3 replies to this topic

[Astbury112]

Is there a sum to work out the ratio of each gear in a box, I have a dam5626 and a dam 2886 I only need to know about 1st and 2Nd gears.
In the 5626 they are 1st: 31/26 2Nd: 20/15 in the 2886 they are 1st: 31/26 2Nd: 21/15

[Anthony30]

Ask guessworks.

[Swift_General]

You need to know the number of teeth on the gear on the first motion (input shaft), the teeth on the laygear where it meshes, then the number of teeth on the relevant gear (1st/2nd etc) and the number of teeth on the laygear where that gear meshes.

Then:

Divide laygear teeth by first motion teeth. (This value will always be the same for any given gearbox regardless of what gear is selected).

Divide gear teeth by laygear teeth. (This value will vary depending on what gear is selected).

Multiply the 2 answers together and you have your gear ratio. For example if the answer were 2.7 then for every 2.7 turns of the input shaft, the main shaft will turn once.

Remember 4th gear is always 1:1 regardless of the gear set fitted.

Obviously if you wanted the overall ratio taking account of the diff then you would multiply by the diff ratio (and factor in any ratio on the drop gears if they were not 1:1).

Edited by Swift_General, 20 May 2016 - 07:19 PM.

[Spider]

There's a bit of confusion in your tooth counts there. Can you get the P/Ns from the Laygears or look at the teeth for markings across the tips of them?