Rear hub bearing replacement - Collapsible spacer

[Geko]

Ola, I'm replacing the rear hubs bearings using the MOSS kit # GHK1015. My local shop pressed the new bearings in and gave me the whole hub assembly back. I installed the hubs on both sides; torqued the lock nuts at 120lbs but I still have a play of the kind that would not pass the MOT (not that I care about the MOT but just want to get it right).

Upon inspection I noticed that the hub housings (29) have a lateral play (end float) of 3 mm on the stub axle using the drive flange (21) as a reference, both sides. I then removed the RH drive flange by hand (yes by hand) and noticed - would you have guessed- that the collapsible spacer (26) had actually not collapsed. Also noticed that the thread of the lock nut (37) is in poor shape.

My questions: should the spacer collapse as a result of:

-the pressing of the cage of the bearings (25 and 27) or

-the torque applied to the lock nut (37) or

-the torque applied to the big nut at the rear of the stub (32) or

-all of the above ??

 

Calling for your sagacity, as always

Tks

Edited November 8, 2014 by Geko

[TriumphV8]

That is horrible!

You could have run into a crash if play

would have been smaller and from that accepted

because that can break easily.

 

First I would recommend to have part number 35 carefully inspected

both for cracks in the area where number 36 is located,

(Magnetic particle would be prefect, red/white is the minimum)

and the thread for number 37 must be in good order.

 

When putting the things together number 36 must be located in the proper depth

seen from number 37 side not let the flange ride on 36 what will destroy the axle shortly.

 

It must be torqued proper together and after that you will never be able to separate 35 and flange

not with "normal" puller and not by hand! There is something really wrong.

 

If all is put properly together the play is set with the two big nuts on the other side.

[Geko]

Thanks, the end float should be around 0.3 mm (00.4-00.6) but I can't figure out where is the source of the problem: collapsible spaced or big locknut torquing the drive flange or the big nut at the rear (32). But I see AlanT around so the problem is half solved already....

[RogerH]

Hi Stef,

have you got a workshop manual - I'm sure it describes it all there. Have you tried the Buckeye site

 

Roger

Edited November 8, 2014 by RogerH

[Geko]

Hi Stef,

have you got a workshop manual - I'm sure it describes it all there. Have you tried the Buckeye site

 

Roger

Hi Roger, I have 2 manuals: Haynes - nothing and the original TR4 for which I miss the the IRS update. Buckeye site: nothing

[AlanT]

Sorry I don't know about these. But I doubt a collapsible spacer collapses very much.

 

Usually these press fit jobs go wrong because of burrs or contamination that prevent something going fully home.

[RAHTR4]

Hi Stef,

 

The Workshop Manual -TR4A Section does not appear to provide a torque figure for tightening any of the nuts.

 

It is shown the tightening operation being carried out in a vice and using a dial gauge to check the end float.

 

The end float they quote as being required is to be between 0.004" and 0.002" (0.10 and 0.05mm)

 

Send me a P.M. with your e-mail address and I can forward a PDF of the relevant TR4A section.

 

Regards, Richard

[Geko]

I had a look again and I think I found out. There seems to be multiples causes: one is the woodruff key protruding on the thread of the stub preventing the drive flange from pressing on the stub axle combined with worn thread on both stub axle and lock nut hence not providing enough torque. Malaysian job.

Will fix that tom and see what's the outcome.

 

Can anyone cast some light about the degree of wear of the axle based on the pic esp the rusted part ?

 

 

Edited November 8, 2014 by Geko

[RogerH]

Hi Stef,

as Richard states - it is not a torque loading but a measurement of the tube collapse.

Warning - if you go beyond the stated figure you must start again. The tube is fit for only one attempt.

 

That surface rust is not in a serious area I would clean it and re-use.

 

Roger

Edited November 8, 2014 by RogerH

[BlueTR3A-5EKT]

Hi Stef,

as Richard states - it is not a torque loading but a measurement of the tube collapse.

Warning - if you go beyond the stated figure you must start again. The tube is fit for only one attempt.

 

That surface rust is not in a serious area I would clean it and re-use.

