15 replies to this topic

[TehMarchant]

So I bought a SC gear set last year and have only just now actually had a look at them.

 

Please have a look at Second, *I think* and let me know if its FUBARD!

 

Ryan

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Edited by TehMarchant, 15 March 2016 - 10:50 PM.

[Dusky]

I wouldn't reuse that

[MIGLIACARS]

fit only for the bin

[MRA]

Are the others like that also ? 

 

Becareful about buying a replacement as it may not be the same gear tooth form (CP, DP or MOD) or size so will need careful checking to get it a replacement, I can help you with this if you need.

[MRA]

fit only for the bin

or a photo shoot .... like your avatar

[ACDodd]

Toast.

Ac

[MIGLIACARS]

 

fit only for the bin

or a photo shoot .... like your avatar

 

yeah that was an expensive do!!!!!!!!!

make a guess which part of the mini gearbox that was!!!!

[MRA]

 

 

fit only for the bin

or a photo shoot .... like your avatar

 

yeah that was an expensive do!!!!!!!!!

make a guess which part of the mini gearbox that was!!!!

 

It looks like a 1st/2nd synchro hub, inner and outer the outer yeeth are too big and the wrong shape to only be  the inner part.

 

Unless it is from a set of SC drops for an automatic.....

Edited by MRA, 17 March 2016 - 01:36 PM.

[jaydee]

Looks like the wrong spec baulkrings were fitted in the past on that SC set

[MIGLIACARS]

 

 

 

fit only for the bin

or a photo shoot .... like your avatar

 

yeah that was an expensive do!!!!!!!!!

make a guess which part of the mini gearbox that was!!!!

 

It looks like a 1st/2nd synchro hub, inner and outer the outer yeeth are too big and the wrong shape to only be  the inner part.

 

Unless it is from a set of SC drops for an automatic.....

 

 

 

That gear in bits in my photo is what remains of a 4th/input gear/drive gear from a full race MBE dogbox.  The rest of the gear were spread thoughout the engine and all over the track at oulton park.

[TehMarchant]

Thanks for the help guys I forgot to follow the topic, I haven't currently this month got the money to buy replacements but I am keen to know where to look. Can I just count the ratios or is there another way to find replacements? 

[MRA]

Thanks for the help guys I forgot to follow the topic, I haven't currently this month got the money to buy replacements but I am keen to know where to look. Can I just count the ratios or is there another way to find replacements? 

 

It's not as simple as that, if you have a gear tooth profiler then it is ......     or if you are really lucky and the gears have part numbers ot other distinguishing features.

 

A cheat way of doing it is to roll the gears together and then if smooth fit them in your gearbox and measure the gap between teeth on opposing gears....  but I stress this could very easily end in tears, very expensive tears

[MIGLIACARS]

buy a brand new set it will prob be easier and cheaper in the long run

[TehMarchant]

Well I am tempted to buy a new set but I spent 250 on these. 

 

Numbers are as follow

 

1st 26265                                                                                               29 teeth    1.93:1

2nd K75                                                                                                 25 teeth    1.13:1

3rd Couldn't see the number without getting the detents out.                        22 teeth    0.95:1     

4th 26259/2                                                                                            19 teeth     0.88:1

 

Lay gear was hand engraved, either 21d or p18 Photo attached.             15, 19, 23 and 25 teeth

 

Would I also be correct saying the ratios are what is stated?

 

 

Thanks for the help.

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Edited by TehMarchant, 20 March 2016 - 10:57 AM.

[MRA]

I know who makes your gears and should be able to get replacements for you.

 

 

Also your calcs above have only been partially finished you now have to multiply through the "compound" gear set...

 

4th is direct and would work without the laygear being fitted, however the teeth on the input gear (19) drives your laygear (25)

 

As the formula is driven / driver = 25/19 = 1.316 (we will use this later)

 

1st ratio between lay and 1st gear = 29/15 = 1.933

2nd ............................................... = 25/19 = 1.316

3rd................................................. = 22/23 = 0.957

 

Now the answer we got first comes in to play...

 

Driven1/driver1*driven2/driver2

 

1st = 1.316*1.933 = 2.54:1

2nd = 1.316*1.316 = 1.73:1

3rd = 1.316*0.957 = 1.26:1

4th = 1*1               = 1:1