4 Speed Gearbox Rear Oil Seal

Has anyone tried changing this with the gearbox and engine in situ?

You would have to remove the propshaft backwards and then work though the transmission tunnel grommet hole with something to level out the old seal and a mallet to drive in the new one. I have a +2 - I am not sure if the positioning is the same for the Elan 2 seater.

I understand from Paul Matty that it is possible with a spider chassis (you can get to it from underneath) but they are nor sure about the Lotus chassis, which I have.

Dave Chapman.

David

I have just removed the rear oil seal with the rear extension on the bench. I had to destroy the seal to get it out, I deformed it using a small chisel and eventually managed to lever it out. The prospect of doing that in situ, even it you can get at it, does not bear thinking about…

You could use a puller but would need a precisely sized collar for the rear face of the extension.

I have just received a new seal from PM - and I see what you mean. The seal is double lipped and mounted inside a steel tube 10mm deep, which is an interference fit in the extension housing. This is not obvious until you see one out of the car.

A puller is a good idea. I would consider packing some cloth behind the seal to catch swarf, and them working through the seal with a junior hacksaw blade - but how do you avoid marking the housing? Cut through the rubber and lever out first, then measure the depth of the cut as you go, and compare against the new seal. When nearly through, grab the protruding steel casing next to the slot with pliers and twist…

Then remove cloth through the hole (with the swarf). Flush gearbox just to be sure. Drive in new seal with a socket that clears the rubber and rests on the steel flange at the back of the seal - that could be tricky if the fit is tight and you are working though that 4 inch hole…

I might try it this winter if I am feeling brave - or I might chicken out and pull the engine and gearbox.

The reason why I am considering changing the seal is that I lose 0.25 litres of oil every 1500 miles through it - I wonder how that compares with others?

Dave Chapman.

Either pull the box or park with the front of the car on the downhill side.

Gary


I think I removed the seal (on the bench, tailshaft housing removed from the gearbox) by driving a screwdriver between the seal and housing and prying it out. The housing is pretty tough.

Ken at Dave Bean reports that he changed a rear seal in the paddock on DB’s race car - so, it can be done. If you are Ken.

Keep in mind that you may need to replace (or resurface) the front yoke of the prop shaft - the part that mates with the tailshaft’s splines. The yoke contacts the seal at a single point along its length (because the diff and engine don’t move much in relation to each other) and can wear at that point. (This from Buckland’s book.) I replaced the yoke as well as the seal last year, and haven’t noticed any leaks.

Thanks everyone.

I was thinking of doing the Hardy Spicer joints in the propshaft anyway - so I will probably pull the engine and box in the winter. Hopefully then ready for a European tour next year!

Dave Chapman.

cgi.ebay.co.uk/12-Heavy-Duty-Oil … 7C294%3A50
I use tool like this

flickr.com/photos/16638375@N … 202952079/

Neil

Hi Andrew,
Can you please advise where you sourced the yoke ?
Thanks.
Regards,
Peter.

Peter, I’m pretty sure I ordered it from Dave Bean. This would have been about two years ago.

Thanks Andrew,
Regards,
Peter.

I managed to change mine in situ, it wasn’t too bad a job, pulled the prop rearwards, removed the drivers seat and changed it through the large hole in the chassis.

Later on I also had to change the U’j’s in a hurry, I did this by removing the diff and cutting a hole in the forward face of the boot with a holesaw allowing the propshaft to be extracted through the boot, I then made a alloy plate to scew over hole afterwards, though you could also quite easily glass the piece back in if you wanted to keep it original.