PTO Selector Jumps

[tony_adrian]

I have a 3320 with the single speed 540 PTO. When shredding if the mower hits a hard spot or I hit a large bump the PTO lever jumps forward and the PTO disengages. This is new. Is there an easy fix for this before it gets too bad.

I searched the site for this issue but couldn't find a previous thread.

TIA,

Tony

 

[Renze]

when you remove the cab floor, you can see a row of 5 bolts in front of the PTO and high/low range levers.
These hold down a spring with a roller underneath. The rollers take up in a notch, thats the clicking sound you hear when shiftng.

Try exchangeing the outer right one (hi/lo) with the outer left one to see if a stronger positioning spring helps.

Also, put into gear untill you "feel" the positioner click: leaving it halfway will allways make it wobble out of gear, and doing that too often may cause the shifting collars to wear uneven, giving the problem a more definate nature...

 

[tony_adrian]

Needed to repack the hydrostatic steering cylinder on the 3320 and while in the shed finally got around to performing the described detent spring/roller change as described above.

While it seems to "click" better thru all four positions I noticed something else as I was clicking thru the hydraulic /PTO selector. It is as though the internal shifting mechanism has moved. Here's what I have when the PTO lever is moved:

- Forward Position - PTO spins with 3 point hydraulics
- Second Position - PTO spins with 3-point hydraulics
- Third position - No PTO (but PTO can be spun by hand), no 3-point hydraulics
- Fourth position - Rearmost position towards the back of the tractor - no hydraulics & PTO is locked. PTO cannot be rotated by hand with or without tractor running & in neutral.

Thank you again,

Tony

 

[Renze]

Easy fix:

Take the cab floor out, and take the gearbox cover off. Then you'll see the gear selector slide rod: It is made in two pieces, with two shift forks: one engages the PTO in the front of the gearbox, one fork slides the sleeve shaft over the PTO shaft to engage the ground speed PTO and the oil pump drive (your 20/40 model probably has an engine mounted oil pump so this selection isnt valid)

Im prettty dead sure the securing bolts of this extendable shift rod have ran loose and slid out of position.

You will have to decide the adjusted length, based on the position of the other clicker bolts: align it accordingly.
What you should have, is a neutral PTO, with only oil pump drive, in the 1st position. 2nd should be PTO with oil pump, 3rd should be total neutral (no oil pump, no PTO) and 4th should be ground speed PTO, giving you 5 PTO speeds and a reverse if you engage the corresponding transmisson gear.

So, it sounds like only the most forward position doesnt work properly: If i remember properly, the fork that shifts the ground speed and oil pump, is on the fixed rod with the clicker notches, and the front fork actuates the main PTO gear. My guess is that you should shorten the selector rod by sliding it in and re-tightening those little bolts. Hopefully you can see some scratch marks on it to know its original position. I have to see it in front of me, before i can determin a 100% certain answer if the rod has to be shortened or extended.

 

[tony_adrian]

I took off the gearbox cover. Inside is clean and no evidence of corrosion. The transmission has two compartments that share an oil supply. The front compartment has most of the transmission. The rear compartment has the mechanism for changing Hi/Lo

I very carefully looked at the PTO/Hydraulic square rod that is actuated by the lever. I was able to slide the rod fore & aft fairly easily. But looking very carefully I can see no forks on either end of this rod. This PTO/Hydraulic selector rod runs thru the back compartment in the differential.

Is it possible that both shifting forks are in the differential housing? I have a manual that shows the fork in the front transmission compartment but that image is labeled for the 540/1000 PTO. I have a 3320 2WD 540 PTO, no 1000.

Again - I greatly appreciate your assistance.

Tony

 

[Renze]

One goes into the rear axle, and actuates the sleeve over the PTO shaft. The other is right in front, you can see inside if you take off the most forward service hatch on the belly of the transmission. But you should also be able to see it when the main cover is taken off, i remember that disassembling the 540/1000 PTO on a 6718 requires one gearwheel to be taken through the bottom cover, and the other through the upper cover.

 

[tony_adrian]

I guess I need to get to the rear axle because the PTO is the problem child. Manaully engaging the forks by hand in the transmission is not correcting the problem.

I cleaned the rear axle top cover & blasted the dust away. I've set up a set of cables with turnbuckles to lift the cover straight up so I can slide it back.

It is 38 celsius (101F) with 60% humidity today. I won't pull the cover until tommorow when I'm rested.

Any recommenodations for brands/type of silicone gasket material for the transmission top cover, bottom cover, and axle top cover?

Tony
Opelousas Louisiana

 

[Renze]

I think you are right, and i was confused: I took the parts manuals of both my tractors, and found out this:
The 3011 has two shift forks on that rod; thats because it has only one PTO speed with no live oil pump.
The later models with live oil pump, have two shift rods: one for 540/1000rpm PTO and one to engage the actual PTO and oil pump.

Because yours only has 540, it will only has one shift fork. Check the mounting of the shift fork on the slide rod, when the rear axle cover is lifted.

I am sorry for sending you into the front transmission compartment for nothing.. :-x

 

[tony_adrian]

First of all - no apology necessary. I think I needed to pull the transmission cover to understand how the shafts & detent springs work.

