Technical Article - Idiot's Guide to 505 Wagon U-Joint Replacement

A road test today proved that I had indeed successfully replaced my '91 505 wagon's U-Joint. [While under there finishing up, I noticed my left steering rack boot was literally in shreds, busted at every accordion fold. Strange; two rounds of inspectors failed to notice this.  My only explanation: Folz-Ra!] Anyway, as a public service, I will run down the wagon U-joint replacement procedure here.  Trust me, if I can do this, almost anyone can.

The Haynes manual is a good starting place, but it is only that.  First, have the right tools.  You will need at least four stout jack stands; two extra light duty ones are helpful.  You will also find the job much easier with two hydraulic floor or trolley jacks, plus one scissors jack (the standard Peugeot tire-changing jack is ideal), plus boards to put under them for stability.  If you're doing this in your dirt or gravel driveway, get a big piece of plywood and a big piece of carpet to go over it; on smooth concrete, use a creeper.  A good flashlight, 8mm and 10mm hex-bolt head sockets (like allen wrenches, only designed to go on a 3/8" drive socket wrench), a 10mm square-drive tool (I ground down an extra 3/8" extension), a cheater bar about a foot long for your 3/8" ratchet handle, a medium Torx screwdriver, a hand winch, an 18mm socket, and an 18mm box or open-end wrench (box is ideal). 

Next, make sure you have the right parts: the U-joint; new transmission mounts; lube and limited-slip additive for the rear axle; gaskets for the rear axle-torque tube joint, and cans of PBBlaster, anti-seize, and rubberized undercoating spray round out what you will need. Oh, almost forgot, a six of brew or a pint of whiskey. And a BIG supply of latex mechanic's gloves. And lots of ibuprofen. In fact, take some now. Prophylactically. Trust me, you'll need it.

Third, understand that this job cannot be rushed and requires a LOT of crawling under and out from under the car. Get used to it, adjust. Now, the procedure: 

1. Jack up the car, as high as you possibly can. Support the front under the jacking bar on two of the jack stands; support the rear under the rear jacking points (just in front of the back wheels) using the other two big jack stands. Let the rear axle hang down for now. Crawl under there with a flashlight and soak every nut mentioned below with PB Blaster. Then leave it for the night.



2. Remove the rear section of the console between the front seats; on the '86 and later 505, you do this by prying up the transmission selector escutcheon, undoing the two torx/phillips screws securing the front of the rear console section, then pop off the rear escutcheon and take out those two torx screws. Then unhook the emergency brake cable ends. Haynes advises you to slacken the parking brake cable adjusters and then remove the cables from the equalizing yoke in the console, but it's easier to remove the three bolts securing the e-brake handle (13mm), which gives enough slack to wheezle out the cable ferrules and you won't have to readjust the brake when you reassemble.



3. Get under the car and unbolt the rear brake compensator spring from the torque tube, and unbolt the compensator itself from the car body (13mm bolts). If you are going to remove the torque tube and driveshaft altogether, also pull the spring clip holding the brake line to the torque tube at about the midpoint, unhook the brake line from the flexible hook near the back of the torque tube, and (optional) unbolt the three-way union from the top of the differential; if you are only replacing the U-joint, you only need to do the compensator unhooking. Note that you do not need to break any rear hydraulic connections, just remove attachment points to get slack.



4. Go to the rear axle area and pull the rear wheels. Put a floor or trolley jack under the differential, oriented north-south so it can roll forwards and back while holding the differential; then jack up the rear axle somewhat. Unbolt the rear anti-sway bar links where they attach to the body (17mm); unbolt the bottom shock absorber connections (18mm nut, 10mm allen-head socket for the bolt head); unbolt the Panhard rod at the lower end (19mm nut, 17mm bolt head, cotter pin). If you're going to pull the torque tube altogether, you may as well undo the bolts holding the torque tube to the differential at this point; if not, don't. 



5. Go back under the centre of the car. Unbolt the c-shaped bar or bars reinforcing the front seat mounts (they curve under the torque tube) (13mm; a deep socket is ideal here). Remove the catalytic converter (note: do not have your face under it when you do; when it wiggles free, it drops fast and is quite heavy. Ask me how I know.) (10mm bolts at the front, with the springs, probably in good shape; 13mm at the back, and probably rusty). Remove the cat heat shield (4 10mm nuts). Get your scissors jack and a small flat block of wood to spread the weight (get a second, larger block if you're doing this on an uneven and/or soft surface), and run the scissors jack up under the transmission pan, to take the weight of the transmission. Raise the transmission ever so slightly.



