The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Roadhog on 06.05. 2018 17:01
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Hi, just rebuilt my plunger back wheel hub and brake drum. Everything is about new. Fitted sealed bearings, all parts fitted as per bsa parts diagram. However when I tighten it all up , solid wheel. Clearly the spacers and bearings are clamping up tight when spindle nut tightened up, any ideas. thanks
adm edit: title edited to reflect topic content
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Maybe one or more of the bearing outer races are not fully seated.
You've got to take the bearings out so compare their width to the old ones using a mic or digital vernier caliper. If they are the same width check the seating for damage or muck.
I'm trying to remember the details but there is some sort of tricky thing in the middle of the hub that has to be properly positioned. Someone with a functioning memory will come along soon.
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How did you get on removing that damned tin dust cover?
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Trying to identify how the bearings are located from this blurry image is tricky
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I had to start from scratch with both hubs as someone previously had fitted wide rims and big tyres, so it was a case of total rebuild, the dust cover on the right hand side was the wrong one initially, I just got a new one which seems to be a push fit, I don't have confidence it will stay in place. Im thinking maybe its the brake drum that is squashing into the drum and locking it up? i will look tomorrow and see if it needs a shim. otherwise its total strip and start again.
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Hi, I got the bearings from Dragonfly, should be right. they are the same as what came out. Everything is clean as its all been sand blasted and the outside powder coated. I ensured that there was just a little play between bearings and the spacer, so that it did not lock together when in place.
Maybe one or more of the bearing outer races are not fully seated.
You've got to take the bearings out so compare their width to the old ones using a mic or digital vernier caliper. If they are the same width check the seating for damage or muck.
I'm trying to remember the details but there is some sort of tricky thing in the middle of the hub that has to be properly positioned. Someone with a functioning memory will come along soon.
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G'day Roadhog.
If the bearings in the hub are seated the spacer should be snug (not tight or loose). When all done up the bearing inner races and spacer are locked, same with the drum.
Cheers
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Yep. that all sounds as it is. I think I will strip it an start again.
G'day Roadhog.
If the bearings in the hub are seated the spacer should be snug (not tight or loose). When all done up the bearing inner races and spacer are locked, same with the drum.
Cheers
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Along the lines of the above, when I put mine together, the right side bearing needed some tweaking to relieve lateral pressure...... I think from memory I left it a bit shy of butted-up, and left the locking/retainer loose and ring and cover right off , tightened the axle nuts, and if the bearing locked did the retainer ring up until it freed-repeat until axle nuts are tight and wheel runs free (or something along those lines).
Do you have the correct chainwheel spacer behind the Brake-plate? It's about a ~1/4" square section one...
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Hi duTch, all spacers and parts are correct going by the parts list and diagram. I think I have found the problem, when I stripped it again. It was the brake drum that was locking up, due to the rubber sealing ring next to the bearing, so when the dummy spindle goes through the bearing it could not seat as the rubber ring held it off and locked up the bearing. However because I have fitted sealed bearings, Im leaving out the rubber sealing ring as its not required.
However, new question. should the Bearing thrust washer go on the left hand side as per BSA parts diagram, or on the right hand side as per Dragonfly part number. The left hand bearing already has a permanent stop in place, nothing for the r/h bearing?
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I don't remember any 'rubber sealing ring', but built from scratch anyway and running sealed bearings, so fairly irrelevant I guess *conf2*
.....However, new question. should the Bearing thrust washer go on the left hand side as per BSA parts diagram, or on the right hand side as per Dragonfly part number. The left hand bearing already has a permanent stop in place, nothing for the r/h bearing?
Now that is *veeerrry* taxing.... If I recall, it took a bit of experimenting to make a choice, but have a feeling I put mine in the right side, but your image up ^^there^^ seems to show it on the left... *pull hair out* (sorry but not pulling it apart to find out just yet), maybe I made a note of it somewhere...
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I stripped the hub and now placed the thrust washer on the right hand side and it seems to work. the rubber seal is the modern alternative for the old felt seal. however it cant be necessary with sealed bearings. Problems resolved. Thanks all.
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Good you got it sorted,I had a look at the parts list which shows the thrust washer behind the left bearing (but the books have been known to be 'wrong'- hey), and the only felt seal I can see is on the RHS, Kinda 'B' in your fuzzy diagram (?)
No matter if it works, it works *wink2*
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Sadly its not actually worked, The brake drum when tightened up into the left hand plunger bracket , spins lovely, when I attached the splined hub, still great, when I put the spindle through wit spacer and half tighten spindle nut , still great, once the spindle nut is fully tight, the whole hub is solid and cant spin. clearly something is getting crushed, but No idea what, any ideas, thanks
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Have we gone past checking bearing thicknesses?
With the wheel out of the bike, what about sticking a length of chunky threaded rod with a couple of large roofing type washers and tighten it up. See how it moves.
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Thanks Greybeared, yep the bearings are the same thickness as the ones that were in , ( if they were right?) unless you have a bearing you can measure for me? I can try a rod , everything is spot on until I tighten up the spindle nut tight.
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I'm pretty sure I don't have a bearing to measure.
It's a good idea to break down a problem to check each section.
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If you put the thrust washer in the right-hand side, maybe it does actually go in the left....as I say I can't remember mine, and didn't have look when we thought it was sorted.
