Good basic KH drivetrain upgrades.

[Lmackattack]

Hi gang.. Im new to this site and this is my 1st post.
I belong to some others foums that I see members here bounce between. and you may know me outside of the model world as I work and drive in the Trucking field.

I bought a King Hauler and flat bed trailer the first month they came out. Over the past 14 or so years I have had it I have been thru 3 bodys, endless drives shafts, wheels, bumpers etc... Its been a fun truck but now I would like to rebuild it into the real 1:1 truck I own. I have an old wester R Model Mack and 22' end dump.

I would like some performance and exterior upgrades. and came here to pick your brain First I would like to slow top gear and reverse down a little. what are my options?...keeping cost in mind.

Where to get these flashy wheels, fuel tanks and stacks?

Any way I can extend my little flat bed into a 48' what are my options?

thanks in advance for any tips.



Trent Blasco

[Snochaser]

4:1 reduction, drive shafts from PMD

55turn motor- wear ever (local hobby shop)

Wheels, air cleaners, - IHB

Air cleaners, bumpers- Russ/True Scale

Stacks- Snochaser or SnP

Grill, steps- Brian in PA

Drive shafts- RC4WD

[pumptech]

Hey Trent welcome to the forum !!:D ,look forward to seeing your build !!:D
I recently changed the pinon gear in my KH ,removed the factory pinon and replaced with a 6 tooth 32 pitch pinon from RC4wd ,works great, speed is just right now ..

[Lmackattack]

Thanks for the tips.

I was also looking to stretch my KH butafter I did some measuring i see the stock KH looks like its 217" WB my old Mack sits at 206" so I think I may just leave the KH frame as is. I just placed an order on eBay for the rc4wd drive shafts. Some stock flat bed rails and misc trailer parts so I can extend it to a more common late 1980's 48' length. I started on the cab and hood years ago but never finished. I will post pics soon.

[doodlebug]

Welcome aboard! I traded my 88 RD for a 97 CL 713, Keep on truckin!
Cheer's, Neil.

[Lmackattack]

Ok went back to eBay and found some old budd rims .man how this truck has come around. When I first bought this king hauler the 3 hop up items were truck lights, trailer lights. And motorized landing legs....that's it! Now it seams endless...

This 4:1 reduction box....how much slower is it. I never really used the stock 3rd gear as it was fast but 2nd was perfect. if this 4:1 box still gives me my stock 2nd gear speed but a much lower 1st that sounds like a win win...


Tires...what's the thoughts on the stock tamiya street tread vs the rc4wd lugger tread. My old Mack will see off/on road use.


Diffs...the factory diffs were open always getting hung up easy has that been addressed with aftermarket parts? I think at one point I locked my diffs so all 4 corners put power down.

Thanks again!

[Claus]

I don't have a King Hauler anymore but when I did I had a Tekin 45T motor and a PMD 4:1 reduction. The speeds were perfect for me but my truck was always in the house, 1st gear was low and great for backing around and 3rd was plenty quick for chasing the cats around the living room.

I grew up with my Dad having Macks, I' a Mack fan too.

[Lmackattack]

Yea I'm a die hard Mack fan myself. Worked on them and driven them all. The old Mack's were always easy and cheap to fix. Give me **** and they come back for more. My 2nd gear was perfect it was hard to roll it over unless you were being real stupid. 3rd on the other hand was like a 85scale mph gear! I will have to look into that 4:1 box. Sounds like its a good deal.

[Claus]

PMD now sells two version of the 4:1, one of them bolts right on the back of your trans mission, the other is a stand a lone type. Depends on your wheelbase, the bolt on version simplifies things while the stand alone can double as a carrier bearing if you have a mile and a half of frame rail behind the cab.
http://www.gardentrucking.com/products/Originals/T1225.jpg
http://www.gardentrucking.com/products/Originals/T1204b.JPG
http://www.gardentrucking.com/index.tpl?cart=136566437415792598

[Claus]

Notice the Mack cab if the far right next to Ric of PMD, you need one of those!
http://www.gardentrucking.com/germany2009/100%5F0406.jpg

[Lmackattack]

That Mack cab looks like a R600 model. Looks cool....

This 4:1 that bolts to the back of transmission looks interesting. I would like to see both how slow in 1st gear and how fast in 3rd. I like a low gear but still want the speed that stock 2nd has...

[Lmackattack]

http://store.rc4wd.com/21-Ultra-Compact-Gear-Reduction-Unit-for-540-Motor_p_776.html

I see this 2:1 reduction that bolts to the motor... Would this basicly cut my stock speed in half when installed?

[Claus]

Yes, exactly.

[RoadFlyer]

http://store.rc4wd.com/21-Ultra-Compact-Gear-Reduction-Unit-for-540-Motor_p_776.html

I see this 2:1 reduction that bolts to the motor... Would this basicly cut my stock speed in half when installed?

They also have a 4:1 bolt on reduction

http://store.rc4wd.com/41-Ultra-Compact-Gear-Reduction-Unit-for-540-Motor-_p_782.html

[dabears]

That Mack cab looks like a R600 model. Looks cool....

This 4:1 that bolts to the back of transmission looks interesting. I would like to see both how slow in 1st gear and how fast in 3rd. I like a low gear but still want the speed that stock 2nd has...

I have 3 different versions of the 4:1 at my house. all work pretty good. I like the integy better though

[Lmackattack]

I just bought the RC4WD 2:1 reduction that bolts to the motor. I think that unit has the least amount of reduction and will still give me the stock 2nd gear speed that I want.

if not I will look into the 3:1 or 4:1... I like the PMD unit that bolts to the back of the box but it may be too slow for me?

[Espeefan]

You can always consider running a higher turn motor as well. Higher turn motors run less RPM, so if you can't quite get the speed you want with a reduction, you can always try a different motor, with or without an aux. reducer gearbox. You can also play with the battery voltages too.

[Lmackattack]

I have a stock 540 and a green machine 27T motor. I will play with those and see what kind of speeds I get with them. I also plan to run 6 0r 7 cell batt packs depending how I fit them into the cab or if I install them on the trailer and run wire leads.

[Espeefan]

Stock Tamiya motors are 27 turn also, so you may not see much difference in speed between the Green Machine that it.

[Lmackattack]

good to know. I took the green machines out of a twin screw R/C boat. they were great motors

[Lmackattack]

Ok got all my drivetrain parts today. Next question is how are people are getting the motor further forward in the frame and over the steering/shift servos. I am making a day cab and trying to have the trans flush with the cab rear wall..


Is there a smaller servo that works better than my old futaba s148?

[fhhhstix]

Ok got all my drivetrain parts today. Next question is how are people are getting the motor further forward in the frame and over the steering/shift servos. I am making a day cab and trying to have the trans flush with the cab rear wall..


Is there a smaller servo that works better than my old futaba s148?

Just make 4 bushings to raise the trans and mount it farther forward.

Travis