HB diffs on a JAMMIN crt - RC-Monster Forums

rchippie · **HB diffs on a JAMMIN crt -** 12.29.2007, 10:18 PM

Which parts are needed & what are the advantages ?.

squeeforever · 12.29.2007, 10:21 PM

I think all you need is the ring and pinions, but the advantages are a lower gear ratio, so you can go with a smaller spur and lower the diff (using CR buggy diff mounts and/or RC-M motor mount depending on your motor mount setup). So basically, lower center of gravity, less rotating mass, and helical cut gears.

rchippie · 10:31 PM

Quote:

Originally Posted by squeeforever

I think all you need is the ring and pinions, but the advantages are a lower gear ratio, so you can go with a smaller spur and lower the diff (using CR buggy diff mounts and/or RC-M motor mount depending on your motor mount setup). So basically, lower center of gravity, less rotating mass, and helical cut gears.

My bad i meant part #'s.

Are this the right ones ?.

http://www3.towerhobbies.com/cgi-bin...?&I=LXJBM4&P=7
http://www3.towerhobbies.com/cgi-bin...?&I=LXJBM3&P=7

squeeforever · 12.29.2007, 11:03 PM

You'll need those, shims (naturally), as well as these (lowers the center diff), this (different front the CR to the CRT, because the CRT has the larger spur which would hit the buggy one), and a Kyosho spur, which I assume you have already. If your using Mikes mount, your gonna have to get the buggy one to lower the center diff. Now, some of this is based on the fact that its brushless, which I would assume it is...

rchippie · 12.29.2007, 11:22 PM

Quote:

Originally Posted by squeeforever

You'll need those, shims (naturally), as well as these (lowers the center diff), this (different front the CR to the CRT, because the CRT has the larger spur which would hit the buggy one), and a Kyosho spur, which I assume you have already. If your using Mikes mount, your gonna have to get the buggy one to lower the center diff. Now, some of this is based on the fact that its brushless, which I would assume it is...

Yes it's BRUSHELESS. I would be using mikes buggy mount . I forgot about the shims, thank's for the reminder

. The plastic mount i new i would need one & the diff plate i may just make one & incorperate a ESC mount into itjust like dans.

squeeforever · 12.30.2007, 01:21 AM

While your ordering parts, you might wanna get a set of diff gaskets and o-rings.

nl12 · 11:02 AM

I have done the conversion to those gears in my crt. Those are the right parts, you will have to shorten the pinions for it to work, it is not difficult with a dremel cutoff wheel just dont overheat the pinion because it is hardened. You can use your same diff top plates and plastic mounts on the other side of the diff, you just need new CR diff posts; I would recomend the aluminum ones to save more weight. I would use a kyosho plastic spur but there is also a good selection of good steel ones. The advantage is saved weight, lower CG, the CR setup is stiffer, better gearing options.

Here are the posts you need:
https://www.carolinasrc.com/Webstore...idproduct=2235

I am 99% sure you will not need the 2 parts that squee linked to, the posts are the thing that lowers the center diff and there are spacers at the top on the CRT so they both use the same diff brace.

squeeforever · 02:14 PM

So the CR and CRT has the same diff holders just the post are different? I wasn't 100% positive, but at Amain, it said the center diff mount was for the buggies and nothing about the truggies but I see its listed under the CRT parts now. You'll need these like nl12 said. The post for the CRT have the spacer on top instead of a new top plate as well. Sorry, I was wrong.

rchippie · 12.30.2007, 06:49 PM

Quote:

Originally Posted by nl12

I have done the conversion to those gears in my crt. Those are the right parts, you will have to shorten the pinions for it to work, it is not difficult with a dremel cutoff wheel just dont overheat the pinion because it is hardened. You can use your same diff top plates and plastic mounts on the other side of the diff, you just need new CR diff posts; I would recomend the aluminum ones to save more weight. I would use a kyosho plastic spur but there is also a good selection of good steel ones. The advantage is saved weight, lower CG, the CR setup is stiffer, better gearing options.

Here are the posts you need:
https://www.carolinasrc.com/Webstore...idproduct=2235

I am 99% sure you will not need the 2 parts that squee linked to, the posts are the thing that lowers the center diff and there are spacers at the top on the CRT so they both use the same diff brace.

how much do you have to cut off ?.

nl12 · 12.30.2007, 08:22 PM

I cut just a little bit off, I cut the end part off that is not machined for a set screw if I were to do it again I would cut a little bit more off, probably 1.5mm more. You just want the driveshaft to seat all the way on the pinion so it doesnt bind up your center diff and allow the pinion to be pushed into the front and rear diff cases. Also because the gears are spiral cut they will tend to pull or push the pinion depending which way you install them I found one way worked better than the other, I will try to get a picture of the way I installed them.