INNER DRIVER & BOOT REPLACEMENT
A Special Thanks to Tom Townsend of TOWNSEND Imports in Greensboro NC for the contributions of this material!
The drive shaft transfer all the power to the wheels. They must be able to do this while the wheels turn and the suspension rises and falls with angles constantly changing. If kept sealed and lubricated they will last for many years. What typically happens is that the boots get broken, dirt gets in the joints and causes the joint to wear out. Replacement of the boots when discovered torn is imperative to prevent Cv joint failure.
This article is broken into topics. At the top is general information about the components common to the cars. Below that is more specific information for disassembly of the different models
Saab 9000 CV Joint Diagnosis:
A problem with an outer Cv joint usually arises as a rapid clicking especially in hard turns. It is evident at slow speed turns. At speed you may have a slight vibration in the steering wheel that is road speed dependent. Most joints failing do so after their boot has broken and the lubricant got out and water and grit in. Under the loads and with the range of motion in the joint, any grit gets worked into the mix well and the lube becomes an abrasive. Not removing this stuff completely when replacing a boot allows the grit to grind away at the joint. Disassemble the joint and clean it out well. They are neat puzzles. An inner joint usually shows up as a vibration under acceleration or load. They usually fail on the right or exhaust side first. The boot and the grease are constantly in a high heat area. A lot of times the boot was fine but the grease became so thin it ran out of the joint where the outer sleeve ends on the cup or just evaporated. You will often find them with rusty needle bearings in the tripod bearings.
CV Boots and Clamps Information:
No special tools other than an end cutter are needed to remove or install most Cv boot clamps. Fancy pliers exist for them, but a pair of end cutters like below work fine, for removal and installation. Use metal clamps. Plastic tie wraps can break and let the boot come loose. Clamps should hold the boot to a clean shaft tight enough that the boot doesn't easily turn on it. Use a small flat screwdriver through the hole on the outer part of the clamp to pry it over one of the tabs on the inner part. The clamp should be snug on the boot. Now use the end cutters to squeeze the folded part of the clamp together and tighten the clamp firmly. Be careful not to cut the clamp, just tighten it. Many people use standard tie straps in place of the boot clamps, these will also work fine and require no special tools at all.
Use a good quality boot to protect the joints. The quick fix split boots often become the quick fail type. Inspect the boots at every oil change. Attend to broken ones as soon as possible. Watch for outers to develop cracks that get deeper until they turn into tears. When the cracks start getting deep, plan to replace the boot. Good boot kits come with a tube of recommended lube and clamps necessary to install them. Really good kits come with new circlip and axle nuts. You may need an extra tube of grease to be sure.
Axle Nuts:
The axle nuts on Saabs need to be well secured. Older style outer Cv joints have a grove in them and the nut for them has a lip in its outer end as a provision to stake the nut to the shaft. They are cadmium colored. These always use a thick washer behind them to secure the outer Cv to the hub. Newer cars use a style="text-decoration: none"> nut with a smaller lip on them and the washer actually made to them. They are black. The lip is made to be out of round and to grip the outer Cv threads. All these nuts are one use. On the early nuts, you may get away with swapping the nuts to opposite sides ( unless you swap the outer joints side to side). Just make sure that the nut has an unstaked lip over the groove when you are finished torquing it. Use a punch and hammer to stake the lip to the joint in the joint's groove. Do not reuse the new style nuts. The nuts have to maintain the torque to protect the wheel bearing from loads that could pull it apart were the nut to back off. On 9000s especially, many strange noises have been traced to loose axle nuts.
Driveshaft Disassembly of Outer CV Joint or Boot:
You can easily remove the outer joints without removing the entire shafts on the 900 & 9000 cars by taking out the lower bolts in the control arm and leaving the wheel on, place a block of wood between the lower control arm and the actual wheel while popping the snap clip to all the shaft to fall out. You then can remove the joint itself while the actual shaft has fallen out of the way. The following directions are for joint removal with the shaft already out of the car.
A vise comes in handy for this phase. If you are removing the outer joint (and you have the shaft out already), before locking the shaft in a vise, pull the boot back and reach in toward the center of the outer joint and find the ends of the circlip. Position the shaft in the vise so you can get at these with a pair of circlip pliers. These are external circlip, you need to spread the ends to release them. Spread them and pull on the outer Cv, it should slide off. Sometimes it takes a tap or two on the inner part of the joint that spline to the shaft while spreading the circlip to get them moving. Pull it off and set it aside. You might want to mark which side it came from. Cut the smaller clamp on the outer boot and slide the boot off the shaft. If you are changing the inner boot too, you can cut its clamp and slide it off the end the outer one came off. Clean the shaft. Slide the new boot on the shaft. You can slide the new clamp with it, but most come open to be fitted around the shaft after the boot is on. It just depends on the type of clamp. When both boots are on the driveshaft, turn to the outer joint and clean and repack or replace it.
If you don't want to go through this part of the job then simply replace the joints. In most cases the joints will have to be replaced anyway.
