Lotus 5 speed wisdom

[vxah]

I am currently rebuilding my 5 speed Lotus gearbox and was considering the large input bearing modification however, this rework it quite involved and as I cannot fit the front cover in my little lathe I would have to send the job out.
So I was thinking, is the mod really worth it on an Elan? I can see that the narrow bearing would be much more stressed on the bigger cars with more torque etc but how does the box fair on small light cars? Anyone running the standard bearing for a good while without issue?
Also, any experience with the most suitable oil, both for longevity and shift quality?

Julian.

[JonB]

My +2 has just over 100k on the clock and the gearbox is fine. I don't think it's modified in any way.

As to the oil, consensus round these parts seems to be that Redline 75W80 synthetic MTL is the right choice.

[Donels]

Call Alan Voights. He rebuilds Lotus 5 speed gearboxes for Paul Matty etc and he can tell you if it's a problem. He will also sell you any bits you require.

[vxah]

Spoken to Alan Voigts several times and ordered most of my parts from him, he says it was built with maxi internals and they were crap to start with! I said how long should it last and he said a couple of months!!! Usually because people don?t know how to build them and cock it up!
His son is the guru apparently, when I spoke to him he said ?I bet if I look at it I will find a load of stuff wrong that you haven?t?
Not making me feel good about it!

[rgh0]

My +2 has just over 100k on the clock and the gearbox is fine. I don't think it's modified in any way.

As to the oil, consensus round these parts seems to be that Redline 75W80 synthetic MTL is the right choice.

Agree fully with the above. The bearing mod was more about availability of the original bearing and if you can find one then you do not need to do it IMHO. if rebuilt right then they have a long life. Doing it is not hard but it does require attention to detail.

cheers
Rohan

[Verve]

For what it`s worth ... as we all hear the horror stories ... I`ve owned 2 Sprint 5`s ... and I was very pleased with the gearbox`s in both of them : ) !

In fact , the 1972 Factory Built car had done over 80,000 miles ... was still working fine ... & the 5 speed box , had never even been out of the car from new : ) !

A bad rebuild , doesn`t mean it`s a bad gearbox ...

Paul .

[vxah]

Rohan, I thought the bearing mod was originally done by Lotus way back when the original version was plentiful but didn?t last very long? I was guessing that this was due to using the box on the new bigger cars so, I was trying to find out how the box fared in the lighter cars?
If there were not really any bearing issues I probably won?t spend time and money on the mod as I have new original style bearings.

[vxah]

Thanks Paul, that?s my wallet wanted to hear!
Maybe modern synthetic oil would help as well? Don?t want to weaken the synchromesh action though! Interesting when you look inside modern boxes with double and triple synchro rings!

[rgh0]

Rohan, I thought the bearing mod was originally done by Lotus way back when the original version was plentiful but didn?t last very long? I was guessing that this was due to using the box on the new bigger cars so, I was trying to find out how the box fared in the lighter cars?
If there were not really any bearing issues I probably won?t spend time and money on the mod as I have new original style bearings.

I was not aware that Lotus did mods to the Elite boxes to put in the bigger bearing, only aware of it been done to Plus 2 boxes during rebuilds due to lack of availability of the original bearing.

cheers
Rohan

[rgh0]

Thanks Paul, that?s my wallet wanted to hear!
Maybe modern synthetic oil would help as well? Don?t want to weaken the synchromesh action though! Interesting when you look inside modern boxes with double and triple synchro rings!

The Redline oil improves the synchromesh action as its friction characteristics are specifically suited for synchro boxes, many modern synthetic gear oils are aimed purely at gear and bearing lube where as Redline have tailored their oil for both gear lube ,bearing lube and synchromesh function

cheers
Rohan

[mbell]

I have Redline MTL in my box. I find the shift very good when its cool but once warmed up its more difficult to get 1st and warn synchro on 4th is a lot more sensitive. I suspect the close proximity of the exhaust to the box is meaning the oil is running at warmer end of the temps.

I plan to switch out to MTL90 (or MT80/85) at some point which will hopefully help and maybe see about a bit more clearance between exhaust and gearbox.

[gjz30075]

Good to hear, Mark. I, too, had that problem with Redline MTL so I switched to the Penzoil Synchromesh, as
suggested in another thread. Not really happy with it, so I'm anxious to hear your assesement of any
lube you use.

[vxah]

Interesting about synchromesh being weaker when the box has warmed up as most ?obstinate? gearboxes suffer more when cold?
My general observation is that 1st gear rarely suffers from a lot of wear issues but poor clutch release raises its head when selecting from stationary?
The bearing mod suggested replaces what might be an inadequate bearing that could wear and allow the first motion shaft to move forward when trying to select 4th gear..

[mbell]

I was considering changing the gearbox oil when I did a service a couple of weeks ago. I was considering going to synchromesh as I have a bottle of the shelf and it's easily available locally.

After some research I found it was "thinner" than the redline mtl. So decided against it. I will report back when I change over to mtl90 but not sure when that will be as have to be organized enough to order it in. But on plus side it is what I use in my daily so good to have on the shelf.

[vxah]

I guess thinner might not be a bad thing though? If the synchro has to speed up gears then less drag may help? Thin might let the synchro rings grip better?