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Front Hubs
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Ray White



Joined: 02 Dec 2014
Posts: 3292
Location: Derby

PostPosted: Sat Sep 21, 2019 5:41 pm    Post subject: Reply with quote

alastairq wrote:
The nut is done up tightly...but then, that's all that stops any wheel coming off.....even today?
[Ford Pop/Prefect/Anglia/Thames of the upright era, relied on the half shaft not snapping to prevent the rear wheels departing.

Which is why I [for one] invested nearly a 4 figure sum for some special steel half shafts to be made up...these ought not to snap! The splitty is to stop the nut turning.....emphasis by all the knowledgeable one's is, never loosen the nut to make the splitty fit.]


On my car the hub nut was not...could not... have been done up properly.

The half shafts are not badly worn but are showing the signs - slight burring - of the "steps" that inevitably lead to failure. I have just taken delivery of a new crown wheel and pinion which coincidentally also have an improved design incorporating taper roller bearings. Also new diff thrust bearings should help to reduce -if not eliminate- much of the damaging back lash.
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alastairq



Joined: 14 Oct 2016
Posts: 1294
Location: East Yorkshire

PostPosted: Sat Sep 21, 2019 7:50 pm    Post subject: Reply with quote

I had nearly a dozen Austin half shafts come with the Cannon [before I rebuilt it],....all had the stepped twist to the splines..luckily,they were all stamped EN8 {IIRC]...so a chum got them from me, and made ..amongst other things, spindles for Morgan 3 wheelers [of which he has one] Two for himself, and three or four pairs to sell on.
_________________
Dellow Mk2, 1951 built, reg 1952.
Ford Mustang coupe, 1967, 6 cylinder auto.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
----------------------------------------------
Ford Pop chassis, Ashley 1172 bodyshell, in pieces.
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Ray White



Joined: 02 Dec 2014
Posts: 3292
Location: Derby

PostPosted: Sat Sep 21, 2019 10:23 pm    Post subject: Reply with quote

The dilemma I am faced with right now is not being able to remove the bearings from the hub.

It is not advisable to drift out a bearing by impacting on the inner race. This will ruin the bearing. Perhaps there is no other way ?

I am pretty sure they are stuck tight with Loctite. There seems no way to attach a puller. I have a good 'internal' puller but the spacer precludes it's use. I also have a 12 ton press but there seems no way the bearings can be pressed out.
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jp928



Joined: 07 Jun 2016
Posts: 247
Location: Australia

PostPosted: Sat Sep 28, 2019 8:02 am    Post subject: Reply with quote

A bit of heat on the hubs should allow you to tap out the bearings, only on the outer races. I see in the diagram at the start that there is a keyed washer with multiple holes in it under the castellated nut. These washers are usually associated with a 'nut' that threads on to the stub which has more holes in it, designed to give you a vernier adjustment of the tightness, and a small pin through matching holes - Rover P1,P2,P3 used this. There is no such 'nut' or pin shown? Certainly looks like the spacer between the bearings is somehow wrong, or the bearings ? Can you see if any part of the hub is binding on some part of the assembly? Also note that if you go to tapered rollers, its critical that the end load, when up to working temp, is very low. Rover used to specify the end float at .003-.004" cold, IIRC, for tapered rollers. They used a 13 hole washer and 4 hole nut, giving a 52 step vernier. The nut was round, and was then locked with a castellated nut.
jp 26 Rover 9
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Ray White



Joined: 02 Dec 2014
Posts: 3292
Location: Derby

PostPosted: Sat Sep 28, 2019 9:39 am    Post subject: Reply with quote

As it is impossible to get to the outer race to drift out these bearings I can only assume that unless they are very loose they will be ruined by impacting on the inner race. This proved to be the case so I have forcefully removed them and discarded.

Now I need to fit the taper roller bearings which I think have to be aligned with the inner, smaller, races facing each other. The spacer needs to be compressed to give greater rigidity to the spindle and there also needs to be a 4 lb preload on the bearings.

I seem to remember being taught that the bearing needs to be tightened until resistance in the hub can be felt then the nut backed of a little so that the hub is free. Then insert the split pin.
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serowman



Joined: 01 Oct 2019
Posts: 2

PostPosted: Tue Oct 01, 2019 8:54 pm    Post subject: Front hubs Reply with quote

Front hubs fitted with taper roller bearings do not normally have a spacer fitted.The spindle should strong enough without it.[/quote][/b]
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alastairq



Joined: 14 Oct 2016
Posts: 1294
Location: East Yorkshire

PostPosted: Tue Oct 01, 2019 9:07 pm    Post subject: Re: Front hubs Reply with quote

serowman wrote:
Front hubs fitted with taper roller bearings do not normally have a spacer fitted.The spindle should strong enough without it.
[/b][/quote]
The spindle in this instance isn't very strong.

