Story of MQ wheel bearings/diff replacement
Posted: Wed Aug 24, 2005 8:51 pm
I've recently had to replace the spider and side gears in the front diff of my 82 SWB MQ. Of course, this required removal of both front axles. For those that don't realise, this is a much bigger job than removing the rear axles! It is certainly one of those jobs that will take a quarter of the time second time around, so if you're trying it for the first time, try to get someone experienced to look over your shoulder.
In summary (from memory) to remove a front axle shaft (manual locking hubs):
0. Jack up and support front axle with a pair of secure axle stands.
1. Take wheel off.
2. Remove brake calliper (two thick 13/16" bolts) and tuck out of the way without damaging the brake line.
3. Remove manual locking hub inner (flat screwdriver on 6 small bolts).
4. Remove surclip from end of exposed axle (use surclip pliers - I didn't!).
5. Remove manual locking hub outer (4 14mm bolts + 2 14mm nuts. No idea why they aren't all bolts or nuts). May take a couple of whacks to dislodge outer.
- Things get very greasy from here
6. Wheel bearing adjustment nuts will be exposed. To remove the nuts, clean all the grease out from around the edge so you can see the locking washer. It's a flat washer that sits between the two nuts and it should be bent backwards and forwards to lock both nuts. Bend the tab away from the outermost nut with a screwdriver and hammer.
7. Remove the outer nut with a 54mm wheel bearing socket (expect to pay at least $25 for socket). It may not be a tight fit on nut, but should be fine - the nut is probably not super tight anyway).
8. Slide locking washer off with a couple of screwdrivers, and remove inner nut with the 54mm socket.
9. The entire hub with disk brake attached is now ready to slide off. There's no need to undo the 6 17mm nuts that hold the disk to the hub (there's 20 minutes I didn't need to spend)!
10. Once the hub is off, the backing plate will be exposed. Undo the 6 14mm bolts that hold the backing plate on.
11. Remove the backing plate, and the axle will be free to move. Probably easiest to leave the axle sheath/mounting plate thingy (name?) on the the axle. It may slide straight off with the backing plate, or it may stay stuck to the axle. You'll recognise it because it'll sheath the splined axle.
12. If you're on the long side (look how far away the diff is from the side you are working on), be prepared to handle a long bendy (at the CV) axle, and slide the sucker out.
To remove the diff:
13. Repeat for the other axle.
14. Remove split pin from top of one of the two tie rod end ball joints.
15. Undo the nut with split pin removed, so that it sits flush with the top of the thread.
16. Make lots of room to swing by turning the steering.
17. Belt the living bejeezus out of the nut (towards the ground), forcing the ball joint apart. What's a ball joint separator dooby worth here - belting is not a great tactic? I couldn't get the drivers ball joint apart, but the passenger finally gave in with a bit of rock persuasion.
18. Undo the nut fully and separate the ball joint's taper from the hole so the steering link is free. Move it out of the way of the diff. Only has to move an inch or so.
18. Put an oil tray under the diff and undo the 12 odd 12mm bolts from the inspection plate on the front of the diff.
19. Crack the gasket seal with a screwdriver (mine was a reusable bit of thin plastic stuff) and let the oil pour out.
20. Mark the bearing caps on both sides of the diff so you know their orientation and side.
21. Undo the 4 17" bolts on the carrier bearing caps (tight - breaker bar time!). My bolt head were oddly tapered so I had to firmly hold the socket on the bolt while undoing.
22. The diff is now held in only by being squeezed in next to the shims on both sides. Belt it with a soft mallet to loosed it up.
23. As you slide the diff out, make sure you note where each shim came from.
If anyone can offer some improvements on that run-down, please do. Now onto the troubles I had:
1. I really didn't know how tight to make the inner and outer wheel bearing nuts. I just used my old bike axle cone bearing method - tighten the inner one up snug so there is *zero* movement of hub on axle, but not so tight so the bearings are grinding. Bend the locking washer back (I straightened the old one out first, but should really have got a new one for <$10) so it snugly holds the inner nut. Tighten the outer nut quite tight to hold the inner in it's place. Should be careful not to inadvertently over-tighten the inner one doing so though! Bend the locking washer over snug against the outer nut.
