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

Howdy,

Just picked up a Jrx-2. It is the first Losi rig I've owned. Diff was melty, shocks are leaky, little bit of light rust on some screws / E-clips here and there with a few alternative assembly "tool" marks on some of the parts and barely a scuff on the rear chassis edge. Looks like it was built and ran until the diff got melted, probably once maybe.

Any tips or suggestions as far as essential upgrades or "diff tips", etc. Or anything else you folks are doing with your buggies to keep them in the light runner status. I might shelf it later, but I ain't never ran no Jrx-2, so I'm going to set it up a bit and run it here and there first.

If you respond with "go mine the forum, a-hole", I will totally understand. Hahahaha.

Mark

You can upgrade to the ball bearing differential. There is a thread going right now that will link you to relative information. Not easy to find the odd thin bearings but can be done. Some guy on Ebay right now is selling original thorp aluminum gear sets with no labels for $20.

For general bashing around though just get some stock parts from the Ebay and build it right. New thrust bearing with black grease, carbide or ceramic balls in the diff with some good lube of your choice and most importantly don't use it as a slipper clutch and run it too loose. Beyond that the LRM tranny in the X2 is quite capable and strong even by today's standards.

"Essential upgrades" I guess would depend on your need. Stronger front A-arms (RPM,can be harder to find), do you intend to run original 5 link or is the car an H-Arm variant? Upgraded steering bell cranks and on and on like any other car here. But do recall Jack Johnson threw an essentially bone stock JrxT on the track back in the day and won the nationals, so it's quite capable as is.

Leaky shocks, melted diff, all sounds about right.

He's got a TRX1, he should be used to breakage

knixdad wrote:Leaky shocks, melted diff, all sounds about right.

X2. I think the most essential part is to ensure that you have the diff adjusted properly. I've acquired way too many LRMs with melted diff gears. I melted one myself BITD, so I'm guilty too. And as stated, the Jrx2 is a very capable car. I have a runner that is all stock with a Reedy Mr. modified in it. What a blast it is.

So pretty sure my Dirt Burners are in at the PO along with some Andy's front arms. As far as the diff rebuild, I was just gonna flip the rings and wet sand them with some billion grit and use some new 3/32 balls, thrust washer(s) don't look bad so was reusing those and the balls. But the Bellville springs, should I reuse these. Thought I saw an SE diff with a thrust spring instead at some point. If it is just dead nuts adjusting, then I think I can handle it. Any suggestions?

Mark

I recently found a diff with a spring type adjustment on the diff. Consensus is a home brew. I'd look closely at bellvilles and if they are still concave reuse them making sure you get in the right order. That's the biggest mistake I see when I have taken apart ebay cars, either they are in the wrong order or missing all together.

If you're just building a light runner as you stated building the diff as the manual shows it with good old stock parts will work just fine. Contrary to internet folklore they don't melt down if you look at them wrong. Only TRX1 parts do that

I also just built a box with a mixture of center Thorp diff gear and stock losi outer differential gears. I don't have more than one battery pack on it but its working fine mix and matched.

I do not put any lube actually on the LRM gears.

Ah hahahahahaha,

So I rebuilt the diff with off the shelf hardware store 3/32" chrome balls and the Thorp gears. Tore it all down, cleaned it up, put some 15W-40 SYN API CJ-4 in the shocks, put an S&K Torque II in it along with Futaba MC 112B ESC, FP-R102JE Rx / Magnum Sport Tx, and FP-S148 Servo. Even built and soldered up a little tin ESC shelf ala RC Car Action Pit Tips. And now I don't want to run it. Ha Ha Ha Ha.

But it all works and throttles up. So tempting.

Mark

Sounds grreat. Let's see some pics please!

RCveteran wrote:Sounds grreat. Let's see some pics please!

Well there are some pics. This thing was pretty clean when I got it. Thanks Limestang.

I am missing the spur gear E-clip because the Thorp topshaft runs one more than the stock and it is in the gearbox. So I guess it's not missing. More properly; I am deficient one crucial powertrain E-clip.

Mark

Somebody is gonna be like "duh". But I just lashed a pair of world's car rere front wheels directly to this thing. A buddy of mine gave me a pair of nip bright yellow-green "Team Losi" rears. Wonder if a guy could print some "Team Losi" circle transparent disc decals and slam them on the world's fronts to match.

Looks great. You clearly need to spend more time over here.

Hey thanks. I probably will. I won't expand, I'll just continue to dote over this thing with additional hop ups, etc. over time. Still need a body. I am hacking up a hacked up B3 body as time permits, making room for the 5 link and posts. Need to find the Dremel. Although TBG has an underpan, body, gear cover for a reasonable price. Anyone familiar with the fitment of these items? Or I could go SabulaTech?

And thanks for the help.

Mark

I've used TBG with no issues. Haven't used sabula tech body plenty of other items from him that are top notch. Check out advertising section here if you want to talk direcrly. He usually gets back within a few days.

TBG works fine. The undertray requires a bit of finesse around the 5 link, but it looks fine and functions well, too. Just in case you do drive it.