17 replies to this topic

[Tomf]

Well iv been stripping down my engine and found out that it has had quite a bit of work done to it in the past, but when it comes to gearboxes i know nothing. So i was hoping that someone could help to tell me what it is. I know the pictures arent amazing as i had the camera on multi shot by accident and only found out when i got home lol.

But all the cogs are in very good condition with hardly any wear on them atall.

So can anyone help me to identify what sort of gear set I have? The engine cam out of a GT so im hoping that it’s a GT gear set, however as most of the rest of the engine is not standard, this might be a gearbox of a different engine or similar.

[Tomf]

BUMP anyone?

[ginigwunkle]

to me that looks std gears, have you counted the cogs on the cw/p?

i would at least have steam cleaned and a cpu.

you had the diff out to see if thats std?

[Tomf]

As i have said i have had no experience with gearboxes yet, so im not sure what the cw/p is... what is that? and ill count the cogs...

Also i havent had the diff, but i will defonately be taking this out as im going to have a go at converting it to pot joints from yoke type driveshafts... so i guess i have to take the drive shafts out whilst doing this.

[ginigwunkle]

sorry its the crown wheel and pinion - the big ones in the diff and the small one just into the box.

itll be something like 59/19 if you divide the bigger by the smaller you get the final drive ratio.



i would reccommend you get the mini expert, it goes through gearboxes, stripping rebuilding ratios and such like!

[Tom Sanderson]

As far as i know there are three different ratio's on the standard gearboxes the earlyiest and closest ratio has no lines on the gears, middle box has one line running around each gear and the latest and fastest box has two lines running around the gears however they are quite rare and it is unlikely to be this one. The cooper gearbow is different again, not sure on the ratio but i am sure it has fatter teeth to make the cogs stronger.

hope this helps.

[Sleepy Stu]

Guessworks is the man to speak to i believe!! Give him a shout he may be able to help!

[ginigwunkle]

there not the ratios sanderson they are the types of gears theres a and a+

theres about 5/6 different ratios from about 2.9 upto arround 4.1

the gearsets have different teeth on either the gears or layshaft

on the front of the housing there will be a number, probably 'dam'****(numbers) can you post that up?

[Tom Sanderson]

i was talking about the gears in the gearbox not the differential gears

[Tomf]

When you say the front of the housing do you mean the front of the gearbox casing? if so that number is: SM 22G1832 i think, well thats me reading it from a picture...

However i think the gear set in the casing is probably not standard to the casing as because these are fitted to an A+ block, but the drive shafts are yoke type drive shafts and im pretty sure these werent fitted to the a+ gearboxes... Thats the reason i asked really, ill get the diff out tomorrow if i get the time, but is there a way i can identify the gear set, i dont really fancy striping down the whole gearbox unless i really have to.

[Tomf]

Well i got the diff out today and they teeth work out as 62 and 17. So that works out at as a 3.647 final drive... was this the final drive that was fitted in the 1275 GT gearboxes?

Also how will this final rive effect the way the engine runs?

Edited by Tomf, 08 February 2008 - 02:24 PM.

[ginigwunkle]

i think its was 3.44 std in the gt

the 3.6 will give you better acceleration over the 3.44 with less top speed.....

[Guess-Works.com]

For starts it's an A series 4 synchro box.

3.6 was used on all sorts, does not necessarily mean it's originally a mini gearbox... but yes the 3.6 was an option on GT's 3.44 being the standard

there are only 2 helical gear ratios for this which are the Standard A series and the GT (cooper S)

The idenitifying feature of the GT is the presence of 22G1040 stamped into the laygear, if that's not there then count the teeth on the 1st motion shaft ( this is what you would thin is 4th gear ).... 17 teeth it's standard 18 its a GT.

[Tomf]

Cheers for that guesworks you always come up with the info i need when it comes to gearboxes.

Here are some pics of the diff:






Sorry me im an armature with gearboxes, could you do a little arrow pointing to the first gear so i can count the teeth, also could you point out the laygear.

Cheers for the help.

Also to convert this to pot joints doi just unbolt the diff so it all comes apart and spar the bits over for the pot join parts?

[Guess-Works.com]

count these teeth...

[attachment=49898:gt1stmotion.JPG]