Diff lock motor brushes

[Andy]

Have spent the afternoon giving my rear diff lock actuator the once over, all in all its in good nick, with none of the corrosion issues, to speak of, that I've heard about.
The only issue was the brushes in the motor.
These were worn right down to the point where the copper wire attached to the brushes was almost rubbing on the armature (prob about 10 thou away).

does anybody know how the wire is actually attached to the brushes, or where I can get suitable new ones?

what I then did was to take out some old brushes from an old electric drill, cut & filed them to fit in the holders, and after much cursing, got them in with the springs behind them & the armature back in (fingers like needles recommended!)
at this stage I was hoping that the contact between the spring & brushes would be sufficient as there was now no wire connected directly to the brushes.

Put it all back together with the cogs & what have you lined up (actuator rod at 55mm when retracted) and time to test......bingo, it works!!!!

but do any of you elecktrickery knowledgeable chaps know if the motor will continue to work of with no direct wire to the brushes, and the contact being made through the spring, or should I try & get the proper brushes or another motor.......... Has any one got a reasonable motor kicking about? Not worried about the condition of the rest of the actuator as long as the motor brushes are ok.

Andy

 

[Dave Burgess]

Sorry Andy, can't answer the question but may have to find out as mine has stopped working... Annoying after only 18 months fitted aand £400 even at Ian's prices.

 

[Towpack]

If Toyota don't supply the brushes separately there's lots of generic carbon brushes in different sizes on Ebay. Maybe you could find some that fit.
http://www.ebay.co.uk/sch/i.html?_f...or+brushes&_nkw=carbon+motor+brushes&_sacat=0

 

[Andy]

Thanks for that, I did find some brushes on eBay that had the wire in the right position but we're a bit too big, got a pair & filed them down & put them in.
seems ok on a bench test, will refit the actuator later & try it, hopefully sved myself a few quid!

 

[frank rabbets]

The copper wire stops current going through the spring. Such current might over heat the spring and weaken it. I did it once.

 

[uHu]

Should be possible to find suitable brushes WITH the little connector cable. Just make sure it is made for a low voltage motor, and not a 240 V.
On higher voltages you can use carbon brushes, but at 12 V you need copper graphite brushes (although they are often called carbon brushes as well, but containing copper graphite)

 

[Andy]

Thanks for that, both frank & uhu,

I did wonder about the springs getting too hot, hence found some brushes on the Internet, as I said, filed them to fit, but have no idea if they are for ac or dc motors, got me worried now that I might have to do it all again!

what would be likely to happen if they are the wrong brushes?, ie ac ones instead of dcones

Andy

 

[uHu]

If you fit pure carbon brushes in a low voltage motor, the motor will be very weak, or not run at all, as the resistance in them would result in a relatively big voltage drop.
(High voltage motors have lower current and hence lower voltage drop, plus that a drop from 240 to 238 volts is not noticable, while a drop from 12 to 10 volts is)