Can we assume you checked for any bent or broken mower blades??
A bent blade will shake like crazy, even if at a glance it doesn't look bad.
A bent blade will shake like crazy, even if at a glance it doesn't look bad.
f935 mower vibrating, shaking to the point of loosening bolts
I can only mow for about 3 minutes before all of the bolts on the gear box of the mower deck pop off. It doesn't matter how tight I get them. Once I engage the PTO, I can watch them start to unscrew before my eyes as if they have a life of their own.
The PTO shaft is in good condition and runs nicely. I've tried re-greasing everything, making sure there's oil in the gear box, making sure there's enough transmission+hydraulic oil. I run the PTO when the throttle is in the 'fast' setting and all of the tires are at the right pressure, spacers on the mower deck wheels are where they should be. The gear box is missing the guard that covers it but that shouldn't affect its stability?
I was given this f935 with a 60" mower deck and managed to get it running but the shaking is out of control. One thing to note is that I had zero mechanical experience before working on this thing.. so maybe I'm missing something painfully obvious?
Any help would be amazing! Thank you
The PTO shaft is in good condition and runs nicely. I've tried re-greasing everything, making sure there's oil in the gear box, making sure there's enough transmission+hydraulic oil. I run the PTO when the throttle is in the 'fast' setting and all of the tires are at the right pressure, spacers on the mower deck wheels are where they should be. The gear box is missing the guard that covers it but that shouldn't affect its stability?
I was given this f935 with a 60" mower deck and managed to get it running but the shaking is out of control. One thing to note is that I had zero mechanical experience before working on this thing.. so maybe I'm missing something painfully obvious?
Any help would be amazing! Thank you
1 - 17 of 17 Posts
Or a bent spindle ,a bad spindle bearing a bad deck pulley or bearing and or unbalanced blades from poor sharpeningCan we assume you checked for any bent or broken mower blades??
A bent blade will shake like crazy, even if at a glance it doesn't look bad.
yep I replaced the blades as well and it was still shaking.Can we assume you checked for any bent or broken mower blades??
A bent blade will shake like crazy, even if at a glance it doesn't look bad.
i guess a bearing needs replacement when it's clearly broken, but are there any other signs that would indicate that a bearing needs to be replaced? maybe the spindle/bearing unit needs some tighteningOr a bent spindle ,a bad spindle bearing a bad deck pulley or bearing and or unbalanced blades from poor sharpening
Take the deck belts off and start spinning pulleys and spindles by hand they should run true, spin easy and not sound like a coffee grinder that would be a start!😎i guess a bearing needs replacement when it's clearly broken, but are there any other signs that would indicate that a bearing needs to be replaced? maybe the spindle/bearing unit needs some tightening
Don't forget to check further back on the driveline as well. There should be a PTO shaft if i am correct from the machines PTO to the gearbox on the mower. A bad u-joint or a if the shaft lost a weight and got unbalanced it will also cause excessive vibration.
U-joints look ok, but I'm not sure about the weights. It doesn't look like my PTO shaft has any weights:Don't forget to check further back on the driveline as well. There should be a PTO shaft if i am correct from the machines PTO to the gearbox on the mower. A bad u-joint or a if the shaft lost a weight and got unbalanced it will also cause excessive vibration.
is there something on this PTO that you would consider weights? I can't see any missing parts on my PTO
It sounds like a failed u joint. Remove the driveshaft and physically check each joint.
Dave
Dave
An unbalanced drive shaft can create a ton of resonance. Where a particular vibration can keep increasing literally from it's own speed and pitch. I had a flail mower with shaft that lost weights and could never get the thing to tune back afterwards. It's a pretty short shaft so it might not be such an issue with the PTO shaft.U-joints look ok, but I'm not sure about the weights. It doesn't look like my PTO shaft has any weights:
is there something on this PTO that you would consider weights? I can't see any missing parts on my PTO
I would start at the blades and move back from there. Remove the blades engage PTO, If it goes away then blades could be severely unbalanced or incorrectly installed. On my 1420 mower the blades fall into a bushing. If you just run them up and they don't set them in you'll get vibration. If you still have vibration after blades removed, Then remove the deck belt and do it again, This will rule out a bad deck spindle. If vibration is still present then most likely it has to be PTO shaft is unbalanced or the u-joints have some slop.
so I've got a bad sound coming from the idlers and one of the spindles... but they are nothing compared to the gear box and idler it's connected to.
