MG T-ABC

'49 TC
'have my pinion housing on the bench, & fully assembled.
waiting for shims to arrive...
is there a trick way to torque the pinion nut (100+lbs) on the bench ?

You just need something to hold the flange from rotating. The first photo shows the factory tool. The second photo is what you can make in a pinch from a piece of angle iron from the local hardware store. You bolt it to a couple of the flange holes.

Great, thanks for the photo!
i'll fab a special tool.

got another question.
the outer (front) race of the double row ball pinion bearing can be pressed home by hand.
should i use some Loctite Bearing Fit #641 ?

I think its ok so go in by hand, but you don't want any actual play. One other note is that those old original bearings with bronze cages are known to fail given enough miles. A modern steel replacement isn't a bad idea, or a tapered bearing conversion. Roger sells them.

They fail like this.
My theory is the cause of failure is low oil, falsely assuming the plug on the right hand side is the correct level.
Better to overfill in this cup than underfill.

Of course that is the fill level plug/hole on the driver (right) side of the diff. The fill plug is on the other side. The ring gear is submerged in the oil reservoir and therefore constantly lubes the head of the pinion shaft. Whenever the car is driving forward, the ring gear acts as an oil slinger that keeps the pinion carrier/bearings slathered in oil. I seem to recall Roger talking about slightly overfilling the diff being OK, but I do not believe it was much more than an ounce or two over.

so one should fill to the top of the cup.?
mine took two quarts to get to the bottom of the cup...
'put Abindon 90 for the winter, 140 for the summer?

The factory calls for just under one quart, which is right about at the bottom of the side plug. I like to put in a full quart just because it makes me feel better. Filling to the top of the filler cap is way too much! I'm not an engineer but it seems to me there would not only be a lot more drag created, but also pressure pushing oil out the scroll seals. It also seems like the oil level that high would be way above the scrolls, so when you park you would have oil pouring out all three ends unless you had lip seals fitted.

I'm coming in rather late to this discussion! Steve is absolutely correct, in fact having too much oil in the diff. will have a churning effect giving heating. The lower level plug is there for a reason: pour oil in until it just begins to trickle out. Replace plug with a new fibre washer.

AS to the original double row split race R&M front thrust bearings, they have been obsolete for very many years, but I have a few. All the diffs. I have rebuilt over the last 30 years have had taper-roller bearings fitted. I have lost count of how many, but in all that time the only two failures were caused by lack of oil! Quite often the outer races are loose in the housing, so I also use Loctite.

Wth the ball bearings, no inner shims are needed, unlike the taper rollers, which need setting up with shims, and also a thicker spacer under the front flange to move the housing forward by 2.5mm due to the offset in the inner & outer races.

Those little screws Moss 265-196 (which they show incorrectly going in from the front!) have special heads so that they are recessed into the flange. I supply these among other things to Moss: in fact I have every other part for the rear axle (and front too)

Roger
AKA "Mad Metrics"

all good to know !

HAPPY 2024 TO ALL !!