67 Farmall 656

[Pete656]

I recently bought this tractor knowing it had a tick in the transmission, as the guy said. I bought it a
On a cold day and drove it quite a ways to warm it up..no noise. Drove it home 15 miles, tick tick couldn't hear it on the seat but here is what I found. Another question, about .025 gap behind on the reverse idler shaft..?

 

[Pete656]

I recently bought this tractor knowing it had a tick in the transmission, as the guy said. I bought it a
On a cold day and drove it quite a ways to warm it up..no noise. Drove it home 15 miles, tick tick couldn't hear it on the seat but here is what I found. Another question, about .025 gap behind on the reverse idler shaft..? View attachment 66147View attachment 66147View attachment 66147

When I pushed idler shaft gear to the rear about, a .025 gap between front of sprocket and housing.

 

[Janicholson]

Something hard got between the reverse Idler and the gear on the countershaft. I think I would run it as is, knowing what is in there is important, but not life changing. Jim

 

[Dieseltech]

I don't think there's anything wrong with the idler, it needs some end play to get oil for lube anyhow. How does the rest of the gears look, AND ring and pinion gear teeth?

 

[rustred]

So what are u saying u found ?that’s probably normal for the idler to slid on the shaft that much. I see what looks like a chunk out of one spline in the top pic at the bottom. Gears don’t look all that bad , saw a lot worst.

 

[used red MN]

Hello Pete welcome to YT! That end play on the reverse idler shaft is not an issue. There are just bushing in there. Here is the parts break down #39. CNHI Farmall 656 parts catalog (FYI, You can view all the parts sections for your tractor from that page) The gears probably just have machined flats that ride against flat surfaces on the case. Very likely what happened to your gear teeth was caused by the poor shifter design on those tractors along with somewhat reckless operation. I believe that is 2nd gear with the distorted teeth. What happens when the shifters wear is that the selected gear will not get pulled into the neutral position. Then the when the next gear selected is engaged, now you are in two gears at the same time locking the drive train. So the damaged gear was not fully engaged and when the clutch was let out the engine torque distorted the teeth, more plainly began the process of stripping the teeth off. In real careless operation this can even be caused by the momentum of the tractor. I know I did it to the 656 we had on the farm growing up. We had a 3 point blade on it. Clean cow lots and also used it turned around to push snow into piles. The shifter on that thing made a lot of trips between 2nd and reverse, also 4th and reverse. It was common to lock it in two gears about once every 15 minutes when doing those tasks. If you moved the shifter back to the gear you came out of it would usually release. Occasionally you had to use a pry bar on the shift linkage up above the transmission to get it right again. If I remember right the coast side of 2nd gear gave the loudest ticking in that tractor after that happened.
rustred, I circled the problem area in this photo.

 

[Mrfred54]

Have seen it before. I take my die grinder with carbide bit and clean the tooth up to match the rest off the tooth, clean up the housing, put everything back together and no more noise