Gearbox ventilation

[Dag-Henning]

Thanks Keith, - seems to be a very sensible mod to do ! I'll definately do it, after having rebuilt my box.

- oil-type ; - I have been using 75/90 ( GL4) .

Dag

[Keith Scarfe]

I also use Redline Lightweight Shockproof gear oil. It is a fluorescent blue colour and is horrible stuff when you get it on your hands and coated on the underside of the car but excellent stuff for lubricating the cogs.

[Dag-Henning]

- Redline have their own way with colours.......

Dag

[grat]

- Redline have their own way with colours.......

Dag

indeed! but there is no mistaking what it is when it is on the ground under the car...

thanks guys, you've given me some ideas to work on.

fj..

[paros]

Dag

Sorry to hear your gear box problem was more than just a leak! I checked my box today - after a long cou-ple of races - about 1.5 hours total and it needed some more oil - a cup full. Underside of car is oily from the Red Line GL4.
I ran a centre main bearing at the race - and continued with 20 psi pressure loss.

Richard

[Dag-Henning]

Richard, - what is "best" ; - breaking your box or your engine.....??!
Racing is hard on old ( expensive !) equipment, but we are too stupid to accept it..
Great fun though......... What's up then ? - a full engine job, lineboring, etc. etc. ?

Dag

[davidholroyd]

Dag, I change my diff and gearbox oil after every rally and now race... and yes it does go down for 'no reason' I also run much bigger breather holes in both the diff and the box as they run a lot hotter in a Race/ Rally Elan than standard and therefore expand more. Each race / rally is just over an hours running flat out ( 40 min race, 20 min practice ) ,and the car takes some hammer... I use the recommended Millers oil. Oil is cheap, an original 4.4 LSD diff or new gearbox is getting very expensive.

Special Stage Rally lotus elan for the last 12 years and now swinging sixties race car.. 3rd overall first time out last month.

[davidholroyd]

Dag ... and ventilation ... cut out a few large round 'access holes' in the boot for access to the rear diff fillers , hand brake pivot etc ...then some more 2" holes above the number plate area that face down .... gets a lot more air through the prop shaft tunnel ! ( as well as 26R diff scoop )

[Dag-Henning]

David, thanks for the good ideas! The sickness of my box however, was easily spotted when taken apart. The rear supporting sleeve for the output shaft had left its place and was no more able to support the shaft. This , of course, was too much for the seal, and the oil "left the building"...The reason for this sudden escape is a different discussion, but the joints of the propshaft was, - to my opinion-, far too stiff. That again sort of picked the sleeve up and forced it forwards.
New joints and bearing-glue has , hopefully, solved the problem........
( - I have fitted two vent-bolts though.. )
Dag

[paros]

Dag
Yesterday I checked, and after a 40 minute race and 20 minutes of practice the box needed nearly a pint of oil. Chassis was well lubricated and won't go rusty. With Red Line MTL.
Not sure what to do, but topping up is a cheap easy answer!
Richard

[Dag-Henning]

- loosing half the oil in 40 mins sounds a lot to me ! Are you able to detect from where it escapes the box ?

Dag

[twincamman]

wellll I have found over filling will cause this on my car ----even when the diff pump is running --so it appears to be able to find the correct operating level using the pressure in the diff -- -ed

[paros]

To reply to where the oil is coming from - well the chassis will never go rusty!
My guess is that it is the seals not liking synthetic oils, and I could add that other damage to the box may also have been the partial cause, anyway the newly rebuilt box now has an extra breather to see if that helps.
Richard