Gearbox input shaft Oil seal.

[Murrayminor]

I have seen the modified input shaft oil seal cover advertised for sale.
As I have the original scroll seal, is the newer seal worth the expense?
Would I be able to ream my existing cover out to take the new oil seal?
Does anyone know if there is enough "meat" on the cover to simply ream the area out for the seal or does it require further modifications to fit?

Regards
Dermot.

[pgp001]

Hi Dermot

I did my own, but machined it in the lathe. The other Phil showed a good set of photos of how to do it.
viewtopic.php?f=4&t=71037&p=645694&hilit=seal#p645694

If I get made redundant in the next couple of weeks, I am considering setting up to do odd jobs like this to make a bit of cash.

Phil

[Murrayminor]

I have been to my local machine shop but they think there is not enough meat in the cover to accept the seal I have.
They were going to weld around the hole, then machine it flat to accept the seal.
At £100 I declined their offer.
Reading the other excellent post makes me think is it worth the hassle as my car will usually be parked in the garage and unlikely to be left for long periods facing downhill.

Regards
Dermot

[pgp001]

Dermot

I am guessing you will have a seal that is too large on the OD.
The one I used is 23mm ID x 30mm OD x 4mm Thick, there is just enough meat in the casing to allow it to be bored out for the seal.

This shows the casting being centred true on the faceplate using a mandrel, the hole in the casting is often worn oval so cannot be centred using a DTI.


This shows the finished bore to accept the new seal.


On this one you can see the shoulder for the seal to press up against.


And finally, the seal is pressed in using the tailstock barrel to keep it all square.


On the gearbox I am currently rebuilding, I found someone has been there before me, and that cover had been modified by TIG welding a new boss onto it for the seal to fit into.

Phil

[philthehill]

If you read my post in the link above you will see that I made the comment that not all the scroll boss's are the same and shape/thickness is dependent upon the manufacturer - so one seal does not fill the one size criteria.

[kevin s]

Did much the same on mine, only took half an hour on the lathe..

rps20180326_223632.jpg (51.19 KiB) Viewed 2731 times

.

Sems to wofk well, no leaks at the moment, i seem to remember my seal was also 30m. OD.

[Murrayminor]

If you read my post in the link above you will see that I made the comment that not all the scroll boss's are the same and shape/thickness is dependent upon the manufacturer - so one seal does not fill the one size criteria.

Phil
I did indeed read your post and very informative it was, my cover appears to be very thin compared to the photographs on both these posts.
I wonder of the Minor cover has a thicker casing, the one I have is from the MG Midget gearbox.

At the moment I don't have access to my Minor gearbox as it is in storage at a friends farm.

Regards

Dermot.

[pgp001]

Dermot

Can you see a part number on your casting ?

Phil

[Murrayminor]

Dermot

Can you see a part number on your casting ?

Phil

Yes its 22G118

[philthehill]

I have a 22g118 front cover made by BIRMAL and there is hardly sufficient metal in the area of the boss to allow a seal to be fitted.
I also have three 2A3087 front covers made by C & A. and BIRMAL.
The internal and external shapes/forms are slightly different in all cases.
I also have three different seals that can be fitted with careful machining.
I will post photos later.

[Murrayminor]

I have a 22g118 front cover made by BIRMAL and there is hardly sufficient metal in the area of the boss to allow a seal to be fitted.
I also have three 2A3087 front covers made by C & A. and BIRMAL.
The internal and external shapes/forms are slightly different in all cases.
I also have three different seals that can be fitted with careful machining.
I will post photos later.

Phil
My front cover Pt No: 22G118 is also made by BIRMAL and as you say there is very little metal around the scroll seal to accommodate an alternative oil seal which is where I got confused, not thinking the covers were different spec.

I will attempt to retrieve or at least view the front cover on my 1098 gearbox and see if that is made by a different manufacturer and maybe suitable for the oil seal conversion.
Thanks you for the insight.
Regards
Dermot.

[philthehill]

Unable to post photos even though they have been greatly reduced.

Will try later

[pgp001]

Phil

Not sure what you are using to re-size photo's, but I have used Faststone for a couple of years now and it works very well and is simple to use.

https://www.faststone.org/FSResizerDownload.htm

Phil P

[philthehill]

Thanks for the link but if it has more than an on / off switch I am flummoxed.
That is why I have a Minor to play around with. Nice and simple
My modern goes to the garage if more than topping up the windscreen washers is required.

Seems to be ok now and they are the same photos I tried to post earlier.

Below - 22G118 front cover. Suitable for 1098cc & 1275cc

Gearbox front cover 2 (2).JPG (853.86 KiB) Viewed 2651 times

Below - the rear of front cover 2A3087 with 23 x 35 x 7 seal fitted.

Gearbox front cover 3 (2).JPG (1.04 MiB) Viewed 2649 times

Top seal - 23 x 30 x4. Springless lip.

Bottom seal - 20 x 30 x 4.5. With spring lip.

Gearbox front cover 4 (2).JPG (356.59 KiB) Viewed 2649 times

All of the above seals are suitable and their use depends upon the thickness of the boss.

[philthehill]

Below - the rear of front plate 22A118

Gearbox front cover 5.JPG (1.8 MiB) Viewed 2640 times

Below - just about the max interface between seal and front plate you can get and it isn't much and no back stop for the seal

Gearbox front plate 5 (2).JPG (871.2 KiB) Viewed 2639 times

Below - seal fitted to a 2A3087 front plate.

gearbox front plate 4 (2).JPG (594.17 KiB) Viewed 2639 times

I did try machining several different plates and they all ended up slightly different.

[philthehill]

A fine gaggle of front plates

Gearbox front cover 1 (2).JPG (914.59 KiB) Viewed 2633 times

[Murrayminor]

Phil

I read that the 2A3087 cover may require further machining to allow movement of the shift rod as the recess on the cover is too shallow, is that not the case?

Regards

Dermot.

[philthehill]

The 2A3087 recess is 20mm deep whilst the 22A118 recess is 21.5mm deep.

The increase in depth can be achieved (if done carefully) with a 1/2" diameter end mill in a pillar drill.

[ampwhu]

i did this very job this afternoon whilst i am rebuilding my gearbox.

gearbox 2.JPG (62.32 KiB) Viewed 2430 times

gearbox 3.JPG (45.95 KiB) Viewed 2430 times

the one on the right was purchased from ESM.

Judging by the amount of metal on the scroll area, i'll ask my machinist mate if he can fit a seal to it so i can move it on to someone else.

[philthehill]

The front cover from ESM has more metal around the boss where the seal fits and I believe a backstop to the seal is machined into the front cover - this is to stop the seal working its way backwards into the gearbox.
The standard Minor front gearbox cover has very little excess metal to play with and care must be taken in selecting/matching the seal to suit the cover. Not all covers with the same part number have the same profile/thickness of metal around the scroll boss as the front covers were made by several different manufactures.