How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask James W Your Own Question
James W
James W, Small Engine Troubleshooting Expert
Category: Small Engine
Satisfied Customers: 3708
Experience:  7 years as Mechanic & Parts Manager for Brother who has Owned Lawn & Garden Repair shop for 35 years
Type Your Small Engine Question Here...
James W is online now
A new question is answered every 9 seconds

how do I replace the drive belt on a Murray 42590A (42 inch)

This answer was rated:

how do I replace the drive belt on a Murray 42590A (42 inch) riding mower manufactured in 1998?

Read all instructions first please.



First, seeing an exploded view will help you, so click here..


Then click on the button labeled 42590A XXXXX.


Look this over...


1. Remove mowerdeck

2. Diagram current belt path around each pully, idlers, and belt guards (esp position of belt guard).

3. Depending on exact unit you will either loosen the belt guards around the rear transmission pully, or if there are not belt guards there, the Frame is being used as a belt guard.

IF this is the case, you MAY have to loosen the bolts holding the transission ON ONE SIDE just enough to allow you to slip belt through the gap. (you may have to drop the transmission several inches without damaging the linkage).

There are also belt guards on the double stacked pully on the engine that have to be loosened as well.

must remove from rear pully FIRST..


Reverse prosses to install new belt.


Double check exact location and placement of belt guards, idler pulleys and drive pullys from you diagram.


Nothing can rub anything..


NOW, We must KNOW why the belt needs replaced in the first place.


Something caused it to go bad.


Could be a bad Idler pulley, a bent idler arm, bad allignment of the pulleys, obstruction, etc..


If you do not determine the CAUSE of the problem to the belt, It is Going to happen again..

Inspect and examine everything while you are down there.

Customer: replied 8 years ago.

thanks for the info. someone else told me that I need to remove the mower deck too.


I have no owners manual instructions for removing the mower deck. I need more details on that particular step in this procedure. once I fully understand that part of it, I think I will be ok as long as I can figure out the proper routing of the belt. the belt jumped off when I was mowing on an angled part of my lawn and I was rushing and almost lost my balance, causing my to abruptly jerk the clutch and i think it just jumped off track.

Again, the exploded view of the drive should help you with belt routing.


Go to the same page I gave you for getting the exploded view of the drive..


Go down further and clikc on the links for the Mower suspension


It will help you to see it..


Lower the deck to the ground (don't know how many people try to do this with the deck suspended up in the air).


First remove tension from the belt.


There should be a spring loaded lever that you can move to move the idler arm enough to take the belt off the double pully.


Then there are some PINS usually with Clips. Take the clips off, pull the pins out (usually 2 to 3 per side).


You should be able to slide it sideways.


DON't Pinch your fingers, cause it HURTS...

James W and other Small Engine Specialists are ready to help you
Customer: replied 8 years ago.
thanks for your help. I put on the belt and now the machine won't move in drive or reverse. Do you think that I may have stretched the belt out of shape to the point where it is not getting enough torque? or did I pop a gear or link in the transmission?

Look for obstructions causing the belt to not move.


You will now this...


IS the belt turning the BIG gear on the top of the transmission?


You will have to either look at it or have someone else look.


If the belt is Turning the gear, then It is Transfering the power to the transmission.. If it is NOT turning the big gear, FIND out WHY?


Is the belt Jammed, is it smoking, is it stuck between belt guards. Is there no tension on the idler?


Why did the belt jump off?


Something caused it to jump off Did we eliminate the cause?


If the big gear IS turning on the tranmission, why is power not getting transfered to the wheels. Is the parking break not hooked up (or is it hooked up).


This should keep you busy for a while.

James W and other Small Engine Specialists are ready to help you