 

Roger

Adjustment of the bearings is done by the big nut (s) at the rear that are locked in place by the second thinner nut and a lock tab. Hence the enormous spanner in the special tools to pull the nut tight against the resistance of the spacer.

 

The outer nut only holds the flange onto the taper - it does no 'adjustment' when torqued up properly at the beginning of an hub rebuild. At the start of the rebuild the big nuts at the back are backed off toward the UJ yoke and a new lock tab is fitted. The internal seat the rear bearing sits on called the 'adjuster' & is often scored/damaged and should also be renewed.

 

You can add shims of suitable diameter of say 10-20 thou thick to recover from an over squashed spacer if you do not have one to hand - This is often found/done in the late TR6 diff pinion set ups that use the collapsible spacer rather than the solid arrangement. But of course you will have to remove the flange to do that, so back to the man with the press.... Be sure he does not get over excited and bend the flange in his effort to separate the tapers.

Remember to pack the hub with grease when re-building as getting it in after is not an easy option - unless you have thought of adding a grease nipple.

Peter W

[Geko]

Thanks Pete for the comprehensive explanation, now I get a clear view on the process. Before refitting I tightened the enormous rear nut with... a mole grip whose leverage could obviously not provide enough torque to make the spacer collapse. That's one cleared.

 

2 more intertwined questions:

 

1/ Should the drive flange be pressed on the stub axle with a press or will it fall into place and be pressed as a result of torquing the locknut? I've read somewhere that the torque should be between 120-145 lbs which seems to indicate that the pressing is actually resulting from the torque applied to the locknut.

 

2/ I'm going to repair the damaged thread on the stub axle so is it better to refit with a locknut or with a castellated nut and split pin? The latter is provided with replacement stub axle and seems to contradict the torque loading assumption since this setup is used when the torque needs to be adjusted at times. If I follow Roger's and Richard's explanation it does make sense to fit castellated nut whereas if I follow Pete's explanation it doesn't. So either it's an unnecessary upgrade and a simple locknut will do or it is a useful upgrade allowing adjustment of the end float without having to remove the whole hub and fiddling with the enormous rear nut....

 

 

Adjustment of the bearings is done by the big nut (s) at the rear that are locked in place by the second thinner nut and a lock tab. Hence the enormous spanner in the special tools to pull the nut tight against the resistance of the spacer.

 

The outer nut only holds the flange onto the taper - it does no 'adjustment' when torqued up properly at the beginning of an hub rebuild. At the start of the rebuild the big nuts at the back are backed off toward the UJ yoke and a new lock tab is fitted. The internal seat the rear bearing sits on called the 'adjuster' & is often scored/damaged and should also be renewed.

 

You can add shims of suitable diameter of say 10-20 thou thick to recover from an over squashed spacer if you do not have one to hand - This is often found/done in the late TR6 diff pinion set ups that use the collapsible spacer rather than the solid arrangement. But of course you will have to remove the flange to do that, so back to the man with the press.... Be sure he does not get over excited and bend the flange in his effort to separate the tapers.

Remember to pack the hub with grease when re-building as getting it in after is not an easy option - unless you have thought of adding a grease nipple.

Peter W

Edited November 9, 2014 by Geko

[BlueTR3A-5EKT]

Thanks Pete for the comprehensive explanation, now I get a clear view on the process. Before refitting I tightened the enormous rear nut with... a mole grip whose leverage could obviously not provide enough torque to make the spacer collapse. That's one cleared.

 

2 more intertwined questions:

 

1/ Should the drive flange be pressed on the stub axle with a press or will it fall into place and be pressed as a result of torquing the locknut? I've read somewhere that the torque should be between 120-145 lbs which seems to indicate that the pressing is actually resulting from the torque applied to the locknut.

 

2/ I'm going to repair the damaged thread on the stub axle so is it better to refit with a locknut or with a castellated nut and split pin? The latter is provided with replacement stub axle and seems to contradict the torque loading assumption since this setup is used when the torque needs to be adjusted at times. If I follow Roger's and Richard's explanation it does make sense to fit castellated nut whereas if I follow Pete's explanation it doesn't. So either it's an unnecessary upgrade and a simple locknut will do or it is a useful upgrade allowing adjustment of the end float without having to remove the whole hub and fiddling with the enormous rear nut....

