flatchat(Chris)
Supporter
ZFQ transaxle failure
- Thread starter flatchat
- Start date
That looks like the ZFQ that I used data from on the recent transaxle thread on here, apparently a repeat offender.
flatchat(Chris)
Supporter
I think it bled fairly well (most of track) and was cleaned up for photo presentation
looks like smashing 3 rd gear must have pushed the gearbox off
Hi Chris:
Is the serial number and/or year of production of this ZFQ available?
The ZFQ box seems to have been improved over the years. Mine is an early one (~2007, with less than 2000 miles on it, 2nd owner) and I plan to have it upgraded or swapped. Upshift from 2nd to third is impossible without a crunch. Downshifts with "heel and toe" works without when you get it right. Cheers
Is the serial number and/or year of production of this ZFQ available?
The ZFQ box seems to have been improved over the years. Mine is an early one (~2007, with less than 2000 miles on it, 2nd owner) and I plan to have it upgraded or swapped. Upshift from 2nd to third is impossible without a crunch. Downshifts with "heel and toe" works without when you get it right. Cheers
Yep its my GT40, the ZFQ broke in half as it had just been rebuilt diff and gearbox. The gearbox has been rebuilt several times as it is a track car. I have had a discussion with Olthoff Racing in the US who have had experienced similar stories unfortunately. We are going to investigate the box to find out what has happened. I'll let you know.
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flatchat(Chris)
Supporter
We feel ya pain mate and I was looking forward to seeing it circulate at pace...........
Anyway, fixerup and give it another crack ---- f#$k it, fix it, fang it- and repeat -that's how we roll
Anyway, fixerup and give it another crack ---- f#$k it, fix it, fang it- and repeat -that's how we roll
Chris Kouba
Supporter
Ooof. The grain structure in the fracture looks like it may relate to a casting defect (said the guy in his armchair looking at pics on the internet).
Ha was getting into it, 250+ Conrod and smooth changes at 6800rpm and pulled 3rd then out of Hell Corner and the party was over….We feel ya pain mate and I was looking forward to seeing it circulate at pace...........
Anyway, fixerup and give it another crack ---- f#$k it, fix it, fang it- and repeat -that's how we roll
Something similar happened to a Renault UN1 box. The box also broke in two halves. In that case the big pin (about 1/2 inch dia) holding crown wheel and pinion in place slipped out and a bit like putting a bar through the spokes of a bicylce wheel whilstin motion, the box internals stopped dead in its tracks but with the weight of a car and full throttle being applied the casing just couldn't take it.
We broke 4 ZFQ in our M1 race car with Chevy LS3 and 15“ wide slicks. The gearbox case is far too weak to take shockloads during downshifts. we changed to Hewland LG 600 and that solved the issue. Compare the design of the Hewland with the very very strong side plates which are clamped with 6 crossbolds and additional 6 studs to the tiny side plates of the ZFQ and no crossbolts. We learned our lesson that the investment is in the gearbox first and then in the engine….,,,
I had a chat with a few GT40 and Lola team mechanics at SPA 6hr race in 2019. They all said the same. GT40 team had several ZF as spares, and they went for overhaul very frequently. The Lola team ran LG600 all season without any problems.
in historic racing a GT40 is only allowed to use the ZF. I know DHG will qualify with an RBT but races the ZF and the team carries a few boxes on spare.
Howard Jones
Supporter
We learned our lesson that the investment is in the gearbox first and then in the engine….,,,
No truer words have ever been said!
No truer words have ever been said!
He could be closed for the holidays. I believe he is closed on Monday's. His email which I use.
Steve@panterasbywilkenson
Steve@panterasbywilkenson
