b6.2 arms and gear diff on B4.1
 

back after a few years of not driving rc cars spare parts for the b4.1/b4.2 has become very hard to get. So I have following questions:

1. Do b6.2 gullwing arms fit on my old b4.1/b4.2?
2. does the new b6.2 gear diff fit the old b4.1/b4.2 diff box?

Any help is highly appreciated

Thanks,
Raimund

Hi mate I found the guys at mb models leeds very helpful for anything you require also bang on next day delivery

Isnt the B4 imperial? Guessing that may cause issues

The b4 is imperial yes but the b4.1/2 has metric outdrives.

I’d have to actually try and fit those parts to a b4 to confirm if they fit. I’d say not at first but always worth a shot.

Ok the arms kinda fit.
The hinge pins are a little slack and you’ll need to shim it out a little in and out.

I’m sorry I don’t have a gearbox to try a diff in but to run a b4.2 ball diff in a b6 you need a shim so I would assume it doesn’t fit the other way.

Great informations and thank you very much Big G for checking in detail! So gullwing arms are the way to go on my old B4.1/2 mixture :lol:

Arms aren't in particularly short supply, infact the UK distributor has some in stock :confused:
The B6 diff won't fit. (too wide)
There's a possibility that the b5 one may, but part supply isn't that plentiful on those either.
My advise would be to get some b4 parts for it and keep it original.

Good morning charlesk, thanks for your advice!
Found a really interesting article at RC10talk. https://www.rc10talk.com/viewtopic.php?t=44438
Seems that a guy fitted a b6 gear diff in a b4.1 transmission case. Another person also stated that the dimension of the b4.1 to b6 gear diff didn`t change. So I give it a try

well, I tried a b6.1 gear diff in my b4.1 and it does not fit! It`s about 1 to 1,5mm to wide. So it`s not a direct replacement!

All the best
Raimund

That would explain why the proper geared diff required a shim of similar size to fit in a b6.