End float

[Richard Browne]

I'm eleven years into a full restoration of my Vitesse- work has been thorough if not particularly speedy.  My first contribution to a forum- although reading them has provided a lot of valuable help.

 

Can I ask for some advice on rear hub endfloat please? I've replaced the bearings, and reassembled the hubs and driveshafts using only the distance piece.  I've torqued up the hub nuts- and, whilst the assemblies turn reasonably freely in the vertical links, there's no play.

 

Does the addition of additional shims increase or reduce end float?  And exactly how is it measured?  I have access to a dial gauge.

 

Cheers,

Richard

 

 

[Pete Lewis]

I guess this is a rotaflex hub ?

 

the spec is 0.0005 to 0.0025" thats quite small to measure , very few shims are on the shelf so

can be hard to get dead right.

 

not easy to mount a DTI

 

this spec just makes sure there is no pre load and hardly any end float

 

if it spins freely can you fit a wheel and check the minimal rock at the wheel ?

[Gary Flinn]

Hi Richard

 

Welcome to the forum, this is a copy and paste from the Canley Classics Website that should Help:-

 

Replacement wheel bearings should be re-shimmed to give the correct end float/preload. In most cases replacing the equivalent shims and spacers from the old unit will give an acceptable result but if the hub has been replaced or the unit assembled from parts, then the following procedure should be followed. Fit bearing cups into vertical link. Fit outer race and outer shell into vertical link. Fit hub making sure it is fully down. Fit inner race. Put spacer and shims in place - measure across bearing inner race with straight edge and feeler gauge such that the hub and shims are 0.001 - 0.002 higher than an inner bearing race. Fit outer axle shaft fully home and tighten nut to 90ft/lb. You should feel VERY slight play - if you can feel end float, reduce shims - if preload, increase shims. When correct, take apart, grease and fit inner seal.

One final word of warning, don't assume that every garage (even classic car specialists) is capable of rebuilding roto wheel bearings. We have seen some shocking bodges over the years carried out on customers stuff brought into us after recent work by 'professionals'.  You need to assertain that who ever  you trust your rotoflex with has a proven track record with the stuff, is regularly practised in the art, and has a ready stock of shims/spacers, etc before he attacks it.

You have been warned!

[Adrian]

Hi Richard

 

I did the same last year with a varying degree of success. I tried to follow the sage advice given on the forum but did find it difficult to accurately measure the end float (I didn't have a dti) . I'm sure if the forum held a practical masterclass in these techniques we would all breath a sigh of relief as you can't beat seeing a skilled individual in action!

 

Nevertheless I obtained some shims from Leacy Classics and followed pretty much Petes advice. Trial and error.

 

Adding shims increases the end float.

If you have greased up your bearings they will bed in and you will need to recheck the wheel wobble (I believe typically less than 1mm).

I did a CV conversion so was 'just' able to flex the driveshaft with the brake pipe still attached to add/remove shims so I didn't have to bleed the brakes each time.

 

One side still isn't quite right as there is a slight rubbing/grinding sound (possibly drum on brake back plate).

 

Hope that helps    

[Paul H]

Hi Richard

 

Welcome to the forum, this is a copy and paste from the Canley Classics Website that should Help:-

 

Replacement wheel bearings should be re-shimmed to give the correct end float/preload. In most cases replacing the equivalent shims and spacers from the old unit will give an acceptable result but if the hub has been replaced or the unit assembled from parts, then the following procedure should be followed. Fit bearing cups into vertical link. Fit outer race and outer shell into vertical link. Fit hub making sure it is fully down. Fit inner race. Put spacer and shims in place - measure across bearing inner race with straight edge and feeler gauge such that the hub and shims are 0.001 - 0.002 higher than an inner bearing race. Fit outer axle shaft fully home and tighten nut to 90ft/lb. You should feel VERY slight play - if you can feel end float, reduce shims - if preload, increase shims. When correct, take apart, grease and fit inner seal.

One final word of warning, don't assume that every garage (even classic car specialists) is capable of rebuilding roto wheel bearings. We have seen some shocking bodges over the years carried out on customers stuff brought into us after recent work by 'professionals'.  You need to assertain that who ever  you trust your rotoflex with has a proven track record with the stuff, is regularly practised in the art, and has a ready stock of shims/spacers, etc before he attacks it.

