Kraton Kraton 4s v2 sloppy front end fixes

[neighborhater383ci]

I found my front end extremely loose which probably wouldn't bother a lot of people, but it drives me nuts to have such “variable” geometry up front being an automotive tech. On top of that slop is what breaks stuff, a lot more impact rather than smooth transfer of force. For the steering block to c hub slop I took the little metal bushings I found come in a granite boosts front steering knuckles and using drill bit same size as existing hole In the hub and cleaning it up, you can press the metal bushings in and it takes up almost all of the wobble there. For the tie rods/uppers you can probably just use a metal pivot balls but I chose a set with aluminum ends and bronze pivot “bushings”. For the servo saver I used a gpm tamiya style high torque aluminum saver, and it’s been doing great and you don’t have to lift the servo at all just sand a tiny tiny bit of plastic on the chassis where the linkage attaches to the servo saver itself. Still working on what to do about the lower control arms, haven’t tried but the same bushings from the 3s c hubs might work there too. The difference in predictability and feel in the front end is remarkable and worth the tinkering time

the only other thing I’d recommend is to use a wide head screw in the end of the axle so instead of the hub only having the cross pin attaching it, the wider head screw presses the hub against the cross pin and clamps it to the axle, noticeable difference there too

 

[pierre1111]

I know what you mean… another hobby is working on my 70s classics 1:1 cars. If there were any detectable wheel wobble I’d freak out.

I’m going to try your bushing trick on the hubs. The lower arms don’t have much “meat” to them for bushings. I thought about using washers there.

My suspension rod ends haven’t developed any play yet but I suspect it’s just a matter of time. Haven’t seen ones that nice before. Can you share a link or model number?

I’m going to try a hot racing aluminum servo saver. It comes with the mall aluminum with metal bushing rod that attaches between the servo saver and rack. That rod did develop play for me and I couldn’t find one that was sold separately from a saver.

 

[neighborhater383ci]

I found my front end extremely loose which probably wouldn't bother a lot of people, but it drives me nuts to have such “variable” geometry up front being an automotive tech. On top of that slop is what breaks stuff, a lot more impact rather than smooth transfer of force. For the steering block to c hub slop I took the little metal bushings I found come in a granite boosts front steering knuckles and using drill bit same size as existing hole In the hub and cleaning it up, you can press the metal bushings in and it takes up almost all of the wobble there. For the tie rods/uppers you can probably just use a metal pivot balls but I chose a set with aluminum ends and bronze pivot “bushings”. For the servo saver I used a gpm tamiya style high torque aluminum saver, and it’s been doing great and you don’t have to lift the servo at all just sand a tiny tiny bit of plastic on the chassis where the linkage attaches to the servo saver itself. Still working on what to do about the lower control arms, haven’t tried but the same bushings from the 3s c hubs might work there too. The difference in predictability and feel in the front end is remarkable and worth the tinkering time

View attachment 357377

View attachment 357378

the only other thing I’d recommend is to use a wide head screw in the end of the axle so instead of the hub only having the cross pin attaching it, the wider head screw presses the hub against the cross pin and clamps it to the axle, noticeable difference there too

I know what you mean… another hobby is working on my 70s classics 1:1 cars. If there were any detectable wheel wobble I’d freak out.

I’m going to try your bushing trick on the hubs. The lower arms don’t have much “meat” to them for bushings. I thought about using washers there.

My suspension rod ends haven’t developed any play yet but I suspect it’s just a matter of time. Haven’t seen ones that nice before. Can you share a link or model number?

I’m going to try a hot racing aluminum servo saver. It comes with the mall aluminum with metal bushing rod that attaches between the servo saver and rack. That rod did develop play for me and I couldn’t find one that was sold separately from a saver.

https://www.ebay.com/itm/2353639321...zPCpOy4RyO&var=&widget_ver=artemis&media=COPY


That is the link for the tie rods I have on there, and let me know how the servo saver works for you

 

[pierre1111]

Thanks for the link.

I just tried this. The block wouldn’t fit over the hub with the bushings in place. The thickness of the face of both or even one bushing was too much. I could force it on as the plastic had enough flex to spread but then it would take too much force to pivot and stress the servo. I dreamed the face of the bushings off - little fiddly but it worked.

Filing down the block in the two spots would work too but you’d have to be careful to not do it excessively and create slop between the two.

 

[pierre1111]

Also - what screws did you use for the hub>axle ? All the 3mm screws appear to have the same size head. Washers may work but the screw length becomes an issue so it’ll still reach the pin

 

[pierre1111]

I ended up with a screw and washer. The axle is a few mm shorter than the hub. I realized the screw doesn’t need to and probably shouldn’t touch the pin. The screw and washer will push the hub back and pull the axle forward, pinching the pin in place.

Genius idea man. I think it’s easier than fussing with shims and is 100% for this particular slip vs just mostly gone. I see they make flange head bolts this small. This is what I came up with locally though.

