Ironhead Upside Down Monoshock IH - A Longterm Project

[paulc]

Checked C/S endplay today - 5 Thou, M/S endplay when pushing lightly on trapdoor bearing still 2 Thou, 12 Thou with no pressure. Pulled the trans and saw inside for the first time. I knew these cases had been repaired and the Trans checked for bore alignment etc. This is what it looks like:



Fitted the splined shifter shaft. Found that the right hand end of M/S had 2 Thrust washers - 32 & 40Thou. C/S had 3- 76, 37 & 20Thou. No problem I have spares that I can bring it down to 1 washer and 2 washers and have the same thickness.

No idea what I will end up using though. Measured the spacing and things are not within spec when all gears are pushed towards trapdoor. Here is what I found:



Very strange numbers Can't see for sure yet if forks are standard size. Once the new C Ratio 4th gears are in place I'll check the spacing again and take it from there. Don't have a press so may take a week or 2 before I get the new clutch gear pressed in.
Paul

[paulc]

Made a bit more sense of the gear spacing. The sliding gear on the M/S moves 40Thou with the trans on the bench. I measured with it as near to the trapdoor as it will go. Measuring gear spacing with the sliding gear in the middle of it's movement, as I read in the Donny Peterson book, gives more sensible numbers - 47Thou & 65Thou. Don't remember having movement on the shaft like this when I did the trans on my 76 but I do with this one.
On the C/S sliding gear has about 35Thou side to side movement on the bench. So still out of spec if I measure in the middle of that movement. Discovered though that there was only one C/S low gear washer between 1st & 3rd gear. Book tells me I should have 2. So I should be able to sort out C/S spacing by playing with the thickness of those washers and maybe changing to a -10 shifter fork for C/S.
It's starting to all make sense again so I'll get there with it.
Paul

[paulc]

Oh joy we have another strict Covid lockdown starting here, things will be tighter than a ducks ass for the next 6 weeks or so. Travel restrictions mean I now can't get to the place I was going to get the clutch gear pressed out and the new one pressed in. Could probably get it done at my local car workshop but only if they stay open. If not then buying a cheap press or waiting are my options I guess. Manual just says use an Arbor press, no details on tons, dimensions required etc and i have no idea what would or wouldn't work. Would a 1/2 ton one of these dimensions work:

https://www.amazon.co.uk/Clarke-Ap50...NFJNRMK1E02PQ2

Shifter fork shaft is nice and tight in the trap door so I would need to allow room for that when pressing clutch gear. Just exploring options at the moment but it might come to buying something if I can keep the cost down by using a 1/2 ton one.
Paul

[ryder rick]

I think you will find a small arbor press is not very useful and will not press the clutch gear.

[chilly]

Originally Posted by paulc

Oh joy we have another strict Covid lockdown starting here, things will be tighter than a ducks ass for the next 6 weeks or so. Travel restrictions mean I now can't get to the place I was going to get the clutch gear pressed out and the new one pressed in. Could probably get it done at my local car workshop but only if they stay open. If not then buying a cheap press or waiting are my options I guess. Manual just says use an Arbor press, no details on tons, dimensions required etc and i have no idea what would or wouldn't work. Would a 1/2 ton one of these dimensions work:

https://www.amazon.co.uk/Clarke-Ap50...NFJNRMK1E02PQ2

Shifter fork shaft is nice and tight in the trap door so I would need to allow room for that when pressing clutch gear. Just exploring options at the moment but it might come to buying something if I can keep the cost down by using a 1/2 ton one.
Paul

Hello Paul
You will need to make sure you have enough height with this arbour press.
Have you a large vice that opens up to take the item,if so maybe worth giving that a try by putting the male part in the freezer and warming up the female part then pressing it on using a piece of pipe that has square ends.
I have a 4 ton press that i could use if your stuck, just send it to me.
Cheers Chill

[paulc]

Originally Posted by ryder rick

I think you will find a small arbor press is not very useful and will not press the clutch gear.

Thanks ryder rick, I suspected that might be the case so thought I'd ask before spending out on one

Originally Posted by chilly

Hello Paul
You will need to make sure you have enough height with this arbour press.
Have you a large vice that opens up to take the item,if so maybe worth giving that a try by putting the male part in the freezer and warming up the female part then pressing it on using a piece of pipe that has square ends.
I have a 4 ton press that i could use if your stuck, just send it to me.
Cheers Chill

Thanks chilly, much appreciated, may well take you up on that. I like your thinking but don't think my vice and flimsy workbench would be up to the job. I'll finish taking things apart at the weekend then see if my local garage have a suitable press. If not I'll send it to you.
Paul

[chilly]

Good luck , let me know if you need my press and i'll send you my address .

Sent a PM with my address if you should need it

[paulc]

Ended up posting my trap door to chilly and he kindly swapped the standard ratio clutch gear for the C ratio one, many thanks chilly.
Have the trans on the bench now with both c ratio gears fitted.




With those fitted I can sort out the gear spacing properly. M/S gear spacings are both fine with a +20 shift fork fitted. Frustratingly I think I need a -10 shift fork to get C/S 2-3 set right. I have a -20 in there and it's too wide. I have spares of -20,std,+10 & +20 but no -10 which I think would be perfect. So time to order one and wait patiently.
Big twin top hats ground down & fitted, hole drilled in case for new pin to catch M/S thrust washer ear. Have some 3.5mm stainless round bar coming, will cut that to length and fix it in with some Loctite 638 when it arrives.
Paul