Serious gearbox oil leak
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
By using this site, you agree to our rules. Please see: Terms of Use
Serious gearbox oil leak
I have a serious oil leak on the gearbox of my 1960 948cc minor. I have replaced the output shaft seal but the oil runs out at the flange to the propshaft. Otherwise the gearbox runs well, no noises or gear issues. The oil leak is consistent and leaves a large pool of oil every time I park up, any ideas or advice would be appreciated
- svenedin
- Minor Legend
- Posts: 3106
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: Serious gearbox oil leak
Presumably it's the rear oil seal part 10G199. I'd have to look up in the workshop manual how this is replaced.
See the ESM catalogue: https://www.morrisminorspares.com/catalogue-i30
Stephen
See the ESM catalogue: https://www.morrisminorspares.com/catalogue-i30
Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
- geoberni
- Minor Legend
- Posts: 4402
- Joined: Fri Aug 04, 2017 11:19 am
- Location: North Leicestershire
- MMOC Member: Yes
Re: Serious gearbox oil leak
I don't know why ESM use 10G199; the original parts list number was 2A 3061, which is widely used by other sellers for various makes/models, including Midget I, Midget II, Minor 1000, Sprite I, Sprite II, & Sprite III.
So there's plenty of sellers out there to find the best price.
I didn't notice the guy remove the old housing/seal on his video, but see here for hammering the seal on....https://youtu.be/2gFDfmidbPQ?t=903
So there's plenty of sellers out there to find the best price.
I didn't notice the guy remove the old housing/seal on his video, but see here for hammering the seal on....https://youtu.be/2gFDfmidbPQ?t=903
Basil the 1955 series II


-
- Minor Friendly
- Posts: 11
- Joined: Fri Sep 22, 2023 9:05 pm
- Location: SWANSEA
- MMOC Member: Yes
Re: Serious gearbox oil leak
I had an oil leak with the rear oil seal on the gearbox of my car and decided to replace it 'in situ' lying on my back with the car up on axle stands.
Getting the old seal and housing off was interesting, although it is just a push fit onto the gearbox housing it was very tight, it took quite an effort and patience tapping it off especially in very little space to wield a hammer! Fitting the new seal was straight forward gently tapping it on with a block of wood to prevent damaging the seal also making sure the seal was centred on the housing and well lubricated. Oh for a four poster lift, no such luxury!
Bill.
Getting the old seal and housing off was interesting, although it is just a push fit onto the gearbox housing it was very tight, it took quite an effort and patience tapping it off especially in very little space to wield a hammer! Fitting the new seal was straight forward gently tapping it on with a block of wood to prevent damaging the seal also making sure the seal was centred on the housing and well lubricated. Oh for a four poster lift, no such luxury!
Bill.
- svenedin
- Minor Legend
- Posts: 3106
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: Serious gearbox oil leak
If I ever win the lottery I want a 4 post lift! Imagine being able to do jobs sitting on a stool comfortably.BILLYWIZ wrote: ↑Mon Apr 14, 2025 7:29 pm I had an oil leak with the rear oil seal on the gearbox of my car and decided to replace it 'in situ' lying on my back with the car up on axle stands.
Getting the old seal and housing off was interesting, although it is just a push fit onto the gearbox housing it was very tight, it took quite an effort and patience tapping it off especially in very little space to wield a hammer! Fitting the new seal was straight forward gently tapping it on with a block of wood to prevent damaging the seal also making sure the seal was centred on the housing and well lubricated. Oh for a four poster lift, no such luxury!
Bill.
Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
Re: Serious gearbox oil leak
Incidentally regarding the rear seal, yes it’s a push fit but the original is also crimped into a couple of indents in the aluminium gearbox, making removal more involved.
-
- Minor Friendly
- Posts: 11
- Joined: Fri Sep 22, 2023 9:05 pm
- Location: SWANSEA
- MMOC Member: Yes
Re: Serious gearbox oil leak
Correct! I had to use a small hack saw and chisel to cut into the side of the seal casing to release it carefully away from the box. It was very tight and access was not easy. Always thinking not to damage the aluminium gear box.
Bill.
Bill.