3 replies to this topic

[andydlc]

Hi All,

After some information on a Jack Knight involute Dog gear kit..

How can you identify what the ratios of the gears are?? Are there codes or any way of finding out by counting teeth?

thanks and hope to find out soon!

Andrew

[Jammy]

I went through this a week or so back....

Basically need to count the teeth on the 1st motion gear, and its corresponding gear on the laygear, and then divide those by the teeth on the gears for whichever gear you want to know the ratio of.

Read the last few posts on this topic - Linky.

[andydlc]

thanks mate

[Dan]

Count the teeth, divide the number of teeth on the driven gear by the number of teeth on the driving gear. First you need to know the laygear ratio though so work out the ratio of the first motion shaft gear first and then multiply the individual gear ratios you calculate by the laygear ratio to get the final ratio for each speed gear. The laygear on these boxes may be 1:1 in which case you can ignore it. I assume you're trying to identify an old JK dog box that you have got second hand or something? You only need to work out the ratio of first gear as all three sets of ratios have a different first gear ratio, there are a couple of second gear ratios and third is always 1.195.

Easier still you could phone Jack Knight and ask them how many teeth you should expect to find on first for example or if there are other identifying marks. 0845 680 1952


Oh, beaten to it by Jammy.

Edited by Dan, 03 November 2007 - 11:48 AM.