From: Glen Larson [bigdadglen@earthlink.net] Sent: Sunday, April 20, 2003 10:28 AM To: 928 Subject: [928] Suspension rebuild w/rear bishings I recently finished a rebuild of my suspension that included replacing the bushings in the rear. As this is, apparently, a rare operation and there was some interest expressed in it, I thought to post the DIY details. What I replaced: * Bushings in rear. * Shocks/springs all around * One ball joint * Upper ball joint boots * Sway bar bushings Yep, rears rarely done. The gentlemen with whom I usually discuss my purchases told me that "those never wear out" and basically not to bother. This was before spotting an auction on eBay where the seller was offering six rear axle bushings and I got them for about $45 delivered. Actually eight were in the box: four for the pins, two for the lower arm to cradle and the two for the shock tops. This left four more for the upper links (~$33 ea.). And the forward "track" adjustment bushing, which I passed on at $200+ ea. Another purchase was most of the nuts that I was going to take off. Having tried to source other special fasteners locally, I knew to just order the solid metal metric locknuts. (The PET can really be handy.) A note there is that my model calls for an odd "tall" lock nut for the lower ball joint. The purpose is to force out the lower ball joint, like a built-in remover. They're kind of pricey and a regular locknut with hat can be used. I got new locknuts for the tops of the shock rods, but chose to not replace the 12 nuts holding the shocks to the body. So I get to it. Most of the rear suspension comes off easily. Just remove the nut and drive out the more stubborn pins or adjusters. One of the lower/inner adjusters would not come out so I used the Sawzall to cut off the bolt on the inside of the cross member. One end went well but the other I had it cocked a little and messed up the Al ear. Nothing too bad and some grinding removed the sharp edges. Turns out the bolt had seized to the inner sleeve of the bushing and the sleeve had separated from the rubber, likely during an alignment. The perplexing part of the rebuild was that the replacement bushings for the inner/lower connection just didn't look like they would work. I checked, and rechecked, the part numbers and talked with my consultants who happen to have this part on hand. A drawing was also sent and sure enough, those are the parts. The one I had got has sort of a dumbbell shape and it doesn't look like the stiff rubber will extend to be like the original ones. 928.331.588.10 is the right part. At the machine shop they also think it won't work, but as one is messed up (see above) it has to be tried. To my surprise and relief they make it work. They don't quite get it all the through, to be even, but far enough so that the metal sleeve protrudes on both sides. You don't wee it until the bushing is out, but the inside of the "collar" on the arm is bevelled and help stretch the bushing. The manual calls out some special tools for installing this, too. The bushings for upper link and the long pin go in without problems. During disassembly I discovered that some PO/mechanic had some of this apart and had not put it back right. This lead to more parts orders, especially since the PET does not show the washers for the upper link to hub carrier right. I needed a solid bevel washer for under the nut, but the PET shows the dish-like stamped washer at that point. Both are called "cone washers." 928.331.575.01 is the big (~4cm) stamped part. 928.331.649.02 is the heavy smaller washer that is similar to the washers that are on the pin on either side of the hub carrier. The rear went back together reasonably well. I chose to put some moly brake lube, very thinly, on the adjuster bolts and on the mating surfaces for the upper links. Also gave the eccentrics a spray of dry graphite. Hope that keeps things moving for a few years. No lube or antisieze on the threads, just new locknuts. The front went fairly well. Consulted the collective on-line wisdom and dropped the lower A-arms to get the shocks out. During re-install I found that proping the upper arm at a small upward angle allowed best movement. Something like 3 cm up from level. Used a pickle fork to separate the ball joints with (unfortunately) predictable results. On one side (first try) I mangled the upper A-arm boot attachment. On the other side, I ripped off the boot first to be clear on what the fork is grabbing. Not fatal damage, but not pretty. Getting that lever-action remover is recommended. Replacing the upper ball joint boots is not hard. The trick is getting that spring "snap ring" back on. I re-lubed and re-packed the joint. Just held moly bearing grease against the ball and worked it around. One thing I learned is to be conservative on how much grease to pack inside the boots. They get squashed nearly flat when the knuckle is installed, so a full boot will squirt grease out, and down the stud. This lubes the stud and makes tightening difficult. Replaced the lower ball joint in three minutes. Did not replace the shock mount nor cut the studs down. They stick out a extra 1 cm or so. (Big deal.) I put on poly sway bar bushings. Lubed them with white lithium grease and wrapped that bar with Teflon tape. (That should fix it.) I wasn't real happy with the bushings as the slots are a bit wide for the bolts and the supplied washers. Also, the mounting points are not flat having two ridges. I got some heavy washers for the outside and added some large washers underneath to shim there. This took about an extra 5 mm of bolt length. I should have gotten longer bolts to compensate. In a miracle that validates never touching the rear sun visors, when I got to adjusting the ride height, it was about perfect at 155 mm all around: exactly what I was going for. Didn't touch anything! Glen '80 Euro S Tabac Metalic - Ready to rock!