Fitting the spacer appears to be the accepted procedure by MG experts....
_________________
Dellow Mk2, 1951 built, reg 1952.
Ford Mustang coupe, 1967, 6 cylinder auto.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
----------------------------------------------
Ford Pop chassis, Ashley 1172 bodyshell, in pieces.
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Ray White



Joined: 02 Dec 2014
Posts: 3292
Location: Derby

PostPosted: Tue Oct 01, 2019 9:49 pm    Post subject: Reply with quote

This is pretty much definitive...

https://www.mgexp.com/forum/t-series-and-prewar-forum.46/spacer-lenght-for-tapered-front-wheel.3858696/
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serowman



Joined: 01 Oct 2019
Posts: 2

PostPosted: Tue Oct 01, 2019 10:01 pm    Post subject: FRONT HUBS Reply with quote

Unless the spacer is a tight fit to spindle how does it add strengh
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Ray White



Joined: 02 Dec 2014
Posts: 3292
Location: Derby

PostPosted: Tue Oct 01, 2019 10:09 pm    Post subject: Re: FRONT HUBS Reply with quote

serowman wrote:
Unless the spacer is a tight fit to spindle how does it add strengh



Oh my GAWD, how many times do we have to say spacers and a tight nut are ESSENTIAL in a MG MMM and TA/TC cars stub axles when using tapered roller bearings. Spacer also essential when using original ball bearings. This has been known, and proven, for over 40 years!! Ignore what is done with American cars, that has no relevance. The complete set up requires a TIGHT stub axle nut, torqued to 70 or 75 ft-lbs in case of original 5/8" BSF castellated nut. The tight assembly has a larger effective diameter and therefore is stronger in bending. PLEASE, use a spacer and tight nut. Yes you will have to add shims to the existing spacer as the tapered roller bearings have a greater off-set. The shims are 20 mm bore, I don't think there is a specific dimension, add shims by trial and error. I strongly suggest crack testing the stub axles on the lower inside to check for cracks. It does happen even if the original tight set-up is used. A crack is much more likely if you don't use a spacer!!
Tapered roller bearings are much superior to original ball bearings, when using a spacer and tight nut.
If you find a crack, I can repair the steering knuckle with a new insert pressed into place.
Email o call me if more info needed. (removed RJ)
(removed RJ)@sympatico.ca


^^^^
This guy knows what it's all about.

(individual's private email & tel no removed, RJ)
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jp928



Joined: 07 Jun 2016
Posts: 247
Location: Australia

PostPosted: Thu Oct 03, 2019 7:20 am    Post subject: Reply with quote

I bow to years of experience with MG hubs, but reiterate the basics of tapered roller hubs. There is a Timken youtube piece available - https://www.youtube.com/watch?v=0RqlrnoiqnY
Basically - 50ft/lb, back 1 TURN, 10 ft/lbs, back 1 to 1.5 flats, adjust nut to set end float .001-.005" with a dial indicator. Excessive end load is fatal to tapered rollers when up to temperature. The small boxes beside railway tracks are heat detectors that can sense hot wheel assemblies and send msgs to stations, so the bearing can be fixed before an accident occurs.
jp 26 Rover 9
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Ray White



Joined: 02 Dec 2014
Posts: 3292
Location: Derby

PostPosted: Fri Oct 04, 2019 7:21 pm    Post subject: Reply with quote

Today I managed to fit the front wheel bearings. I found the job a bit fiddly because there is a very fine line between avoiding pre load and too much end play. Only the slightest movement of the hub should be evident. The distance piece needed a bit of tidying up on the lathe and a combination of 1mm and 0.1 mm 20/35 shims were needed to achieve a free hub at 80 ft/ibs.
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Ray White



Joined: 02 Dec 2014
Posts: 3292
Location: Derby

PostPosted: Sat Oct 05, 2019 11:16 am    Post subject: Reply with quote

I have had a set back with the new front hub bearings. The previous bearings, as I have mentioned, were stuck in place with Loctite; or similar. The problem is that the new outer taper roller race is a slack fit in the hub. I imagine a previous bearing must have 'spun' on it's seat as the race can be rotated easily by hand.

Do I need to replace the hubs...or can I resort to the previous 'Loctite' remedy??
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jp928



Joined: 07 Jun 2016
Posts: 247
Location: Australia

PostPosted: Sat Oct 05, 2019 1:28 pm    Post subject: Reply with quote

I believe there is a Loctite product for exactly this case, but have no direct experience. I have seen the case where there is wear on the stub where the inner race of the inner bearing runs, and that race is loose - in this case you can raise the surface by marking with a centre punch.
jp 26 Rover 9
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Ray White



Joined: 02 Dec 2014
Posts: 3292
Location: Derby

PostPosted: Sat Oct 05, 2019 3:33 pm    Post subject: Reply with quote

jp928 wrote:
I believe there is a Loctite product for exactly this case, but have no direct experience. I have seen the case where there is wear on the stub where the inner race of the inner bearing runs, and that race is loose - in this case you can raise the surface by marking with a centre punch.
jp 26 Rover 9


This wear is worse than I first thought. With the final adjustment done the hub rocks on the bearing and makes a "click" sound. The effect is like too much back lash but it only takes the removal of a single 0.01mm shim to induce binding.
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