Birfield observations
I just completed the Birf job, along with new wheel bearings, new trunion bearings, new rotors and brake pads. Whew!!! It took me four days of work to finish this. Fortunately I had another car to drive during that, and didn’t need to move the cruiser from the garage.
Separating the axle from the birfields was a piece of cake. I realized I had a long enough piece of schedule 40 PVC pipe (that's the heavier stuff). After cutting a length to about 38 inches or so, and finding a piece of plywood for the axle to fall onto instead of the concrete, it took one drop of the pipe on the long side and three on the short side to separate the axle from the birfield joint.
My birfields had been clicking in uphill turns for some (a long) time. (Clicking since high 80K, now have 109K, so about 18 months and 18K of clicking) There was some wear on them. I suspect that this is common, although I had let mine go a long time without doing this job. The wear is in the inside of the “bell” housing, in the six tracks that the ball bearings ride in, and occurs at the point where the balls are oriented when you are driving straight ahead rather than turning. There is a very slight, smooth depression where the ball contacts the outer housing when the wheels are driving straight ahead. The back side of the “track” in the bell housing also has a similar wear pattern, but it is less pronounced since it only gets wear when there is braking going on, not when the wheels are driving. Also, the inside “race” (shaped like a starfish) has similar wear. I swapped the birfs from left to right, which put the less worn “braking side” into the “driving position” and vice versa, which as some have pointed out should extend the life.
You need a wire brush or two in this project. The three piece Sears brass drift set was essential and served me well. Sears bearing packers worked very cool. I don’t see how you could duplicate what it does by hand, and it does it in about 4 seconds.
One of the spindles had a bushing that rode loosely in it, and could be removed by hand. The other was tight. I cleaned them both up and couldn’t detect any wear on either one.
Cdan’s one tap on the flange, rotate and tap again,……method worked well to remove the cone washers. Note that you have to look closely or you won’t see that they’ve popped. Keep the nuts on the studs so they don’t ‘fly off.
I had not planned on installing new races, but ended up doing it since I had all new bearings. It wasn’t bad. You just have to make sure to strike the races no more than twice per side before moving to the other side. The metal is SO hard that once it is even slightly “cocked”, it won’t move again till you square it up. I used the old races to drive the new ones in for the wheel bearings, and just used the brass bar on the trunion bearings.
The biggest frustration was that I had a #%@!*@!!!!!! Of a time reassembling the birfield joints. I wasted three hours on a job that should have taken about 40 minutes. This was because the FSM is WRONG. The starfish or inner race part has a so-called flat side/protruding side referred to in the manual. The manual show it going in exactly backwards from the right way!!!! A BETTER, more foolproof way to show that would be to say there is a side of the inner race (starfish) where there is more room for the ball bearings and a side where the channels for the bearing narrows. [This is EASY to see as you look at each side.] The side with more room HAS to go to the “open side” of the birfield bell….in other words, towards the inboard of the vehicle. IF it’s the other way, the birf won’t move and will lock up. The cage difference also hard to discern in the manual. The manual shows a wide side of it and a narrow side, but they looked virtually the same to me. What IS different is that if you lay it on a flat surface, it will leave the imprint of a circle, or ring. One end of it will make a much thicker ring imprint than the other. The side that would make the thicker ring imprint on a piece of paper should also go to the open side of the birf...in board to the vehicle. [At least, thats the way I did it, and it seems to work and not bind up----if anyone disagrees with that, please correct it here so I won't screw anyone else up.] Lastly, because of the way I disassembled it, I didn’t realize that the ball bearings would fit through the race from the outside if tapped very gently. They will, and I finally got them reassembled
As you are assembling the birf, MAKE SURE YOU DON’T HAVE THE CIRCLIP ON THE AXLE, and reinsert the axle part way to check that the birf moves freely in all directions. If it is binding, you’ll feel it. Mine locked up when I checked it after reinserting just three bearings since I had the inner race backwards initially.
