Lotus Elan

5 speed breather

PostPost by: vincereynard » Thu May 11, 2017 12:08 pm

I've read about ensuring the gearbox (5 speed) breather is not blocked.

Can someone point out its location please.
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PostPost by: 10kph » Sat May 13, 2017 11:20 am

At a local meeting I was speaking to Alan Voit who rebuilds gearboxes and has made 5 speed elan conversions. During the conversation he said " make sure the gearbox has a breather by drilling a hole to the right and forward of the gearstick mounting plate". My Lotus box did not have a breather so I drilled and tapped the alloy cover and screwed in a small tube with 1/8 " internal hole and protruding say 20 mm high.
Without a breather the box when hot will expand the oil and more important the hot air inside the box will expand considerably and push oil out past the seals.I presume that Lotus rectified this with later produced boxes.
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PostPost by: vincereynard » Sat May 13, 2017 1:09 pm

10kph wrote:At a local meeting I was speaking to Alan Voit who rebuilds gearboxes and has made 5 speed elan conversions. During the conversation he said " make sure the gearbox has a breather by drilling a hole to the right and forward of the gearstick mounting plate". My Lotus box did not have a breather so I drilled and tapped the alloy cover and screwed in a small tube with 1/8 " internal hole and protruding say 20 mm high.
Without a breather the box when hot will expand the oil and more important the hot air inside the box will expand considerably and push oil out past the seals.I presume that Lotus rectified this with later produced boxes.
Tony


Tony,

Many thanks.
As it happens I was considering doing something very similar. I had guessed that the best place would be over the gear shift "slider" as it would be protected from any oil splash. At the moment the only breathers would be the oil seals!

Thanks to your advice I shall go ahead.

Cheers
Vince
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PostPost by: gjz30075 » Sat May 13, 2017 7:34 pm

Tony, does the tube have any cover at all? Any pics, maybe?
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PostPost by: vincereynard » Sun May 14, 2017 3:26 pm

I was thinking something like - http://www.ebay.co.uk/itm/332201787804

With a short length of pipe connected.
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PostPost by: gjz30075 » Fri May 19, 2017 11:21 am

10kph wrote: During the conversation he said " make sure the gearbox has a breather by drilling a hole to the right and forward of the gearstick mounting plate". My Lotus box did not have a breather so I drilled and tapped the alloy cover and screwed in a small tube with 1/8 " internal hole and protruding say 20 mm high.


Which cover? The gearbox or the shifter? I noticed the gearbox cover bolts do not protude into the case
and the cover overhangs the case so before I go drilling, can you point out exactly where this is done? If
possible, detach the attached picture, put an arrow, or something, where the breather should be, and re-
attach?

Or does Alan mean somewhere along the vertical plane of the case?

Thanks,
Attachments
dsc09484.jpg and
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PostPost by: vincereynard » Fri May 19, 2017 1:55 pm

I'm planning about here -

breather.jpg
breather.jpg (67.6 KiB) Viewed 591 times
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PostPost by: gjz30075 » Fri May 19, 2017 2:51 pm

Perfect. Thanks Vince
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PostPost by: 10kph » Wed May 24, 2017 11:47 pm

Hi, The gearshift plate marked with the red x is where I placed my breather tube.
Oil will not splash up there and so no need for a cap or plastic tube extension.
Regards Tony
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PostPost by: mbell » Thu May 25, 2017 12:55 am

I was thinking that fitting something like:

https://www.mcmaster.com/#9833k18/=17rsp9t

In the location mentioned might be a good idea. Should allow the box to breath but prevent any gear oil escaping with out messing bends and tubes.

Another thing for when I am swapping the chassis.
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
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PostPost by: vincereynard » Thu May 25, 2017 8:17 am

mbell wrote:I was thinking that fitting something like:

https://www.mcmaster.com/#9833k18/=17rsp9t

In the location mentioned might be a good idea. Should allow the box to breath but prevent any gear oil escaping with out messing bends and tubes.

Another thing for when I am swapping the chassis.



That is neat, in fact rather neater than my installation.

screenshot-from-2017-05-25-13-55-36.png and
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PostPost by: mbell » Thu May 25, 2017 6:31 pm

That looks quite neat to me. I am not 100% sure the breather would fit between the ribs on the cover or not.

Must remember to order one next time i order from there.As regularly find the odd drip of oil under the gearbox and with no obvious cause. Hopefully this would address that.
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
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