WR or CR gearbox?

[autograss_racer]

Had a look at my box today, trying to tell what it is - could only see serial numbers and F10 in big letters.
Where is it stamped?
And what models were each box fitted to? Would be nice to have a choice of boxes at each track.
I can only use F10/5, CR or WR

Thanks

Chris

[floydy13]

look at the gearbox end, there is a little lip and on it will say w 4.18
c 3.94 etc. might need a \wire brush to clean it off

[Novasport]

Would be a wide ratio box, dont think they did a close ratio F10.

[floydy13]

they did, ive just swapped my cluster and diff from a sr to a sri. both f10 but the sr was a w4.18 and the sri was a c3.94, makes alot of difference

[autograss_racer]

Thanks for the quick replies - I will have a little look for it I take it you mean its around the end near the passenger wheel with the input shaft screw? I'll take a closer look with the specs on :cool:

[floydy13]

yeah thats right look in behind the passenger wheel!, youve got the end cover, thats got about 9 bolts holding it on, then the cluster which will have a further 4. look under the end cover on the cluster!

[grasser26]

Hi-I don't know if it's a race car box or a road box but if it's for autograss racing and you're in class 2 double check your rules to see if you can swap between boxes.If you do a search on here there's a guide on doing a cluster change and a link in the guide to the various ratios/diffs.Another thing to look for if you have the diff cover plate off it to check the crownwheel for notches-

6 Notch 3.5
5 Notch 3.7
3 Notch 3.94
0 Notch 4.18
2 Notch 4.5

As above though it's easiest to check the end plate for a "w" or "c" and the numbers