Movement in the rear hubs

[265bhp]

Hi all

Advice please

I have rebuilt the entire IRS with what I still think it the correct end float on the hubs in the hub carriers....but as it is all together I am now able to detect a minute amount of play with a tiny knocking noise...if I grab the threaded end of the hub and wiggle it within the aluminium hub carrier...a vertical movement with the unit lying on its back on my work bench

I am fairly sure it is not movement in the outer fulcrum shaft bearings

I have taken one of the hub carriers off and measured the end float to be .003 so I think that is ok...

Not being a professional mechanic I am at a loss as to whether this is normal..or I have done something wrong...

It's the same on both sides..which makes me wonder if it is normal tolerance...

Regards
Jonathan
Jonathan

[christopher storey]

Jonathan : if you have measured 3 thou then it is probably OK . However, I have found that it is difficult to measure accurately with a dial gauge because the car itself can move and spoil the reading unless you can bolt your gauge on somewhere securely. I tend to do it by feel : if you can take hold of the top of the hub carrier , push it inwards, and can then only feel a " jog" of movement when you pull it outwards, that is about the right setting . It slightly worries me that you can hear a click which is suggestive of more movement than " a jog " . Like elephants , however, the correct setting is hard to describe but you know it when you see it ! . If you are getting more movement than you think is right, then it is important also to look for and exclude other sources of end float such as a duff UJ on the drive shaft

Incidentally, I have found that if your setting was ok before you changed the wheel bearing, and you used the same shim, it is usually still correct : it seems to be the length of the individual drive shaft which governs the setting rather than of any variance between bearings

PS Having re-read your post, I see you are doing this on the bench - I have never found that terribly reliable, and I think you are better off measuring it on the car - or at least by reinstalling hub carrier and driveshaft on the rear suspension - which is more laborious if you have to alter it, but more reliable ( but doing it on the bench probably explains the noise you hear )

[mgcjag]

Hi Jonathan.....you say you are gripping the threaded end within the hub carrier and can feel movement....do you mean the threaded end of the drive shaft......this should have the center hub nut on and done up really tight how do you even get in there to get hold of it.... Steve

[265bhp]

Hi guys

Thanks for the advice...bearings are part new and part re-used (as they were unmarked so I have assumed the old spacer would need to be changed
The threaded end is the main coarse thread for the wheel spinner

But reading what Christopher wrote and having had a further think I am doubting my setting of the end float...so I am going to drift the inner bearing out a touch and start again..

All part of the learning process..and double checking will give me peace of mind

Regards
Jonathan

[abowie]

With the wheel mounted there is a discernable amount of play.

[265bhp]

Hi Andrew

Interesting..I did wonder.....

since returning from watching Paddington 2 with my daughter...I have had a slight change of mind....

...I will use each splined half shaft end and re-check the end float in each case with its actual shaft....(just in case the two splined shafts are not exactly the same) ......assuming I have more float that I thought....I think I then just add the extra float I measure (over and above the preferred 2 thou minimum) to the spacers I have already and just buy two new spacers to suit...that should nip them up assuming I was amis in my measurements


Regards
Jonathan

[Geoff Green]

The closer you get to zero with end float the harder it is to measure. I set mine dry and when I get to the factory amount I add a spacer of known thickness (say .005) and measure again which gives a check on the previous measurement and when finished I remove the spacer to return to my setting at factory specifications greasing the bearings and adding seals with the final assembly.

Once on the car any part of the axle assy can add free play and noise when testing by pulling on the wheel or threaded part of the hub; diff output bearings, u-joints, hub bearings. Once assembled I wiggle and pull things to make sure nothing is loose to cause a problem when driving. And when the car is off the ground I go around checking anything and everything. Takes about 10 minutes.