RC10Talk - The Net's Largest Vintage R/C Community

Since it is so slow in this section right now, thought I would post a video of us having fun. I have been busy testing the lower shock mounts for the JRX2 JRXT and was running a Novak Ballistic 8.5 with no slipper. I forgot to check the diff for slip. Picture of it is below, right out of the truck. Later we decided to see what it looked like inside but couldn't get things apart very easy.

[youtube]watch?v=-fmzHj263QU[/youtube]

I've melted a few of those over the years

Haven't melted one, just sheared off some teeth on a couple..

Shawn

I remember when the jr first came out with the original thrust bearing...lots of melted diffs. Everyone was using their diffs to try to control their traction problems.

I have melted a few just like that. mine were from running them to loose. they seem to run better very tight at least for me

This is actually the first time ever melted a diff down. I have had some get chewed up, but no melting. But then again I have always doubled checked how loose it was in the past. I guess this time I was just too excited to be testing the new parts and it slipped my mind.

Let me know if you need some gears I have a ton of the center gear nip and a few of the others used

I have also melted a diff gear. Not that badly! Just warm enough to rigidly seat the diff balls into the gear. I also recently bought an oval converted Jrx-2 with a mid motor setup of the LRM gearbox. Diff felt weird. After a rebuild and cleanup, I discovered that someone prior had also cooked the diff balls right into the diff gear. Its nice knowing that I'm not the only one.

Losi came out with a solution for this...it was called the XX trans

I personally have never cooked a LRM diff....but I've always used a slipper and kept the diff properly tightened.

I received a parts lot in the mail today. A bunch of Losi stuff - LXT stuff, wheels and tires... Anyway, among all the gearbox parts, was another diff gear, with all 12 balls melted right into it. This was either a more common issue than originally thought, or people are going a little too crazy with brushless in their vintage losi's. Good thing I have half a dozen gears in my stash.

I have a couple that had some heated driving, not enough to kill the diff but set the balls, as mentioned. Definitely a weak spot but not super fragile.

Also received a JRX2 with a melted diff today... not so bad luckily but main diff gear and balls are gone for sure.

Over the years I have also run into several diffs built incorrectly, with the conical thrust washers backwards or all the same direction or the thrust bearing washers in the wrong place, etc. I never thought about it as much as the melted diff gears, until tonight when I tore down another diff that was all goofed up. I never would have thought that there could be so many different interpretations of the instructions!

hondaman wrote:Haven't melted one, just sheared off some teeth on a couple..

Shawn

then you haven't tried hard enough

highwayracer wrote:I remember when the jr first came out with the original thrust bearing...lots of melted diffs. Everyone was using their diffs to try to control their traction problems.

yup, i melted one just like the one pictured running my jrx2 on a dirt oval in 1989, using the diff to control traction issues.

heven't melted one since i learned to use my finger as throttle control. lol