Jump to content

my new gearbox? (Mazda MX-5 to TR)


Recommended Posts

  • Replies 458
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

Ups, the adaptors are already delivered, I'm really surprised about the laser cut surface! Tomorrow will be first fit, please keep fingers crossed for me.  

Thanks Russell and Andi, thank you very much, all worked well, fit was 100% on first attempt, the 8 mm drills are exaxtly to the point they have to be for the 5/16" bolts! Btw, the bar is on

Talking of gearbox changes, back in the 8o`s when I was involved with Jaguar racing we converted a V12 XJS from a GM 400 auto box to a Cosworth T6 manual 5 speed by a cut and shut of the two bell hous

Posted Images

I don't want to tell you stories about what doesn't work,

just take sharp drills up from 4 mm in steps of 0.5 mm, a lot of oil and drill it out.

Take care not to slide through and not damage the aluminum housing this way.

chfzbk9MG51F9GjI34gM9UO6j7rDDrqNbBsJu4AB

Edited by Z320
Link to post
Share on other sites

That looks a good result.

Mick Richards

Link to post
Share on other sites

Yeah, to lift off the shifter housing should be an easy job now?

Before I placed two punches with the distance between them (165 mm) to make all parts the same distance shorter.

kCG3SEHXx5fzxFV18h3CFsLejCD7UyewlZ8j_sxA#

Now just remove the 4 bolts, slip the housing backwards and the same time the "shifter block" off from the shaft?

That's great, fast and easy!

1zi8i3V5zpkuqpGiquKueG_cF7nULEDIMuAHtQhF

But when I removed the 4 bolts I realized - and wondered about - how generous wide the 4 holes are drilled, about 9.5 mm for M8!

How do they adjust and bolt the housing in the factory in the correct position this way?

?

?

§$)!&%!@@!! - with 2 dowels!

iF9mEV0LrJKcRIaNgUg46dDjK-ow8v9QTtAfR--e

They unable me to slide back the housing.

And the little play in guides in the gearbox and in the housing unable me to lift the housing over the dowels.

VNrgvkD39adE1-_QgeZUXiKDgT90hEb50mZPR_Pm

Well, time for a short brake and think about: to open the gearbox or looking for another way.....

On the front bolts two short cuts left and right of the tube?

 

Edited by Z320
Link to post
Share on other sites

Hi Marco,

can you shorten the casting (and the shaft) once it is removed by 165 mm with machining Once you have removed it?
If that is already the plan or not a good idea sorry, I do not follow your project in detail.

Cheers,

Waldi

Link to post
Share on other sites

Hi Waldi,

165 mm is more than I can make it shorter, I could also punch 180 mm.

With the housing removed my idea is to drill it from behind for the shaft going through (later I will plug it).

So I will slide the housing forward and make it shorter step by step, always shure the shaft slides easy / the housing is axial correct.

Finally I measure perhaps 17 mm (or what ever) between the 2 punches, so I have to drill the shaft 165 - 17 = 148 mm in distance from the factory drill,

make the shaft 148 mm and the tube 148 mm shorter and can calculate how long the offset for the gearshift leaver must be.

Any other ideas are welcome.

Ciao, Marco

 

Link to post
Share on other sites

Sounds like a good plan Marco. You could Consider to tilt the lever a bit back or forwards (Probably forwards if you would re-locate a bit less than desired) in the final position to allow easier gear selection once the box is installed.
Waldi

Link to post
Share on other sites

Hi All.

Referring  to my previous picture of the gear lever set up.

 Vitesse have done the same as Marco is proposing. Vitesse moved the gear lever forward by about 45mm with a small extension plate welded to the original Mazda gear lever base. As you can see by the picture the gear lever itself still does not come to the original location, more or less in the centre of the tunnel opening. I further modified my Vitesse gear lever by making the extension plate even longer. About 75mm brings the gear lever into about the correct position. For the side screen cars with their upright gear lever this is a real improvement over the standard Vitesse set up. From inside the car it is hardly noticeable. With the TR6 car, the Vitesse set up is much more acceptable.

