L4300DT Loose Alternator Belt Problem

Big Joe

New member

Equipment
L4300DT, Bush Hog, Rhino PHD
Oct 21, 2009
3
0
0
Fayette County, Texas
My L4300DT is approximately 5 years old (but only 75 hours on it) and has the original battery which, according to the green dot on top, is still in good shape. A couple of weeks ago I found that the alternator belt had excess slack in it. I tightened it (cranked down on the bolt pretty hard), but it is loose again. While tightening it again yesterday, I noticed that it has, what appears to be, a brass washer instead of a steel lock washer as on most alternators that I have worked on. I'm thinking that the soft washer is not allowing the bolt to torque up enough to hold good tension on the belt. Will it hurt anything to replace this brass washer with a lock washer?
 

Ob1kubota

New member

Equipment
M9540DT
Jul 26, 2009
316
0
0
Birmingham, AL
Big Joe Welcome and the way to really tell if you have a brass washer use a magnet to see if it will stick, brass will not, and I personally don't see anything wrong using a steel lock washer in it's place but would use a torque wrench on the bolt so you won't strip the threads from too much Cranking... I'd see what happens at 40-50 lbs max. otherwise the belt may have reached its elastic limit and will need replaced. ;)
 

Big Joe

New member

Equipment
L4300DT, Bush Hog, Rhino PHD
Oct 21, 2009
3
0
0
Fayette County, Texas
Thanks OB1. I called my dealer about the problem. The mechanic confirmed that the washer is brass, but I would not be able to simply replace it because it is pressed onto the bolt. He saw no problem using a steel lock washer, but would require a new bolt also.

He suggested that I remove the negative battery wire/cable at the frame and scrape off any paint and/or rust for a better contact surface. He said that he had seen a lot of problems associated with that.

Also, found out that the battery, although having a green light showing and having been charged, was generating only a third of the cold cranking amps. I will find out this morning if any of this solves the problem.