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Feb 17, 2021, 10:45 AM
Registered User
hey guys,

i had a very nasty front diff, and just ordered a kyosho diff to put in , after reading it would be a simple swap.
well the stub on one side do not fit in (the longer stub) the diff housing, so i am playing with mixing and matching parts, but they do not seem to play together nice at all, and most parts will not work.

any ideas?
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Feb 17, 2021, 11:02 AM
Low budget fun
Beaver_XT's Avatar
You'll need long universal shafts/CVD "27mm" to make Mini-Z diffs work. You can find them on Aliexpress. I've got a lot of report that now Banggood has changed its stock and their 27mm isn't the correct size anymore.
https://www.aliexpress.com/item/1005001865504882.html
Feb 19, 2021, 10:42 PM
Registered User
Quote:
Originally Posted by Beaver_XT
You'll need long universal shafts/CVD "27mm" to make Mini-Z diffs work. You can find them on Aliexpress. I've got a lot of report that now Banggood has changed its stock and their 27mm isn't the correct size anymore.
https://www.aliexpress.com/item/1005001865504882.html
so im not terribly interested in spending much more on this little guy, and since buying axles (that might not work) falls into that category, I would like to see if anyone can assist in fixing my current diff.

the spider gears are not hitting the ring gears very well, from the looks of it just the edges are barely touching. so it usually results in a non functioning diff, and 2wd.
tonight i tried shaving plastic down in a few places with no resolution, and comparing to the other diff i cannot see any issues.

any ideas on what/where i need to shave to get contact?
Feb 20, 2021, 05:25 AM
Low budget fun
Beaver_XT's Avatar
Check the plastic plate that house the spider gears. If that plate has some excess plastic they gears won't make contact.
Feb 20, 2021, 05:13 PM
Registered User
Quote:
Originally Posted by Beaver_XT
Check the plastic plate that house the spider gears. If that plate has some excess plastic they gears won't make contact.
ive gone over the center part, and the channel it sits into on both sides of the housing 3-4 times now trying to clear this issue up.
so which part is the best one to shave down to fix this?

the center plastic, the stubs that the screws go into, or both?
Feb 22, 2021, 01:06 AM
Low budget fun
Beaver_XT's Avatar
Check only the edge of that plate. If that still doesn't work then I'm afraid it's a write off. You'll have to lock it of you want to continue using it.
Mar 02, 2021, 12:13 PM
Jimmy2609

K989 drift


Hi this thread is a wealth of info, I’ve finally finished reading this front to backup took me weeks lol ��
I’ve had my K989 3 weeks now I’ve done the following mod’s locked rear diff, moved steering arm up to top of steering servo arm, 5grams of weight up the front mini z wheels with ds racing LF-4, it’s drifting pretty well too! (On laminate floor)
I would like know what you guys recommend to make the K989 a better drifter, I would like to upgrade the Tx & Rx I would also need a ECS right? What about adding gyro would that help me? Is there a better or upgrade motor to? I going to to do the other steering Mod like adjustable steering arm and new servo too! Thank you in advance.
Mar 03, 2021, 01:27 AM
Low budget fun
Beaver_XT's Avatar
Upgrade the Tx & Rx will have the biggest effect. Yes, you'll need an ESC too.
Adjustable steering arm & servo will also help a lot.
Upgrading motor is not that big of deal, the stock one is plenty fast enough.
Mar 03, 2021, 11:13 AM
Jimmy2609
Thanks beaver-XT for the reply could you recommend a Tx, Rx, Esc and servo for me. What about a gyro? Also I have watched so many of your videos they are a great source of info to thanks.
Mar 03, 2021, 05:37 PM
Low budget fun
Beaver_XT's Avatar
Tx & Rx: Radiolink RC4GS, the best if budget category. If you want to buy once and use forever then Flysky Noble NB4 or Sanwa MT-S. They are both mid-range racing grade radios. The latter one is on discount right now in RCmart.com. I'm not sure if the shipping cost would worth it though.
RC4GS: https://bit.ly/30Uw0wl
Noble NB4: http://bit.ly/2FVvIdy
Micro receiver for noble: https://bit.ly/2NqtV3m

MT-S: https://www.rcmart.com/sanwa-mt-s-4-...-mt-s-00066929
Then get a micro receiver (this will make it cheaper than getting the radio with receiver): http://bit.ly/3sJ2fJV

ESC for stock brushed motor: DumboRC 10A and a small buzzer.
ESC: https://www.aliexpress.com/item/4000143341038.html
Buzzer (choose 5V): https://www.aliexpress.com/item/32966574206.html

As for the gyro, if you stick with AWD/4WD it's not necessary. Radiolink RC4GS has gyro integrated receiver and it's good for AWD if you want one. This won't work that well if you want it for RWD so you'll need an external gyro like AFRC GYS-2 V3. https://bit.ly/2XD0Xms
Mar 04, 2021, 04:56 AM
Jimmy2609
Thank you beaver_XT much appreciated with all this helpful info, I think I’m going to go with the RC4GS Tx, Rx, with the Dumbo RC 10A & buzzer with AFRC GYS-2 V3, I believe that on the RC4GS there is an option to turn the stock gyro off? So I can use the GYS-2 ? On my K989 I’ve locked the rear diff the front diff is stock, can the front diff be replaced with a one way diff? Or is only to be used with a CS Mod? Once again thank you.
Mar 05, 2021, 12:11 AM
Low budget fun
Beaver_XT's Avatar
Yes, you can turn the gyro off. Click the button on the receiver 3 times. I think the stock receiver is off as default.
Mar 05, 2021, 03:05 AM
Registered User
I'm late to the party, but I have a K989 on order! I found my old Losi Micro Rally in a box and am now itching for an indoor car since that one is hard to find parts for.

Working my way through the hundreds of pages here!

Is it confirmed the K989 comes with metal dogbones now?
Mar 05, 2021, 05:33 AM
Low budget fun
Beaver_XT's Avatar
Yes, it now comes with metal dogbones for sure. And if you are lucky it'll come with metal motor pinion too which is pointless IMO, what we need are metal centre shaft pinions.
Mar 07, 2021, 07:40 AM
Registered User

K989 Throttle Dead Spots-Can it Be Modified


I have two of these and my wife and I have had a blast.

I have a spare transmitter that had a plastic piece broken inside it and I was wondering if there was a component that could be modified/replaced that would make the throttle respond when first squeezing the trigger. I have nothing to loose since this transmitter is "parts" now.

I know there are upgrades to the TX/RX and I have watched the Dual Rate conversion by Beaver but I am not sure that that fixes the issue with the throttle not responding for the first part of the trigger pull/push. Reverse takes much longer to respond.

Thanks and have a great day!


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