Hi all I’m on the hunt to try and fix my RR4 gearbox and struggling to find much, I’m finding many more RR6 RR7 gearboxes about. Does anyone know if this would fit straight into the RR4 as it looks the same but I’ve noticed part numbers appear different. Thanks in advance
AFAIK there is no difference between the two other than the colour of the side casing, which could explain the difference in P/N.
that is interesting, the cogs do have different part numbers too which is what’s stopping me ordering parts from the later box
I wasn't aware of that. Nobody has pickup up on anything about the gears being different other than the RR6/7 being 2 up on the rear sprocket.
The RR6 gearbox has undercut gears which the RR4 doesn’t is my recollection. Check number of teeth and thus ratios on the parts fiches
Oh ok, thanks for that, so on that basis the gears should be interchangeable between years the teeth are the same throughout the box
The opposite to be fair, you would have to change the whole gearbox as undercut dogs won’t work with normal cut dogs. But I think you’ll be able to swap boxes out ok. Another alternative would be to use Nova gears. They are brilliant. Much stronger than stock gears. I put a few in the NS after shearing a dog
As others have said they used different gears etc, but they are on the same shafts, bearings etc. I would be very surprised if the 06/07 didn’t bolt straight in but without having both engines in front of me it’s difficult to judge. If you can pick up a cheap 06/07 box it would be worth a punt, you can always resell it if it turns out to be incompatible.
