5 th gear blown at Le Mans

[Duvalof]

Just come from a track day at Le Mans (bugatti track) The 5 th gear on my UN1 Renault box blown /ubbthreads/images/graemlins/frown.gif
We got by the road with the car and were a bit confused to get the 40 back home ! Hopefully a nice guy with a truck carrying several race car had a free place (the last one remaining on the 8) accepted to bring the car back to Paris in the evening ... I think i will invest in a trailer !
Does anyone tried to open the UN1 ?

 

[Tony Hunt]

Hi Fred,
Sorry to hear your bad news and lucky that you were able to hitch a lift.
Apparently the UN1 box is easy /ubbthreads/images/graemlins/confused.gif to take apart, but I would leave it to the specialists.
In UK, most people use Chris Cole of Mach 1 Transmissions. He does a strip down and rebuild for GBP150 plus any parts you may need. He is on +44 1952 222155.
Alternatively, try Stuart Burchall at Competition Transmission Services +44 1582 840008. He provides a similar service, possibly a little cheaper.
Will you have it repaired for Spa on 11 August?

 

[Fred/Belgium]

Fred,

Good to hear from you but not in these circumstances.
I was at Croix en Ternois over the weekend and blow up my 2 rear tires (losy Hoosiers) and going home one of the tires blow up from the trailer at arround 15km from the circuit...and no spare!!!So round trip the day after.
Be carefull on reassembling the UN1 box if not familiar with it.Eighter you find a specialist in Renault gearboxes in France (look at the Alpine club of France) or give it to Chris Cole.Myne was broken on the way to Goodwood last year and with the help of Frank Catt and Cris Cole everythyng ended up OK.
Fred /ubbthreads/images/graemlins/cool.gif

 

[Duvalof]

Guys,

It is nice to hear from you too, as i see i am not the only one with troubles, that's what i didn't want to do do Fred, leave the car alone, even at Le Mans! In 8 years i must say that i hadn't so much problem (except a broken crankshaft in the begining) but here it is a big deal ! The box is now in thousand pieces open like a human heart, i'll post some pics for you to see, never saw that before, the two pignons of the gear 5 are totaly grinded. At first i was thinking opening just the rear of the box but when i saw the filings everywhere i understoud that i'll have to fully open it, and i was right !
Now i wonder what to do, assembling a complete new set of crabot gears from SADEV (Venturi LM 400 where equiped with) or QUAIFE or just change the destroyed gear ?? /ubbthreads/images/graemlins/confused.gif
Who's running a race box here on the forum ? Just to have a feedback?

Tony, thank you again for the phone numbers and infos /ubbthreads/images/graemlins/wink.gif
I won't be at Spa as i'll be in the south of France with the familly for summer holidays, a pity as i'd love to come ...

 

[Fred/Belgium]

Fred,

Sugest you give a call to Chris Cole.
I just bought a flywheel from him and explained your problem.
I am sure he will be able to give you the right advise.
Rgds
Fred

 

[Duvalof]

here the box removed

 

[Duvalof]

what i found when the box was open, look at the gears, some teeth are missing !!! /ubbthreads/images/graemlins/shocked.gif

 

[Lee]

Fred
Exactly the same happened to me on my first trip to Castle Combe for a track day. It was on the road driving to the circuit when it happened accelerating from a roundabout. As soon as I put it into 5th, BANG. No teeth left on those two gears just like you. That was back in '99.
Chris Cole sorted me out also.

 

[Duvalof]

I called Chris this week, sure he's a fair guy ready to help you and has the spare parts on shelves for 200£ (set of 2 gears) if you want to reach the "mystic" 300 Km/h (190 Mph) he also has the set on shelves for 400£.
May be Dave Champ could tell what he think about it, don't you Dave ? /ubbthreads/images/graemlins/wink.gif I know now why i couldn't follow you in Mulsane straight ! /ubbthreads/images/graemlins/grin.gif

 

[Howard Jones]

Fred how much power do you think your motor makes?

 

[Duvalof]

The engine was given for 350 HP, but it was never test on a bench. In this case i think the trouble comes more from the very high torque for the transaxle. For those of you running UN1 box i recommend to have a look to Derek Bell's web site, very interesting.
www.bell-performance.co.uk/gearbox%20upgrade.htm

 

[Paul W]

The Derek Bell conversion hasn't been available for a few years now - the website is out of date. Not sure if anybody else is going to get any made - minimum order 10 to make it worthwhile I would suspect.