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


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55 minutes ago, Z320 said:

Hi Peter,

I do this because you can get the flat countersunk drill M10 only with 3 pin sizes:

- 8.5 mm (to cut a thread)

- 10.5 mm (small gap to M10)

- 11.0 mm (wide gap to M10)

What do you recommend?

I could make a bush 8.5 mm x 9.00 mm and use the 8.5 mm one, later drill 9.5 mm...

Ciao, Marco

OK I think understand what you are doing now.

You are counterboring - here is one with 9.52mm pilot (3/8")

https://www.drill-service.co.uk/products/countersinks-counterbores/counterbores/cb-hss-counterbore/

image.png.b198dc28e5ef411da16b439406ec3d16.png

Peter W

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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

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You'd confused is by talking about a countersink, which is a tapered recess at the beginning of a hole so that a countersunk head screw, which has a head that is triangular in cross-section, can fit flush to the surface. What you are using is a counterbore, which produces a flat-bottomed recess concentric with a hole. Yes, often used with hex socket (Allen) cap head screws.

Pete

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That's because of my poor translation,

at Germany we use "senken" for 45deg tapered and "flachsenken" for what you call counterbore.

I'm learing every day, but sometime I think: just write it, the understand anyway.

 

BTW: ddi yuo konw yuo cna raed a snentece as lnog teher aer all leettes tehre adn the frsit oen is sitll teh fisrt  oen?

Edited by Z320
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Next is to bolt the MX-5 gearbox on the adapter by using the complete lenght of the threads.

Sadly the flange of the gearbox is different solid on each of the 8 fixing points,

so all 8 screws must have individual lenght and will fit only in one position!

So my idea is to make identical bolts, glue them in and use washer and nylon nuts.

That's very simple and later there is nothing to puzzle.

p_BumRNME2PbTsTk9CPZUmenqtSgDDk52LRz9NrZ

Screws are 3/8", quality is 12.9, they are from Screwcorner.com,

it was pretty interesant to cut the head off and the thread on there...!

The next photos should be self explaining (the nuts later will be nylon nuts)

JTmWpojvRcdC8wWpg3jIgJEtdnZVdukf38f7bEAF

1pO7qmRGx_HuDlLxlczGdd62Skx83oF7ubHxMfxa

Edited by Z320
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On 11/1/2020 at 12:17 PM, Z320 said:

That's because of my poor translation,

at Germany we use "senken" for 45deg tapered and "flachsenken" for what you call counterbore.

I'm learing every day, but sometime I think: just write it, the understand anyway.

 

BTW: ddi yuo konw yuo cna raed a snentece as lnog teher aer all leettes tehre adn the frsit oen is sitll teh fisrt  oen?

Ctna ustendarnd a wdro yuo aer sigayn sorry.

Kveni

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Hi,

while I'm waiting for another tool I had an idea how I could level another surface, inclined for about 3 mm.

I do not own a mill, but could it work with my little Dremel?

E1N8-aTME7Ie_rAB_anmPdcqAecH2pmRlhVc9p9s

Fixed on a wooden support, sliding on the work bench like this (work already nearly done)?

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Not so bad...

spcx9OpzmHwv7_pHvw5iKSkVUB_9_aaiTLvqkv7F

q6XxZbFBmx23sZyy7J7WZmFCpcDZ5busxXZ9FcWq

That's good enough, I'm pleased

MRdEO0aJCRV7vyySzE1Y_EnRZLsz4MDvWZ1XlZpG

 

 

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Hi Roger,

indeed you are absolutely right: it would be a challenge to get the gearbox on a mill in one unit and to mill this surface.

wg7yKr8anC-UpD1uj5wOsQRadog_gsKUBZ3k99B9

You will see this later when I drill this hole on the other side of the gb on my drilling machine.

Ciao, Marco

 

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The same position on the right side of the gearbox is the one I had to drill through,

sadly I did that with my hand drilling machine, so the hole is about 1 mm too low.

AibIIPiwpjYRwT5A8YmH-4At69UjA-CdxfVdAEpN

With a file (and some patience) I lifted it up..

byO2Nqr0eWl_Hd0LiND_-e9QmWUdGsw0_ZSiKvNZ

now it is too wide for the pin of the counter bore, a POM bush over the  pin saves the situation...

uTXGOjm9ISVirpKcaFE_yVXxGnKYxvdGlS3bXiSv

My small and old drilling machine is tall enough to drill this - but only with the cover off

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ready, at all 30 minutes of joy in my workshop

HGnExfEnbmgPZnTOYi7nITK6hVliGTgiXz2et-un

So...why did I drill this and did not use my Dremel?

