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MG Midget and Sprite Technical - Rear Axle Drip

I've just been freeing up the rear brake adjusters and found a slight oil leak from one of the hubs. It's enough to have contaminated the brake shoes so replacements are on order. I'm sure the axle wasn't over-filled but will be making certain before it all goes back together.

I don't really want to get into pulling the half-shaft to replace the oil seals so has anyone got any suggestions?

The bearings seem fine so I don't want to disturb them unnecessarily.

I wondered whether just easing the joint open a bit and squeezing in some sealer might do the job - or is that just bodging it?

Maybe the only sensible thing is to do it properly!

Any thoughts or suggestions?

Colin
Colin Mee

Funnily enough, I've just done this tonight on the drivers side. Took about 45 mins in all with 25 of that fiddling with the springs on the shoes.

The modern paper gaskets look too thin to me so I usually have a thin smear of silicone sealant on both sides (and I mean thin so it doesn't get anywhere near the bearings).

Also, when the drum goes back on I screw two wheelnuts (not the closed end type) on and tighten to encourage the drum and halfshafts to seat properly.
Align the screw holes properly.
The screw keeping the halfshaft on I can usually get another 1/2 turn despite doing it up as tight as I could before (accessed through the none shamferred hole).
Also put the drum retaining screws in at the same time and use two screws. BL intended it that way for a reason.

Hope this encourages you to do it properly, it's the only solution as oil leaks generally don't improve.

As well as overfilling, the breather should be checked in case it is blocked causing preassure build up when the axle is hot.

Rob


Rob aka MG Moneypit

Thanks Rob

"it's the only solution as oil leaks generally don't improve." - So true, and I knew that all along really but was hiding behind the hope that it might go away!

Thanks for the other suggestions about tightening it all up, and the oil breather.

Colin
Colin Mee

I suppose I ought to suggest verifying that the leak is actually gear lube vs. brake fluid from the slave. Been there.

Best,

-:G:-
Gryf Ketcherside

It's not a difficult job to pull the halfshaft and replace the seals. Good advice re blockage of the vent, and making sure it is oil rather than brake fluid first. If it is a leaking hub seal, definitely pull the hub and replace all seals, it's the only way to go unless you want constant re-work and that feeling in the back of the mind "is it leaking again?"
Dominic Excell

Thanks Gryf - I'm an habitual mis-diagnoser but on this occasion I'm sure it's the oil seal.

The brakes are stripped down and the cylinder and the area around it are perfectly dry. The oil is definitely dripping from the hub/half-shaft joint.

Colin
Colin Mee


In addition to replacing the oil seals , I find that using a # 207PP bearing (cheap on E-Bay) stops those pesky oil drips dead , 100 % .

This bearing is the sealed version , I run a tiny bead of " The Right Stuff " Permatex RTV 'round the inner edge of the hub to ensure no possibility of oil weeping , several years of hard daily driving and rallying where I regularly get the car on three wheals and the brakes remain bone dry .

-Nate
Nate

"The modern paper gaskets look too thin to me so I usually have a thin smear of silicone sealant on both sides (and I mean thin so it doesn't get anywhere near the bearings)"

I would disagree with that. Thicker gaskets can create more play in the hub/bearing. The gasket thickness should be matched to remove play. I found gaskets from various suppliers to be of varying thickness and in the end went with no gasket (but keep o-ring). But I think my hubs are a bit worn.

I did write up some notes on this but never got round to posting, this might encourage me to do so tonight.

Advice on the two countersunk screws is good. Crank things tight with wheel nuts before tightening the screw to secure it all. Repeat when you put the brake drum on.

I used "posh" grade allan screws instead of the cheese grade pozi-drive so that I could get a bit more clamping force.

Malcolm
M Le Chevalier

Success.

I had been dreading trying to pull the half shaft as my previous experience of extracting broken ones from my Minor involved hours of tussle. The Sprite was as good as gold - both shafts just pulled straight out. Very slight wear on the splines, little more than polishing really, and no distortion or twisting so I'm happy.

The none-leaky side had an O ring and gasket, the leaky side had just the O ring and a failed smear of plumber's silicone sealer! They both now have O rings and gaskets with a very thin smear of coppa ease.

The original object of the exercise was to free up the brake adjusters. Now that new wedges and screws are fitted I have discovered just what light work adjusting the brakes can (should) be.

I drained off about 100ml of excess oil - probably not enough to have caused the problem, and checked and cleaned the breather so I think (hope) this one's sorted.

Thanks for the advice on using the wheel nuts to aid tightening. An obvious method really but it really helped - an extra quarter turn at least on all screws. Must see if this also helps the next time I need to remove the drums.

This afternoon I managed a good 20 mile run on the back roads to help bed in the brakes shoes. It's not the smartest Sprite but driving it just gets better and better!

Colin
Colin Mee

Did anyone mention axle vent....make sure its not clogged

Prop
Prop and the Blackhole Midget

I thought I did: " checked and cleaned the breather"!

Thanks for the reminder anyway Prop.

Cheers

Colin
Colin Mee

This thread was discussed between 01/04/2014 and 06/04/2014

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