Note: before reassembling, grease the surfaces completely but lightly like you would coat a cake pan or a muffin pan.(ask your wife or girlfriend). AFTER you get the birf back together, but BEFORE reinserting the axle, then pack it up complete with grease. I used my WorkMate workbench to hold them upside down, which made packing and reinserting the axle easier. Compressing the circlip is a little tricky, but easier with the birf in this position and accomplished using only pliers and a screwdriver. Once it appears almost totally compressed, a tap on the top of the axle caused it to slide right in.
I think you could clean the birf effective with brake cleaner and a needle sprayer and not have to disassemble it. Next time I do this, !!!??!!!, I’m going to try that.
I screwed up the preload adjustments on the bearing nuts initially, not realizing that after you tighten and loosen twice at 43 foot pounds, the final number for the adjusting nut is actually about one foot pound (48 inch pounds!!).
Other screwups. I stupidly installed the axle seals before I wire brushed off the backs of the knuckles, so ……..it SEEMED like a good idea to put a paper towel in the axle grease seal hole so no dirt would fall in there. WRONG!!! When I removed the paper towel plug from the seal, the round coil spring “bracelet” that squeezes the rubber lip to the axle popped off into the axle housing, and was IMPOSSIBLE to replace the spring without pulling the seal (which of course destroyed it). I was lucky to even notice this, as I only saw it as I removed the second paper towel. The springs had come off of both seals, so I dashed to the dealer and got replacements. DO NOT PUT THE SEALS IN UNTIL YOU ARE READY TO INSERT THE COMPLETED AXLE/BIRF ASSEMBLY. Also, because of that experience, I put a good greasing on the seals first so that if I had to pull the axle back a little, it would slide more easily without inverting the rubber on the seal and popping off the spring. So grease up your seals then don’t touch them with your fingers once they’re seated lest you dislodge the doggone spring. Because of that, its worthwhile to have two extra seals, not just one….would’ve saved me a trip to the dealers.
The axle seal position does not appear to be critical to me. Once it’s driven in flush to the opening, it seems like it would be pretty much OK. The axle actually has a thicker diameter where it passes through the seal in order to make the seal fit tighter and be more effective.
Getting the axle seated in the differential seemed to be no problem, although it was hard to tell that it went it, especially the first one (drivers side).
Clicking observations: The clicking has stopped. This is interesting since the only difference is the grease now in the birf (plus the fact that the birfs are swapped and the size of the "drive-wear" groove is smaller). No one has discussed, that I have seen, what causes the clicking. My speculation is that once a slight groove has been worn into the wheels-straight-ahead position, the ball bearings now have to travel back and forth across that groove when the wheels are turned hard to one side (and rolling). Each bearing crosses the groove twice in every 360 degree wheel rotation when the steering wheel is turned off dead center. I think that it what causes the clicking. [It would be interesting to know if a brand new birf without any grease would click. I think it wouldn’t because there would be no groove yet in the wheels-straight-ahead position] Why the clicking should stop when the grease is better is anybody’s guess, but I suppose it is the combination of better friction control, and damped acoustics. In any event, with mine as the example, you can still have wear on the birfs, but no clicking. Maybe they would still cllick if I hadn't swapped the sides.
I did have some wear on the axle where the seal contacts it. Based on how little it was and on how hard I found the steel to be (and on the fact that I don’t go off-road) I can’t see much possibility that the axle would fail because of a little shine in that area. Famous last words.
Other thoughts. Adding grease through the knuckle fill-hole seems to me to be nearly worthless, and possibly counterproductive. Its 99.9% certain that none of that grease will get to where it’s needed. By the same token, it seems useless to overfill the knuckle with grease. The service manual says about 3/4 full, but I serioiusly doubt that filling it more than half does much good at all. It truly appears to me that the only grease doing its job is what you've put into the birf, and the rest of it is not going to get in there.
Thanks to all and to Cruiserdan for the guidance from all the previous posts. Sorry about the length.
