One of the first jobs I did 3 years ago when I got the 1300 Dolly was to replace both rear wheel bearings and oil seals because one was noisy, so I did both for good measure. Ever since there has been a clunk from the rear when going around left hand corners which I took to be axle bushes, so replaced those but still the clonk persists. Today I found the cause, the rear o/s axle half shaft is moving in and out by approximately 3 mm. Had the wheel off and checked that the bolts holding the backplate on are all tight, which they are, and the large nut holding the hub on to the taper is also tight. Only way I can think that this movement is happening is because either the new bearing is not being clamped into the axle tube or the hub itself is not clamping the inner race tightly. Other than that could it be the cheap bearings, which seem to be all one can buy now, have too much side play or are narrower than the originals.
I am reluctant to buy another set of cheap bearings, these have done less than 2000 miles, does anyone know of a source of quality bearings or a part number for the same.
Thanks,
Ralph
1300 Endfloat in rear axle
1300 Endfloat in rear axle
Last edited by Ralph on Mon Jun 02, 2025 6:48 am, edited 1 time in total.
Re: 1300 Endfloat in rear axle
Following up on the above, I have just stripped out the half shaft assembly, and as you can see from the attached picture, when the bearing is pressed fully down onto the raised portion of the half shaft, and the hub is tapped down as far as it will go on the taper end of the half shaft there is a 3mm gap between the bearing inner race and the end of the hub. This is the 3mm that is allowing the half shaft to slide in and out and causing the clunk.
I think part of the problem, if not all of it, is that the bearing has very large radiuses, and the half shaft larger diameter that is supposed to act as the stop for the bearing is only 23 thou larger at 1.023 than the shaft that the bearing fits on which is exactly 1 inch. So the step that stops the bearing is effectively .0115" or 11.5 thou, and this is allowing the large radius of the inner race of the bearing to slide over the top of it by 1 to 2 mm.
I don`t know whether I have a suspect half shaft or whether I should have some kind of stop washer on the shaft to prevent the bearing sliding on too far, but from what exploded images there are in the Haynes manual I can`t see anything I`m missing.
I appreciate there must be a small gap between bearing and hub otherwise it would prevent the hub pulling fully down on the taper when torqued up, and I can feel a very slight play on the opposite side wheel.
I wonder if the bearing should be a much tighter fit on the half shaft, so again is it the cheap bearing at fault I wonder.
I have another bearing kit ordered from Canley Classics, if that one is slack too I may resort to Locktite bearing fit and glue the bearing to the half shaft to prevent movement.
Ralph
I think part of the problem, if not all of it, is that the bearing has very large radiuses, and the half shaft larger diameter that is supposed to act as the stop for the bearing is only 23 thou larger at 1.023 than the shaft that the bearing fits on which is exactly 1 inch. So the step that stops the bearing is effectively .0115" or 11.5 thou, and this is allowing the large radius of the inner race of the bearing to slide over the top of it by 1 to 2 mm.
I don`t know whether I have a suspect half shaft or whether I should have some kind of stop washer on the shaft to prevent the bearing sliding on too far, but from what exploded images there are in the Haynes manual I can`t see anything I`m missing.
I appreciate there must be a small gap between bearing and hub otherwise it would prevent the hub pulling fully down on the taper when torqued up, and I can feel a very slight play on the opposite side wheel.
I wonder if the bearing should be a much tighter fit on the half shaft, so again is it the cheap bearing at fault I wonder.
I have another bearing kit ordered from Canley Classics, if that one is slack too I may resort to Locktite bearing fit and glue the bearing to the half shaft to prevent movement.
Ralph
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Re: 1300 Endfloat in rear axle
Hi Ralph, The answer to your question may be in the early 1850 manual (sheet 2, 51.10.01 ) which is the only reference I have, being an 1850 merchant !
Now the 1300 / 1500 / 1850 rear axle casings are identical the only difference being the diff; gears and crown wheel.
The 1/2 shafts and bearings seem to be identical , apart from the keyways on the 1/2 shaft on later models.
Now 51.10.01 Item 19 states ... Press the bearing onto the axle shaft until the dimension given in DATA exists from the bearing to the threaded end of the axle shaft...
