Tranny going bad?

[D3SKIP]

I have an older JD120 with a 48" mower. Just lately it seems to be struggling to come up hills. I've replaced the drive belt, but it still struggles even with my 115 lb. wife driving. Could it be the transmission is going bad? It still goes good on fairly level ground even with me at 260 lbs. mowing. Any suggestions will be appreciated.

 

[mechanic mark]

[Uhttps://www.greenpartstore.com/John-Deere-Transmission-Assembly-AM131580.htmlRL unfurl="true"]https://www.greenpartstore.com/John-Deere-Model-L120-Lawn-Tractor-Parts.html[/URL] See page 4 for parts.
Did you replace idler pulleys when you replaced drive belt? Bearings at center of pulleys do go bad, did you inspect by hand & visually?

 

[Rivets]

Check to see if the tensioner arm is moving freely and both idler pulleys are not worn.

 

[CaptFerd]

change out the hydro fluid.

 

[Hammermechanicman]

Does the tranny whine and whine louder on the hill when it slows down?

 

[Deleted member 97405]

The L120 transmissions were too light duty for the machine. They have to work hard to turn the oversized tires just to move the machine. If you run it on hills, they wear out in a few seasons. It's just their nature. Usually they will drive fine until they heat up, then they are sluggish or just refuse to go up an incline. They cost more to fix than to replace. Although, your tractor is worth about what the transmission would cost. This series is engineered for a 5-7 year lifespan in order to compete with MTD. I work at a dealership, and, unfortunately, this is the issue with this series when operated on a yard with hills.

 

[Dajanasa1]

Hey D3SKIP,

I have the same lawn tractor/ mower.
I had the same problem as you, wouldn't go up the hills (my yard is all hills and steep)
The first time I changed the fluid in the transaxle, it was better, but still would heat up and slip.
So I would let it cool down and then finish mowing.
This winter I changed the fluid again and put 15 - 50 Mobil 1 in it and now it works much better.
Unless it is real hot, I can now mow the whole lawn at one time.
These transaxles are real garbage and must be maintained more than a real transaxle.
Hope this helps.

 

[Gord Baker]

Just replaced the tranny on my X320 at 280 flat lawn hours!!!! Garbage. Tranny, new drive belt and idler pulleys, $1,810 Cdn. I tried adding some 80-90 Hydraulic fluid to very clean trans oil. No help. When hot you better be at the top of a small grade!

 

[Freddyfreeze]

Sounds like a K46 tranny that needs oil change. I use a 20-50w synthetic oil that will correct the problem if the pump hasn't burnt up. I change it every 100 hrs.

 

[gotomow]

have an older JD120 with a 48" mower

Could be that this older JD120 is from the early 70's and not a recent model.