Wednesday, January 31, 2007

Installing torsion arms - Part III

If you’re following along from parts I and II, the bus is still in the air, but we’ve made some progress. The lower torsion arms and the sway bar are on. The ball joints are attached to the steering knuckles and the brake backing plates are on. If you were fortunate enough to have a handy friend around, and you were able to convince them to do step 8, or if you’re just going to re-use your bearings as they are, you can skip step 8. Like the other torsion arm posts, here's the reference picture. Lets get to it.

8) perform optional wheel bearing maintenance.
This is an optional step that I took, and I recommend others taking. At this point, you’re pretty deep into your front end, and if you’re like me, you don’t want to have it in so many pieces again anytime soon. The front wheel bearings are supposed to be re-packed with grease every 30,000 miles. Odds are pretty good that yours are overdue if you haven’t been keeping track.
Anyway, the outer bearing probably fell out when you pulled the hub off the spindle or when you separated the hub and rotor. If you’re putting in fresh new bearings, you’ll just want to find it so the neighborhood dog doesn’t choke on it later. If you’re planning on keeping the old bearings, you better track that outer bearing down. Judging the quality of old bearings is totally your call. Look for marks or obvious wear on the bearings or the races. If you’re not sure, use new ones or find someone that can qualify them for you.
Assuming you’re replacing with new bearings, the bearing races need to be driven out. Don’t waste time trying to get the grease seal for the inner bearing out by itself beforehand. I did, and in the end, I gave up and the seal popped out while I was driving out the bearing races. I was able to drive each race out of the hub with a simple hammer and chisel, hitting one side and then the other. If you’re like me, you’re probably not too comfortable banging on your vehicle. Once the race starts to move, you’ll see that you’re not hurting it and you will work with greater confidence. There are some good pictures on this page.
The bearings don’t come pre-greased, so you need to force grease into the bearings. Drive the new inner race into the hub until you hear the change in the way the metal-on-metal rings. Then plunk the well-greased inner bearings into the race. Replace the grease seal. Repeat for the inner race and bearings. Don’t use the hammer and chisel method to drive in the new races, use a large diameter socket.
Now, slobber grease inside the hub between the races. Press it deep into the hub, and keep pressing it in there until there’s only enough room to slip your finger through end to end. Now you’re ready for step 9 and you have 30,000 miles before you need to do it again.

9) put the hubs on the spindles.
It seemed like no matter how much grease I put inside the hubs, I could have put more. I got the hubs on the spindles, pulled the outer bearings, and shot more grease in there with a gun. I tightened the clamp nut down, then removed the hub and put it back on. This seemed to force the air pockets out so I could get a little more grease in. Torque the clamp nut down by rotating the hub while tightening the nut. There is no published ft-lb for the clamp nut, but the bolt in the clamp nut needs to be torqued down to 11-14 ft. lbs. This is important as the clamp nut and bolt are what prevents your wheel from falling off!

10) grease front end.
As long as the front end is in the air, and you've opened the torsion arms, you probably need more grease in there. I cranked a good 25 times on the gun on each fitting. This also gives you a chance to see if your fittings (aka zerks) are good. I needed to replace a couple, which might explain some of the front end noise I heard before the clunking started.

- Wipe down your tools, and change your gloves. This ends the greasy portion of the job. Reward yourself with a snack! -

12) Put rotors (brake disks) on.
This should be pretty straightforward. The rotor will only fit on the hub one way and it bolts on with 2 6mm allen head bolt. Torque to 14-18 ft. lbs.

13) attach brake calipers.
Carefully thread the brake hose through the holder that you put on in step 6. There’s a steel/brass ring that protects the rubber line from rubbing against the holder. Its this ring that needs to be in the holder. Check the reference picture at the top for orientation. Thread the 2 mounting bolts through. Depending on the year of the bus, the torque value changes. For the first 2 years of disk brakes (1971/2), torque to 72 ft lbs. For all other years (1973/9) torque the bolts to 116 ft lbs. using a 19mm socket.

14) brake pad retaining plates, pads, retaining clips, pins
If you have the pad backing plates, slip them in first. I don't have them, like most folks, and I haven't noticed anything unusual it. Some think these are a really big deal. I’ve heard these plates have an effect on how much your brakes squeal. If you have them, use them. BusDepot had them on back-order, so I didn't put them in during this step myself. But then, my brakes squeal in the morning, so maybe I should follow up on this myself. Anyway, press the pistons away from the disk with either your fingers or something non-metallic (like, wood, dude) and slide the brake pads in. If you got new ones, great! Don’t forget to make note of the mileage so you’ll know when you need to replace them again. Put in the release spring thing and drive the pins in with a framing hammer from the inside. Once the pins are in, you just have to drive the locking clips into the brake line holder. The clip is oriented correctly when the bend is on the upside (like a hill not like a valley). Hold it firm with a pair of needle-nose pliers and whack it with the side of your hammer.

15) put wheels back on.
Torque to no more than 94 ft lbs. You'll have to take the bus off the stands for the final torquing, but you're done with it in the air at this point anyway. Don't hook up the air tools to get these nuts on like they do at the tire shops. Oftentimes, they over-torque these nuts, and that just makes it impossible to get them off when you're roadside.

16) install upper snubbers.
Others have said to put the snubbers on much earlier in the process. You could, but its more work. Once the wheels are on the ground, the upper torsion arm rises off of the steel bar and the upper snubber can easily set into place. You have to get on your back and all, but slipping it between the torsion arm and the steel bar thing is easy. Slide the stop clips as far as you can, and drive them in with whatever is handy. I used the side of the head of my framing hammer and it worked dandy. You'll have to whack it, though, just wiggling with pliers won't cut it. If you didn't get new stop clips, you'll realize about now why you should have. I broke one at this point and had to wait for mine to ship from
Canada. Grrr..

17) install shock absorbers.
Slide the lower end on first, then push the bolt through on the upper mount. The nut for the upper mount goes behind, so you'll be working blind, but setting a vice-grip or crescent wrench onto the nut works for torquing. Use a 19mm socket for both upper and lower. Once the upper is torqued down (36 ft lbs), do the lower (18-25 ft lbs). I don't know why the torque settings are different, but the VW engineers must have had their reasons.

18) hubcaps, test drive.
Hammer on the hubcaps with a rubber mallet and take a test spin in a relatively confined area. Remember, you just had your steering completely changed, so the handling will be different, and potentially unpredictable. If the bus wants to go careening in one direction or another, and pointing the bus in the right direction is more of an effort than it used to be, take it (or have it towed) to an alignment shop, and get the alignment done. If you've followed the steps above, the only issue is with the eccentric bushing not pointing straight forward. Alignment shops have the right wrench to set the alignment. If you can't actually turn the wheels from stop to stop, check the brake lines to make sure that they are connected properly and not hanging up on something.
When I test drove mine around my neighborhood, and it was like taking victory laps. By the time I got to this point, everyone knew what I had been doing, and most of them had dropped by to lean and watch a bit. The test drive was like being in a one-bus parade with the waving and the shouting. Fortunately, everything worked as it was expected, and I got to the end of the parade route (my beer fridge) without any issues.

Almost 6 months after I’ve completed this work, Hapy's front end is still nice and smooth. I haven't had to take it in to get aligned either. I just drove through some really gusty conditions, and Hapy handled it very well.... better than I did. I should probably put those backing plates on and check the torque values on some things, though.

until next time ...

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