Only slop left is the rod ends. I have a set of those eBay finds coming.

 

[Glitch]

View attachment 358311
I ended up with a screw and washer. The axle is a few mm shorter than the hub. I realized the screw doesn’t need to and probably shouldn’t touch the pin. The screw and washer will push the hub back and pull the axle forward, pinching the pin in place.

Genius idea man. I think it’s easier than fussing with shims and is 100% for this particular slip vs just mostly gone. I see they make flange head bolts this small. This is what I came up with locally though.

Only slop left is the rod ends. I have a set of those eBay finds coming.

Are you using the stock screw that goes there?

 

[pierre1111]

Are you using the stock screw that goes there?

No. Stock screw at that point is a flat head with bevel in the back to match the bevel in the axle (it doesn’t touch the red hub).

I used a pan head - flat on the bottom - so it has full contact with the washer.

 

[neighborhater383ci]

Also - what screws did you use for the hub>axle ? All the 3mm screws appear to have the same size head. Washers may work but the screw length becomes an issue so it’ll still reach the pin

I used Traxxas style flat face screws and the screw doesn’t need to touch the pin inside the axle stub because the screw puts pressure on the wheel hub and therefore also puts pressure on the pin. Instead of the screw being a “set screw” it works more like a pinch screw clamping the hub to the axle via the pin. Also I just forced my steering knuckles on and used some wd40 and repetitive back and fourth steering to clearance

 

[pierre1111]

The traxxas 3931 screws worker well and didn’t have to fuss with a washer. Nice wide head that still let the wheel nut slip on.

Just got my link sets. How long have you had yours? I’m wondering about longevity…. I thought these were like normal rod ends. I didn’t see the o-rings in the pictures. Should be better than stock but could be better with true rod ends. Guess I was expecting too much for the price.

 

[neighborhater383ci]

The traxxas 3931 screws worker well and didn’t have to fuss with a washer. Nice wide head that still let the wheel nut slip on.

Just got my link sets. How long have you had yours? I’m wondering about longevity…. I thought these were like normal rod ends. I didn’t see the o-rings in the pictures. Should be better than stock but could be better with true rod ends. Guess I was expecting too much for the price.

Have had mine for a decent while and haven’t ran into any issues other than bending a few but that was after cartwheeling at 50-60 mph or so on pavement

 

[neighborhater383ci]

thinking about trying these link ends out with the factory turnbuckles to retain the larger m4 size.

https://www.ebay.com/itm/1749843123...ar=474133368830&widget_ver=artemis&media=COPY

Could use these turnbuckles and those links and make your own even beefier set. Just need to measure exact length needed
https://www.ebay.com/itm/1234866353...ar=424371687267&widget_ver=artemis&media=COPY

https://www.ebay.com/itm/1234866622...zPCpOy4RyO&var=&widget_ver=artemis&media=COPY

 

[Glitch]

thinking about trying these link ends out with the factory turnbuckles to retain the larger m4 size.

https://www.ebay.com/itm/1749843123...ar=474133368830&widget_ver=artemis&media=COPY

Could use these turnbuckles and those links and make your own even beefier set. Just need to measure exact length needed
https://www.ebay.com/itm/1234866353...ar=424371687267&widget_ver=artemis&media=COPY

https://www.ebay.com/itm/1234866622...zPCpOy4RyO&var=&widget_ver=artemis&media=COPY

What about 6s links? Would those work?

 

[neighborhater383ci]

What about 6s links? Would those work?

6s rear rod ends would work on the factory turnbuckles yes but it kinda defeats the purpose of what I’m trying to do which is have a super strong reliable and high tolerance fit.. the front tie rod ends and turnbuckles are m3 factory on the 6s trucks

Factory 6s tie rod on left factory 4s is installed on the 6s platform. If I’m correct I had to use the longest of the 4s tie rods there

 

[Glitch]

Hi all, wanted to follow up as I am still confused on this hub screw thing.

So AFAIK, the stock screw doesn’t hold the hex at all but it does push on the crosspin.
Are people using a screw that holds on the hex but NOT the crosspin? Or is it the perfect length to both hit the pin and tighten down onto the hex?

 

[pierre1111]

Notice that the axle sits behind the face of the hex by a few mm.

The inside of the axle is threaded. The stock screw has a narrow head - it does not touch the hex. It is long enough to touch the center of the pin and push the pin back towards the body. It has minimal affect on the hex as the hole in the hex that the pin slides through is bigger then the hole in the axle.

If you use a wide head (or screw with wide enough washer), it will touch the hex. Remember the axle is short and recessed in the hex. Once the screw touches the hex it will push the hex back and pull the axle forward. The hex will keep going back until it touches the pin, pinching it in place and securing it all tight.

Make sure you use a screw as long but no longer then the stock one. You do not want it touching the center of the pin in this case. Also do not use shims on the hex.