 

 

Did you get a copy of the service instructions for rebuilding the rear hub?

The instructions clearly state fit the flange to the stub axle and tighten to correct torque. No mention of pressing it into place.

The next step is to feed the big nut from the rear by finger up to the stone shield then check end float and tighten to give 0.004" max. to 0.002" min. measured end float - lower than 0.002" and you have to start again with a new spacer.

Cheers

Peter W

[Geko]

thanks Pete, loud and clear now !

[BlueTR3A-5EKT]

PS It is best and easiest to rebuild the hub out of the car and held vertically in a vice as the photo in the service manual shews.

 

Cheers

Peter W

[keith1948]

Just rebuilt 2 rear hubs for TR4A.

Tools required - preferably a 4 stud hydraulic hub puller such as US PRO that is available from various suppliers on line. Also needed are bearing pullers such as Machine Mart Clarke CHT253. Also very large 52mm spanner (I found a 50mm one and filed out to 52mm) for large nut and a thin adjustable wrench for locknut

Parts required:

Hub seal GHS 131

Hub seal GHS 133

Tab washer 139057

Nyloc nut 138563

Rear bearing spacer ULC2188

Collapsible spacer 138272

 

Bearings, I used Timken from Bearing King

44649/44610

29749/29710

 

Undo nut securing end of hub shaft, remove washer underneath, put some WD40 around threads so it can seep down past woodruff key, replace nut to protect end of shaft. Fit US Pro hydraulic puller and gradually torque down the puller. Tapping sides of hub gently with a hammer can help 'shock' the hub off the shaft. It goes off with a bang. Remove hub and pull off bearing carrier. Using bearing puller pull off outer bearing from hub and smaller bearing and both collapsible and solid spacers from shaft. Check shaft is ok and not cracked or damaged. Back off large locknut completely, remove large nut and fit new tab washer, replace large nut, backing it off. Fit stone guard, new solid spacer (old one will be scored) and pull rear bearing onto shaft using bearing puller fitted to back of shaft where you will find central hole/dimple to locate puller. Do not drive bearing on with a hammer as it is likely to damage it. Fit collapsible spacer. You may need to clean shaft with a little fine emery and WD40 to assist in fitting bearing and solid spacer.

Drive out grease seals and bearing housings from bearing carrier and clean out old grease. Save bearing housings to refit new ones. Using old bearing housings, press new bearing housings into carrier using a vice. Again no hammering. Press in grease seals. Push new outer bearing onto inside of hub. Use old bearing centre to press it on using a vice.

Pack bearings with grease. Put bearing housing onto stub shaft followed by hub (don't forget woodruff key) and fit washer and new nylon nut. Torque this nut to 100 ft lb. This nut simply holds hub onto shaft and plays no part in adjustment.

Next using a dial micrometer measure float between hub and the carrier. Tighten large nut with large spanner a bit at a time constantly checking end float. It should end up at approx. 0.003 inch (manual says between 2 and 4 thou. Make sure you have pushed hub carrier up and then down fully between measurements. You need a bit of torque to tighten up the large nut hence the large spanner but don't overdo it or you will go too tight on the end float. Tighten locknut and before locking tab washer measure free play again. Tap bearing carrier gently up and down with soft faced hammer to ensure free play is accurate. I erred on side of caution with first hub and had too much free play and had to readjust after bending back lock tab which was not ideal.

Once hub is on car there should be only 'slight' play on the bearing when the wheel is on.

One of the hubs I rebuilt was a recon exchange unit I got some time ago that had been on the car some time. Upon disassembly I discovered that the bearings were 'budget' and the grease seals were different designs. We will have to see how the ones I have done fare.

Not a job to attempt without the proper tools!!! Could not have done it without the hydraulic puller, bearing pullers and large spanner.

Good luck

Keith

 

[ChrisR-4A]

My local Triumph garage has the big spanner and the handle is over 1 meter (3ft) long! They also use a bench mounted hydraulic press with jigs to suit the shape of the hubs.