TA Rear Axle Hubs

[Rob Reilly]

When I first removed my right rear knockoff, a lot of gear oil came out. I figured a bad seal and bought TC seals because everybody said they were the same.
The axle is now up on saw horses.
I see grease fittings inside the hubs.
Now I have removed my outer hubs and axle shafts, and there was no grease in there, just gear oil.
I see big nuts holding the inner hubs. It looks like somebody tried to chisel them loose.
I will have to buy a 52 mm socket to get these off.

Questions for today:
Are they both right hand thread, or is one left hand?
How much torque is on them?
Any other tips?

[Kregg Hunsberger]

It looks like the lip seal conversion has been performed on the axle. Although the seal in the nut looks to be missing. From The Frame Up has a kit including replacement Nuts with seals, bearings and shims to perform the conversion from stock (oil Slinger insert) . FTFU Part number is CH201 or CH202 depending on axle shaft diameter. Moss also has the nuts and seals as a Kit. The nut should be a 50 mm (2 inch) and is torqued to 130 Ft-lbs. The left side is a left hand thread and the right side is a right hand thread. The forward travel wheel rotating direction tightens the nut.

[Duncan M]

Mostly the grease fittings are no longer used to grease the hub bearings, as the bearings usually
get replaced with (rubber seals) sealed bearings. TC uses 6208-2RS. I like SKF in that size, made in USA. Sorry, do not know the number for the seal.

You have found out about the limited lifespan of the newfangled rubber seals. The original scroll seals back there also have a limited lifespan, but if you park the car with good scrolls and come back 20 years later they will still be good. A couple of articles on replacing the scrolls from this site.
http://www.mg-tabc.org/library/oil_bushing_removal.htm
http://www.mg-tabc.org/library/TC_rearaxle_rebush.htm
http://www.mg-tabc.org/library/rear_axl ... hrower.htm

[Steve Simmons]

Agreed, the original nut was not a hex, at least on TC. The hex nut size is normally 2".

The rubber seals don't work well on the original axles unless you install speedi sleeves on them. Modern tapered axles are often machined smooth enough to run a seal on, and they are also much stronger than the originals.

You can buy sealed nut kits from Bob G, and Roger F.

[Rob Reilly]

Thanks for the information.
Left hand thread on the left side.
Curious to know, what is the source of the 130 foot pounds (176 Nm) torque spec?
My Blower just says remove and tighten.
Two discrepancies; page fourteen of the T Midget Instruction Manual shows a hex nut, and I measure mine at 2-3/64" across the flats, which is 52 mm. I have ordered a 52 mm impact socket on Amazon $28.
We'll see if the impact gun can get these nuts off, and what turns up when I do.

[frenchblatter]

Rob, when when these cars were made the only thing a torque wrench was used for was heads and cranks. I have a few old manuals lying about and none have torque reading for anything but engine bolts and screws.

[Steve Simmons]

Interesting, maybe the TA used a hex nut and they switched to the slotted nut for later cars.

[Duncan M]

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Rob, proper tools will ease it right off with hardly any effort.

[Rob Reilly]

Yes, I have that proper tool.
I looked on the Moss website and see the picture of the slotted nut, so now I understand what you meant. What tool do they use with those, a hammer and punch?

[Steve Simmons]

I have a homemade socket for the slotted nut, but most people just use a hammer and chisel to take it on and off. Better yet is to replace it with a hex nut so it can be tightened properly.

[Duncan M]

No special tools required to change out the TC slotted nut. Having to buy a special big socket was fairly traumatic for people back in the 40's and 50's. I think most people would be able to figure out that if it was real hard to get off, it probably should be put back on good and tight. Using a torque wrench to install is undoubtedly ideal.

[Kregg Hunsberger]

The 110 to 130 Ft-lb torque is that recommended by FTFU. It is based on the thread diameter for the desired preload. The outer race should also be preloaded by the installation of the hub. This can require additional shims to set the load path from the hub through the outer race to the bearing carrier. Recommend hub to bearing carrier gap to be about 0.004 inch minimum. The paper gasket can be removed and replaced with a sealer if wanted. Just have to make sure it does not limit the lad path through the outer race. See a discussion in "TC's Forever" fist edition pages 106 & 107, Oil leaks - Rear Drums, Rear Hub to Carrier Assembly.

The original slotted nuts torque was set by how far do you want to peen over the edges of the nut.

[ROGER FURNEAUX]

hi Bob - I see you also posted your query on the mg-exp.com forum, to which I replied, so for the benefit of others, here it is.