Wash or wipe off as much of the old grease as you can first. Leaving some in the joint makes its disassembly easier. Tap one side of the middle ring in the joint down so a ball comes up out of the cup. You may have to pop the ball out of the hole by gently getting a small flat screwdriver behind it. Keep removing the remaining balls the same way. When all the balls are out, turn the inner part so one of its "arms" is in line with one of the holes in the middle part (cage). Rotate the middle part so its holes line up with the "arm" on the outer part. Turn the middle part on its end and remove it from the outer part. The inner part will come out of the middle part now. Wash it all up. Look on the thrust surfaces of the inner and outer parts. You may see worn lines across the face of the inner part and depressions on one side of the faces on the outer part.
If you reassemble the joint, put some new grease in the outer part first, insert the inner part into the middle part. Note the inner part has an inside and an outside. The circlip goes to the outside, facing you so from the end the driveshaft inserts. Put the middle part back in the outer part and align its holes with the grooves in the outer part for the balls. Turning one grove and hole up at the time, insert the balls, one to a groove. Its easier to me to insert them on opposite sides as you go one to the next. Pack the joint well with grease . Good quality boot kits come with a new circlip for the outer joint too, us it. The circlip installs into the inner part of the outer joint.
Now, if you cleaned the spline well, the joint will slip back on the driveshaft. Put whatever grease from two tubes I have left after packing the joint, into the outer boot. Line up the spline ( universal, no 'master' spline) and push the joint back on. Sometimes tapping the end of the joint with a soft hammer is needed to spread a new circlip to let the joint start on. If you have to beat the joint on, something is wrong. When the joint feels like it went home, pull back on it to make sure the circlip fell into the groove on the driveshaft.
Pull the outer Boot up onto the outer joint. Give the joint a few twists through its range of motion to burp out air and get the grease moved around. Make sure its groove is in line with the groove on the joint for the big outer clamp. Install the boot clamp as you did the smaller inner ones
Replacing the Tripod Bearings:
If you need to replace the tripod bearings, place the driveshaft in a vice and remove the circlip on the end of the shaft. Tap the old tripod bearing off, noting that one of its faces is tapered. This face goes on the shaft first so the bearing will seat deep enough to allow the circlip to be reinstalled. Not much of a problem getting the old one off as putting ht new one on. With the old one you can fail away, just don't damage the spline on the drive shaft. With the new one, you have to be careful not to loose a cap. A socket that fits the edge of the inner part of the tripod bearing can be used between it and the hammer to protect the caps from getting struck. Be sure and use a rubber band around the caps to help keep them in place. A punch may be necessary to fully seat the tripod bearing on the shaft, never strike the caps to seat the bearing, just its inner most part, near the spline. Be sure and start the tapered face of the tripod first, just as the old one came off. Its seated when the circlip will go on the end of the shaft and fit in its groove there.
9000 CV Joint Disassembly:
Break the axle nut and lug bolts loose before jacking up the car. Then lift the front wheel off the ground for the first side. Remove the tire and then reach in or from underneath, loosen the clamp on the inner Cv boot. If its original, it can either be a 7 mm worm clamp or a non adjustable clamp. If its a non adjustable clamp, cut if off. We use worm clamps in its place, like a big version of the cooling hose clamps. The lubricant in the inner joints usually is runny like oil. Have a pan under it to avoid a mess when you gently pull the boot off. Start the boot off in one place and then work it off, don't pull straight on it to remove it.
Remove the 19 mm on the tie rod end. Smack the spindle with a big hammer where the taper of the tie rod end is. Turning the wheel so the tie rod and spindle are as far out as possible will make getting a good smack on it easier. Keep the nut on the end threads of the tie rod end to protect them. Loosen the nut enough so you can turn it with your fingers to remove it, but leave it there. When the tie rod end separates from the spindle, remove the nut and swing the tie rod out of the way.
Remove the two 17 mm bolts holding the spindle to the strut. No need to worry about the strut spring, its not going anywhere. They have 19 mm nuts. Later models have a bracket on them for the ABS wheel sensor harness. All have a bracket for the brake line. Remove the sensor and the brake line from their brackets. Take care not to damage either the line or harness, don't make them hold the spindle or pull on them too much when trying to remove the driveshaft. Better to spend an extra few minutes and remove the caliper and the sensor from the spindle than to have to replace more parts you broke. The wheel sensor is held with one 10 mm bolt.
DO NOT TOUCH THE SET SCREW IN THE SIDE OF THE SENSOR THIS SETS ITS DEPTH
Remove the 10 mm bolt and hopefully the sensor will come out of the spindle. Don't damage it trying to force it out if it is stuck. Just work around it. I leave the caliper in place personally and support the spindle with a Bungee cord while I'm working to keep any tension off the harness and line. If you are scared, Before you remove the bolts, make sure the outer Cv will move in the hub. If it is stuck, don't beat it out. Get a punch and strike it in the center, or use a block of wood. Don't damage the threads on the Cv or it will take more work or parts to put it back together.
The spindle should now come out of the strut, lean it to you and turn it so you can remove the driveshaft. Slip the outer joint out of the spindle and then out of the inner driver as the driveshaft is removed from the car. A bit of brake grease on the spline in the hubs on the back of the brake pads and slides if you removed the calipers makes things nicer next time you're in the area. If you have ABS, cleaning the bottom of the sensor and the teeth on the Cv joint for the sensor is a good idea.
