<o:smarttagtype namespaceuri="urn:schemas-microsoft-com<img src=" http:="" www.gt40s.com="" forum="" images="" smilies="" redface.gif="" border="0" alt="" title="Embarrassment" smilieid="2" class="inlineimg"></o:smarttagtype>UN5 is from a Renault Master van. Stock ratios are too low for a GT40.
1st = 4.455 (11x49)
2nd = 2.438 (16x39)
3rd = 1.480 (25x37)
4th = 1.037 (27x28)
5th = 9.868 (38x33)
Final = 5.857 (7x41)
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Aftermarket replacement gears are however made in <st1:country-region w:st="on"><st1lace w:st="on">Australia</st1lace></st1:country-region>.<o></o>
A 3.44 final is available along with the following:<o></o>
1st & 2nd: (3.36 & 2.38<u1></u1><u2></u2>), (3.36 & 2.06<u1></u1><u2></u2>). (3.00 & 2.06<u1></u1><u2></u2>), (3.00 & 2.00<u1></u1><u2></u2>), (2.77 & 2.00)<o></o> <o> </o> 3rd: 1.85, 1.76, 1.67, 165, 1.53<o></o> <o> </o> 4th: 1.62, 1.45, 1.39, 1.33
<!--[if !supportLineBreakNewLine]--> 5th: 1.40, 1.29, 1.18, 1.13, 1.08, 0.96, 0.92<o></o> <o> </o> Between the stock and custom gears that are available, you could build a suitable close ratio gearbox from a UN5.<o></o> <o> </o> The issue would be the cost. <o></o> <o> </o> The last quote I received for gears were as follows (In Australia dollars):<o></o> Final = 2400, 1st & 2nd = 1980, 3rd = 670, 4th = 670, 5th = 715<o></o> <o> </o> If you changed all the gears, it would cost 6435 AUD which is about 5600 USD.<o></o> <o> </o> They can also make a one piece input shaft instead of the standard (weaker) original design. More $$$$$<o></o> <o> </o> Custom ratio gears can also be made for the UN1.<o></o> <o> </o> Discounts were available for multiple sets.<o></o> <o> </o> An advantage of the UN5 is that the differential has 4 spider gears where as many of the UN1’s had only 2.<o></o> <o> </o> The aftermarket gears are also supposed to be of superior material and strength as compared to the originals. <o></o> <o> </o> You could build a very strong and suitable gearbox from a UN5. But would it be worth the price you would have to pay?<o></o>
UN1-021 available in the UK. It says that it comes with 3.44 final instead of the 3.89 that came stock in the UN1-021. I would verify this. Also comes with 302 adapter and he is willing to ship to the USA.
The Renault UN1 gearboxes still turn up often in Europe, but are difficult to find in the USA. The Vixen RV and the Lotus are the only USA vehicles that I know of that came with a genuine UN1.
The 369 used in the Delorean is nearly identical to the UN1 and comes with a 3.44 final. A Delorean gearbox would have to be taken apart to have the ring gear flipped as it is set up for a rear engine configuration. They are still available new from DMC for about $3k.