rod. having the car body on jack stands and using the floor jack under the differential I found that by jacking up the differential it swings the center joint around into perfect line......the bolts went right in without any huffing or puffing. Good thing cause it was about 120 in my garage and I was tired of this job. Thanks for all your help.

Next repair on the list.......fixing the front seat mount where it ripped thru the floorboard......sheesh.

[jakob]

Just installed a new donut, torque tube rubber mounts and upper/lower stops. Seems like the torque tube is in a bind against the upper stop. Is this normal Can't figure any other way to assemble it, pleaseeeee help.
Look in at the top part of the picture

[namba209]

Just as a cursory glance, it appears the upper and lower stops are reversed from how they are installed to how they should be installed. Of course I could be wrong, when I had the ZF posi put in my rear-end, the shop installed all new poly and rubber when they had it all torn down, and I can't check, the car's at the body shop. :o

[jakob]

I thought of that to, but what good would the upper stop be on the outside of the central support? The support bolts solid to the car, the only thing moving is the torque tube supported by the two rubber damping blocks. I compared the urethane to the original rubber damper, and they look to be about the same hight and the two urethane are identical. Did not see this 'problem' when I took it apart since the rubber donut was all gone.
I'll install it and see how it goes

[namba209]

Jakob, what I meant was, looking at the pic the two blocks appear to be different heights. I was suggesting you swap them. But if they are the same height, then something else is not right.

[RallyBob]

Actually, it all looks perfectly normal if you installed all new parts. It will 'settle' once you install it and drive the car. FWIW, the lower stops never wear out, the upper stops get destroyed with time. The lower one doesn't even contact in normal use.

[namba209]

Bob, thank you very much for bailing me out on this one. I just never really looked at mine because the folks at Pro-Gear here inSANe DIEGO rebuilt the whole thing with the ZF posi. I just got it and put it in after painting it. Your extensive knowledge is amazing and very well appreciated. Thanx again.

[jakob]

Thanks Bob! Good that some people actually have seen new parts installed and not the temp. repair most of us do. I'll install it tomorrow, after changing the front differential seal, thats what got me started on this whole rebuild of the central joint. Don't want to run the differential housing dry

Have read that a lot of people put rubber hose/belt pieces between the donut and the support. Should I do this even if the donut is brand new

[soybean]

Jakob, I put 5/16 fuel hose around the donut and support when I put mine in this past summer. I didn't rebuild / replace what you have though. I wouldn't think it would be needed as you have all new parts. Jarrell