646-75lbh Restoration

[Eugen]

Hello @Spike188 , I know you are busy, but when you do get a little time, could you please post your findings of the yellow paint you used for the backhoe?
thank you!

[Spike188]

This is the system that CarQuest, a local supplier to repair shops made for me. Unfortunately the can does not show the formula. I am impressed with the finish but the supplies were anything but cheap. I took a part to them that still had a sheen to it and they matched the color.

[Eugen]

Thank you @Spike188!

[Seabee]

Spike my cousin has a 6018 loader tractor that the steering went nutso yesterday. I wonder if he could call you or some one else on this board about your restoration (experience with the banana plate and mechanism).

If you send PM phone number I will get it to him.

Thanks!

Bill Moyer

[Spike188]

Update on the 646bh. This project got put on hold due to workload and health. If a plan comes together, the engine, transaxle, and hydraulic pump will get attention this winter. Wish me luck. Covid has been breathing down my neck for the past 2 weeks. Now the wife is kicking my butt every time I mention doing a service call. Sometimes a guy just can't win.

[Spike188]

Guy's I have been running on reduced energy for 2 years and this project got put on the back burner. With @thebuildist and @Eugen both working on D100's it seems appropriate to add to this thread. The D100 rebuild started before this site was began. It may take me a while to migrate the complete rebuild over.

For now I will pick up the rebuild as it stood on July 20, 2020

This is my second 646 restore. There was a big learning curve on the first one. Based on the end results of the first loader there are things that will be approached differently.
#1 Assess the parts needed and prioritize which should be sourced first.
#2 Do not put off getting each step completed.
#3 Commit to replacing end of life parts before proceeding to the next step.
#4 Have a plan.

Thise time around the engine will get more attention.

The kicker here is that the exhaust is missing and not available new. I would like to find a 646 exhaust manifold and figure out what kind of muffler will be used.

The engine that came with the tractor is a CCKA MS/280J 0475 93480S.

A cold compression test showed zero on the LH side and 95 on the RH side. Being able to feel air movement at both the exhaust port and sparkplug hole indicated a stuck valve. After removing the carburetor manifold and valve inspection covers a stuck intake valve was confirmed. The left hand head was removed.
Using a light hammer and some very hard hits the intake valve was freed up. While the head was off a visual inspection of cylinder and piston fit bottom dead center egg shaping of about 0.015" was visible. The upper ring could be seen clearly at the top of the piston. At top dead center the egg shaping disappeared, hiding the upper ring, leading me to think that the cylinder boar is the issue. With the head reattached a compression test with the possibly bent valve was LH 95/ Rh 85.
​

[Spike188]

July 24, 2020
The 646 came with an extra Honda engine. I was not keen on installing the Honda because of wanting to keep the rebuild as original as possible. Getting your feedback help confirm that the CCKA replacement is the proper way to go. I have watched enough exhaust videos that build a muffler will be easy.

Exploratory surgery was preformed on the CCKA-sm j earlier in the week. Wiping down the cylinder walls and looking at the piston clearance made me cringe. The compression ring can be seen when the pistons are at bottom dead center.

One tool missing in my arsenal was a short inside micrometer set. A quick look on Kijij and I found a Starrett inside mic set and picked it up last night. The inside mic along with the outside set already in the toybox confirmed my suspicion.

The pistons are shot, upper ring groove has .015 slap, the piston wear below the oil rings was measurable and above the compression ring off the charts. Boring the cylinder 0.010" would clean the bottom dead center ridge up.

I did find a couple of surprises. I woke up in the middle of the night and realized that the armature was missing. I overlooked that when pulling the flywheel. Why would someone intentionaly attempt to run a tractor without a charging system? Another surprise but understandable was the nice aluminium weld job where a mounting foot had broken off of the oil pan.

I have seen the short blocks advertised but am considering doing the rebuild myself. ​
My guess is the Honda will go a long way toward putting a CCKA back into the tractor.

Digging in,
Eugene

[Spike188]

July 27, 2020

I love it when a plan starts coming together. Lionel came through with a new muffler, and several sources for engine rebuilds are helping out.

Now for the sad story. The tractor was pressure washed Saturday. Once the deep layer of dirt and oil were removed the abuse this tool received was apparent. A previous owner used the loader bucket to "plant" the tractor when over working the backhoe. The frame was nearly torn in half before being patch welded back together, hidden inside the tower and frame.

The cross member is bent and ripped loose on both sides of the frame.

The under carriage bracket bolts are sheared on one side. This explains why the under carriage arms have the pin locator holes crudely torched out.

The cross member could be cut out cleanly and duplicated and pulling the tower back to its proper location could be accomplished. Metal fatigue can not be overcome without glove plating. Replacing the complete frame would facilitate
finding the original under carriage hole centers easier.
​
If an 75 or later 646 Loader frame can be found, replacing the frame makes sense. A loader frame will not have been stressed and weakened like this frame is.

So this is a distress call. Does anyone know of a 646 loader frame for sale? ( I did some horse trading with @SylvesterCalzone aka Mike for a 74 646 frame)

Eugene

[Spike188]

July 27, 2020

This is the one Mike sold me. I gave him a Cub Cadet in partial trade.

[Spike188]

Mission accomplished! A nearby CCI member had a basket case 646

and I had a bait tractor. He wanted a Cub Cadet 125

that I had purchased from a neighbor a few years ago, so a trade was made.

I thinks we are both happy.

The donor tractor is missing the travel control valve, loader valve, bucket, engine, and serial number plate. It is one of the tightest, low wear tractors of this era that I have seen.

Next step is back to work on making an engine.

Digging in,

Eugene