DATA :- Bearing to threaded end of axle shaft = 2.84 in ( 69.94 mm ).
( Wife says I'm a bit of an anorak ! )
HTH Tony.
Now the 1300 / 1500 / 1850 rear axle casings are identical the only difference being the diff; gears and crown wheel.
The 1/2 shafts and bearings seem to be identical , apart from the keyways on the 1/2 shaft on later models.
Now 51.10.01 Item 19 states ... Press the bearing onto the axle shaft until the dimension given in DATA exists from the bearing to the threaded end of the axle shaft...
DATA :- Bearing to threaded end of axle shaft = 2.84 in ( 69.94 mm ).
( Wife says I'm a bit of an anorak ! )
HTH Tony.
Re: 1300 Endfloat in rear axle
Hi, thanks Tony, yes I think the key word there is "pressed". With the bearing I have and the half shaft I have you can push the bearing on with your fingers, so either the half shaft is worn ( although it does measure exactly 1 inch diameter", or the bore of the bearing is too big. I will wait and see what the new bearing is like, another cheapo one I`m afraid, otherwise I might be resorting to the locktite.
Ralph
Ralph
Re: 1300 Endfloat in rear axle
OK, so decided not to waste this good weather, as it`s due to change tomorrow for the bank holiday. Went into garage for a good look again at the situation.
Pressing the bearing onto the half shaft by 70mm as suggested by Tony above doesn`t even get the bearing off the keyway groove in the halfshaft, but I assume that when the hub is torqued on it would push the bearing that little bit further. Close examination of the shaft showed signs that the bearing had been spinning, and although it wasn`t detectible with a micrometer there was certainly play when the bearing was slid on which it did easily.
So I degreased the shaft and bearing inner race, slid the bearing on and re fitted the hub and torqued it up fully. I stood the halfshaft upright on the bench standing on the wheel studs and made sure the bearing was up against the hub. I then ran some Locktite high strength retainer around the join between the inner race and the shaft, being careful to avoid it getting into the bearing, although there was plenty of grease in the bearing so I doubt it would have done any harm. This stuff is very searching and will pull itself into the smallest of gaps. After 10 minutes it had set enough for the hub to be removed again (thank god I bought the proper puller), so I could run some more Locktite around the hub side of the bearing. After another 10 minutes the excess was carefully wiped away .
Everything was fitted back to the car, torqued up and brakes bled. Result no more movement in and out of the halfshaft and no more clunks. been out for a 20 mile drive in the country lanes chucking the car left and right to try and induce the clunk, but nothing, the Locktite has done it`s job, hopefully permanently.
I am still waiting for the new bearing kit I ordered, but it will be interesting to measure the diameter of the inner race. It will go into stock now anyway for me if I need to do it all again, or the next owner, but for now job done.
Ralph
Pressing the bearing onto the half shaft by 70mm as suggested by Tony above doesn`t even get the bearing off the keyway groove in the halfshaft, but I assume that when the hub is torqued on it would push the bearing that little bit further. Close examination of the shaft showed signs that the bearing had been spinning, and although it wasn`t detectible with a micrometer there was certainly play when the bearing was slid on which it did easily.
So I degreased the shaft and bearing inner race, slid the bearing on and re fitted the hub and torqued it up fully. I stood the halfshaft upright on the bench standing on the wheel studs and made sure the bearing was up against the hub. I then ran some Locktite high strength retainer around the join between the inner race and the shaft, being careful to avoid it getting into the bearing, although there was plenty of grease in the bearing so I doubt it would have done any harm. This stuff is very searching and will pull itself into the smallest of gaps. After 10 minutes it had set enough for the hub to be removed again (thank god I bought the proper puller), so I could run some more Locktite around the hub side of the bearing. After another 10 minutes the excess was carefully wiped away .
Everything was fitted back to the car, torqued up and brakes bled. Result no more movement in and out of the halfshaft and no more clunks. been out for a 20 mile drive in the country lanes chucking the car left and right to try and induce the clunk, but nothing, the Locktite has done it`s job, hopefully permanently.
I am still waiting for the new bearing kit I ordered, but it will be interesting to measure the diameter of the inner race. It will go into stock now anyway for me if I need to do it all again, or the next owner, but for now job done.
Ralph