2. I don't have surclip pliers (would have saved me a ton of time by now if I did!) so couldn't get the surclip back on the end of the axle with the manual hub on. Instead, I removed the manual hub and slid the surclip past the first non-splined section in the axle to the second non-splined section. This held the axle out against the sheath hub thing and in against the manual hub, and seems to be doing the trick. I've had one comment that this is a no-no. Can anyone shed more light on this trick - is the second non-splined groove (the one furthest from the end of the axle) not to be used to hold a surclip? Are both supposed to be used? Should I immediately remove the surclip, get some pliers and put it on the end of the axle after the manual hub outer??
3. When doing up the backing plate bolts on the passenger (long) side, the axle seemed to get stuck against the side of the sheath and wouldn't move. I removed the backing plate and axle sheath/hub thing to find the small cylindrical roller bearings from the carrier on the inside of the sheath/hub thing falling out all over the place. I immediately concluded I'd smashed the bearing, gave up for the night, and went bearing shopping the next day. I rang around for MQ front wheel bearing kits: 4wd spare parts store $90, first bearing shop $83+GST not in stock, second bearing shop $50+GST. Turns out when I went looking for the latter store, I visited its neighbour by mistake. They wanted $87 until I told them that the other bearing store (which turned out to be 2 shops down!) said $50+GST. A bit of murmuring on their behalf and they sold it to me for $55. Who sets these prices?
Of course, when I finally got back (the treadly getting a massive workout - its wheel bearings are next) I discovered that the wheel bearings in the kit were not the one on the inside of the sheath/hub thing. The bearings in the kit are the tapered outer raceway and 4mm roller bearing pairs on the inside of the big hub/disk assembly. Almost ready to burn the lot, I realised that the a couple of the rollers from my "collapsed" bearing slid smoothly back into the carrier. Miraculously, I found all but one of the rollers, and the bearing seemed to operate smoothly. Packed with bearing grease, I slid it all back together and operation seemed smooth. What potential for damage have I caused, running this bearing one roller short? There are maybe 30 rollers in the bearing.
I choose to end my story now. Please post up your thoughts.
PS. massive thumbs up to beefie for his vocal assisstance with the diff and coming through with the parts!
In summary (from memory) to remove a front axle shaft (manual locking hubs):
0. Jack up and support front axle with a pair of secure axle stands.
1. Take wheel off.
2. Remove brake calliper (two thick 13/16" bolts) and tuck out of the way without damaging the brake line.
3. Remove manual locking hub inner (flat screwdriver on 6 small bolts).
4. Remove surclip from end of exposed axle (use surclip pliers - I didn't!).
5. Remove manual locking hub outer (4 14mm bolts + 2 14mm nuts. No idea why they aren't all bolts or nuts). May take a couple of whacks to dislodge outer.
- Things get very greasy from here
6. Wheel bearing adjustment nuts will be exposed. To remove the nuts, clean all the grease out from around the edge so you can see the locking washer. It's a flat washer that sits between the two nuts and it should be bent backwards and forwards to lock both nuts. Bend the tab away from the outermost nut with a screwdriver and hammer.
7. Remove the outer nut with a 54mm wheel bearing socket (expect to pay at least $25 for socket). It may not be a tight fit on nut, but should be fine - the nut is probably not super tight anyway).
8. Slide locking washer off with a couple of screwdrivers, and remove inner nut with the 54mm socket.
9. The entire hub with disk brake attached is now ready to slide off. There's no need to undo the 6 17mm nuts that hold the disk to the hub (there's 20 minutes I didn't need to spend)!
10. Once the hub is off, the backing plate will be exposed. Undo the 6 14mm bolts that hold the backing plate on.
11. Remove the backing plate, and the axle will be free to move. Probably easiest to leave the axle sheath/mounting plate thingy (name?) on the the axle. It may slide straight off with the backing plate, or it may stay stuck to the axle. You'll recognise it because it'll sheath the splined axle.
12. If you're on the long side (look how far away the diff is from the side you are working on), be prepared to handle a long bendy (at the CV) axle, and slide the sucker out.