Today here's what I did

-1- Pulled the PTO shaft cover. I cannot get the PTO to come out, will look for my old slide hammer. The circlip that holds the PTO shaft was broken. The bearing looks good. The PTO shaft is not easy to turn by hand but when it is turned it is smooth and does not grind. I'd like to pull the PTO shaft and look at the splines

- I pulled the rocker shaft cover. The PTO shift fork is in place and not broken. The sleeve moves back and forth smoothly. The rear gear that engages the PTO pump looks fine with all teeth intact and not worn.

Until I pull the PTO shaft I'm not sure I can diagnose what the problem is. If anyone has any sage advice on pulling it I'd appreciate it. The shaft does move a little fore and aft but I cannot get it to pop out.

I am thoroughly impressed with the clean simplicity and quality materials and workmanship. This 3320 is a machine that is elegantly simple.

Thanks again,

Tony

 

[tony_adrian]

I may have figured out the problem.

The circlip (snap ring) that holds the PTO shaft against the spacer at the rear of the tractor was broken. This allowed the PTO shaft to travel about 5 to 10 mm fore and aft. Since this shaft could travel back and forth as the connected implement rotated and moved, the moving implement would pull the shaft slightly in and out. This would cause the fork to move causing the shaft to push out of the detent spring.

I looked very carefully a number of time at all of the mechanisms. Everything clicks and slides into & out of place as one would expect. The only thing that is sloppy is that PTO shaft coming and going.

Would you think that 5 - 10 mm of PTO travel could result in my problems as described in the original and the follow up third question?

tony

 

[harald]

I had the same problem on my 3011 , even the rear snap ring was broken,, I had to replace the hollowclutschshaft and the gliding gear to fix it it was the worn gears on the hollowshaft that forced the pto forwards and the pto level to move out of position,, se pictures.
http://www.flickr.com/photos/50597480@N04/4644520268/

Harald

 

[tony_adrian]

I may have avoided the catastrophic failure as seen in your images.

When moving the PTO/Hydraulic shaft by hand and turning the PTO manually all of the gears mesh and turn as they should, all of the detent slots line up. I'll double check to see if the end play is 0.10" to 0.15" as per the shop manual then will start reassembling and see if it works.

CORRECTION: manual states 0.010 to 0.015 inches (0.254mm - 0.381MM)

 

[Renze]

Would you think that 5 - 10 mm of PTO travel could result in my problems as described in the original and the follow up third question?

From my memory (i think its been 10 years ago that we had one of these newer transmissions open) the 5-10mm sounds about close to the distance over which these shifts are made. I am pretty confident this is your problem.

 

[tony_adrian]

Broken snap ring at the aft part of the PTO was the problem. Access was thru the rear PTO cover. Less than $1.00 to fix.

I was able to shred deep, thick, overgrown grass and weeds yesterday for hours without a problem.

 

[bigdoug]

Always nice when the fix is cheap and easy!

 

[donagin]

Howdy. I just "inherited" an Agri-power 5000 (Zetro 5211???) with some land I bought. I have the same exact issue with the PTO selector - except that mine oil stays in hydraulic pump drive for a few seconds after I select it, and then it pops out. I almost decided to sell the tractor, then found this forum and thread. I pulled the floor, and swapped the detent springs. I have 4 firm selection positions. I opened the gearbox, and I also have the single PTO slide fork (contrary to my "book", which shows the 2 piece bolt together style). No adjustment there. I'm guessing, then, that it is the circlip on the PTO shaft. But I haven't figured out how to get access. Do I drain the differential and pull the bolts (4) around the plate that was supposed to hold the (long gone) PTO shield?

Thanks for any help on this. Some of you guys obviously love your tractors. At this point, I'm kind of wishing my compact Mitsubishi back! Still, this hulk is growing on me...

-Don

 

[donagin]

Oh yeah - I can't feel any fore/aft play on the PTO. Could you sense this on yours before pulling the cover? Also, I have to rebuild the hydraulic lift cylinder for the 3 point, so I THINK I need to pull the top of the differential anyway. How likely is it that the shift fork is loose in there? I have to manually "feel" to engage the PTO by the detent. Then it stays in for a few seconds to a few minutes, and pops back out. Any knowledge is appreciated. I am having trouble making heads or tales of the parts and maintenance manuals .

 

[tony_adrian]

Renze's advice to check the leftmost detent spring on the bolt on the cab floor is the easiest. Then try looking at the snap-ring at the back where the PTO exits. That's about a 15 minute job and can be done in a hurry.

Between those two I'd guess your chances of success are about 90%.

Tony

 

[donagin]

I removed the rear PTO guard, caught the tranny fluid, and confirmed the missing snap ring mentioned before in this thread. It just simply wasn't there, and the PTO shaft was a good 6 mm forward in the tractor. I contemplated the situation, as I could not pull the shaft rearwards into location, and I don't have fancy pullers. Suddenly it dawned on me that my mower has a shaft puller attached to it. I took the front half of the mower shaft, and coupled it to the PTO. Using the universal joint as a pivot arm, I pried against a strategically placed block of steel (http//www.donsplans.com/zetor .jpg) and set the PTO shaft back where it belonged with a minimum of effort. The snap ring was available at the local John Deere Dealer, so we set it in place. So far, it seems to have completely cured the issue. Now if I can just figure out how to shift the PTO into hydraulic drive without either stopping the engine or grinding the gears, I will be in good shape!