Arrma compatibility between 3s and 4s models

[quiznatodd bidness]

I’ve been researching a bit on what parts I can pull from jennysrc 4s kraton/outcast to upgrade my 3s granite. I already am closely watching the differentials and pinions (new ones are metal-crowned on the 4s) for when they’re in stock, but it looks like I could put the kraton center diff gear as the spur on my granite. Is that correct? Any other parts you guys know are backwards compatible?

 

[GraniteFox]

Correct, the motor mount and spur/slipper will bolt right on. Diffs and input gears are good to go as well. Motor and ESC if you are interested in 4s. That's about it.

 

[quiznatodd bidness]

Good to know, thanks.
Looks like the drive shafts and steering are totally different sizes, unfortunately.

 

[Velodromed]

Good to know, thanks.
Looks like the drive shafts and steering are totally different sizes, unfortunately.

Steering bell crank/servo saver is the same. The hubs, arms, turnbuckles are very different. Towers as well, taller and made to fit sway bars on. The center drive shaft is longer on both 4s models.

 

[quiznatodd bidness]

I was wondering about the steering. Is that better quality stuff? The 3s stuff is not great.

 

[Velodromed]

I was wondering about the steering. Is that better quality stuff? The 3s stuff is not great.

It’s the same bellcrank and servo saver as the 3s line. I picked up one of these alloy bellcranks a couple of months ago and absolutely love it, so I just got another one. They’re on sale right now.

You can always remove the S651 servo that comes with the 3S cars and put in a S652 that comes on the 6s and 4s cars ($19 on Jenny’s). I have it and four cars right now and haven’t had one in fail in over a year. It also works with the goofy Arrma 23T servo saver. I bought a bunch of several steering assemblies (bellcrank, link and servo saver) off Jennysrc.com for a couple bucks each and swap them out whenever steering suffers.

GLOBACT Aluminum Alloy Steering Bellcrank and Steering Link, with Ball Bearing Upgrade Parts Set for 1/10 Arrma Senton 4X4 Granite 4X4 Typhon 4X4 Kraton 4X4 Big Rock 4X4 Replaces AR340132 (Red) https://a.co/d/2MlwItF

 

[quiznatodd bidness]

Ha yeah that’s the bellcrank I got a couple months ago. I had to grind down the top of that first pivot point because it hits the servo when it turns.

Do you know off the top of your head what the strength of the S652 is?

Do you have a preference on the servo saver, or do you always keep that as stock?

 

[Velodromed]

Ha yeah that’s the bellcrank I got a couple months ago. I had to grind down the top of that first pivot point because it hits the servo when it turns.

Do you know off the top of your head what the strength of the S652 is?

Do you have a preference on the servo saver, or do you always keep that as stock?

Something may be installed wrong because it should not hit the servo when it turns. When you get a chance post a picture of the linkage. I don’t know what the s652 is off the top of my head. I just know that it works good enough. And yes, I stick with the stock servo saver and change them out every few months or so. I’ve tried th hot racing servo saver and the Kimbrough 124. Both of them failed me after a bit, so I just stick with stock. For two bucks for the whole steering assembly off of Jenny’s it’s easy to get a whole bunch of them.

 

[quiznatodd bidness]

The issue is almost certainly that the hobby store sold me this :https://www.amazon.com/Hot-Racing-S...32162&sprefix=hot+racing+servo,aps,491&sr=8-2

Instead of the direct replacement one. I decided to shave off the ears and make it work, but I don’t know what other dimensions may slightly different. I also had to use a nut and bolt for the non-threaded holes. So between the Amazon servo and the slightly incorrect saver, I had to mess around for a while shimming things to make it line up and give me full range of motion.

 

[Velodromed]

The issue is almost certainly that the hobby store sold me this :https://www.amazon.com/Hot-Racing-S...32162&sprefix=hot+racing+servo,aps,491&sr=8-2

Instead of the direct replacement one. I decided to shave off the ears and make it work, but I don’t know what other dimensions may slightly different. I also had to use a nut and bolt for the non-threaded holes. So between the Amazon servo and the slightly incorrect saver, I had to mess around for a while shimming things to make it line up and give me full range of motion.

OK, that makes sense. Man, I hear more stories about hobby shops giving new RC enthusiasts bum information. Pretty lame. Very good that you figured it out though.