Esprit Turbo project car - part3 - the further continuation

[Rolls]

Please consider either backlighting or spotlighting the engine area 😆 

[Lotusfab]

Discs Rear

I cleaned them up and found they were scored and pitted. So a new set arrived from PNM next day delivery. The old ones have a number on them, which helps when ordering B079J4000F (early type). I'm still fitting the brake callipers.

The driveshaft shims were installed incorrectly - behind the disc, so I have corrected that!

Turbo

well you may remember I rebuilt it about three years ago, I didn't balance the shaft. This  has always been nagging at me. I finally caved in and took it to a Turbo specialist near Guildford. It's been tested and the shaft was out of balance! Anyway they are sorting it!

Exahaust

Whilst the originals are intact the flexible connectors look like hey have gas leaks. So I have a new Stalinless exhaust from S and J, just need to fit. No point in scrimping the new exhaust will last another forty years! 

I found a problem with the carb tops, they were loose with the screws fully tightened?? Obvious reason screw too long, only problem is they weren't! I then took it apart and realised the  top covers are threaded as is the body. The new screws were fully threaded, so were  never going to tighten up. All I can assume is Dellorto threaded the cover so the screws would not fall out when taking them apart. The only way this  could work is with a part threaded screw. I contacted  Eurocarb who were very helpful. They said they had never gone across thus before, but managed to find an original screw and sure enough it was part threaded. They measured the screw and I located the old screws which I kept. I then used a dremmel to remove the upper thread from the new screws to match, job done! 

Choke lever and connection now installed and all working. I had to remove the cement guns from the choke lever, it would have been far to messy and not helped cold starting! 😄😄😄

[Lotusfab]

Roger Moore actuating the cement guns! Yes I have lots of interesting pictures!! 

[910Esprit]

1 hour ago, Lotusfab said:

so the screws would not fall out when taking them apart.

Yes thats true.

Brakes - Have you had a dial guage on your rear discs?   I generally struggle to get them in tolerance by luck!

[Lotusfab]

Hi Steve, I have new rear discs what dial guage adjustments are you referring too please? I can't find much in the manual.

[910Esprit]

Hi Fabian.  Max runout is specified in the manual as 3.5 thou.    So if you rotate the fitted disk at its rim  you can measure the run out.   If within tolerance all fine, otherwise,  I start by checking the disk is true by placing the hub side on a surface plate and check the disk at the rim at 3 points adjacent to the mounting holes).   I also remove the 3 studs of the the gearbox output shaft to ensure that is running true.   If I cant find an optimum position from the 3 permutations, I shim one of the mounting studs.    Of course the whole thing is a faff as you need to keep removing/refitting/retorquing the disk & driveshaft adaptor.   But its worth doing it properly and I have found that the standard Turbo brakes can be subject to judder if not carefully set up.       

[Lotusfab]

Thanks Steve.

Gear selector

well I thought I had this beat. I made a new pushrod and despite all the adjusting was unable to get reverse. So I disconnected the pushrod and manually tried. It would not engage. I tested it prior to installation and it worked  perfectly. All I can assume is now the clutch is connected the engine is preventing rotation of the shaft and because reverse has no synchro it needs a depressed clutch so the shaft can rotate slightly for reverse to engage. Any thoughts? Can anyone get reverse consistently without depressing the clutch? 

[Lotusfab]

Well this is annoying. Clutch working perfectly with fluid. Unable to select reverse manually direct from the selector shaft. I tested it before and could easily get all gears. 😡😡😡😡😡😡

[Lotusfab]

Will have to put a borescope inside the fille hole and take a look. 

[Lotusfab]

Well I can't get the angle on the borescope. So this only leaves taking the top of the gearbox off. I think it's unlikely now the clutch works that the gear is fouling on the idler gear. It all worked when I put it in. Now it's impossible to get reverse. Something has changed. I can feel the selector is in the reverse gate, but the reverse selector shaft won't move. Why? Well all I can  think is the selector fork has moved, or the shaft is ceased? Any thoughts before I take it apart? 

