Technical Rear wheel bearing replacement

[thepuddlejumper]

Hi, just discovered the rear bearing compressible spacers in my recently acquired Panoramica haven’t been crushed only tightened up resulting in slightly loose bearings. I had to replace rear bearings in my gamine when in Italy, not easy getting the spacer crushed, It took a 1.5m bar to compress it. Can someone tell me the point of this spacer as the cups to the timkin bearings are set on a shelf so torquing the bearings up without should work ok as in other similar situations on other types of car. It’s not as though the bearings are floating and need physically separating. I’m having great difficulty in crushing these particular spacers.

 

[the hobbler]

Hi, just discovered the rear bearing compressible spacers in my recently acquired Panoramica haven’t been crushed only tightened up resulting in slightly loose bearings. I had to replace rear bearings in my gamine when in Italy, not easy getting the spacer crushed, It took a 1.5m bar to compress it. Can someone tell me the point of this spacer as the cups to the timkin bearings are set on a shelf so torquing the bearings up without should work ok as in other similar situations on other types of car. It’s not as though the bearings are floating and need physically separating. I’m having great difficulty in crushing these particular spacers.

As far as I can ascertain, by crushing the spacer, the bearings are 'pre-loaded'.There are 2 types of spacer--a 'goldish' coloured version which is just about impossible to crush, and a 'silver' coloured version, which as far as I can remember (and it was MANY years ago that I was fitting "factory supplied crushable spacers") are just about the same specifications as the 'factory'original and crush as per the factory specifications. In the Factory 'book of words' they show a "rotational torque" tool by which to register the correct bearing resistance. This pre-load torque is the equivalent of:--1lb @ 4.3ins. (500 gram @ 11Cm)--for which we can thank Peter (Fiat 500)-- from the hub centre. I made myself a simple tool which consists of a 1 lb weight which I can hang on a length of 8mm aluminium bar. Yes, the nuts ARE done up very tight, and the n/s hub is a lot easier to do than the o/s hub. A combination of bars, looooong extensions and the ability to think a little bit out of the box as how to hold the hub still whilst doing up the nut is required (plus copious cups of tea---and some Tunnocks tea-cakes?). I made a very long tool by which I can hold the hub still---if you would like a picture of it, contact me direct--- [email protected]

 

[fiat500]

If the bearings aren't preloaded the taper rollers will be able to slightly move laterally, particularly on corners.
Although an enormous effort I'd need to start the crush, effectively only a tiny force is applied to the bearings because once you feel it "give" you will not need to apply much more torque to get 1ftlb of rotational resistance at thr bearing.

 

[thepuddlejumper]

If the bearings aren't preloaded the taper rollers will be able to slightly move laterally, particularly on corners.
Although an enormous effort I'd need to start the crush, effectively only a tiny force is applied to the bearings because once you feel it "give" you will not need to apply much more torque to get 1ftlb of rotational resistance at thr bearing.

Hi, I understand what you have said but you do preload the bearing’s whether with the crusher piece or not. On cornering the force goes to the relevant timkin and if any movement occurs this would still translate through the axle and crusher so I can’t see a benefit. The same argument can be used on the front axle bearing which are under much greater turning forces yet there is no crusher spacer, I understand the front inner and outer bearings are a different diameter. I had a chat with no bearing specialist supplier and he didn’t know why a spacer would be required. I’m going to experiment and build without the spacer and see what happens.