Brushcutter clutch spring keeps breaking

KonaHemaHema

LawnSite Member
Location
South Kona, HI
Aloha!

My Redmax BCZ400 brushcutter keeps breaking its clutch spring. This problem didn't start until the machine was about 3 years old, but now it happens after about 15-20 hours of use. It's fairly easy to replace the spring, but I no longer feel like I can trust the machine at client sites. When I use it, I do work it pretty hard. It's great for overgrown areas with tall, thick grasses and some brush - stuff that my Shindaiwa 302 has a harder time with. Any thoughts on what else I should look at? Does the clutch drum or the shoes wear out?
 

Breezmeister

LawnSite Silver Member
Location
South Jersey
Any thoughts on what else I should look at? Does the clutch drum or the shoes wear out?

There are a few things that can effect the springs.

The bolts that the clutch shoes pivot on can where out.


IMG_1173.JPG


The bushings in the clutch shoes can wear out too.

The shoes can wear out....

IMG_0236.JPG


The newer shoes don't have a coating on them like brake shoes so it's had to tell when they need to be replaced......Also, the shoes ( metal on metal ) will cause the clutch cup to get hot. The metal clutch shoes will slip easier if you run to much string.....More friction, more heat......

IMG_0351.JPG


All that heat will also be transferred from the hot clutch shoes to the springs, so the springs will lose their temper.......
.
 

flintknapper

LawnSite Senior Member
There are a few things that can effect the springs.

The bolts that the clutch shoes pivot on can where out.


View attachment 388630

The bushings in the clutch shoes can wear out too.

The shoes can wear out....

View attachment 388631

The newer shoes don't have a coating on them like brake shoes so it's had to tell when they need to be replaced......Also, the shoes ( metal on metal ) will cause the clutch cup to get hot. The metal clutch shoes will slip easier if you run to much string.....More friction, more heat......

View attachment 388632

All that heat will also be transferred from the hot clutch shoes to the springs, so the springs will lose their temper.......
.
I hate a spring that can't control it's temper.
 
OP
K

KonaHemaHema

LawnSite Member
Location
South Kona, HI
That was far more informative than I expected. I took a closer look inside the clutch assembly, and I do think the shoes are worn - shiny and worn on the outside, except the ends.

Thank you, Breezmeister!

There are a few things that can effect the springs.

The bolts that the clutch shoes pivot on can where out.


View attachment 388630

The bushings in the clutch shoes can wear out too.

The shoes can wear out....

View attachment 388631

The newer shoes don't have a coating on them like brake shoes so it's had to tell when they need to be replaced......Also, the shoes ( metal on metal ) will cause the clutch cup to get hot. The metal clutch shoes will slip easier if you run to much string.....More friction, more heat......

View attachment 388632

All that heat will also be transferred from the hot clutch shoes to the springs, so the springs will lose their temper.......
.
 

BigFish

LawnSite Fanatic
Location
chesapeake, va
You prolly got it back together by now, if not, ya wanna take a close look at the clutch drum. They will wear out at times.
Also wanna sparingly lube the pivot bolts.
I use a moly lube. Don't use Neve seeze.
 

Top