I just completed the Birf job, along with new wheel bearings, new trunion bearings, new rotors and brake pads. Whew!!! It took me four days of work to finish this. Fortunately I had another car to drive during that, and didn’t need to move the cruiser from the garage.
Separating the axle from the birfields was a piece of cake. I realized I had a long enough piece of schedule 40 PVC pipe (that's the heavier stuff). After cutting a length to about 38 inches or so, and finding a piece of plywood for the axle to fall onto instead of the concrete, it took one drop of the pipe on the long side and three on the short side to separate the axle from the birfield joint.
My birfields had been clicking in uphill turns for some (a long) time. (Clicking since high 80K, now have 109K, so about 18 months and 18K of clicking) There was some wear on them. I suspect that this is common, although I had let mine go a long time without doing this job. The wear is in the inside of the “bell” housing, in the six tracks that the ball bearings ride in, and occurs at the point where the balls are oriented when you are driving straight ahead rather than turning. There is a very slight, smooth depression where the ball contacts the outer housing when the wheels are driving straight ahead. The back side of the “track” in the bell housing also has a similar wear pattern, but it is less pronounced since it only gets wear when there is braking going on, not when the wheels are driving. Also, the inside “race” (shaped like a starfish) has similar wear. I swapped the birfs from left to right, which put the less worn “braking side” into the “driving position” and vice versa, which as some have pointed out should extend the life.
You need a wire brush or two in this project. The three piece Sears brass drift set was essential and served me well. Sears bearing packers worked very cool. I don’t see how you could duplicate what it does by hand, and it does it in about 4 seconds.
One of the spindles had a bushing that rode loosely in it, and could be removed by hand. The other was tight. I cleaned them both up and couldn’t detect any wear on either one.
Cdan’s one tap on the flange, rotate and tap again,……method worked well to remove the cone washers. Note that you have to look closely or you won’t see that they’ve popped. Keep the nuts on the studs so they don’t ‘fly off.
I had not planned on installing new races, but ended up doing it since I had all new bearings. It wasn’t bad. You just have to make sure to strike the races no more than twice per side before moving to the other side. The metal is SO hard that once it is even slightly “cocked”, it won’t move again till you square it up. I used the old races to drive the new ones in for the wheel bearings, and just used the brass bar on the trunion bearings.
The biggest frustration was that I had a #%@!*@!!!!!! Of a time reassembling the birfield joints. I wasted three hours on a job that should have taken about 40 minutes. This was because the FSM is WRONG. The starfish or inner race part has a so-called flat side/protruding side referred to in the manual. The manual show it going in exactly backwards from the right way!!!! A BETTER, more foolproof way to show that would be to say there is a side of the inner race (starfish) where there is more room for the ball bearings and a side where the channels for the bearing narrows. [This is EASY to see as you look at each side.] The side with more room HAS to go to the “open side” of the birfield bell….in other words, towards the inboard of the vehicle. IF it’s the other way, the birf won’t move and will lock up. The cage difference also hard to discern in the manual. The manual shows a wide side of it and a narrow side, but they looked virtually the same to me. What IS different is that if you lay it on a flat surface, it will leave the imprint of a circle, or ring. One end of it will make a much thicker ring imprint than the other. The side that would make the thicker ring imprint on a piece of paper should also go to the open side of the birf...in board to the vehicle. [At least, thats the way I did it, and it seems to work and not bind up----if anyone disagrees with that, please correct it here so I won't screw anyone else up.] Lastly, because of the way I disassembled it, I didn’t realize that the ball bearings would fit through the race from the outside if tapped very gently. They will, and I finally got them reassembled
As you are assembling the birf, MAKE SURE YOU DON’T HAVE THE CIRCLIP ON THE AXLE, and reinsert the axle part way to check that the birf moves freely in all directions. If it is binding, you’ll feel it. Mine locked up when I checked it after reinserting just three bearings since I had the inner race backwards initially.
