congo181
Well-Known Member
My brain is telling me that with what I have now (+1.5mm), if the original spacer was back in it would be locked up solid. It doesn’t seem right.
EeEk
Well-Known Member
Out of all the diffs Ive done with crush washers Ive never heard of taking it back apart to check anything or fit a seal......the idea being you crush the washer until you get he correct torque on he gauge....thats it done. If you go to far you need a new washer. if its not enough you crush it a bit more.....but you don't take it all to bits again 
If I didnt have a gauge id just guess there should be no play but not to tight
If I didnt have a gauge id just guess
there should be no play but not to tight
congo181
Well-Known Member
I completely agree with you, and if the numbers had added up I’d have done just that.Out of all the diffs Ive done with crush washers Ive never heard of taking it back apart to check anything or fit a seal......the idea being you crush the washer until you get he correct torque on he gauge....thats it done. If you go to far you need a new washer. if its not enough you crush it a bit more.....but you don't take it all to bits again
If I didnt have a gauge id just guess
Having stripped it, I just don’t understand how come the new crush sleeve is longer than the old one by so much. Maybe I’m over thinking it.
congo181
Well-Known Member
Ok so I’m looking at it from the viewpoint of the original being correct, but you are right. If the original was very worn then there’d be a load of end float and a lack of pre-load, and the new crush being +1.5 could be correct. I wish I’d checked it beforehand. Hindsight hey
Tall Ratbag
Active Member
The crush tube doesn't set the bearing preload. All the crush tube does is to provide a near constant resistance force for the pinion nut to tighten against.
If there were no crush tube, the force between the pinion nut and flange / washer would be just equal and opposite to the relatively small preload. By incorporating the crush tube the relatively small preload force is now achieved with a larger force under the pinion nut, and less chance of slippage in service.
If the tube were solid and shimmed, then the tube would actually set the preload.
If there were no crush tube, the force between the pinion nut and flange / washer would be just equal and opposite to the relatively small preload. By incorporating the crush tube the relatively small preload force is now achieved with a larger force under the pinion nut, and less chance of slippage in service.
If the tube were solid and shimmed, then the tube would actually set the preload.
congo181
Well-Known Member
Understood. I think I meant that the length of the tube maintains the bearing separation which is what sets the preload? So the tube is passively maintaining the gap whilst allowing the nut to be torqued to stop it all coming undone.
Is that what you said?
I’m still worrying why the original crush tube is so
Much shorter than the newly crushed one.
frostythor
Well-Known Member
I have had a similar problem with my Morris minor, the new crush sleeve was 2-3 mm longer than the original one because it was used and possibly worn down by a rotating bearing face , I cant see the year of your LR, but my Morris is 57 years old, so I used old ways to solve my problem, simply distance times weight,, I used a 200 mm spanner lock tight on a flange bolt hole set it horizontally with a container and water calculated amount of water to give the correct preload, the simply tightened the pinion nut until the container did not drop down, the weight of water I used was a mid range preload setting, to allow for the weight of the spanner,
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congo181
Well-Known Member
I’m leaning towards the old crush sleeve being worn now and giving me a false idea of how long the new one would end up. The old sleev is indeed belled out at each end which looks like possible wear.
I have a suitable dial torque wrench to set the preload but your water idea is sound. Thanks.
I will use a new crush sleeve and set the preload again and leave it be.
Many thanks all, Jim
Tall Ratbag
Active Member
>>Is that what you said?
Not quite.
The crush tube doesn't set any distance - it just crushes.
As it crushes, it provides a reaction force - giving the pinion nut something to tighten against. That's all it does.
Without the crush tube being fitted at all, you could still set the bearing preload, but, the torque you would need to apply to the pinion nut to achieve the correct preload would be tiny, and the drive flange would not be clamped against anything.
So, you do need the crush tube, and you should not re-use an old one. The crushing at a constant force is important.
The length of the crush tube when removed depends on how much springback you get when you undo the pinion. It's not something to worry too much about.
The important thing is that the bearings are properly seated, and properly preloaded.
If you are using the drag torque method, and you are going to use a lever arm, take the torque applied by the mass of the lever arm as well as the torque applied by any mass you hang off the end of the lever arm.
Not quite.
The crush tube doesn't set any distance - it just crushes.
As it crushes, it provides a reaction force - giving the pinion nut something to tighten against. That's all it does.
Without the crush tube being fitted at all, you could still set the bearing preload, but, the torque you would need to apply to the pinion nut to achieve the correct preload would be tiny, and the drive flange would not be clamped against anything.
So, you do need the crush tube, and you should not re-use an old one. The crushing at a constant force is important.
The length of the crush tube when removed depends on how much springback you get when you undo the pinion. It's not something to worry too much about.
The important thing is that the bearings are properly seated, and properly preloaded.
If you are using the drag torque method, and you are going to use a lever arm, take the torque applied by the mass of the lever arm as well as the torque applied by any mass you hang off the end of the lever arm.
congo181
Well-Known Member
All good thanks.
I have a dial torque wrench so that’s not a problem.
I have made a tools to lock the flange so that’s not a problem either when doing up the nut.
I have a second unused crush sleeve (be prepared!) but what’s concerning me is that it as-new length is less than that of the current sleeve.
frostythor
Well-Known Member
As Tall Ratbag said it gives resistance to the to tightening the pinion nut but it also holds the roller cage in place on the pinon shaft, check out the manual,, if the new crush tube is smaller than the original then it is possible the wrong one as in it uncrushed state it should be longer than the old crushed one
Tall Ratbag
Active Member
>>as-new length is less than that of the current sleeve.
Yes, that doesn't sound right. Are you sure the new crush tube is the right part?
I have no idea what the length of the new crush tube should be. As long as it crushes, it's not critical.
However, you can check to see if the crush tube will work. Assemble without the crush tube, and very gently take out all the slack with the pinion nut. Measure the depth of the nose of the pinion shaft relative to the face of the drive flange. Then, assemble again with the crush tube,and verify that the drive flange sits further out,i.e., that the crush tube will actually crush.
Yes, that doesn't sound right. Are you sure the new crush tube is the right part?
I have no idea what the length of the new crush tube should be. As long as it crushes, it's not critical.
However, you can check to see if the crush tube will work. Assemble without the crush tube, and very gently take out all the slack with the pinion nut. Measure the depth of the nose of the pinion shaft relative to the face of the drive flange. Then, assemble again with the crush tube,and verify that the drive flange sits further out,i.e., that the crush tube will actually crush.
congo181
Well-Known Member
They were both bought at the same time but the one not in use wasn’t as good fit and needed reaming. I’ve now seen it’s also shorter as described.
mick the builder
Well-Known Member
Reading this thread with interest as I have to do mine at some stage. I have a noise that resembles a tube trains motor accelerating and de accelerating if that makes sense. The noise goes when I remove the rear prop. The t box is relatively new and I've replaced the half shafts and drive hubs so assumed the diff is the problem. Mike at landrover Restorations did a bit of a video on it but reading this thread doesn't fill me with confidence to do it myself. I need to see it being done rather an explanation.
frostythor
Well-Known Member
try these
congo181
Well-Known Member
These videos are both for rover diffs and mine is a Salisbury. Not sure what mikethebuilder has.
frostythor
Well-Known Member
that maybe true, but the principles are the same, OK so look for
British Atlantic video of you tube he does a Salisbury axle
British Atlantic video of you tube he does a Salisbury axle
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mick the builder
Well-Known Member
Salisbury
