Case 646 Repairs

Case 646 Repairs:

Needless to say it took a little work, Money and time to get the $1400 non-running tractor into the shape its in now.  As of Spring 2019, the 646 has had:

The Rear Axle / Transmission had to be torn down and rebuilt. Transmission - Rear end rebuild and modifications

As part of the transmission rebuilt I decided to go ahead and run a full gallon of Gear oil in the transmission, that should ensure that the axle shafts are bathed in oil all of the time: Transmission fill levels, how to put 1 gallon of oil in the Rear end.

I knew if I added a 3 point hitch on it the tractor it would be much more useful.  For example to move the flatbed car hauler trailer around the yard, and to use the rear blade on the driveway, etc.

3 POINT HITCH

The OEM 3 point hitches for the loader models are kind of rare. What most often is available are the newer Ingersoll HH-34 model of 3 points. Which are REALLY nice.. But after putting $1400 into the tractor and not yet having had it out of the shop and running, I wasn't going to sink another $500- $800 on a 3 point hitch. I found a home made unit that was designed for a 4xx series, which meant I had to modify it to fit.  Modified 3 point  

Now with a 3 point hitch on the back of the tractor, the weight box can not be bolted back on, so I made an adapter for the weigh box so I could use it on the 3 point: Converting OEM Weight Box to 3 point mounted

IGNITION COIL

During the process of getting the tractor up and running, I somehow blew up the original Onan ignition coil. Apparently Onan dual output coils will fail if you crank the engine without grounding the sparkplugs.. Which kind of contradicts the directions in the owners manual on how to drain the oil,...

Therefore I needed a replacement ignition coil.  And Onan Coils are NOT cheap. The OEM part tops $150.  I found some information on using a GM DIS (Distributorless Ignition system) coil, which just happens to be a dual output coil just want is needed for an old Onan flathead. I documented the process I used on the CCI forum.

REAR TIRES

The original rear tires were basically bald, so I replaced the rear tires, not once, but twice. New Rear Tires, first 15 inch rims, then 16 inch rims to accommodate 160 Pound "combine" wheel weights

The first set of tires worked really well, but the 15x7 rims on the 646 are kind of hard to find tires for.  I REALLY needed more weight on the axle or in the tires, which keeps it OFF the axle bearings in the rear end (that I had previously completely rebuilt). Weight in the wheels either as liquid ballast or wheel weights do not bear on the rear end bearings.. Weights in the wheels only come into play when you lift something, of course it's also good for traction and the stability of the tractor...

The 646's loader can pickup more than it could handle even with the weightbox full of cement.  The best option I came up with was to move up to 16 inch rims (I had scrapped a Case 446 tractor, so I had a pair of 16 inch rims that would fit).

The 16 inch rims allow me to put these 'combine' weights in the wheels, so that I have  320 pounds of wheel weights on the tractor. Plus the new tires, Carlisle 7-16's are filled with 'Rimguard' - beet juice liquid ballast for another 220 pounds. So not counting the rims and tires I have 550 pounds of weight on the rear end.  And we can still pull the rear end off the ground.

Travel Control & 'BANANA Plate

I can understand why Case wanted to stay with the 'Direction control' handle on the Loader tractors, because that was the setup used all of the Colt and Case garden tractors had used before..

But when running a loader, you're kind of got your hands full, literally, usually steering with one hand and controlling the loader with the other hand. Therefore, Case added a foot pedal to operate the travel control, in conjunction with the existing Travel control lever.  The original travel control lever on the loaders determines the direction of travel; forward or reverse.  And the right side foot pedal controls how fast the tractor goes..

BUT, having two controls lead to the design of the much talked about "Banana plate" in the loader tractors. The travel on all CCI tractors is controlled by a hydraulic spool valve, pull the valve spool out the tractor travels in one direction, push the valve spook in and the tractor travels in the other direction.

Which means the linkage from the pedal to the valve needs to reverse the action of the pedal for this to all work.  To go in one direction, pressing on the travel pedal needs to pull on the spool valve and in the other direction pressing on the pedal needs to PUSH on the spool valve.. So how does one engineer such a mechanism?  You use a 'toggle' or as it is called on Case Loaders, the Banana Plate.

You can click on that parts diagram to get a larger view.  The travel pedal on the lower left has a pin bolted into it that moves the left end of the 'Banana plate' (our toggle) forward as the pedal is depressed.  The direction control handle and the rod coming off it, sweeps back and forth in the curved slot of the banana plate and that rod and bushing is actually the pivot point for the banana plate.

When the direction control is pushed forward, so the tractor will move forward, the rod and bushing are located to the far right in the slot of the banana plate.

That point on the far right is now the pivot point for the banana plate.  When the travel pedal is depressed the Pedal control rod (#7 in the diagram) moves the left side of the banana plate forward, the spool valve is connected in the center, which results in the pedal pulling the spool valve OUT, routing oil to the drive motor, and the tractor moves forward.

