# Ford 850 5 Spd Popping out of Gear



## ErnieChilton (Jul 25, 2014)

When my main tractor went down for repairs, I decided to hook my bush hog up to the Ford 850 that I spent several years rebuilding, I had a couple of surprises:

1) If any of the lift pins on what you are hooking up are bent, it is next to impossible to hook up stabilizer arms. I had to remove them and use chains.

2) The 850 has a single clutch, my main tractor had a double clutch. This means that ever time you need to shift, the pto must be disengaged if the blades are still turning.

Those are things that I can live with. My biggest problem is that it wants to pop out of gear, making the pto disengagement a real pain. Have to disconnect, put back into gear and wait for the blades to stop before engaging the pto again. I have to hold the gear shifter in place while steering a non-power steering tractor with the other hand. I installed a “red neck power steering adapter” (sometimes called a spinner), which helps a little, but fixing the gear problem is the real answer. Here are the particulars:

1) It happens in 3rd gear (haven’t tried the other gears), especially when you relieve the pressure on the gears when going down a slope.

2) Have not had it pop out of gear just riding around with no attachments and without the pto engaged.

3) The keyway on original shifter shaft was badly worn giving a lot of slop in the shifter. Drilled a hole in the shifter and tapped it for a set screw. This takes all the slop out and is very tight. I can buy a used shaft for $100 but don’t see how this would solve the problem since there is no play in the shaft now.

Is there anything internal to the transmission that could cause the problem? Also if I remove the top cover does the gear shift shaft (NDA 7212) lift out cleanly or would I have to tear into the transmission to replace it?


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## RC Wells (Dec 26, 2008)

Take a look here: https://partstore.agriculture.newholland.com/us/parts-search.html#epc::mr55137ar396440

The top section is usually removed by removing the shift lever first, then the case plate. The shift arm itself will pull up and out with a bit of working it around the interlock plate.

The interlock on these is the plunger and spring under the plug #13. It rides over grooves that serve as the detent locks in the bottom of the shift arm. 

The usual culprit is a weak spring #11, or a worn out plunger #10.

Other causes of blowing out of gear are the lock bolts and nuts on the shift forks get loose and allow a gear to only partially engage, the lock bolts on #36 and 37 work loose, or the interlock plate wears out. Or, a gear gets so worn it is beveled and blows out of mesh from torque.

If you pull the shift arm, drain the oil first, then remove the components under plug #13.


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## sixbales (May 18, 2011)

Howdy Ernie,

I copied the following post written by *HB~~in NC* on the YT forum":

"You may not have as much of a problem as you might imagine. The 5 speed transmission has a tendency to jump out of 3rd and reverse, since these are across from each other at the top of the shift pattern, and get used more than the other gears. Often times it will jump out of gear because the gears do not fully engage. This is because the tapered, square head, set screw that holds the shift fork in position on the shift rail, has loosened and will not fully engage the gears.
If you catch it when the problem first begins, often times tightening the set screw will let the shift fork push the gear into the fully engaged position and eliminate the problem of jumping out of gear. While you have the top off the transmission, tighten the set screw on all 3 shift rails and be sure to replace the safety wires.
If this problem has been going on for a long time, my suggestion may not solve your problem. In that case, get ready to spend some money. However, the 5 speed transmission is a very good transmission and is worth putting back into shape."


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## ErnieChilton (Jul 25, 2014)

Guys -

Thanks for the replies. I like the way you present the various solutions, easy first with ball busters last. I at least don't get discouraged as soon as I read the first sentence.

One new bit of info, this morning I did some more bush hogging only this time I used 2nd gear, slower than I would like, but no problem with it popping out of gear. I think this isolates the problem to 3rd gear, don't know about reverse since I find it difficult to bush hog in reverse.

Using the solutions you listed, I will first try replacing the plunger/spring. However this seems more unlikely now that I have isolated the problem to 3rd gear. If that doesn't work then I will lift the cover and check the shift forks. If it turns out it's a worn gear I will put off tearing into the gear box at least until I get my main tractor up and running.


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