[jonwat]

1 hour ago, Lotusfab said:

 Any thoughts before I take it apart? 

It's possible the gear teeth are meeting head on, try turning the engine a little to move them. 

[Fridge]

A pal found that the selector fork had bent in some way which caused this same problem. However in his instance he thinks it had been forced post rebuild. Which is probably unlikely in your case. Good luck. Sounds like a nightmare.

[Lotusfab]

Thanks chaps. Will fix it and report the solution.

[Lotusfab]

23 hours ago, jonwat said:

It's possible the gear teeth are meeting head on, try turning the engine a little to move them. 

This seems possible but begs a question. If the clutch is depressed the idler gear should be free to rotate. Surely the reverse should engage? If it doesn't then what stops this situation occurring when you drive the car? My S1 always engages reverse easily, engine running or not. When I tested it reverse was always easily selected. I believe I can feel the selector shaft move into the reverse gear shaft selector, butbthen it doesn't move which would be explained buy the gear teeth on the reverse and idler gear not meshing. Not a good design really. Would have thought the teeth were shaped to allow the gears to mesh?

I may have got lucky and the idler gear stoped in the million to one position where the gears won't mesh!

[Lotusfab]

Gearbox

Ok there are lots of threads on here about gear problems, but no detailed analysis- explanation of how it all works. When I put it back together I did not really need to understand the shafts, as the selector positions are fixed. The bolts locate them in holes in the shafts. However, now there is an issue it's time to understand how this all works. I could be wrong (disclaimer!) as I have not experimented with it yet(that will come later), but this is what I believe happens......

Here's the selector shaft. The gear change lever mechanisms simply  push it into the gearbox, pull  it out and rotates it to get the gears. So you can do this by hand to select gears for tests. That's what I did and it all worked perfectly until I bolted the engine on!😡😡The short lever(bottom of top picture) on the shaft actuates the selector shafts 1/2 and 3/4 gears.  The longer one near the crank arm does 5/Rev. So far easy! The spring in the centre keeps the shaft sprung to the 3/4 selector fork position. So rotating the crank without pushing the selctor in or out of the gearbox will engage 3/4. 

When the shaft is pushed into the box the short selector arm leaves the 3/4 selector fork and aligns with the 1/2 shaft cut out. Then  rotating the selector lever with push the 1/2 shaft  engaging 1/2 gears. Only one shaft can move at a time due  to the interlocks.

So the troublesome reverse. On the right hand side of the bottom picture you can see where the longer selector arm fits. I have called it shaft in the above and labelled it yellow -sorry! 

 

[Lotusfab]

Reverse - not sure about this, maybe someone could confirm? I will be sure after I have taken the top off the box! 

I believe the long selector shaft arm sits in the rectagular gate (top right) . For 5 th the arm is in the retangle bit and pushes the rectangle to the left to engage 5 th gear. When you select reverse,buy pulling the selector shaft out of the gear box, (not sure about this next bit) the arm moves through the gate and engages with the fork on the reverse shaft. When you then rotate the arm it pushes only the reverse selector leaving the rectangular bit stationary. 

The position of the rectanglular bit and ref fork on the shaft is fixed because the bolts locate in holes on the shaft. The only adjustment is the position of the reverse gear, which is set using a measuring tool.

So why can't I engage reverse? Well the easiest solution would be if the gear teeth are not meshing on the idler and reverse gear because the are in the worst possible meshing position( very unlucky if this is the case). Then rotating the engine would fix it.

I can feel the arm moving through the gate detent but then it's stuck. This could also be because it's jamming in the edge of the rectangular bit and nit cleanly passing through the gate. Why because the selector arm is slightly bent as David said. 