How 'snug' is your R/H bearing in the hub ? Mine was very hard (a bitch) to remove but had no doubt been in a long time...I ask because the hub I was using I *believe* may be from a '54/5 swingarm model with no retainer ring (I'll add a pic from phone shortly), and the R/H bearing is just a snug sliding fit which enables it to 'self-locate', whereas the bearing in the proper Plunger hub was a tighter fit which I don't think would butt-up to the thrust washer anyway soooo...... with that logic, maybe I put it in the left after-all.... *dunno*.
I'm trying to envisage in my mind, the difference of having the thrust washer of the left and feel it may make a significant difference (or not)...
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Hard to say, you pose as many questions as you ask. LOL. The trust washer would not fit in the left as then no room for the bearing adjuster to be screwed in flat. It fits the r/H side no problem, and gives the bearing a stop? the hub turns smooth and nicely but when the spindle is tight all locked up. I seem to have all the right parts in all the right order
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Bent left hand bracket? Pulling the nut tight will then pull the brake drum out of line. But then again, you would notice when pushing the spindle in I guess
I remember mine had the right hand bracket bent. Some PO solved this by adding an extra spacer above the right hand bottom spring for the bracket to sit lower. On the rebuild I left the extra spacer out but then couldn’t get the spindle in. I ended up straightening the bracket by heating and bending.
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Ah the plot thickens. Many years ago my rear sub frame was misaligned, one side higher than the other. I had similar problem but not locking up solid. You can stand behind the bike and view the axle against the riders footpeg mounting studs.
Cheers
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My argument for the thrust washer/ring (65-5884) in the left side is also based on that the bearings have a radius on them, so need more area to bear against, and the thrust-ring has a square/rectangular section to butt up to the shoulder in the hub, and there is very little of a shoulder in the RHS, and I don't believe the Right-hand bearing needs to butt up hard on the O.D...better to 'float' a bit as the swing arm ones do (same thrust-ring, same side in the parts book)
I had another look at my spare hub and there is a more pronounced shoulder LHS to back up my argument... *dunno*
My frame was also bent, and had it straightened, but don't think it had anything to do with my issue...
*edit/disclaimer...I may be completely wrong on that ^^, but it seems valid to me and I still don't know which side mine is and not opening a can o' worms to find out *conf* .....(GB came along in the meantime)
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Roadhog, have you been able to test the hub out of the frame as I suggested?
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Thanks everyone, I will get on top of the ideas by the weekend, sadly work takes up my time. Get back soon once I have tried the threaded bar and tightening up the hub first, to see if it locks up. Then see if my brackets are bent, but dont think so, however I do note that the R/H bracket is 3-4 mm higher than the R/H side one. clearly springs and spacers in the shock are slightly different.
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I managed to get some time. I stripped the hub and started again. This time I left out the Thrust washer from the left hand side. I slackened off the plunger unit on the left and tapped it downwards a small amount, which levelled up the spindle brackets. I then rebuilt everything and it all works fine. The brake drum and hub spin nicely. It looks like it was two things, spindle brackets on the plunger suspension not in line with each other and the Thrust washer forcing the left hand bearing to far out. Thanks all.
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Good news!
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Sounds rosy and good you've had some apparent inspiration.....but I won't patronize you by blowing hugs and kisses and other crap, because I'm not convinced.
Sure two changes made a difference, but was it the axle lug/s, or the thrust-ring, or a combo ? You need to do one at a time to be sure.
The thrust-ring must be there for a reason.
Which side bearing did you install first ? It makes sense to me to do the (busy)drive side first (which may explain why the retainer ring doesn't end up flush- maybe it doesn't need to be ?) and add the right-side bearing when the other is properly in place (leave out unnecessary bits until needed).
Removing the thrust-ring will move the wheel/RIM/tyre *off-centre* to the left 3/32" (thickness of ring by all accounts I can find), that will affect your ride.
Yes- I'm struggling to give an actual answer, but I know I had issues here that I can't document just now, and some things are not worth short-cutting, but good luck with it and I hope the frame isn't bent.
All I know is when it's properly sorted, it'll be a great ride.
Remember- this is a learning curve for all of us, and some in the future, and the standard you accept has a potential to set a precedent for others, whatever it may be.
My today is bergers tommorrow *beer* *beer* *smile*, (and so is tommorrow)
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Hi DuTch, all seems good now. The frame aint bent, checked it out at the start of stripping the whole bike. All plunger suspension parts are new, but were out by 3mm. that's now sorted, it did not cause the lock up, but it did make it hard to get the spindle through. The thrust washer when placed in the left drive side just made it difficult to get the bearing lock in place, on the left hand side inside the hub is a permanent shoulder for the bearing to sit up against, this thrust washer just made that shoulder twice as thick, which in turn caused the lock up. It did fit in the other side but then stopped the slack needed to allow the bearing to float when tightened. all tightened up now and the drum and hub spin nicely. Also the thrust washer on the L/H side stopped the hub pushing right onto the splines on the brake drum. So looks like the thrust washer was to blame.
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Ok so long as you're happy, doesn't make sense to me, but don't lose the thrust ring...one other that came to mind but forgot to throw in is the bearing spacer # 67-6061....the one I bought had the 'scalloped' bits on the same way...and one or other was interfering with the rivet heads and potentially jamming the wheel, so I reversed one so the 'scalloped' flanges are at the ends (outside the rivets), and it is ok- just sayin'.....good luck with it.
pic pending