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MG TD TF 1500 - Holes in rear axle housing?

I found a curious thing on my rear axle from my 1951 TD which I am unsure if it's nothing or a major problem. Near the differential on one side there are 4 holes about 1/4 inch or so spaced evenly around the circumference. Through each you can see the half shaft turn. You can see that there are holes in both the differential half as well as the axle tube and it appears that the axle tube is rotated a couple of degrees as the holes in the differentiall cover don't mate with the holes in the axle tube. On the other side there appear to be similar holes but with plugs or pins in them. I'm guessing this is not normal and the pins somehow fell out and the axle tube rotated some. Has anyone ever seen this happen before? Can this be remedied or do I need a new axle housing?

J Cosin

Another picture--clamp is in hole

J Cosin

Close up of hole so you can see where the inside hole and the outside one don't line up

J Cosin

JC,
I have a TD diff. hanging on my wall in the garage. All the holes are filled with some kind of plug which I assume keeps the tube from rotating as shown in your 3rd image. This should be corrected before use.

George
George Raham [TD4224]

Checking mine and it is plug welded.It might pay to dismantle the total unit and checking it for trueness.One of those tubes could be slightly askew and then your axles will be at risk of premature breakage.
Sandy
ss sanders

I've copied this to Dave Clark to see if he's run across this with his conversions. Bud
Bud Krueger

Yes, those are steel dowel holes (pins) that keep the axle tube in the castings. I have had one of my core axles missing a pin but everything was inline so I tapped threads for a 3/8(?)fine bolt cut to length and put in with red Locktite. A very good repair I believe. With the mis-alignment of yours I would not consider a repair.

Your '51 has a BSF axle so be careful in finding a relacement. I think the later one would work fine but it will have a funny triangular tab just inside the spring mount pad. It looks like you need the small half and if so I can help.

I do the TD-TF rear end conversions on an exchange basis so I've seen around 60 of these axles and know them well. My information is on Buds' ttalk.com

Dave Clark
c180av8tor@gmail.com
Bud Krueger

Another strange one. That last post was from Dave Clark, but my ID showed above. It's probably because I copy/pasted the thread header in my email to Dave. Bud
Bud Krueger

Does any one know what the smaller hole to the left of the diff housing in the axle tube is for? I have he same in mine and wonder if it is a breather. The diff oil was water contaminated and should a proper breather be fitted?
p embury

Yes that is a breather it used to be covered by the brake pipe clips. Best to plug it then drill and tap the diff filler plug to fit a proper one.
Ray TF 2884

Ray Lee

You can resize and tap the hole to fit a breather from an MGB rear axle. Moss sells them @7.75 US. PJ
Paul S Jennings

The breather allows rust formation on the half shaft. The image is from 'the53' after sitting for 40 years. Bud

Bud Krueger

JC
I have just fitted a new 4.3 rear axle form Dave Clark and this is the vent being spoken about.
Not sure if it is MGA or MGB but it screws into a small hole on top of the axle on the left hand side.

Rod

Rod Jones

I used a "mushroom" from an M.G. A in the breather hole. Looks very much like the one in Rod's pic above. It requires a BSF taper tap. I took the opportunity to install it when I had the rear end apart & the diff converted to the 4.3 ratio as I was concerned about swarf dropping into the axle housing & finding its way into the bearings. Not sure about the wisdom of covering the hole as its purpose is to allow the rear end to breathe. Though visible the M.G. A mod achieves this & also keeps crud, mud & water out of the assembly. Also used another mod from the A in the form a pair of metal "load spreaders" that fit between the U bolts & the axle housing as my housing was showing signs of wear there due to incorrectly tensioned U bolts. Almost impossible to see them so they shouldn't be a problem for the purity police. Cheers
Peter TD 5801
P Hehir

+1 on the load spreaders under the U bolts.

Dave Clark supplied them with the new axle as part of his conversion kit along with the MGA vent. In the photo above I have not painted the shield semi-gloss black yet.

The vent, which is actually in two parts so you can clean it every year or so, is made of plastic or nylon and is very easy to cross thread. So be real careful when screwing it into the axle. He mentioned this in the excellent instructions for the install.

Rod.
Rod Jones

Thank you to all that have help solve my first problem of what I predict to be many more to come questions as I start the restoration of my 54 TF MG
Whilst I have the differential apart I will fit a proper breather to the hole
thanks Peter
p embury

Wondering if anyone has taken the venting of the differential to a whole new level and copied 4WD practices of venting the breather above water splash level.
G Evans

A worthy point Mr. Evens,
But to be fair - the holes in the breather are quite small and there is a mushroom type trap on top to prevent direct flow into the axle. Holes are also off set.
Even if you were to ford a brook, which would also mean wet feet in my TD :) I don't think water would get into the Axle.
Only the slow change of barometric pressure would allow air to pass in and out.

JMHO
Rod.
Rod Jones

From my learning venting is there because as the diff heats and cools during normal driving and stopping conditions expansion and contraction of the internal air/gases occurs. The cooling phase is when moisture can be sucked into the diff, the same applies to wheel bearings.

I am not advocating a T Series being used as a submerged
object just curious regarding other peoples opinions.
G Evans

The T series rear axle vent hole can be opened up then tapped to take the MGB axle vent Moss part # 267-040. does anyone know what the thread and size is? I intend in putting one in my modified 4.3 axle.
Many thanks
Rod Murray 54 TF
Rodney G Murray

Rod,
That's the same part number as the MGA I supply. Tap it to 1/8 NPT.
Dave
Dave Clark Arizona

Thanks Dave
Rodney G Murray

This thread was discussed between 08/09/2014 and 08/10/2014

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