1. the gearbox is leaking tons of oil onto the idler and across the deck.
2. when i try to spin the PTO the gear box is very sticky and very noisy. this is definitely main issue.
3. the idler under the gearbox rocks side to side a LOT.
4. the oil coming from the gear box is very viscous and dark in colour... almost like engine oil??? I'm draining it now.
I can't figure out how to disconnect the idler that's connected to the gearbox. it's not a normal cap screw. any suggestions? here's a pic
![]()
Have ordered new idlers and bearings for the bad spindle (it's over $800 for the whole spindle thing so not gonna replace everything)
- btw for reference this is a rear discharge 60" deck from 1989
1. the gearbox is leaking tons of oil onto the idler and across the deck.
2. when i try to spin the PTO the gear box is very sticky and very noisy. this is definitely main issue.
3. the idler under the gearbox rocks side to side a LOT.
4. the oil coming from the gear box is very viscous and dark in colour... almost like engine oil??? I'm draining it now.
I can't figure out how to disconnect the idler that's connected to the gearbox. it's not a normal cap screw. any suggestions? here's a pic
Have ordered new idlers and bearings for the bad spindle (it's over $800 for the whole spindle thing so not gonna replace everything)
- btw for reference this is a rear discharge 60" deck from 1989
Attachments
-
292.8 KB Views: 175
We had an JD1145 which would be similar vintage as this mower, the center blade was connected to the gearbox, if you hit anything substantial it would put the gearbox shaft out of true, we rebuilt the box a few times before abandoning it for an aftermarket deck which stood the test of time.
on you last photo there is a roll pin holding on the pulley, tap it out with a drift. I would be concerned with the hole elongation in the pulley and why it has happened.
on you last photo there is a roll pin holding on the pulley, tap it out with a drift. I would be concerned with the hole elongation in the pulley and why it has happened.
your observation about the hole elongation around the roll pin is very astute. This may have been the root of the problem actually. I've taken the pulley off and opened up the gearbox- the gears and spindle appear to be in good condition. the pulley on the other hand can move around quite a bit when it's on the spindle.We had an JD1145 which would be similar vintage as this mower, the center blade was connected to the gearbox, if you hit anything substantial it would put the gearbox shaft out of true, we rebuilt the box a few times before abandoning it for an aftermarket deck which stood the test of time.
on you last photo there is a roll pin holding on the pulley, tap it out with a drift. I would be concerned with the hole elongation in the pulley and why it has happened.
That pulley should be super tight, and a royal PITA to remove.your observation about the hole elongation around the roll pin is very astute. This may have been the root of the problem actually. I've taken the pulley off and opened up the gearbox- the gears and spindle appear to be in good condition. the pulley on the other hand can move around quite a bit when it's on the spindle.
I no longer remove them to sell separately, and now bundle gearboxes with the mount and pulley when I resell them.
yes I'm quite worried about the pulley and why it became loose in the first place. the gearbox i have is actually a 'peerless clinton mich' - i have not been able to find a replacement seal for it that i need and am worried that its spindle will also be a slightly different size than the JD gearbox's spindle. do you have any experience working with these offbrand gearboxes?That pulley should be super tight, and a royal PITA to remove.
I no longer remove them to sell separately, and now bundle gearboxes with the mount and pulley when I resell them.
I don’t believe that a Peerless gearbox is an off brand gearbox. I would take that over the Spanish gearboxes that we are seeing elsewhere.
Dave
Dave
1 - 17 of 17 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Green Tractor Talk
A forum community dedicated to John Deere tractor owners and enthusiasts. Come join the discussion about towing, PTO’s, reviews, attachments, modifications, troubleshooting, maintenance, and more!
Full Forum Listing
Recommended Communities
