zr1s10

My Feedback: (2)

Ok I've got an xtm .21 conversion kit, when I mount the motor up the end of the crank hits the tranny!! It doesnt look like a normal sg crank since it has a C clip on the end of it, but its not threaded all the way either.

I'm super confoosed [:@]

curtisMAXX

i have a xmt conversion on my truck and never had any problems with the motors. do you have a picture of your engine

ThunderbirdJunkie

My Feedback: (3)

use a normal T-maxx 2.5 clutch nut

fhm101

The 2.5 uses a non standard clutch nut so it won't work on any other SG style crank but the traxxas 2.5.

What you have is a standard SG crank which is somewhat longer than the traxxas version of a one piece crank. The way to get it to work is to first get a nut that will fit the crank, then grind the face of the nut until your clutch pack will fit and space correctly off the flywheel. I always take the nut down until a single .3mm clutch shim is needed to get the correct fit. Once you have this done, assemble the flywheel and clutch to the engine and put a .2mm and .3mm clutch shim on the crank so they rest on the front clutchbell bearing, and measure the distance from the top shim to the tip of the crank nose. This will be the amount of crank you will need to cut off. Before you cut the crank, make sure there will be enough thread depth left in the nose for at least 6mm of the M3 retaining bolt, and you will need to use a button head bolt instead of the usual cap head. It's best to cut the crank a bit long and then sneak up on the final dimension with a grinder. Check your fit often to avoid taking too much off. Once you have trimmed and squared your crank nose, assemble the clutch pack using only the .2mm shim out front and install the retaining washer and bolt as usual. This will give you the required .3mm of endplay in your clutch pack. After all this it may still rub on the transmission case, but it won't be enough to hurt anything and will "mill" out a tiny spot in the case the first time you run it.

If you don't have enough thread left in the crank nose to take a retaining bolt after it's cut, you can simply lop the crank off just ahead of the flywheel nut threads and use a pilot shaft nut. The nut you will need is available from OFNA, GS, or Kyosho. You may need to do a little fitting and grinding to get the nut snug to the flywheel and the clutch pack to sit right on the nut, but it can be made to work. I would only use this method as a last resort as I've had some very spotty luck using a pilot shaft nut on big block engines. They work OK, but I've seen enough of them break on big blocks that I would personally buy another engine rather than use a pilot shaft nut on a big block.