When the direction control handle is pulled BACK, so the tractor will move backward, the rod and bushing are located to the far left end of the slot in the banana plate.  Now the pivot point is on the opposite side of where the spool valve is connected. In this case pressing the travel pedal will still move the extreme left side of the banana plate forward, but the plate will now pivot on the left end of the slot and push the spool valve IN. So the oil to the drive motor flows in the opposite direction.


I have had my share of fun correcting the issues on my Tractor, and there is more information on the CCI forum if you are working on this area of your tractor.

Correcting Banana Plate wear & alignment:

Banana plate part by part breakdown (Lionel)

How Banana & TCV work and adjustment procedures

The Photo above is from a repair I did on a "new" Ingersoll 6020 where the bushing was popped out of the banana plate, read all about that repair here


We also replaced the main hydraulic pump, rebuild the loader valve, added a Divider valve for the power steering system we built. The tractor now includes a hydraulic filter in the return line.  And Lots and lots of other repairs..

Most of this is documented on the Case Colt Ingersoll forum, so I will post links instead of recreating all of that.













Temporarily patching suction - Air Leaks in the Hydraulic system.

Basically if you have a Case 646 with a serial number before 9758236 you REALLY should replace the hydraulic pump. The suction line on the OEM pump will start leaking air and you will experience a significant power loss.

"Banana Plates" or correcting Speed & Travel issues.

Onan CCKa Engine:

Another area of the Case 646 that is different is the Onan CCKa engine in them.  On the one hand the CCKa is Onan's industrial version of their twin cylinder engine. The CCKa has a 1 gallon oil pan on it instead of the 3 pints on the B series. Which means monitoring oil level is not that Critical and more oil means the oil does not become contaminated as easily. There is also a spin on oil filter and pressure lubrication.  The CCK is a really a solid engine. Its rated at 16.5 HP constant output instead of other engines being rated at PEAK HP.

What makes the CCKa a challenge is some of the unique parts on it, like the Marvel Schebler Carburetor.  The CCKa has a MS VD-65 carb on it.. Which are not as common as the Nikki and some other carbs. There are parts available and some alternate parts sources also exist..

Marvel Schebler VD 65 Manual

Steering

My Case 646 is a 45 year old tractor and it had not seen an easy lift. One area where proper maintenance could have really helped were the front steering spindles and bushings.  When I got the tractor, the grease fittings on the front axle had been broken off and I have no Idea how long it had been running with out being greased, which lead to some extensive repairs to the steering..

Its is kind of interesting how basic the front Axle design is on these Loaders, the Literature describes the front axle as being designed to handle 3000 pounds.


And my Tractor ran fairly well for a about a year until the fall of 2018 when the ring gear came off the flywheel.  Because I had to disassemble the tractor to the point of getting the engine off of the frame, I spent about 6 months (November 2018 -> May 2019) doing a major rebuild of the tractor including designing, building and installing power steering on the 646

Once I got the engine off the tractor I found that the loader control valve needed work

And the steering Sector Gear was worn and needed work

As part of the Power Steering install, I wanted to add a Hydraulic PTO valve to drive a Rear tiller and maybe log splitter. Plus I wanted an additional hydraulic remote circuit, the 3 point used the OEM "lift" circuit, so I could run a grapple or Thumb like device on the bucket or pallet forks. So I used a "TCV" dual spool valve from a Case 446 that I scrapped.


Tire Chains
http://casecoltingersoll.com/showthread.php/72770-Tire-Chain-Modifications

Bucket Hooks
http://casecoltingersoll.com/showthread.php/73346-Bucket-Hooks-for-the-646

Mufflers:
http://casecoltingersoll.com/showthread.php/71586-New-member-646?p=596506&viewfull=1#post596506
http://www.mytractorforum.com/11687569-post332.html
http://casecoltingersoll.com/showthread.php/73482-Ingersoll-648-muffler

Loader Fenders
http://casecoltingersoll.com/showthread.php/70106-600-series-loaders

Oil changes:
http://casecoltingersoll.com/showthread.php/69570-Hydraulic-Oil-Change-648BH

Loader bucket Slop
http://casecoltingersoll.com/showthread.php/75721-646-bucket-slop

3 Point Differences - Modifications:
http://casecoltingersoll.com/showthread.php/76369-644-rear-pto-3point-question?p=638969&viewfull=1#post638969

The Mighty Loader:
https://casecoltingersoll.com/showthread.php/78234-The-Mighty-little-LOADER-(646)


Lionels 646 REBUILD
http://casecoltingersoll.com/showthread.php/39073-Case-646-75

Lionels 648 REBUILD
http://casecoltingersoll.com/showthread.php/54474-Case-648-81

155 3 point:
http://casecoltingersoll.com/showthread.php/60825-Home-Made-3-Point-on-Case-155


Rust Welding: https://casecoltingersoll.com/showthread.php/83443-Corrosion-amp-Rust-Welding

Worn JIC Connectors: https://casecoltingersoll.com/showthread.php/83331-Worn-JIC-connectors-Tractor-age

Tiller repairs - remove the stub shaft: https://casecoltingersoll.com/showthread.php/83543-HT41-Tiller-Repair