To remove the diff:
13. Repeat for the other axle.
14. Remove split pin from top of one of the two tie rod end ball joints.
15. Undo the nut with split pin removed, so that it sits flush with the top of the thread.
16. Make lots of room to swing by turning the steering.
17. Belt the living bejeezus out of the nut (towards the ground), forcing the ball joint apart. What's a ball joint separator dooby worth here - belting is not a great tactic? I couldn't get the drivers ball joint apart, but the passenger finally gave in with a bit of rock persuasion.
18. Undo the nut fully and separate the ball joint's taper from the hole so the steering link is free. Move it out of the way of the diff. Only has to move an inch or so.
18. Put an oil tray under the diff and undo the 12 odd 12mm bolts from the inspection plate on the front of the diff.
19. Crack the gasket seal with a screwdriver (mine was a reusable bit of thin plastic stuff) and let the oil pour out.
20. Mark the bearing caps on both sides of the diff so you know their orientation and side.
21. Undo the 4 17" bolts on the carrier bearing caps (tight - breaker bar time!). My bolt head were oddly tapered so I had to firmly hold the socket on the bolt while undoing.
22. The diff is now held in only by being squeezed in next to the shims on both sides. Belt it with a soft mallet to loosed it up.
23. As you slide the diff out, make sure you note where each shim came from.
If anyone can offer some improvements on that run-down, please do. Now onto the troubles I had:
1. I really didn't know how tight to make the inner and outer wheel bearing nuts. I just used my old bike axle cone bearing method - tighten the inner one up snug so there is *zero* movement of hub on axle, but not so tight so the bearings are grinding. Bend the locking washer back (I straightened the old one out first, but should really have got a new one for <$10) so it snugly holds the inner nut. Tighten the outer nut quite tight to hold the inner in it's place. Should be careful not to inadvertently over-tighten the inner one doing so though! Bend the locking washer over snug against the outer nut.
2. I don't have surclip pliers (would have saved me a ton of time by now if I did!) so couldn't get the surclip back on the end of the axle with the manual hub on. Instead, I removed the manual hub and slid the surclip past the first non-splined section in the axle to the second non-splined section. This held the axle out against the sheath hub thing and in against the manual hub, and seems to be doing the trick. I've had one comment that this is a no-no. Can anyone shed more light on this trick - is the second non-splined groove (the one furthest from the end of the axle) not to be used to hold a surclip? Are both supposed to be used? Should I immediately remove the surclip, get some pliers and put it on the end of the axle after the manual hub outer??
3. When doing up the backing plate bolts on the passenger (long) side, the axle seemed to get stuck against the side of the sheath and wouldn't move. I removed the backing plate and axle sheath/hub thing to find the small cylindrical roller bearings from the carrier on the inside of the sheath/hub thing falling out all over the place. I immediately concluded I'd smashed the bearing, gave up for the night, and went bearing shopping the next day. I rang around for MQ front wheel bearing kits: 4wd spare parts store $90, first bearing shop $83+GST not in stock, second bearing shop $50+GST. Turns out when I went looking for the latter store, I visited its neighbour by mistake. They wanted $87 until I told them that the other bearing store (which turned out to be 2 shops down!) said $50+GST. A bit of murmuring on their behalf and they sold it to me for $55. Who sets these prices?
Of course, when I finally got back (the treadly getting a massive workout - its wheel bearings are next) I discovered that the wheel bearings in the kit were not the one on the inside of the sheath/hub thing. The bearings in the kit are the tapered outer raceway and 4mm roller bearing pairs on the inside of the big hub/disk assembly. Almost ready to burn the lot, I realised that the a couple of the rollers from my "collapsed" bearing slid smoothly back into the carrier. Miraculously, I found all but one of the rollers, and the bearing seemed to operate smoothly. Packed with bearing grease, I slid it all back together and operation seemed smooth. What potential for damage have I caused, running this bearing one roller short? There are maybe 30 rollers in the bearing.
I choose to end my story now. Please post up your thoughts.
PS. massive thumbs up to beefie for his vocal assisstance with the diff and coming through with the parts!