Well done Marco, all really interesting. Russell

Link to post
Share on other sites

Marco you are very patient and a deep thinker...excellent, great job  !

Mick Richards

Edited by Motorsport Mickey
Link to post
Share on other sites

tool making for the lathe

vRp1DsqhmHkbxsU3L2Qnov-Gs6XD9SQFyswjkLkR

the next photos should be self explaining

3KYIp_63HvQk6Yg0uHnctGEzBSWiEoDCaZcSk6yn

iP6rJMl90YD5i0a97sAdnsqioSogi-lA6gCGjeg2

KZJ26i5zQE32nMZpoXCzV3-ezksTuGji07gl6_qh

PfBFuk7cMgX-Z4p-3QSC5axq-Dm6fn_S6x0_fFrC

JgWVD9yoZkWUqFv1zTPTNuu5jSsXLIlkSA0iqJwZ

first fit

agTgzmynTJeFlSABqGcJ_V5mV3yRwANknWH9SDII

here the housing touches the gearbox

M1REHaHeMXXFaIMhew2vlKXiiHOGhAOBnF3YzHNf

_VY645H9clzXdA5Dai2Mwlu6h5iPmhfxltZ5Yivy

0bbRH0pozPYG77ORsQWrDfbqYufgK-ogyEHCSlYA

Us5wOwg9R__jpi9QNld55InCchv3OGA59NRT-GoH

CpG1K4LQZthqzDyG9l0bXpFMvGa6HxaVLhdwDcd-

140 mm, but 10 mm more I want to go forward

Edited by Z320
Link to post
Share on other sites

Wow there is certainly Problem solving matched to engineering skill here. :o :D

Link to post
Share on other sites

Hi Marco

Is it possible to reverse what's left of the housing onto the shaft, and would this bring the gear lever opening nearer. Does it matter if it is back to front. Or plane some material from the top of the tailshaft housing?

Or are these suggestions foolish?

Kevin

Link to post
Share on other sites

This it looks like after remove some material off

5V9ev7cXnWy9TxW8cOs9vpjiXEaF0cM3-7tTRJe1

All you need are some files, patience and patience

27JC4SN_ygCHyl5Et2KKevKRxd-g611OHRu8cOyu

as I suggested the shaft still in its position and going through the housing was very usefull

4vDfSnlznBk26lVPLp8BqT7CP1YrHqFUjYZ2nWBl

distance is now reduced to 6.5 mm

e9pU69KUqmfiztaIm9FkJG9VMhuhUfVBds2_bMbp

another 3 mm would be possible and still have the two holes to fix the housing,

up to maximal 14 mm, but only with cutting the holes half away, so I did not

bx1U_m2TjqbRSdnbNlP9dQVTshHSJRz4PAmpxlXM

next issue was what I expected on the right side: parts of the housing (not the housing itself!) touch the gearbox

HpDSPZxuXiENq5R7pXAjSO4qatV8tghBJ-H2csrM

first preparing the cover with a file

tortn93rMHCVBOH-bzZCEdAhyTG10n2TNzOg-ekd

CfJnpvM1vx1KDJjE1ZRYdL8gb6B1n_YKRCPVnOWz

next the gearbox itself

Muq5iabVf5eaHQnaIwaQDPFj0-8HypslkiAhFgG5

fits now

tbdSR48PHFCLvjNh-fo88x-EXhggkQe9oKroZEyM

next the right side (another day)

7tswNA85twCFUTlpRDdVAuT4yGS218Q9ItZ20Ypd

Ciao, Marco

Edited by Z320
Link to post
Share on other sites

Hi Marco

Out of interest could you slide the housing on backwards and send a photo. I wanted to see how far it would go if pushed on back end first? I realise this might not be possible if some of the rear of the housing hits the tailshaft housing.....and whether the bolt holes in the housing would be anywhere near the threads in the tailshaft?

Kevin

Edited by boxofbits
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.