Marauder324

Hey guys,
I just completed building the Tamiya Knight Hauler kit with MFU. Im having a issue and I cant seem to resolve. When I bench tested the electronics, I would shift through the gears on the controller and the motor would spin faster in the order of the gears 1-2-3 with 3 having the motor spool at top RPM.
I put the entire truck together and now the engine is doing the opposite, It spools faster in 1st gear then in 3rd. The transmission is shifting perfectly and Icant seem to find any other issues that would be causing this.
Is there something that has to be switched over or something I didnt install correctly? Iran through the book and did the test 3 times to make sure that the functions are working. I just dont understand what went wrong from the bench test to the installation.

Thanks for any help!

FireFrenzy

no idea if this is even possible but is it possible its in reverse or something?? or that the thingy which shifts the gears is confusing 1 with 3 somehow (reverse polarity????)

lee172

if it was reverse polarity, the motor would be running backwards, bear in mind that the motor will be at the same max rpm (at max throttle) whatever gear its in, the only difference is the gearing, eg: first gear will be good for inclines, but also gets to max revs instantly, third is the gear for maximum speed.. and second is obviously a bit of both.

Marauder324

Thanks for the replies!

Ihavent had enough road to really see what this thing can do, I just know that1st gear is way too fast and 3rd gear is way too weak. Ill try to post a vid of the rear tires in the airto showwhat it looks and sounds like. It just seems thatit dont have enough power to do anythingwhen I throw 3rd gear. All of my wires are installed correctly, I know the tranny is built and installed correctly I just feel Im having aMFU issueor thats the way this will run. I really dont want to pull the motor and tranny out to test.

lee172

the tranny sounds fine, and all the semi trucks ive seen with MFU and stock motor are fast in any gear, what batteries, (make and mah) do you use?

also, is your rig equipped with bearings?

Marauder324

Ihave the stock brass rings in there and Ill post up what battery pack Im using when Iget home. The hobby store raved about this pack and for the price Ipaid it better be good!

First gear is like a rocket, 2nd gear has some good power but going from second to third it just falls flat. I would have to get some long distance runs to really make sure.

Thanks for the replies!

lee172

bearings are a must.. i wouldnt run any kit without bearings, let alone a heavy kit with lots of bushings in. i know you'll have to re-build, but it will be worth it.

http://www.stellamodels.net/catalog/...oducts_id=1561

The Collector1

My Feedback: (2)

What radio are you using? Your left stick should be left 1st, center 2nd, right 3rd, maybe the servo is reversed or the linkages are backwards

Marauder324

Iwill upgrade to bearings later on down the road,right now Im recovering all the cash I spent for the truck.

My stick and tranny are set up correctly accordingtothe manual, the rod gets pulled out for 1st, middle for second and pushed all the way back for 3rd. I also noticed that even the lights on the roof are showing opposite gears. When I put the stick to the left and forward, all 3 lights light and the truck takes off, then 2nd is the normal 2 lights and then only 1 light will light when I put the stick to the right and up for 3rd gear.
Im really thinking something is messed up in the MFU. I plan on getting to it to the hobby shop to have a professional look at it. Im using a Duratrax DTX5000 7.2 battery pack with the Futuba T4GWD-AM radio. I tried reversing the servo and it didnt help at all.

The Collector1

My Feedback: (2)

If you tried reversing the servos, the linkages and it seems you have it setup right, maybe the MFU is messed up, I hope you can get that straightened out, I have heard on other forums about MFC problems

Marauder324

Tonight I finished off my trailer and hooked it up. Now the truck is acting the way it should!All 3 gears with plenty of power. Once I drop the trailer, Im back to no power at all. I know the MFUcranks up the RPMs when the trailer switch is activated but now even 3rd gear has speed and power. All the more reason why I think this MFU has some issues.