Lola T91/50 gearbox oil ?

Figured I’d ask for help before I just start removing bolts/caps.
Nothing in my collection of info on my Lola T91/50 delineates how to check, fill or drain the gearbox oil. I only have notes for type and capacity of oil.

there are two places I suspect that one may be the appropriate fill point. And one potential drain. My old PFM didn’t have a drain, you just had to unbolt the rear cover.

here’s the top of my Lola box:

https://www.apexspeed.com/forums/att...d=102807&stc=1

The silver bolt appears to have a center bolt within it? What would this be for?
Also there is the blue bolt on top of the rear cover. Is fluid level measurable at either point? None of my info packs indicate how far below the top the oil level should be. So I wonder if the only way is to drain the box and then put a known quantity back into it?
Would it matter which of these two locations I used to fill from?


There’s what appears to be a blue drain plug on the bottom of the rear cover also. I’d prefer to drain from here vice separating the rear cover if I can.

https://www.apexspeed.com/forums/att...d=102809&stc=1

My notes say Keith Averill last inspected this box in 2013 (Derek Harling owned it at the time)

Appreciate you all sharing knowledge and advice as always. I’m very close to being ready to get out on track!

cheers,
mike

Unless there is debris in it or very old oil.
Mitty vac shall do the trick of sucking all oil out
and i would assume big double nut bolt on top to fill back in..

two cents...

This may be of some help...according to the Lola Heritage website:

"The new one-piece gearbox/bell-housing featured a drain gallery and spray lubrication system to keep oil temperature down"

As both the upper and lower plugs are more 'obvious' than others, I would think these may be the fill & drain points? Bearing in mind the gearbox must have been drained & filled many times, do they show signs of regular use, eg. wear on the flats?

Not sure what the double plug is, however.

The info pack doesn't show the rear cover anywhere, but the double silver plug, or at least the outer portion of it does appear on this page, although no part number or name is given:
https://www.apexspeed.com/forums/att...d=102810&stc=1

P/N B9150-13019 is labeled as "Oil Feed Plug", so perhaps the "double silver bolt/plug" is unused on this car but could be for a turbo application oil feed on a different car using this box?

Your 13019 is the lube feed to the ring and pinion. If you pull it out you should see the ring and pinion. It looks to be fed internally by the rib down the center line on top. It would be nice to have parts diagram of the rear section. I would think there is a cleanable pickup screen on the rear section also.

There is no way to measure it in the box that I am aware of - just recommended measured qty back in every time the rear cover assy was off. There are a couple of places to get most of it out without that and use the top pinion feed plug to refill it ( the blue ones on the very rear i recall were for an oil cooler if used)

thanks for the input guys. I will drain and see how much comes out. If by chance the required qty drains out and looks good, then I won't bother opening up the rear cover for now.

will let you all know what I find

I used to use a "flexible dipstick" (tie-wrap) down through the filler hole - wait as long as possible after putting in oil so there is less chance of oil on the teeth wiping off on to the tie-wrap. Use judgement as to the oil height to ensure the rotating (lower) gears would stir up the oil. Road racing is not as critical as oval racing in this regard - but do not overfill. Modern oil is very good on lubricating even if lower level than ideal.

Please remember it is now over six years since I last did that so might have forgotten something - use your common sense. Derek

Thanks Derek, good to hear from you, hope you're doing well!