If the engine rotating doesn't fix this I shall remove the selector shaft and experiment. Then if I still can't get it to work the top cover will be coming off. I will post the solution here and confirm operation of the reverse gear, unless someone else can confirm this post is correct? Thanks.

 

[Andyww]

That all seems correct. Is the adjustment of the long fork which moves the reverse idler correct? The two clamp bolts holding it onto the shaft? Thinking about rotationally rather than axially on the shaft.

[Lotusfab]

Yep that's a good point. I was thinking about that also. There's no mention of any rotational adjustment in the manual, as far as an know. But we all know there are glaring emissions! Not sure if the rotational position is adjustable. Will look into it if an cant get this working, theoretically if the shaft is rotated it could jam the long selector arm as the gap would be reduced.

[Lotusfab]

Here's  better picture. I wonder how many reverse gear problems are to do with tthis gate? In the picture the bolts are out.for the selector arm to pass through the gate smoothly the edges need to be aligned. But also notice the rotation of the reverse shaft. If as in the picture the reverse shaft is rotated towards the rectangle the width the slider arm has to slide is reduced. It seems plausible the gap may not be wide enough which would impede reverse selection. I shall remove the shaft from my gearbox and take some pictures. If I need to adjust the fork the top will have to come off. A pain but not that difficult.

[Lotusfab]

Here's my finished box. You can see the edges of the gate arn't perfect. They are set by the bolt detents in the shafts. Maybe a small adjustment is possible. I could rotate the reverse gear selector fork at the other of the shaft to increase the gap for the selector arm. A photo of this on a working box would be a great help if anyone has one?

[910Esprit]

If you give me an hour or so - I'll give you pics of 2 working boxes from the top?!!

 

Edited August 3, 2019 by 910Esprit

[Lotusfab]

Thanks Steve. I'm not sure my description of the reverse is correct. It's possible the selector arm always stays in the rectangle which tilts to allow the arm to move reverse shaft only. I will have to remove the top cover and explain on here. 

[Lotusfab]

1 hour ago, Lotusfab said:

Here's  better picture. I wonder how many reverse gear problems are to do with tthis gate? In the picture the bolts are out.for the selector arm to pass through the gate smoothly the edges need to be aligned. But also notice the rotation of the reverse shaft. If as in the picture the reverse shaft is rotated towards the rectangle the width the slider arm has to slide is reduced. It seems plausible the gap may not be wide enough which would impede reverse selection. I shall remove the shaft from my gearbox and take some pictures. If I need to adjust the fork the top will have to come off. A pain but not that difficult.

 

1 hour ago, Lotusfab said:

Here's my finished box. You can see the edges of the gate arn't perfect. They are set by the bolt detents in the shafts. Maybe a small adjustment is possible. I could rotate the reverse gear selector fork at the other of the shaft to increase the gap for the selector arm. A photo of this on a working box would be a great help if anyone has one?

NB these posts could be incorrect! I can't edit them. We will know when I get the gearbox top off.

[Lotusfab]

Hopefully Steve pics will explain this, if they don't I'm going to take the cover off put a camera inside the box and confirm how the reverse selector works. I just found this pic, which  was taken prior to the dismantelling. You can see reverse is engaged. If this is assembled correctly it shows the selector arm remains inside the rectangle. But if that is the case why have a cutout? Hopefully Steve's pics will explain more.

[Lotusfab]

Think I may have a solution! The manual says the notch in the operating dog on the reverse shaft should be verticle. I used the manual and a combination of the pictures I took to reassemble the box. I think the above picture shows the reverse shaft was incorrectly assembled. When I bought it as a non runner it was impossible to select reverse. I put it down to cable adjustment. Maybe it was put together wrong! As the rebuild emulates this it's also wrong. Just need a picture of a working box to confirm the notched operating dog is verticle and I have a relatively easy fix, fingers crossed! And if this picture above is wrong then my explanation of how reverse works is probably correct! I know it's boring but just something  that has to be resolved. Here you go!