Cougar347

Hello guys, newbie here. Just getting started in electric on road racing. I figured I'd get my feet wet with something that wouldn't break the bank, so I decided to purchase a RJ Speed Legends car. The club that I will be racing with has a Legends class, I thought this would be a good way to get started and have some fun.
I'm having problems with the front suspension and I'm hoping that someone here can tell me what might be wrong.
It's a very basic front suspension system consisting of kingpins and axle shafts. The kit comes with all the pieces, including the kingpins, axle shafts and the corresponding nuts and lock nuts to assemble everything. As soon as I started putting the kingpins together, I knew something was wrong. The nuts didn't thread on the shaft more than a couple of threads. The shafts and nuts are "supposed" to have 5-40 threads. When I put the nuts on one of the 5-40 screws that come with the kit, they go on fine. When I hold the kingpin threads up against the 5-40 screw threads, they look identical to my naked eye. I was able to get one of the nuts threaded part way onto the kingpin and then it stripped. It never felt right, I had to force it and I know you shouldn't have to do that. Now it won't go on, can't get it off.

I apologize for coming on here, first posting and hand over a problem. I'm hoping to be able to contribute more meaningful stuff as I get more experience. If anyone can help me troubleshoot this problem, I would really appreciate it. I'm kind of stuck, I can't do anything until I figure this problem out. I'm hoping someone on here has built one of these cars and can tell me what I'm not seeing, or do I just have poorly threaded kingpins and axles?

Thanks guys.

Nerobro

iTrader: (2)

Yeah. You might have gotten a bad nut, or maybe a bad kingpin. But if I were to guess... they're not wide nuts, and the lead in can be a little funny. I bet it started off cross threaded and you forced your way through it.

Drop RJ speed an e-mail. The e-mail address is [email protected] I'm sure they'll respond fairly quickly. RJ speed isn't the powerhouse company Bolink used to be, i'm sure they're not a 40 hour a week occupation for the people that remain.

The site says they're made in the USA. They're a small company, they're making the best they can of it.

The legends are "old" technology. I believe they were an offshoot of the digger project.. Or is it the other way around? Either way the kit has been since 94 or so. It'll be fun if you can find something new with the kit. Though.. having someone out there collecting the last 20 years of knowledge would be awesome. (Documenting things is something the RC community is really bad about)

In case you want to "just get things going" Replacement kingpin sets are $5 at tower. https://www.towerhobbies.com/cgi-bin/wti0001p?&I=RJSC5377&P=FR&gclid=Cj0KCQjwmPPYBRCgAR IsALOziANlMB_qSKxZeb6NYgHxQ7z28soxRY-eOwUb4G7s9rPderVgPLHFrPkaAtAjEALw_wcB

the rc guy

this happens in our hobby. either get a thread chaser or die, and use it or you might try new nuts of correct thread count.
if it was me ld use 1 of my thread chasers.

Nerobro

iTrader: (2)

It's probably a better idea to just get replacement parts. ;-) Don't buy cheap dies or taps.

Cougar347

Hey guys, thank you for your quick response, much appreciated.

I also sent an email to RJ Speed last night, I wasn't sure how quickly they would get back to me, thus my reason for reaching out to this forum.

Rick from RJ responded to me during the night (wow, Sunday evening, talk about great customer service). He explained that the tolerances on these parts were very tight and both were made of stainless steel. Perhaps I just got some bad threads, I don't think I cross threaded it.

He offered to send me replacement parts ASAP, I'm very impressed with RJ Speed. I hope to have this car on the track in no time. Thanks for your help.

I guess while I'm on here I might as well double down. Does anyone have any tips on setting up the RJ differential, or should I just put it together the way they recommend and go run it? It seems that this is the secret to getting the power to the ground, if there are any ways to make it more effective, I'm all ears.

Thanks again.

AHR43

Hello Coug. Welcome to the hobby and the forum.

I've bolded in quoting you what may be an additional issue. I try never to use stainless on stainless as a fastener combination. They tend to seize together during assembly. Options are to use the tiniest dab of 'Never-Seize' or comparable anti-seize compound. Or, use a dis-similar fastener combination, such as carbon steel to stainless, or aluminum to stainless. Either way will prevent thread seize during assembly.

You've started in the hobby with a classic kit. Even if you upgrade later, hang onto that RJ / Bo-Link. Its a fun car. Good luck. AC

Nerobro

iTrader: (2)

wow, I didn't know those parts were SS. I... last built a Bolink car in 92 or 93. My kingpins went together well. At least I remembered them going together without a hitch. :-) ... I think i'm getting old.

ASM

iTrader: (30)

Building a smooth diff does require some practice. Finding some good diff lube can really help. If you'll PM me your address, I'll send you some that I have (which I used to sell some years back). The course thread on the axle makes it trial and error to get it set just right but you'll get it. There's lots of little tricks that add up, it's just how much time you want to spend on it....considering the class.

Also, on a Legends car, you want to keep the chassis screws just a touch loose. This builds in flex and helps the car get through the corners.

the rc guy

dies aren't cheap.live n learn
build diff as rj manual says

biz77

iTrader: (47)

Depending on which spur gear they included in the kit you may or may not need to use a prop reamer to make sure the spur spins freely on the shaft since it does not ride on a ball bearing like all other modern pan car spur gears do. If it spins freely you are good to go. The kit comes with six diff balls IIRC. I like to run all 12 if you are allowed per your club's rules.