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MG MGB Technical - Axle and hub removal

Just removed my Mk1 Left rear axle and hub assembly.

Now I am horrified - only a small grub screw holding it in place!! I know the screw cannot come out - even if it is loose.
Even so...........

I heard the MGB rear axle arrangement described as agricultural. That might be putting a positive spin on it!!!
Anyone ever lose an axle on the road??
John
John Minchin

John, it's held on by the wheel nuts too when the wheel is bolted to the drum and the hub as well as the two screws holding the drum to the hub. It's not going anywhere!

The one that worried me was that the octagonal nut that holds the hub to the axle was finger tight on my car! I only found it after three years or so. OK, there is a tab washer as well as a left hand thread to stop it loosening but it might be good for you to check this on your car.

Mike
Mike Standring

Mike
Mine is an early mk 1 with wires. There are 4 nuts holding the brake drum to the hub. The axle is a press fit into the hub - no nut to worry about!!

So there isn't anything preventing the whole assembly sliding out of the axle tube apart from the small screw which can't come out because the brake drum is covering it.

Strange but true

John
John Minchin

John, you are mistaken. It is the Octagon nut that retains the whole assembly from coming out of the axle tube, together with the ability of the bearing to take side loads. Refer to the WSM sectional drawing. You are safe!
Art Pearse

The screws merely holds the axle flange onto the hub until you tighten the lug bolts. The big 8 sided nut and tab washer hold the hub assembly to the housing. As I remember this is a 150 lb-ft torque connection.

I replaced a leaky axle seal in my Mk I many years ago. This required hub removal. I didn't have the special tool for the octagonal nut. So I used a trick used to remove the generator/fan nut on air-cooled VW's. Use a punch and whack on a corner of the nut. It works, you make a mark on the nut but not really a problem. I used the same technique to reassemble. No problem in very many miles. Alternatively you can buy a socket from Moss for $US90 or so.

The design of these banjo axle hubs essentially means no vehicle weight is carried by the axle. But, the assembly is quite different from contemporary designs.

Bob McCoy
Robert McCoy

If you ever remove this octagonal nut, be sure to tighten it properly. A friend of mine very nearly had a serious accident with his MGB Mk 1 because the half shaft complete with wheel came out of the axle casing. The big octagonal nut holding the bearing had finally worked itself loose through 15 years of regular driving, in spite of the tab washer. You find the explanation here:

http://mgaguru.com/mgtech/rearaxle/ra102.htm

Tore
Tore

Is this high torque figure just for the early banjo axle. Wondered what it should be for the later one held on with a split pin.
Trevor Harvey

FWIW My Leyland (C1976) Aussie factory manual nominates 180lb.ft. for the "rear axle bearing retaining nut" for the 18G/18GA cars ie to October '64. For cars from then to 18GG (Aug '71) 150 lb. ft. for the "axle shaft nut".

I presume the latter figure applies to all cars assembled in OZ to end of local production circa Nov 1972. Not sure what torque figure may apply to cars post that date eg imported ex NA vehicles. Our British/American friends may care to comment.
Roger T

150ft.lb for all tube/Salisbury axles, even though it is retained by a split-pin.
PaulH Solihull

The reference from Tore is quite good. Thanks for sharing it.

I guess in this case I'm a DPO. Luckily I haven't had any trouble but I'll check my axles. Maybe I'll have to invest in the proper tool. (I do think I got more than 30ft-lb with the punch but I couldn't tell you how much.) The punch method did remove the nut which was I'm sure factory original. It may have loosened with use as the reference states.

Robert McCoy

Thanks everyone
I was wrong (thankfully)
Managed to ghet a copy of an öriginal workshop manual"- the one with the very clear drawings. It is now more obvious how everything works!

John
John Minchin

Well, New hub pressed onto axle shaft and attempting to reinstall it. It came out very easily but I'm having a devil of a time getting the spline to mate and allow the shaft to slide fully home.
Taking advice from a local expert I have been rotating and tapping the hub to try and get the spline into mesh. But it doesn't want to!! Apparently mostly they go together easily but not always.

I have carefully filed the end of the splines to ensure there are no burrs that might prevent engagement but it still isn't working.

Anyone got any ideas apart from gentle persistence and a few choice words??
BTW this is a Mk1 Banjo rear end with the axle and hub pressed together with no nut.

John
John Minchin

Maybe turning the half-shaft is turning the diff socket as well. Try locking the prop-shaft then turning the half-shaft. No experience of banjo but there might be scope for quite a lot of lateral movement at the inner ends before the splines engage, so it may not even be lining up with the socket. It might be difficult lifting the whole inner length of the shaft to the right position just by levering the outer bit.
PaulH Solihull

Yes I think the weight of the axle is working against me - definitely locked the prop shaft. Also tried lifting the opposite wheel off the ground and got someone to rotate that while I moved the shaft. Quite a few times the shaft locked"" but then let go again. I tried hitting the end of the hub inwards with a hammer when it was "locked, but it just bounced outwards."

I'll start a new thread with a different title to see if anyone has had this exact problem
Thanks
John Minchin

This thread was discussed between 12/01/2012 and 30/01/2012

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