You have been warned!

Please forgive the newbie questions - 

 

"You should feel VERY slight play - if you can feel end float, reduce shims - if preload, increase shims. When correct, take apart, grease and fit inner seal."

 

Q1 I understand VERY slight play , but what is end float ?

Q2 What is preload ?

 

Thanks in advance

Paul 

[Pete Lewis]

End float ....the taper roller bearings have room to move a small amount , the assembled distance between the roller races is bigger than the distance between the cones , if can measurs the

push pull on the hub and witha wheel fitted will allow you to feel some slack rock at the rim

 

pre load is when the races are closer together than the cones and there is some level of effort to

overcome the friction , this is more for diff case bearings and pinions so when under load there is no

shift of the meshing components in old money The force /effort needed to rotate the assy is measured in torque of lb ins.

 

where as end float is measured in clearances 0.001" increments

[Pete Lewis]

I can type but not on a tablet

[Paul H]

End float ....the taper roller bearings have room to move a small amount , the assembled distance between the roller races is bigger than the distance between the cones , if can measurs the

push pull on the hub and witha wheel fitted will allow you to feel some slack rock at the rim

 

pre load is when the races are closer together than the cones and there is some level of effort to

overcome the friction , this is more for diff case bearings and pinions so when under load there is no

shift of the meshing components in old money The force /effort needed to rotate the assy is measured in torque of lb ins.

 

where as end float is measured in clearances 0.001" increments

Thanks Pete for the definition - appreciated 

[Pete Lewis]

if you got the gist of that waffle youre doing well  ha !!  

 

the best float is some cream on top of some Irish coffee

 

Pete

[dave.vitesse]

Rotoflex - The end float has to be measured dry, without grease and with the drive shafts on the bench. As everybody has said it is difficult to measure and without the original test kit, as a result is trial and error.

 

Maybe the nearest you can get is to clamp the drive shaft in a vice and wangle the upright.

 

There should be a very very, tiny, amount of play. Not unlike the front hubs. After setting this up them pack with grease.

 

The above is the method I use, but having spent time in QA and looking for definite's I will say its very subjective.

 

Dave 

[ludwig113]

i did suggest this last year but it didn't happen. i would definitely attend .

 

paul

 

"I'm sure if the forum held a practical masterclass in these techniques we would all breath a sigh of relief as you can't beat seeing a skilled individual in action!"

 

[Pete Lewis]

I did a tappet and twiddle tutorial day last year with Aidan and Paul

 

I dont do rotaflex , , but in the spring we could do something else of interest

 

if theres support , means you have trip to sunny Luton

 

but carb balance , front hub end float , geomerty, gearbox examinations etc.

 

 

Pete

[Paul H]

I did a tappet and twiddle tutorial day last year with Aidan and Paul

I dont do rotaflex , , but in the spring we could do something else of interest

if theres support , means you have trip to sunny Luton

but carb balance , front hub end float , geomerty, gearbox examinations etc.

Pete

I went to the tappet demo with Pete last year and found the visit well worth while and would like to attend any further demos

Paul

[Pete Lewis]

Oh Bu**er now I have to dream up a plan

Ha !

 

Paul youre top of the list

 

pete

[dave.vitesse]

Rotoflex - Generally if you are having problems measuring the end float - 

 

One of the problems with measuring the end float is that the oil/grease seals tend to mask this and will cause some drag when you are testing for bearing drag making it even more difficult to obtain meaningful results. 

 

Therefore, start with some end float to judge the drag effect of the seals. Then reduce the clearance until you can feel the bearings drag, then increase the clearance by a very small amount and check the drag.

 

A very very small amount of bearing drag is about right as they need to bed in. However, the bearings should not be binding.

 

When carrying out the tests ensure the, stone guard, spacer, inner and out bearing are fitted correctly, no gaps, plus the hub is torqued down to the given figure.

 

Final check - The bearings are not binding and the other way there is not a large end float. Then pack with grease.

 

Tip - As the splines tend to twist after many miles of use, ensure you fit the hub on to the shaft in the same position it came off.

 

Dave