WK Diff Gearing questions.

[Timmahh]

hey peeps, i figured you guys here would have the most informatoin available on the diff in the WK Axles.

first ? is does anyone know what the gear ratio is on the stock diff?
2nd ? is what options are their for gearing change, or a different HPI Diff/pinion i can use to get a gearing change?

i want to speed up the diff from stock form. if it is say for instance a 4.5:1 ratio. then i need to go to a 2.3:1 ratios. so i need a larger pinion and smaller diff ring gear setup.

what are my options?
thanx.
Tim

[caymin last]

Count the teeth and work it out:
http://www.rcuniverse.com/community/gearwizard.cfm
http://www.rcracing.com/Gear_Ratio_Program_1100.cfm

[HAAS599]

The stock pinion is 21t and the stock spur is 90t

I know a smaller pinion and/or a bigger spur will speed up the truck

Don't expect a drastic change in speed by just changing the gears though. The easiest way to make your truck a lot faster would be to go to a 20t motor. I haven't tried it myslef, but I've read that a 20t motor is the quickest motor that the stock ESC can handle.

[Timmahh]

im not talking about the motor pinion and tranny spur, i am talking about the diff pinion and diff ring gear. its around a 4.3:1 off the top of my head. its not hard to figure out. but i dont know HPI stuff (if it was a Baja 5B wouldnt be a problem) that may work in the diffs to allow for a lower gear ratio.

[caymin last]

The internet is amazing, you just type in what you need and voila!
Hpi Wheely King Manual, Differential Bevel Gear 38 teeth #A855(a)-Dif pinion 13 teeth #A855(b)
WHAT IS A GEAR RATIO?
The gear ratio is S:1 (say "five to one"), which means that the pinion must make five revolutions to turn the spur gear one revolution. It's that simple.

http://www3.towerhobbies.com/cgi-bin...?&I=LXJYM2&P=Z

http://www.rocky-road.com/calculator.html

[Timmahh]

yes i know the internet is Amazing. Ive worked with it for 12 yrs now. i also know how to figure out what a gear ratio is.

i was HOPEING someone would know most this off the top of their had from previous experience.

Google is Good. but asking a specific question usually means SOMEONE IS LOOKING FOR A SPECIFIC ANSWER fairly quickly.


with that said, i take it no one here has done any of this type of work, or isnt experienced enough to answer it.

I know a smaller pinion and/or a bigger spur will speed up the truck

your backwards, that will give you slower wheel speed.
you want a Bigger pinion and a Smaller spur to gain more topspeed.

but i want to add as much speed as i can thru my diff gearing. so i am looking for diff pinion/ring gear options. as i stated above, i have found one option, but was hopting to find a smaller ratio than the one i found so far.

[caymin last]

I didn't mean to be sarcastic, as far as I can figure out there are no direct aftermarket options for changing the diff gear ratio for a wheely king, but there are a couple of guys who have modified this by using diff gears from other models, by experimenting, trial and error type stuff.
Using the search function produces pages of results for 'diff gears', 'WK diff ' ect. I know it's a PITA to go over all of them.
Hpi does have a GRU for the WK, http://www3.towerhobbies.com/cgi-bin...&I=LXVLE9&P=SM
other than that , although I tried I could not find any info on what you asked for, Sorry!

[Top_Ramen]

Here you go bro. This r&p has a 14t pinion with a 36t ring gear.

http://www3.towerhobbies.com/cgi-bin...&I=LXJYM3&P=FR

The stock input should fit. I think I saw one person with them installed and required just a little grinding if any.

[Timmahh]

np. i know how forums work and go.

i spent a day searching this forum and few other with and without using the actual search tool (is really quite terrible with VB, and it seems more pronounced here for some reason.

Thanx for that info. it gives me a line to go on.

i seen the mod for the 14/36 gearing which takes the ratio form 2.91 to 2.57 i think it was. so better and in the rigt direction, but im hopeing to find something in the 2 to 2.25:1 range.

[Top_Ramen]

I've searched high and low on r&p's before and I really don't think there is anything you're looing for. The gear ratios in these axles are pretty standard and won't get much different.

[Timmahh]

while having a brain fart tonight, a thought crossed my mind. Dangerous prospect i know, but....


Doesnt the Axial AX 10 ring/pinion fit the WK diff? i know the locker works, but what about the ring/pinion on the diff? if it does work, then i can get the 14/36 setup when its out. am i brain farting, or will that work?

i konw the NRS4 gears will work with minor pinion gear mod, but if the axials work, then i can go that route for an better final gear ratio of the diff.

[sloppy]

you are correct the axial gears will work so when they new ones come out we will all be in good shape

[TrailDawg362]

New diff gears is good news for all of us Wheely Kingers. Just out of curiosity, what is the difference between gearing up the diffs and gearing up the trans? Wouldn't it have the same effect?

T.D.

[Nate08]

Originally Posted by TrailDawg362

New diff gears is good news for all of us Wheely Kingers. Just out of curiosity, what is the difference between gearing up the diffs and gearing up the trans? Wouldn't it have the same effect?

T.D.

At the end of the day the effect is the same yes, but lowering the diff gearing does have some advantages over changing the spur/pinion on the trans. Have a look see at this thread for a detailed how and why.

Why no r&P gearing options from vendors?

[Timmahh]

EXCELLENT (in my best Mr. Burns voice). COME ON AXIAL i need that 14/36 combo.

changing the diff gears has a greater effect on wheel speed thru the axle, and less effect on torque twist and torsion ect...
in my case, that wont matter for me, as my use isnt crawler based. i just need more wheel speed.

[EHeye]

axials diff r&p are totally different than a HPI. Savage RS4 use a different tooth count but the tooth count is basically the same as stock. I just did a bunch of digging around cause I nuked mine and I ended up getting stock replacements for $7.99. The hardened bevel gear was $40 and would eventutally just eat the pinion gear cause of the strength. Just replace them as they break and put bolts through the diff housing to snug it up.

[TrailDawg362]

...and don't forget to shim the r/p for a tighter mesh

T.D.

[ClaySlayer]

In my opinion, the only time you should be messing with the diff gears is to put a set of the HDs in...

http://www.hpiracing.com/products/en/86336/

[Timmahh]

keep in mind my project (reason for thread) is not a crawler.

changeing the r/p in the diff is VERY COMMON on 1:1 crawlers. and most will tell you they would rather do the ring/pinion gear change than tranny changeing, not only due to ease, but the end effects.

COMEON AXIAL< get those Gears out!!! lol

[Creep]

Hey I am one of those guys that wants to use as much HPI/WK parts as possible on my tuber. So forgive me if I am missing something here in your logic... but what is the problem with the HPI #86336 Heavy-Duty Final Gear Set (P1x38T/P1x13T)? Why would you wait for the Axial gears to come out if HPI already offers the same thing that we know works @ $10 a set?

Also, can someone educate me as I rediscover the search function and the internet? J/K... I plan on ordering a Tekin FX combo for my only working crawler. If I knew I were going to use the HD 38/13 gears after I destroy the weak stock 36/14, should I order the 55t Tekin instead of the 45t I was planning on? Or would the 65t be even better? The stock ratio HD gears are more expensive than the 38/13's so I would prefer not to use them - and for now, I only want one motor. Looking for wheel speed when I need it and... ok, I am just like everyone else. Thanks for any advice!