I want to lift the surface again up to same high as this surface has on the left side of the gearbox by glueing a plug in there - tomorrow.

Sleep well, ciao, Marco

 

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Loctite 638 was my choice, d=20 mm outside, 10 mm inside

V-fEn4tGbBItUUvaYJ1xfamYv0jNg1XZQ6wWtL_M

Behind are about 10 mm full aluminium, from inside I also glued in a plug, also next on the left side of the gb

WT0zQi2vxMUIuyD6ZDcibDdlk-6eqNCtxm8AriSX

This is to fix this 2 point as good as possible because on the upper part I have to cut parts of the housing off.

Edited by Z320
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Today I started to chop the front end of the MX-5 gearbox

xhgD1UXHH6y1E9WPwbFc5z9kFBdASYrLEukvaqTm

SCBtrh3jCVMk3AbHNx3rhU8PgxWnPNwZkE609mDW

To be honest: this scares me myself somehow,

but the other way would have been to modify the bulkhead.

Ciao, Marco

Edited by Z320
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After I smoothed the surface with a file I'm pleased about the result and I'm not longer scared about myself.

snSPidzj32QvemUbzQjWDfaj2_PgvLeiQ8W6hyLD

A closer look on the top of the MX-5 gerabox shows you how I made both holes there smaller to avoid any movement there.

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Next chapter is how to fix the electric starter.

Sadly I have to buy a modern one and sadly this will cost me more money than the gearbox itself...

To use the original TR starter I have to cut out the gearbox housing too much.

bRWgYO10sPQ9X0-WPE3TDJldkZky1bmTOshfV_xi

As you may see I can put the screws for the starter in only from the engine side, this later will be bolts, glued in, with washers and nuts.

What I need is a modern starter which allows this washers and bolt between its flange and the starter housing itself.

Any advice is welcome.

A last impression for today from my workbench....

  rFOuZQmyCqgp0SpACOwYhBB3BamLDyiPwgkfZxVK

Ciao, Marco

 

 

 

 

Edited by Z320
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This sort of thing?  Adjustable rotationally.  I would think a man of your skills would eat that task before breakfast.

https://www.classiccarperformance.com/collections/britishstarters-com/products/triumph-tr3b-tr4

image.thumb.png.ca204127bce450d208c006653b13d141.png

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Hi Peter,

thank you for the photo and link,

I think I give a small supplier and club member at Germany a call at Monday.

On his webside he offers a starter with less information and only one photo - but it seems to be the same starter.

You can have a look at http://www.ttsmausbach.de/

He wants some more money but shipping from the USA + tax +

the sleeping folks at our customs office + time to go there - it will be better to give him the order.

Ciao, Marco

 

edit: $190 + shipping $80, + customs 46 Euro, I'll give my club mate a call

Edited by Z320
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Hi,

the starter was already in the next day and it seems to look good?

It is possible to twist the flange in steps of 20x18°.

3JZofhMaTpFqWhTNfJR1P-vyxNmxqHGFgGXh4gMH

In the original positon everything is OK.

UVtQ0x8SdxuoDvHlyM2rjC3wgzJ6a8R9xkv3l48k

You see the only 7 mm wide gap between the flange and the starter body.

To twist it only 1 position to the engine

fUi5WJ1SqAqrxZS07jApy_Z_EZNpjBi3PEPxauvC

does not allow to fit a nut - but the starter touches the engine.

qgAZZwGKrJ1GUYUBETXt5apJNA9Crh4QId3bxnnv

To twist it less than 2 positions away from the engine makes it possible to use a nut!

IR-I_cc8VRlwI1cV4f5Daeswc-vLo9vxTk_caqST

But the starter touches the car body....

JgDqu9HKdfCLTX5_sCNgCdY56P8DAG7z1pKsH3rN

The problem is the very close construction of all this modern startes for our TRs.

wzSU84MoTGrSXD9WiZMYkSvR3SYN41u8GYUex-Eq

Is it possible to cut this off.....?

At last I remembered a post from anywhere from anyone like "I fitted it upside down",

the context I do not remember but I did it this way ....

SczgDiadIg-kHzLapXXvdhMT6zezk9iSnw-al03U

pTu4UKhCULvuWTpESGlYTOg9zm5iSzW46L8Cd1NQ

EWYOG1eD_9lqC_tpLAWEYWYaPI73CX6GnwWkTGwy

Any idea why the starter should not work upside down - or who's the one who also did it this way?