6. Remove the transmission mount. Simple to say, not so simple to do. For the later model cars, it goes like this: First, remove the big bolts holding either end of the mount links. One end is high and forward, just under the ball socket at the front of the torque tube; to remove that bolt, you work your 18mm box-end through the second access hole from the front, and put it over the nut; then assemble an 18mm socket, u-joint, longish extension, and ratchet handle, and loosen the bolt. Note that you won't have to hold the box-end wrench over the nut, which is good because you'll need both hands to hold the socket extension in position to apply torque, and apply torque. You may need your cheater bar.
   
   Once you ease out the front link bolts, you need to get the rear link bolts out; they're easier, but the procedure is more or less the same. You may need various pry bars to ease the process here. Once the link bolts are out, wrestle/tap the links themselves out the rear of the transmission mount. Then unbolt all twelve bolts holding in the mount itself (17mm, plus you'll need your extension) and wiggle the mount out. It'll be hard to get out, and it won't be obvious why, but it will come out. Have a hard look at the transmission rubber mounts, which are pressed in from either side; chances are they are cracked or worse. Don't futz around with them; get new ones and pay the $15 to have a machine shop press out the old ones and press in new ones.



7. Now crank the jack under the transmission to lower it a few inches; the front of the torque tube will drop a few inches also. This makes the four 10mm allen-socket head bolts holding the ball joint to the transmission somewhat easier to access. Using your 10mm allen-head socket, a u-joint and a long extension, remove all four bolts. Recover the lock washers also.



8. Put your second hydraulic jack under the torque tube, positioned to take the weight. Go to the back of the car and drop the rear axle as far as you can, or at least far enough so that the rear axle will clear the bend in the exhaust pipe as you pull the axle backwards. Now pull the rear axle assembly rearwards a few inches. If it doesn't go easily (and you've not forgotten to remove all securing bolts), then attach your hand-winch to the car's body and the torque tube; I did this by wrapping a cable around the torque tube midsection and then hooking the winch to that and to the rear spare tire clamp, which is in a straight line with the torque tube. 
   
   Note that you can only pull the torque tube back a few inches before the ball joint hangs up in the body recess. Next, drop the centre jack a few inches, so that the ball joint can clear the body recess, and winch the axle back another few inches. Repeat until you have enough clearance for the front of the torque tube to clear the rear of the transmission. Then drop the middle jack (and the front of the torque tube) about half a foot. To accomplish this drop, you'll have to wrestle the torque tube left, to clear the front and rear exhaust pipes. 



9. The U-joint is now exposed. Shine a flashlight into the rear socket, and you should see an 8mm allen-head bolt. Reach in with an 8mm allen-head socket and an extension (with a u-joint or wobble connection if necessary) and remove that bolt (it unscrews normally, i.e., counter clockwise). Then slide the U-joint off the transmission tail shaft. Make sure you recover the thin but large copper washer between the front of the u-joint and the rear of the transmission.



10. If you intend to remove the torque tube and driveshaft, at this point prop the rear axle/torque tube stays so they cannot flop downwards, then undo the attachment point where the rear axle stays come together at about the midpoint of the torque tube (either a single long bolt or two 10mm allen-head socket bolts, depending on model), and then pull the torque tube forward, off the differential. Do not pry the torque tube off the differential; the spacer used back there is aluminium, and likely easily damaged; use the winch if need be. Extract the driveshaft rearwards from the torque tube; watch out, there is a rubber gaiter over the back end, and a spring stuck inside the rear of the driveshaft; don't damage or lose either. The ball joint cover up front clamps over the ball joint with two bolts; remove them, undo the clamshell, and recover the rubber O-ring. Clean, inspect, lubricate thoroughly.
    
    At this point, test the fit of the U-joint over the front of the driveshaft; it should slide easily. Ram a cleaning rag repeatedly through the torque tube until the inside is as clean as you can make it. Grease the centre bearing surface of the driveshaft well, then reinsert the driveshaft into the torque tube. Put the spring and gaiter back if you removed them. Grease the splines, generously grease the inside and outside of the ball joint, reassemble the ball joint clamshell (be careful to reposition the O-ring in the slot in the clamshell while reassembling. To keep everything clean, at this point cover both ends of the torque tube in plastic bags, like the ones that they use to put newspapers in, and then cover the bags with stretched latex gloves, to hold everything tight and neat. 



11. If you took out the driveshaft and did step 10, now do step 11: Replace the gaskets at the front of the rear differential. Put the torque tube on your centre jack and align it with the differential splined shaft and studs. Make sure the torque tube is oriented right (hint: the grease fitting in the middle of the torque tube faces more or less down, the pentagon point of the rear of the torque tube (the only corner of the flat plate back there which is not drilled for a stud) faces down, and the centre clamp point is positioned to re-clamp to the rear axle stays). Remove the dirt protection at the back of the torque tube. Pull the drive shaft some distance out of the torque tube and slip it over the differential splines. Then slide the torque tube itself rearwards, over the driveshaft, until it mates up with the differential studs. Bolt it into place. Bolt the front of the torque tube stays to the torque tube. 



