Esprit Turbo project car - part3 - the further continuation

[Lotusfab]

Gearbox

Unless your a real enthusiast and have some mechanical skill and a lot of time take it to Alan Voigt or Harry Martens!

having said that I'm a bit keen and have just installed all of the selector shafts. I quite enjoyed this job and have derived a great deal of satisfaction from it. The only one left to adjust is the 3/4 shaft end adjustment. It's not difficult but very time consuming and with out the Lotus tools you have to be a bit inventive. This will be sweet as a nut! Just wire lock to put on, then the 5 th gear. Loctite 518 used to seal it up. I have tested all of the interlock plungers and gear operation, all working very well. I used the tool in the picture to set the fork on the 1/2 shaft. The gear idler I useda 3 mm piece of steel. Make sure you get the set screws correct on the rear casing. They are different lengths! 

[Lotusfab]

[Lotusfab]

This looked like it should have an oil seal. Having checked the parts manual it doesn't. So there nothing to stop oil leaking  round it. Solution silicon or an O ring. Any ideas?

Interestingly there's a grease nipple on the angle drive. 

[Andyww]

There should be an O-ring there.

Where there is no oil seal is on the actual shaft which the gear is connected to. Oil leaks out into the right angle drive.

[Lotusfab]

It makes sense for a O ring,  but I can't find it in the parts manual. The Anglw drive has a grease nipple. If you block the hole opposite with a finger when you top it up the grease is forced down the shaft. Maybe enough to seal it? You can see the hole in the centre of the angle drive. If you block this the grease is forced up the shaft.5 th gear in. Should finish the gearbox tomorrow.

[Andyww]

Thats a good point, maybe regularly filling up the angle drive with grease might help.

Harry has mantioned this issue before, on the Citroen the rotation of the gear throws oil away from the speedo drive but on the Esprit it throws oil directly at it. Using synthetic such as redline makes gearbox oil leaks worse.

I wonder why Lotus moved the right angle from the other end of the speedo cable on the S1 to the gearbox end. It would be much easier to seal up just the cable exiting the box. The only function of the right angle is to reverse the direction of the speedo cable so can be anywhere.

[Lotusfab]

just need to source a grease that's impervious to gearbox oil.

[Lotusfab]

Gearbox

just set the endstop position on the 4 th gear selector. Core plugs back in and all wire locked. Rear casing just about to go on and the top covers - should be finished today!

Very pretty, but will it work?

[910Esprit]

No - because you have forgotten that the silencer mount attaches to the rear cover!   🙂

Edited June 17, 2019 by 910Esprit

[silverfrost]

I am sure it will be fine Fabian,  your skills are pretty damn good chap with two Esprit builds under your belt,  ok 1 and 3/4 lol ,  do not underestimate yourself !

[Lotusfab]

Well just some washers order then the diff. Bearing pre load and backlash to set. Oh and the exhaust system! I was going to sort the exhaust mount later. Now it looks as if I'll have another job! 

[Lotusfab]

Well I wouldn't have got any sleep so found some M7 washers and the exhaust mount! Tested gear changes - real smooth! Once I get some Redline in there! Coated in ACF50! 

 

[Lotusfab]

Ordered a 2.5 x 22 mm O ring fir the speedo outer drive. Hopefully it will fit! 

[drdoom]

8 hours ago, Lotusfab said:

just need to source a grease that's impervious to gearbox oil.

Recall my earlier reply citing the stuff sold via Aircraft Spruce as I expect it would serve the purpose.

Cheers

[Lotusfab]

Yep I think that would work. Needs to be a cartridge so it can be injected.

[jonwat]

On 16/06/2019 at 23:05, Andyww said:

Using synthetic such as redline makes gearbox oil leaks worse.

I'd read that synthetic oil contains chemicals that causes rubber to swell so reducing leaks. When I filled the transmission on a Stevens' Esprit with Mobil synthetic the constant dip on the bottom of the box stopped. 

[Lotusfab]

Thanks John.

[Andyww]

I have had the opposite experience when switching to Redline on my Esprit and Ferrari, although the shifting is much better on both.

It probably depends on where any leak is coming from. Not much rubber on these. The common factor on both is that I used Loctite 518 to seal both. The leaked fluid, which is not a lot of amount, is sticky and seems to contain 518 dissolved in it. Its a known issue that some sealants dont like the friction modifiers used in synthetic gear oils. 

Synthetic engine oils also tend to leak more readily through flange joints. 

I am planning to re-fit the Ferrari gearbox cover in the next few days using Permatex gear-oil resistant sealant, and see how that goes.

[jonwat]

5 hours ago, Andyww said:

It probably depends on where any leak is coming from. Not much rubber on these. 

The driveshaft oil seals are made of rubber.

[Andyww]

3 hours ago, jonwat said:

The driveshaft oil seals are made of rubber.

OK I was thinking Viton but you could be right.

[Lotusfab]

For anyone who is interested this is how I set up the gearbox.

Selector fork 1/2 no gear synchro

with no synchro gauges I used the tool in the previous picture. The Ferrrari method won't work as the synchro touches the adjacent gear wheels when engaged. I kept adjusting the spacer tool and moving the fork until au had exactly the same clearance  on each side. Time consuming but effective.

4th gear stop adjustment

I found the synchro slider touched the 4 th gear pinion with slight pressure to the fork. So I spaced it at 0.5 mm as I consider Y in the calc yo be zero.(see manual)

reverse gear

The wording if the manual is wrong. All you need. To do is space the reverse idler gear 3 mm away from the 1st intermediate gear. I used a 3 mm shim.

now I'm setting the bearing one load on the drive shafts and the pinion backlash.

Im using a balance guage with the diff clamped in position and a piece of string( method 2 in manual). Then luckily I have a dial guage to measure the backlash. All in all a satisfying job. I am tempted to take apart my S1 gearbox and rebuild it , trouble is is working perfectly! I may rebuild it out of boredom when this car is done.

[Lotusfab]

Auto correct! bearing preload in the above!

[Lotusfab]

O ring for this of 22 mm x 2.5 mm doesn't fit, the diameter is about right, but it's too thick at 2.5 mm. Now trying a 1.5.mm O ring. Plan tomseal,with silicon as well. 

[Lotusfab]

Don't tickle, paint!this is my Picasso! Tanks again!! About six times or more in and out, now they are perfect and I've switched back to the original connectors!

[Lotusfab]