Another thing to look at on my 648

[JSinMO]

First the disclaimers:
1) I have no doubt this has been discussed 1000 times. Please keep in mind this is my first GT. And first time working on a hydraulic drive system.
2) ras101 has posted a similar topic on travel control, but my understanding is the 446 and 648 are set up different. If that is not the case please let me know and we can discard this post.

So now that I’ve started using the machine I notice it seems to have trouble moving on uneven ground. Part of the problem is I don’t know what the characteristics of the 648 or any similar tractor should be. I would put it at anemic bordering on gutless going up hill.

I got my first clue the other day backing it out of the shop. When I depressed the foot control I noticed the direction control lever moved on its own. I held the lever in place and had much better response and a much better pedal. It was soft with a lot of free travel before.

A quick check of the owner manual showed me this is a common adjustment point.

I’ve looked through the technical data here and read quite a bit online. It seems pretty straight forward. I see where the wear points would be. And how it should work.

You guys have made this repair before, I have not. What are the tips, short cut, things to know that a 1st timer wouldn’t pick up from looking at pictures and reading technical data.

Just like the power steering cylinder, I don’t think this repair is an emergency and may get put off till fall depending on how the other irons in the fire go.
This may come down to just needing adjustment, or, I may be rebuilding the linkage.

At this point I’m just gathering information, it makes it a lot easier for me when I’m actually turning wrench.

Thanks for taking a look and for you thoughts.

[Eugen]

I'm following this with interest as this is something that I need to look into in the future!

[JSinMO]

I took a quick look underneath this morning and checked it out. The control plate seems to have quite a bit of play in it. I can move it quit a bit by hand. My first thought was to weld the egg shape holes shut and re drill them, but I don’t know, might be smarter to just get a new plate and linkage.

I adjusted the travel control lever per the instructions in the book, but it really didn’t help. The lever still moved on its own when depressing the foot lever. This indicated to me the friction disc is either well worn or nonexistent at this point.

I guess I need to decide how I want to make repairs and go from there.

[Spike188]

@JSinMO I have a new banana plate here and the 646BH bare frame on stands bottom side up. I might be able to get some pictures of the plate that will help you in the morning. These would be easier to adjust on a hoist but my method will be to do all of the bottom side assembly before flipping the frame. My Mrs says that she will be dead before it is finished because I haven't learned how to tell customers "No". I am learning slowly.

I put a new plate, linkage, and bushings on the 646L and have never finished the proper adjustment. Part of the reason is that the new plate is a bit thicker than the original and binds in the frame.

Spike

[JSinMO]

@JSinMO I have a new banana plate here and the 646BH bare frame on stands bottom side up. I might be able to get some pictures of the plate that will help you in the morning. These would be easier to adjust on a hoist but my method will be to do all of the bottom side assembly before flipping the frame. My Mrs says that she will be dead before it is finished because I haven't learned how to tell customers "No". I am learning slowly.

I put a new plate, linkage, and bushings on the 646L and have never finished the proper adjustment. Part of the reason is that the new plate is a bit thicker than the original and binds in the frame.

Spike

I gladly take any pictures and advice you can offer!
A hoist would be nice. My plan is to set the tractor on cribbing and slide underneath when go to make the repair. It always make me nervous laying under something that’s not supported good!
Your Mrs is probably right, mine tells me the same

I appreciate the info.

[Harry]

When I replaced the control plate, Banana plate on my 646, I just jacked it up and supported it with jack stands. On my 644 I lifted it with the stabilizers on the rear and used the bucket to lift it up, then put jack stands under it. The I rebuilt the fame that was cracked by welding the frame and reinforcing it with custom made plates over the cracked areas. All welded in the overhead position. It took two days of hard work to complete.
Safety first boys. Always take the time to support it properly.

Keep the Peace
Harry

[Spike188]

I have been cleaning shop and reorganizing because the banana plate parts were hiding.

The black plate is the new one with ball joints and a different moon profile.

But the biggest difference is the overall plate thickness.

When replacing the plate on the 646L I may have not opened the frame mount enough or did not get the mount angled correctly. Hopefully work on the 646BH will commence soon.

[JSinMO]

I have been cleaning shop and reorganizing because the banana plate parts were hiding.image.png

The black plate is the new one with ball joints and a different moon profile.image.png
But the biggest difference is the overall plate thickness.

When replacing the plate on the 646L I may have not opened the frame mount enough or did not get the mount angled correctly. Hopefully work on the 646BH will commence soon.

Thank you for the pictures and info.
So the new plate is thicker to accept the ball joints. I can see why that would bind on the frame mount without adjusting it.
Looking at all the pictures of yours and mine it appears the moon or banana cut out on the plate really doesn’t take the wear. The linkage points are the real problem spots. That kind of takes me back to my first thought of marking the center point welding them up and redrilling my existing plate.
It also make me think that while they work together the control lever moving on its own probably should be addressed first.

Dang it, now you’ve got me wanting to go tear into it!
I might have to move this up on my list of thing to do!

[Eugen]

This topic is timely and applies to me as well, the lever on my 644 gets stuck sometimes in Forward or Reverse, and it takes quite some wiggling to get that unstuck.

[JSinMO]

This topic is timely and applies to me as well, the lever on my 644 gets stuck sometimes in Forward or Reverse, and it takes quite some wiggling to get that unstuck.

Sounds like yours may be worn more that mine. If you can get a couple of pictures of it maybe we can compare them all against spikes new one.