12. Look at your new U-joint. It has a front end and a back end; the front end's socket is closed, with a small hole in the middle for a bolt; the rear end's splines are more or less open to the U-joint. Check the fit of the new U-joint over the tail shaft splines. If all appears correct, grease the U-joint thoroughly, place the thin washer over the transmission tail shaft, then slide the front of the U-joint over the rear of the tail shaft and slide it home. Take the 8mm allen-head bolt and run it home. If you've done this part right, the U-joint should flop freely to a limited extent in any direction; if it's rigid, you put the U-joint in backwards.



13. Pause here and drink a few beers. You're about to earn them.



14. Place the centre jack under where the torque tube stays meet the torque tube; orient the centre jack so that it can roll forwards while holding up the torque tube; and jack the torque tube up slightly. Pierce the front of your plastic/latex dirt protection, reach in to the front of the ball joint and pull the driveshaft as far forwards as you can. Jack the front of the torque tube upwards while wrestling it left, to clear the exhaust pipes, until it is more or less even with the rear of the transmission. Then align the torque tube with the centre of the driveline left-right. Remove your ball joint dirt protection completely. Now, ease the torque tube forwards (use the hand-winch here) until the rear of the u-joint is close to the front of the driveshaft. Readjust the centre jack and/or the jack under the transmission until the alignment between the u-joint and the driveshaft is as good as you can possibly get it. You'll have to guesstimate this by eyeballing the outside of the torque tube and by curling your fingers around the edge of the ball joint and touching the end of the u-joint; you cannot even see where the u-joint actually mates with the driveshaft, and can't really horse around the components. 
    
    Ease the torque tube forwards some more, and repeat adjustments. At some point, you will (barely) feel the ends of the u-joint socket and the driveshaft splines starting to come together, such that you can no longer push the u-joint socket out of the way of the driveshaft, but you won't be able to tell if they are really aligned, and you'll have to remove your fingers at this point to avoid losing them (the ball joint edge is very sharp). Ease the torque tube forward some more, while wiggling the front of the torque tube slightly to facilitate engagement. You can also try jiggling the rear axle brake drum with your foot to rotate the driveshaft to ease spline alignment problems. If Folz-Ra is smiling on you, the U-joint female receptacle will slide over the driveshaft. You may have to do this procedure repeatedly (and I do mean REPEATEDLY) until Folz-Ra does smile upon you. I had a LOT of trouble with this; others do it so easily that they never thought of this as a trouble spot. I repeat that using two jacks, including a fine-adjusting hydraulic one under the torque tube, eases alignment problems considerably. 



15. Manipulate the ball joint until it aligns with the rear of the transmission, then winch the entire driveline tightly home. Put in the 10mm allen-head bolts which secure the ball joint to the transmission. Using the jack under the transmission, jack the transmission back up, then replace the transmission mount (easier said than done, I know). You will probably have to use a ball-peen hammer and some creative gymnastics to drive home the bolts holding the front of the transmission mount links. Secure all 12 nuts, then replace the heat shield and the catalytic converter. Now you can drop and remove all centre jacks. Resecure the brake line components while you are under there. Make sure the handbrake cables are slid forwards into the car body, and the handbrake adjuster barrels are properly seated in their ferrules. 



16. Go to the back of the car and raise the rear axle slightly. Rebolt the sway bar links, the bottoms of the shock absorbers, and the panhard rod end. Make sure the springs are properly seated top and bottom; if not, drop the offending side and reposition the springs, then re-raise the rear axle. Using the 10mm square drive, undo the fill plug and refill the differential. You may find it a good time to change the rear axle fluid altogether; make sure you use the proper additive for limited slip differentials. 



17. Get back in the car and re-hook the cable ends to the handbrake equalizing yoke. To get the proper slack for the next step, simply pull up hard on the handbrake handle. Don't worry that it isn't bolted in place, you're just taking out the slack. Now place the front of the e-brake handle mount back on its stud and put the nut in place, then put the rear bolts (2) in place and tighten everything. Reassemble the console. 



18. Put the wheels back on. Drop the car as seems best. In the process of doing so, use rubberized spray undercoating to repair the parts of the undercoating you damaged doing this job (and there will be quite a few of them). That's it. You're done. Others will no doubt sneer at me, but I figure this at about a 5-6 hour job for the average Joe/Jolene. Considering that a shop will charge you about a grand US for the job, and the parts are maybe $250 from The Usual Suspects, it's not a bad job to DIY.

Marty Karo
10 September 2001

(originally from the Yahoo Peugeot List)