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Lotus 5-speed gearbox

PostPosted: Wed Sep 19, 2018 3:54 pm
by wbmoore
Hello all. A ?simple? question for you:

Is the Lotus 5-speed transmission a good gearbox to use in a somewhat daily driver. The car is an Anglia Estate. The engine is a 170 hp Zetec out of a Caterham that was too slow for the owner.

The Estate weighs about 1820 pounds.....a fat 300 pounds more than an Elan.

I?m not building a hot rod to beat on, but rather a ride that will go down the freeway in a happy manner.

I have a T9 that I was planning to use in it but, having sold my Elan, now the Lotus 5-speed is just sitting there. Also, with the T9 the ratios might be odd.

Thanks for any thoughts. Brad Moore.

P.S. I hope this post will not offend anyone because of it?s Non-Lotus car orientation. It is after all a Lotus part I am asking about. Thanks.

Re: Lotus 5-speed gearbox

PostPosted: Wed Sep 19, 2018 6:47 pm
by Esprit2
Brad,
The Lotus 5-spd is a mix of Austin-Maxi gearsets, Ford internal shift rails/ forks/ parts, and a bespoke housing. The result was okay in the lightweight Elan with the Twink's modest ~106 lbs-ft of torque.

However, Lotus used a long-tailshaft version in the Elite/ Eclat with the 160 Hp/ 140 lbs-ft 907, and in that application the gearbox was prone to shedding teeth. Especially 2nd gear. After 1975 ('76 ??) Lotus tried polishing the gear teeth to remove stress risers. That was an improvement, but not a cure.

At 1820 lbs, the Estate is quite light; but the Zetec's 170 Hp doesn't strike me as compatible with the Lotus 5-spd. On the other hand, the selection of ratios is very good, and the shift action is great... as long as it all lasts.

The problem with the T9 is that it's a 'family' of gearboxes with different internal ratio combinations for different applications. Just because you have a T9 doesn't mean that it would be the best set-up for a 170 Hp Anglia Estate.

Regards,
Tim Engel

Re: Lotus 5-speed gearbox

PostPosted: Wed Sep 19, 2018 7:39 pm
by Foxie
The T9 with the long 2.98 1st gear conversion (available from Burtonpower ) would be a good gearbox.

But the gear lever position might be awkward.

I've been using Alan Voigts T9 conversion with the 2.98 1st in my +2 with 160bhp+ for Hillclimbs and circuits for 14 years with absolutely no problems. :)

Re: Lotus 5-speed gearbox

PostPosted: Wed Sep 19, 2018 8:00 pm
by mbell
Given the first main use of the box was the +2 which are 1800/1900 lbs I don't think the weight is an issue.

As pointed out they struggled with the 160bhp in the elite/eclat and those boxes had a updated wider input bearing.

The narrow input bearing was an issue in the +2 so if you do decide to go ahead make sure the box has at least had the updated wider bearing (and input shaft changes) fitted.

There is a white paper around somewhere that covers the changes to wide bearing and few other improvements to selector mechanism.

In good order it's a nice box with nice great selection with a few tweaks but isn't the strongest or most robust...

Re: Lotus 5-speed gearbox

PostPosted: Thu Sep 20, 2018 2:33 am
by wbmoore
So it sounds like a T9 with a 2.98 first gear is the way to go. Hopefully it will be just as easy to rebuild as an Elan gearbox. Thanks for the input. Brad Moore.

Re: Lotus 5-speed gearbox

PostPosted: Thu Sep 20, 2018 4:14 pm
by alan.barker
If your Speed is the one for the Elan you can sell it for a good price which will easily pay for the
T9 OR a T5
Alan

Re: Lotus 5-speed gearbox

PostPosted: Thu Sep 20, 2018 6:18 pm
by Spyder fan
Using a Miata 5 speed gearbox might be a better proposition for your intended use. Some good reading here http://www.retro-ford.co.uk/shop/conten ... it-mx5-001

Re: Lotus 5-speed gearbox

PostPosted: Fri Sep 21, 2018 6:03 pm
by englishmaninwales
If you go to the Type 9 gearbox, have a chat with Chris at BGH Geartec as the make a variety of longer first gear ratios, heavier duty bearings and syncromesh to suit your needs. He?ll also arrange the courier for you.
Malcolm

Re: Lotus 5-speed gearbox

PostPosted: Fri Sep 21, 2018 11:16 pm
by wbmoore
I already have the T9 so I?ll check out Voigt and GBH. I was wanted to use the Lotus box with hopes that it would just fit. The T9 will require sheet metal work to the tunnel.
Thanks again for the input.