BTW contrary to a remark that the seal is missing, you not only have very old original nuts (no seal) but very old hubs, with the "hollowed out" centre (all modern hubs are solid). The seals in my hub nuts will last for years, although I recommend every 3000miles to be sure. You also need to remove the brass scrolls to ensure the seals have oil to stop them overheating. You have since found a socket, but if it is the hexagon type (not bi-hex) it will work on the 50mm nuts which I supply to Moss and FTFU.

Good luck finding a 52mm socket, it is not a preferred metric size! Those nuts you have are as shown in the TA manual, but actually very rare, most have been replaced by the slotted nuts which are equally difficult to remove: when new a special tool could be used, but most people did not have one, so resorted to using a drift, or even worse a cold chisel. The risk of course, is that tiny shards of metal find their way into the grease, not good for unsealed bearings!

The grease nipple is (was) for Castrol Heavy Grease, no longer made, the idea being that it forms a sort of bung inside the hubs to prevent oil escaping from the axle and getting onto the brake linings - very primitive! Modern grease will not work, it is soap based, but I believe some new hubs still have the threaded hole (Moss?) although British made hubs have not had them for years.

I have all the parts that Bob G has, but I am in Olde England. When I started making lip-sealed hub nuts over 25 years ago, I used 52mm hexagon bar (actually 2.050"winking smiley but this, and the sockets, became unavailable, so I changed to 50mm AF, which can also be driven with a 2" AF socket). The lip-sealed nuts are completely effective at keeping oil out of hubs, and I have supplied many 100s over the years - and in N. America they are sold by Fromtheframeup.

Roger Furneaux (roger.46tc@gmail.com)

[Rob Reilly]

The 52 mm impact socket arrived today. The nuts came off with the impact driver as easy as pie, took about 2 seconds for each. Just like a NASCAR pit stop.
The hubs pulled off easy with a 2-jaw puller.
The hubs have nice rubber lip seals in them. They are marked DIRING (an abbreviation for Elring Dichtung, a German seal producer) and N11 in one and N13 in the other (probably a production mold number) and G300 v 145.62.10 (probably a code for the size in mm).
In millimeters they measure about 62 x 47 or 48 x 10.
In inches they measure about 2-7/16" x 1-7/8" x 3/8".
They look new.

That said, I have figured out why oil came out the end when I took the spinner off. The axle was overfilled, nearly up to the top of the filler cup on the left side of the differential. There is a fill level plug like most diffs have, located on the right side, to gauge the full level, which looked like it had not been touched in a long time. The fiber seal fell apart when I took it out.

[Duncan M]

Rob-
Curious what arrangement of bearings they used on the pinion shaft of a TA diff? TC had similar spiral bevel setup and used a double row angular contact bearing on the driveshaft end of shaft, and a cylindrical roller bearing on the gear end, with a spacer in between. That was tucked into a bearing carrier, and the insertion depth was moderated by a shim pack.
Pic of loaded TC carrier--

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[Rob Reilly]

The 1936 T Midget Instruction Manual shows a picture with a pinion roller bearing, a bearing distance tube, and a pinion thrust bearing. Then there is a pinion housing, a shim, and a pinion housing cap. The same picture is shown in my Blower Manual.

[Duncan M]

Rob, actually I was trying to maybe solve the mystery of the Blower manual Fig 5 of the rear axle section. Figures 2 and 4 clearly show a double row thrust bearing for the 1 1/4 model and the 2.6 model. Figure 5 appears to show a single row bearing for the TA, TB and TC. We know the TC used a double row thrust bearing, but we do not know what the TA or TB used.
I always figured the erroneous Fig 5 might be correct for a TA or TB. Did you find a double row or single row thrust bearing on the TA pinion?

[Rob Reilly]

Sorry, I didn't take the differential apart. It is not worn, good backlash. Near as I could tell, it matches Fig 5.

[Duncan M]

Process for checking the pinion thrust bearings. Note the suggested mile interval. Can be done with differential mounted in car, but much easier while out.

http://www.tcmotoringguild.org/techinfo/TClinic-30.pdf

[Rob Reilly]

Well, Duncan, thanks very much for posting that link dating from 1971.
When I read that, I decided to pull out the differential and pinion housing. Turns out I could have just pulled the pinion housing, 4 nuts off and it slid right out easy, but better to pull it all for a good cleaning.

Here is what I found. The front double row ball bearing was half destroyed.
Seems like every time I turn around I find another reason to regret buying this car.
Fortunately the bits of brass ball cage confined themselves to the pinion housing, and the crown and pinion look to be alright.

To answer your question, it appears to be the same as TC, except this bearing has two outer half-races (one is still inside the housing in this picture) where the Moss catalogue shows a bearing with a single wide one. The From the Frame Up list says early TA used the roller bearing front and rear (terrible lack of basic engineering if so, to use a straight roller in axial thrust loading), so maybe Fig 5 is correct for early TA's.