Ciao, Marco

 

Edited by Z320
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34 minutes ago, Z320 said:

Hi,

the starter was already in the next day and it seems to look good?

It is possible to twist the flange in steps of 20x18°.

3JZofhMaTpFqWhTNfJR1P-vyxNmxqHGFgGXh4gMH

In the original positon everything is OK.

UVtQ0x8SdxuoDvHlyM2rjC3wgzJ6a8R9xkv3l48k

You see the only 7 mm wide gap between the flange and the starter body.

To twist it only 1 position to the engine

fUi5WJ1SqAqrxZS07jApy_Z_EZNpjBi3PEPxauvC

does not allow to fit a nut - but the starter touches the engine.

qgAZZwGKrJ1GUYUBETXt5apJNA9Crh4QId3bxnnv

To twist it less than 2 positions away from the engine makes it possible to use a nut!

IR-I_cc8VRlwI1cV4f5Daeswc-vLo9vxTk_caqST

But the starter touches the car body....

JgDqu9HKdfCLTX5_sCNgCdY56P8DAG7z1pKsH3rN

The problem is the very close construction of all this modern startes for our TRs.

wzSU84MoTGrSXD9WiZMYkSvR3SYN41u8GYUex-Eq

Is it possible to cut this off.....?

At last I remembered a post from anywhere from anyone like "I fitted it upside down",

the context I do not remember but I did it this way ....

SczgDiadIg-kHzLapXXvdhMT6zezk9iSnw-al03U

pTu4UKhCULvuWTpESGlYTOg9zm5iSzW46L8Cd1NQ

EWYOG1eD_9lqC_tpLAWEYWYaPI73CX6GnwWkTGwy

Any idea why the starter should not work upside down - or who's the one who also did it this way?

Ciao, Marco

 

Does your exhaust run under the starter Marco? Otherwise I can’t think why it won’t work.

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Hi both,

because I twist the starter up from the upside down position it is not that close to the exhaust.

But a " heat nappy" on the exhaust pipes would not be so much wrong.

 

Edited by Z320
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12 minutes ago, Z320 said:

Hi both,

because I twist the starter up from the upside down position it is not that close to the exhaust.

But a " heat nappy" on the exhaust pipes would not be so much wrong.

 

You can also get a heat sleeve designed to fit over starter motor. Are the wires protected from the engine heat?
 

Paul

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Hi Paul,

yes, the contacts are safe,

a heat sleeve is also a good idea and less inconspicuous 

- as long as it is not the reason for another annoying rattle....:wacko:

Marco

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On 11/19/2020 at 9:34 AM, Z320 said:

Hi Paul,

yes, the contacts are safe,

a heat sleeve is also a good idea and less inconspicuous 

- as long as it is not the reason for another annoying rattle....:wacko:

Marco

Hi Marco

The sleeve I put on mine is a fabric type silver material which can be cut if need be so there should not be any squeeky rattles from it. It also helps protect the motor from water and other things settling on the starter that might cause issues later.

Still very impressed with the work so far, keep on trucking.

Paul

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Hi,

today I started to drill the gearbox with a core drill on the position where the starter cog moves in.

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This looks a bit primitive - but works well. The centering drill helps to hold the drilling machine and core drill in position.

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Sadly at the position where the centering drill has to be was exactly where the gearbox already had a hole.

So I had to plug this first with a bolt of aluminium (glued in with loctite) and pre-drill it.

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I'm pretty much surprised by my own how simple this works.

Tomorrow I will drill the smaller diameter for the shaft.

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Ciao, Marco

Edited by Z320
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Hi Roger, thanks!

I think for the simple tools I used this is OK.

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That's it with the starter in position, for the photo I pulled the cog out in the "engaged position"

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Perhaps I fit a cover, same situation from inside, I'm pleased with the result.

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Next is the gearbox on the engine to continue with the crossmember or the spigot bush.

-gj_fFwZ4g-EbjeiW05QaYY5xPOOoQLdt77yjpbe

URf0py7YjX47GMVHUCuNN4TPfxQ_cN1FTT5y1wwQ

3K_glCR41V-HkUyMURo1mXUkWr13U_f9pQFQsv1t

I will do the spigot bush, clutch and slave cylinder first.

Ciao, Marco

 

Edited by Z320
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