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Discussion Starter #1
I purchased a 4240 tractor at auction last summer (1981, approx. 9000 hours)

The previous owner said that the "park" function stopped working after a transmission selector cable broke and had to be replaced.
When I bought the tractor the linkage cable for the "park" function was tied with baling wire so it could not be physically put in to park.

I have been told that its either an internal issue (likely related to the park pawl mechanism) or something external, related to the adjustment of the cable linkage.

I'd like to narrow it down to either internal or external.

Someone mentioned jacking up one of the rear wheels, making sure it will turn freely by hand, then engaging the park pawl lever by hand (with the linkage cable disconnected) and seeing if the wheel locks up?

Any opinions would be appreciated.

Suggestions on safely jacking up one wheel, etc. would also be great.

Thanks,
 

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4240 - brings back memories of days working a dairy farm. We had one and I serviced it quite a few times. What was suggested, as a test, sounds very reasonable to me. Jacking with a high capacity hydraulic floor jack, while on a stable surface should not present any issues. You are not removing a tire/wheel, so there is very little concern for safety. Good luck with finding the issue - hope it is just a cable.
 

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I purchased a 4240 tractor at auction last summer (1981, approx. 9000 hours)

The previous owner said that the "park" function stopped working after a transmission selector cable broke and had to be replaced.
When I bought the tractor the linkage cable for the "park" function was tied with baling wire so it could not be physically put in to park.

I have been told that its either an internal issue (likely related to the park pawl mechanism) or something external, related to the adjustment of the cable linkage.

I'd like to narrow it down to either internal or external.

Someone mentioned jacking up one of the rear wheels, making sure it will turn freely by hand, then engaging the park pawl lever by hand (with the linkage cable disconnected) and seeing if the wheel locks up?

Any opinions would be appreciated.

Suggestions on safely jacking up one wheel, etc. would also be great.

Thanks,[/QUOTE
suggestions--u can find on u-tube @one lonly farmer's channel, a video of just this problem being fixed on one of his tractors. which one :dunno:i can't remember, i can say it has been in the last 5 yrs worth of them.

do a search on u-tube, and see what comes up. good luck.
 

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4240 - brings back memories of days working a dairy farm. We had one and I serviced it quite a few times. What was suggested, as a test, sounds very reasonable to me. Jacking with a high capacity hydraulic floor jack, while on a stable surface should not present any issues. You are not removing a tire/wheel, so there is very little concern for safety. Good luck with finding the issue - hope it is just a cable.
Ditto what Phil stated. My guess is "new cable" was incorrectly installed IE not clamped at correct locations.
 

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Discussion Starter #5
Testing to see if "internal park pawl" is working

My heavy duty bottle jack arrives on Tuesday, so I plan to perform my test early in the week.

Is there a difference as to which rear tire I jack up in the air?

With the selector in neutral, the tire should turn relatively easily, correct?

Then, by-hand, I will push the park lever on the gear box as far forward as it will let me and that should lock it in gear.
At this point, I should no longer be able to rotate the tire?

Let me know if my process/logic seems correct.

A bit of history: I bought the tractor at auction and was told the "park" function did not work. They had used baling wire to tie the park cable in place so that you could not push it in to "park". That being said, I've never tried engaging park because I didn't want to damage something internally if indeed something was amiss with the "park pawl" in the gear case.
I removed the baling wire (with the tractor OFF and parked on level ground) and I was able to move the selector lever in to "park". When I did this the actual lever on the transmission case did move forward. But, I don't know if it is moving forward enough.
The cable is free and not frozen, but adjustment could be an issue- or of course it could have something to do with the park pawl mechanism internally.
 

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My heavy duty bottle jack arrives on Tuesday, so I plan to perform my test early in the week.
Cool. :good2:

Is there a difference as to which rear tire I jack up in the air?
Lift the tire/wheel on the same side as the park pawl lever. This way, you can turn the tire while moving the lever. :thumbup1gif:

With the selector in neutral, the tire should turn relatively easily, correct?
This is correct.

Then, by-hand, I will push the park lever on the gear box as far forward as it will let me and that should lock it in gear.
At this point, I should no longer be able to rotate the tire?
This is also correct.
 

