Lotus Elan

90 degree Speedo drive oil leak.

PostPost by: Grizzly » Thu May 11, 2017 6:32 pm

Hi all,

I know this is a old well covered subject but i must be missing some thing.......

My gearbox is dropping oil from what looks like the threads of the 90 degree speedo drive, i've take my time and made sure the O ring and paper seal are fitted perfectly (not weeping) i've also cleaned the gear box breather.

So i've just driven the car out of the garage and it's made no difference :roll:

My question is should there be a seal inside the 90 degree drive? it's acting like the 90 deg drive it's self is leaking but i didn't notice a seal?
User avatar
Coveted Fifth Gear
Coveted Fifth Gear
Posts: 1964
Joined: 13 Jun 2010
Location: Cheshire/UK

PostPost by: elanner » Thu May 11, 2017 7:19 pm

Oh gee - let us know if you find a true fix for this. I figure that there are about five different potential leak points in this gruesome little widget, and every time I think I've fixed it I find soon after that I haven't. Winter stopped play last November, so I plan to try again in the next few weeks.

speedodrive.jpg and

Using the numbers in the diagram, the leak points seem to be:

(a) Gearbox housing to #3 (#2 being the rubber O ring seal)
(b) #3 to #5 (#4 being the fibre gasket seal)
(c) #5 to #7 (sealed, or not, by the thread with the knurled cap - I put a viton washer between the mating surfaces to stop this leak)
(d) #7 to #10 (the speedo cable knurled cap - with another washer to seal it)
(e) leaks past the 90 degree gearbox housing cover at the end of #7

I've fixed (a) and (b). I think I've fixed (c), but wouldn't swear to it. (d) has never shown any sign of leaking. So I'm left with (e), which is next on my list. I'm not sure how to fix this, so I'm currently planning to clean it thoroughly and seal with silicone caulk, if possible. Given historical precedent my chances of success seem to be distinctly less than 100%..... ;-)

User avatar
Fourth Gear
Fourth Gear
Posts: 514
Joined: 14 Sep 2010
Location: Boston, MA, USA

Total Online:

Users browsing this forum: No registered users and 2 guests