Measuring pinion height

[tkathulevej]

Constructed a simple tool for measuring pinion height (attached) 🙂

...Consists of 8 mm (very straight and uniform thickness) rod from scrapped printer + 3D printed piece to hold things in place + standard digital caliber. Good thing is that it measures the distance from the bottom of the bearing cup  ...Because as someone discovered before me the mating face between gearbox main housing and clutch housing is actually not (always at least) centered to the CW axis. Procedure:

 

1) Reset caliber on rod diameter.

2) Mount it in the holder resting on rod.

3) Push caliber pin to pinion top face and do reading.... And of course to get real pinion height you need add radius of the bearings (40.00 mm).

 

Until now it produces fairly comparable individual results. - But will 'paint' and check pattern in the end too !

 

BTW: Went with US sourced reversed CWP (...without going into the endurance discussion there has been about that). So far things look good and I'm pleased. - Although reversed CWP is probably not that necessary on almost stock 907 engine (..and not doing 7.000 rpm clutch dropping at every traffic light.  

 

 

[910Esprit]

That's a neat idea that the plastic part is not material to the measurement.   Also, when I checked my inexpensive digital vernier using gauge blocks, it was surprisingly accurate.

It makes me laugh that pinion depth is measured to 0.01mm - but my detailed measurement of a set of cases suggested they are not machined to an accuracy of 0.01!   

 

[tkathulevej]

11 minutes ago, 910Esprit said:

That's a neat idea that the plastic part is not material to the measurement.   Also, when I checked my inexpensive digital vernier using gauge blocks, it was surprisingly accurate.

It makes me laugh that pinion depth is measured to 0.01mm - but my detailed measurement of a set of cases suggested they are not machined to an accuracy of 0.01!   

 

 

...That's corrrect. You'll see far more variance than 0.01 mm when spining the pinion or measuring on either sides.

[PrecisionMike]

On 28/03/2023 at 11:01, tkathulevej said:

Constructed a simple tool for measuring pinion height (attached) 🙂

...Consists of 8 mm (very straight and uniform thickness) rod from scrapped printer + 3D printed piece to hold things in place + standard digital caliber. Good thing is that it measures the distance from the bottom of the bearing cup  ...Because as someone discovered before me the mating face between gearbox main housing and clutch housing is actually not (always at least) centered to the CW axis. Procedure:

 

1) Reset caliber on rod diameter.

2) Mount it in the holder resting on rod.

3) Push caliber pin to pinion top face and do reading.... And of course to get real pinion height you need add radius of the bearings (40.00 mm).

 

Until now it produces fairly comparable individual results. - But will 'paint' and check pattern in the end too !

 

BTW: Went with US sourced reversed CWP (...without going into the endurance discussion there has been about that). So far things look good and I'm pleased. - Although reversed CWP is probably not that necessary on almost stock 907 engine (..and not doing 7.000 rpm clutch dropping at every traffic light.  

 

 

Very impressive. I'm in the process of re building my early c35 box and am having great difficulty in undoing the speedo drive nut on the other end of the pinion shaft. Please can I ask.....Is that nut a normal direction thread ie anti clockwise to undo or is it a left hand thread. 

All help very much appreciated.

[910Esprit]

Normal clockwise.    I made an 'infallible' tool for doing this job after a modified openender wasn't up to the task.   Search out my previous thread on the subject which has some info I've not seen discussed previously.

 

 

 

Edited April 24, 2023 by 910Esprit

[PrecisionMike]

22 minutes ago, 910Esprit said:

Normal clockwise.    I made an 'infallible' tool for doing this job after a modified openender wasn't up to the task.   Search out my previous thread on the subject which has some info I've not seen discussed previously.

 

 

 

Thankyou for your rapid response. I had adopted a similar approach for the speedo nut but with a 46 mm socket which is a snug clearance fit over the speedo drive.

When you say "normal clockwise" I assume you mean clockwise to tighten.......just to make sure.

Please can I ask how you reacted the torque applied to the speedo nut.

Many thanks and thanks for the link to your tools stuff.....I guess I'll be making those too!

[910Esprit]

Oops yes, I meant standard Right hand thread!.  

Yes, I gently supported and clamped main case in a floor standing press.

You maybe correct on the 46mm I'd need to double check.  NB My socket has stress relieving cutouts in each point of the 6 sided socket.  these perfectly accommodate the 8mm pucks. 

TBH If that doesn't work, you're in trouble!

Oh - and have you slackened off the reverse gaer selector so you can select 2 gears at the same time to lock the geartrain?

 

Edited April 24, 2023 by 910Esprit

[PrecisionMike]

22 hours ago, 910Esprit said:

Oops yes, I meant standard Right hand thread!.  

Yes, I gently supported and clamped main case in a floor standing press.

You maybe correct on the 46mm I'd need to double check.  NB My socket has stress relieving cutouts in each point of the 6 sided socket.  these perfectly accommodate the 8mm pucks. 

TBH If that doesn't work, you're in trouble!

Oh - and have you slackened off the reverse gaer selector so you can select 2 gears at the same time to lock the geartrain?

 

Hi. Yep. I've locked the gears. Warmed the nut. WD 40 and two people. The tool held but it didnt budge. I'm in trouble🤔

Not sure what to do now other than open  bottle of wine🍷

[910Esprit]

I've seen those 'nuts' for sale  - If you can find one at a reasonable price it maybe angle grinder time...   

 

[dsvitesse1]

try the other way first, a little bit clockwise. After that counter clockwise loose. It must come loose.

 

You need to fasten the casing on something steady.

 

cheers,

 

Harry

[PrecisionMike]

Thanks guys for the tips . I'll try again and let you know how I get on.

[tkathulevej]

I also re-used someones idea about the 46 mm socket:

 

 

My speedo-nut was really insanely tight, but I think this type of tool will loosen anything out there. Of course - as Harry says - be careful to hold your gearbox because very much force is to be applied here. I used two pieces of wood with holes made for the clutch housing studs. Then these were secured above the ground and I could place the gearbox vertically on top. That gave a good position for me to loosen the nut without help from other and in controlled manner:

 

 

 

 

/tka