36v shudder.. motor? alltrax 400. Pics

[justmizell]

hoping i can get a little help here with my dads cart. bear with me, i will post as much as i can think of. 2005 txt i think. has 400 amp alltrax controller. recently the cart has started shuddering upon acceleration. i've read that most of the time a shudder is from a bad connection, so i have went over everything and made sure it was all tight. ever since controller was installed, sometimes you would press the pedal and the solenoid would engage but the cart would not move. he'd keep turning key on and off, switching back and forth f and r, pressing the pedal and eventually it would engage.

all connections are tight, although i can move the bolt itself if i push hard enough on some of the f&r connections.

i also found a wire going from f&r to the motor that was rubbed almost completely through. so i took it off and made another to replace it. heres a useless pic of f&r connections and a pic of motor to know which wire was replaced. rear of motor, right connection.




Something else i noticed while the rear of the cart was lifted

when pedal is pressed and solenoid engaged cart sometimes would not move. sometimes it would, but maybe 1/3 times it would not. however, if i rolled the tires just a hair the motor would engage and tires would move.. with a shudder. i did this several times in a row. sometimes motor would engage, sometimes it wouldnt and when i moved tires a hair it would jump to moving but i could still feel the shudder.

so this is where i am. batteries are all good with no bad cells, good connections, with all reading 6.2 or better. and the pack reads like 37.2 or something. not sure if it was fully charged or not but that sounded pretty good to me.

are we looking at a new motor? or could the problem be somewhere else? thanks in advance for any help.

[rabbitreborn]

37.2 volts is pretty low at rest.... When you press the pedal down and the solenoid clicks, what is your pack reading at that point?

[justmizell]

checked again. at rest was right around 38. when solenoid engaged it went to 37.3 or so.

so i need to know whats causing the shudder, and why sometimes it wont move when pedal is pressed unless you roll the tires a tad.

[scottyb]

Maybe the brushes are worn or not setting correctly. When you roll the wheel you turn the motor.

[justmizell]

thats what i was thinking. think it could cause the shudder as well?

[justmizell]

btw, the motor says M06-1192.. if that helps any.

[justmizell]

MO6-1192
A95-4005A-LR3.5

Ok now I'm leaning back toward f&r. Got on a minute ago and it would not move. Rolled the cart and tried, nothing. Finally it kicked in and about broke my neck. I can Engage the motor while keeping the wheels from moving an it will shudder.

This thing is hard as crap to shift between forward and reverse. Im thinking about replacing the f&r and see what happens from there.

should i replace the whole f&r? or should i just replace the cam? or should i take it all apart, clean, and reassemble the current one? as far as i know it is original stock.

tomorrow i'm gonna do some more checking with my multimeter to see if i can isolate the problem.

[sonicj]

try cleaning the f&r before replacing. denatured alcohol & a toothbrush, paper towels and compressed help as well. use a protective lube like boeshield, corrosion x, or preservIT.

imo, sounds brush related. you can remove the motor endcap to inspect, clean and/or replace the brushes. unevenly worn commutators can be serviced by your local motor repair shop. (or anyone with a suitable lathe)
-sj

[JMGreco]

jm, any update on your situation? I am starting to get a shudder when I put the cart in reverse. Would like to hear if a new F/R switch helped.

[scottyb]

Re-reading this I notice in the F&R pic that the bottom lug at 6 0'clock is blackened? IF there is a color change on any of the lugs it is likely from heat damage and your contacts could be compromised... in which case you would benefit from either a rebuild or replacement... I suggest a HD switch cam and new lug studs IF the housing (which is very easily damaged by heat) is still holding the studs in their original positions, meaning they are not tilted or sunken ... Once the housing gets hot you should just get a new unit because the contacts will loose their alignment and contact percentage will be compromised...