ChitownRC

Some of the guys at LHR had 1/8 buggy clutches on their Revos.

My Revo 3.3 ate 2 already with no signs of cause.

I know the bell gear and spur pitch is different on the buggies so I would need the clutchbell and the spur gear.

Couldn't find the parts on Google.

PM or post any info.....

You won't need a new spur gear. All you have to do is move the tranny up forward and put the 1/8 clutch on there.

Well, I owned a t-maxx 3 years ago or so and I always had clutch slipping issues. Especially once I went big block. Constantly frying shoes, breaking springs, overheating the bell and ruining bearings... It just got old. Then I bought a savage, installed a 3-shoe and ran it for over 10 gallons without doing anything to the clutch other than replacing a set of bearings. I also would sand the gloss off the shoes every gallon or so.

Then I got a revo... back to the crappy traxxas clutch again. I've only run about 1.5 gallons through it total. 1/2 gallon with the 2.5R, about a gallon with my os 18. Busted the spring last weekend, which in turn marred the bell and messed up the shoes. Yay...

I noticed someone had posted on another forum about using a 1/8 clutch. So, since I had an extra 3 shoe savage clutch and a 15T bell laying around, I figured I'd give it a shot.

I only had to move the trans about 3mm-4mm forward. I drilled a set of holes in front of each trans bolt, dremelled into a smooth slot to the old hole, dremelled about a quarter inch off the chassis by the brakes so it could slide forward, drilled/tapped a couple new holes in the trans case flange to keep the trans from sliding backward (extra insurance) and re-did my brake linkage. On the engine, I just had to make a shoulder bolt out of a 3mm bolt and nut to gain the extra 1/8 inch needed for the CB to ride on.

Now I have a 1/8 scale clutch on it. I also now know how much power the TM really has!

However, the TM apparently idles a bit higher than a BB, so the clutch engages way too early. I drilled a hole in each shoe tonight to lighten the shoes a bit so it will engage later. I'm just hoping I didn't get too aggressive.

Sorry for prattling on... Here are some pics:

This is without moving the trans just to see how far I had to move it:


I also had to grind a bit off the throttle servo box:


You can see my extra bolts near the center of the trans:


A photo from the top so you can see how much I had to move it from a different angle:


And, the holes I drilled in the shoes:


I do know from today that it's faster on the top end, which means the old clutch slipped when in second gear. I geared down a little bit from 36/15 to 38/15 to try and keep the top speed a bit closer to my liking.

BTW, I need to remove more material from the shoes, it still engages too early for my taste. It's better than it was, but still really low in the RPM's.

This is on a 2.5 chassis revo with a OS 18TM.
These are the extra parts I used: OFNA Bell, Savage flywheel/Shoes

The t-maxx and other 1/10 nitro's have different gear pitch than buggies and 1/8 scale. The revo has the same pitch as buggies and 1/8 scale.

Exactly what I needed to know!! No spur gear needed in the conversion. I don't know what it is with this Revo. 3 clutches after taking it out of the box and still trouble.

[attachment=673]
Lost about 3mm of material

[attachment=674]
All this stuff isn't oil and will be hard to remove

No drive train problems or over gearing either. No real know cause of all this wear.


Did you run into any issues of the holes not being right in line and having the transmission slightly twisted? Bad for your spur gears.

There are a lot of different spring rates sold for 1/8 buggies all of which will fit the Savage setup. Higher stall, or lower. Any hobby shop shouldl have them. 1.0 is pretty much a medium spring. A 1.1 is much stiffer causing a big increase in RPMs before engagement. The Savage springs are probably lighter than a 1.0. I would think a 1.0 would be what you need. You may need to experiment until you get it right were you need it.

I think savage springs are real light, like .7 or something.

olds, you need to swap the clutch springs out to some fresh 1.0 and your early enguaging clutch will function normal.

Marke, you are a good fabricator, this is cake for you. Oh and I noticed if you click on your pics they are bigger

NitroNuisance Wrote:Did you run into any issues of the holes not being right in line and having the transmission slightly twisted? Bad for your spur gears.

I just made sure to have it straight before tightening things down and drilling the holes for the holder bolts.

Tex Wrote:olds, you need to swap the clutch springs out to some fresh 1.0 and your early enguaging clutch will function normal.

You don't happen to have a link do you? I tried tower and it comes up with a few different sets, but I'm not sure which to use.

After seeing these shoes I am ready for the conversion - Just need to get the parts.

Funny thing is my Tmaxx had a Savage .25 motor in it with the stock Tmaxx clutch set-up (steel spur) and those shoes lasted over 6 months witout any trouble???????

FWIW, you were running that .25 way rich everytime I saw it running

Olds, the mugen 1.0 springs were the ones I always used. They last a long time.

What's FWIW tex? From what I watched? IDK

FWIW = "For what it's worth" I believe.

Hey Tex, do you mean these: http://www2.towerhobbies.com/cgi-bin/wti...LXNJ81&P=7

Never really got it very hot, your right. But after 7 gallons I can still barley turn it over from the flywheel.

damn that's good engine life Marke, but it's no fun when you don't drive it like it's stolen...lol

olds, yep those are them.