Note: before reassembling, grease the surfaces completely but lightly like you would coat a cake pan or a muffin pan.(ask your wife or girlfriend). AFTER you get the birf back together, but BEFORE reinserting the axle, then pack it up complete with grease. I used my WorkMate workbench to hold them upside down, which made packing and reinserting the axle easier. Compressing the circlip is a little tricky, but easier with the birf in this position and accomplished using only pliers and a screwdriver. Once it appears almost totally compressed, a tap on the top of the axle caused it to slide right in.
I think you could clean the birf effective with brake cleaner and a needle sprayer and not have to disassemble it. Next time I do this, !!!??!!!, I’m going to try that.
I screwed up the preload adjustments on the bearing nuts initially, not realizing that after you tighten and loosen twice at 43 foot pounds, the final number for the adjusting nut is actually about one foot pound (48 inch pounds!!).
Other screwups. I stupidly installed the axle seals before I wire brushed off the backs of the knuckles, so ……..it SEEMED like a good idea to put a paper towel in the axle grease seal hole so no dirt would fall in there. WRONG!!! When I removed the paper towel plug from the seal, the round coil spring “bracelet” that squeezes the rubber lip to the axle popped off into the axle housing, and was IMPOSSIBLE to replace the spring without pulling the seal (which of course destroyed it). I was lucky to even notice this, as I only saw it as I removed the second paper towel. The springs had come off of both seals, so I dashed to the dealer and got replacements. DO NOT PUT THE SEALS IN UNTIL YOU ARE READY TO INSERT THE COMPLETED AXLE/BIRF ASSEMBLY. Also, because of that experience, I put a good greasing on the seals first so that if I had to pull the axle back a little, it would slide more easily without inverting the rubber on the seal and popping off the spring. So grease up your seals then don’t touch them with your fingers once they’re seated lest you dislodge the doggone spring. Because of that, its worthwhile to have two extra seals, not just one….would’ve saved me a trip to the dealers.
The axle seal position does not appear to be critical to me. Once it’s driven in flush to the opening, it seems like it would be pretty much OK. The axle actually has a thicker diameter where it passes through the seal in order to make the seal fit tighter and be more effective.
Getting the axle seated in the differential seemed to be no problem, although it was hard to tell that it went it, especially the first one (drivers side).
Clicking observations: The clicking has stopped. This is interesting since the only difference is the grease now in the birf (plus the fact that the birfs are swapped and the size of the "drive-wear" groove is smaller). No one has discussed, that I have seen, what causes the clicking. My speculation is that once a slight groove has been worn into the wheels-straight-ahead position, the ball bearings now have to travel back and forth across that groove when the wheels are turned hard to one side (and rolling). Each bearing crosses the groove twice in every 360 degree wheel rotation when the steering wheel is turned off dead center. I think that it what causes the clicking. [It would be interesting to know if a brand new birf without any grease would click. I think it wouldn’t because there would be no groove yet in the wheels-straight-ahead position] Why the clicking should stop when the grease is better is anybody’s guess, but I suppose it is the combination of better friction control, and damped acoustics. In any event, with mine as the example, you can still have wear on the birfs, but no clicking. Maybe they would still cllick if I hadn't swapped the sides.
I did have some wear on the axle where the seal contacts it. Based on how little it was and on how hard I found the steel to be (and on the fact that I don’t go off-road) I can’t see much possibility that the axle would fail because of a little shine in that area. Famous last words.
Other thoughts. Adding grease through the knuckle fill-hole seems to me to be nearly worthless, and possibly counterproductive. Its 99.9% certain that none of that grease will get to where it’s needed. By the same token, it seems useless to overfill the knuckle with grease. The service manual says about 3/4 full, but I serioiusly doubt that filling it more than half does much good at all. It truly appears to me that the only grease doing its job is what you've put into the birf, and the rest of it is not going to get in there.
Thanks to all and to Cruiserdan for the guidance from all the previous posts. Sorry about the length.
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