U-Joint Installation on rear wheel drive automobiles & light trucks for the do-it-yourselfer
Most rear-wheel-drive driveline u-joints are held in place with either “inside” or “outside” circlips or snap-rings. If you are mechanically inclined, and have needle-nosed pliers and/or circlip pliers, a vise, and a hammer with a brass drift (wide punch), you may be able to change your own u-joints.
Please note: If the u-joints in your driveshaft do not have inside or outside snap-rings, and are held in place with welds, punch marks (“staked” u-joints), or metal epoxy (GM Saginaw driveshafts), you will likely need professional help. For our Vancouver Island, Gulf Island, and Powell River customers, please call Thompson Machine in Nanaimo BC 1-800-982-3350 for an estimate.
If you spotted circlips or snap-rings and wish to proceed …
1) Remove the u-bolts or straps holding the u-joint to the differential (don’t lose them), or on some designs, unbolt the driveshaft yoke from the differential flange. If the vehicle has a long enough wheel-base to have a two piece driveline, you will have to remove the bolts holding the center support bearing (a.k.a. “steady” bearing) to the underside of the truck. You then slide the front slip-yoke out of the transmission, or on some designs, unbolt the yoke from a flange.
2) It is important that before disassembly, the driveshaft is marked in relation to its slip yoke and- or companion flange before removal, to assure correct re-installation. Use white touch-up paint or some other method to mark the alignment. With the shaft removed, the following procedure should be used.
3) Using a soft brass drift and hammer, tap outside on needle bearing cap to loosen snap ring tension. Do not hit the bearing directly with a hammer. If you miss and hit the yoke, you can damage it. Tap bearing only hard enough to break assembly away from snap ring. If this isn’t happening, spray area with a lubricant/rust remover and wait 15 minutes to try again.
4) Remove snap ring from slip yoke or tube yoke. Turn joint over and remove opposite snap ring.
5) With exposed journal bearings on soft vise jaw covers, tap on yoke until top bearing is forced out of lug. NOTE: If cross is not long enough to force bearing all the way out of yoke lug, turn joint over, clamp vise on exposed bearing and tap yoke from underside.
6) Turn joint over and remove opposite bearing in manner similar to above.
Reassembly (Snap-ring construction)
1) Insert bearing assemblies into outside of lugs, press in with arbor or vise.
2) With soft drift, tap bearing caps to the center position and insert snap rings. (Centering the u-joint is critical to avoiding driveline vibration)
Note: Many modern u-joints don’t have lube fittings. At this point, on a u-joint without a grease fitting, repack the four grease cavities in the u-joint cross with a high quality extreme pressure (EP) grease recommended by lubricant manufacturers for universal joints. Additionally, pack each bearing and needle rollers – filling the bearing approximately ¼ the roller length with grease. Do not over fill.
On u-Joints with lube fittings, grease only after assembly is completed. Grease should be added thru the lube fitting only until grease flow is slightly noticed at all four bearing seals. Overdoing it can damage the seals, which are supposed to prevent dirt and water from getting in.
3) Install the reassembled driveshaft in the vehicle. Be certain the bearing caps are centered (fully seated) between the outside lips of the rear-end yoke or damage and driveline vibration will result.
Of course u-joints, driveshaft yokes and tubing, as well as constant-velocity joint (cardon unit) parts are available at Thompson Machine 1-800-982-3350 or 250-758-4671