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Also, check to see if this pin(#14) is missing.

Everything to the LEFT of the red line is Internal. To the RIGHT of the red line is External.

RP841__________UN01JAN94.gif
Some of the Internal items can be accessed by removing the transmission case cover.
 

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Also, check to see if this pin(#14) is missing.

Everything to the LEFT of the red line is Internal. To the RIGHT of the red line is External.

View attachment 334554
Some of the Internal items can be accessed by removing the transmission case cover.
Just an observation to prevent any confusion. Parts 11, 12, and 13 are internal also. The cam #10 is 1/2 inside and the shaft protrudes outside like the red line shows.
 

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Discussion Starter #9
(Some great news)... And next Steps.

So I raised the right-rear tire, verified it spun freely, then manually engaged the park lever on the transmission and it indeed does lock park.

Based on what I observed watching the cable move when connected, and what I had to do with my hand to turn the lever to engage parkion when the cable was disconnected, it appears the cable is not moving the lever far enough to actually engage the teeth.

The cable moves the lever on the transmission maybe 3/8 to 1/2 of the way of the turning radius.
When I engaged park by hand, I had to turn the lever about 5/8-3/4 of the way of the turning radius to make it lock.

So, I suspect I need to do some cable adjustment- which I'm very green at. No prior experience.
Additionally, what is the likelihood that the other cables for selecting gears need adjustment as well.

Does anyone have any suggestions as to the proper sequence and steps for cable adjustment?
Should I have a professional do the adjustment?

Attached is a photo showing how far I had to move the lever to get it to "lock". Does this look normal?

Thanks!
 

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My observation from viewing parts schematics is I think the cable adjustment choices are very limited. I wonder if something in trans selector is worn therefore not moving cable far enough to engage park pawl.
 

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Discussion Starter #11
Park doesn't function, 4240 (UPDATE)

As mentioned previously, the park pawl mechanism in the transmission works normally, based on jacking a wheel up and verifying that it locks.
I then verified that the cable moves freely (not seized or limited in range).

When trying to move the shifter back in to "park", it can't go behind the neutral detent.

(For those of you interested in back story, I was told at the auction that I bought the tractor at, that it was suspected that the park pawl was broken. They had used baling wire to prevent the shifter from going back in to the "park" detent, so I never tried to put it back in to park prior to verifying that the pawl worked. At this point of investigation, it is clear that the pawl would have easily been ruled out if I had checked the shifter function with the cable disconnected initially.)

So, forgive my lack of proper terminology, but here goes:

There is a "prong" on the "gearshift lever" (I highlighted it in red on the parts drawing) that comes in to contact with the "needle roller" on the "cast iron lever" (highlighted in pink).
When moving the gearshift lever aft (for park) the prong hits the needle roller on the cast iron lever and stops, it cannot move the linkage from there. It appears stuck/bound.

In my attached photo, I highlighted the same two components with the same colors (red, pink) to better show the parts I am talking about.

I am trying to determine, firstly, if these components appear like they are all in the correct position and that the way they "are supposed to work" seems correct. Secondly, if this all looks normal, then I'm looking for suggestions on diagnosing the reason the linkage cannot move aft to move the cable for "park".

I have a .pdf of manual TM-1181, but the scanned quality is so low that I can't see what they are explaining when they go-over assembly and adjustment of the entire shift mechanism.

Thanks!
 

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Discussion Starter #13
Issue within the shifter mechanism assembly (UPDATE)

I took 30 minutes today to play with the cable and mechanism and observe how things are working.

As mentioned previously, the cable functions freely and the park pawl indeed engages.

The issue seems to be within the mechanism of levers (for lack of a better term).

The actual shifter mechanism and the cast iron mechanism that appears to engage park don't seem to be working together properly.
The problem is, since I don't have a functioning 4240 to compare to, I don't know how they ARE supposed to function with one another.
The "prongs" don't appear to engage eachother correctly, but that's just my assumption, since I don't have anything to compare to.

Any opinions/suggestions?

Thanks in advance.
 

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