JD 445 FD620D rebuild

[beenthere]

Thanks Richard..
I found that K&T Parts House too, and printed chapter 6 pages 1-14 (or pages 93 - 106) and find the illustrations (figures) are too dark from photocopying to see any details.

If your service manual pages show clear illustrations, I can PM an email if you would be so kind to send just the Camshaft/Crankshaft section. If the same as K&T, then let's don't bother.

I may be able to decipher enough when into the engine from the dark pics to get by, but if would like to strive for better pics.

Thanks

Member buckshot721 sent me the eBay seller link who has a kit for the cam gear change-out. Looks like $280 including shipping, but not the water pump. JD parts and buckshot said it worked well for him.

 

[Zebrafive]

I replaced the cam gear in a JD 285 in 2016. It was the liquid cooled Kawasaki engine. Gear broke when trying to start.
I used the John Deere CTM39 (Component Technical Manual).
Drawings are great, pictures just OK, some worse than others.

I found a mistake in the section for the water pump. They labeled the mounting screws A B & C. They say to torque all to 70 lb - in, except B 186 lb - in. It is C NOT B that should be 186 lb - in. It's easy to see one screw is a larger diameter and takes more torque. That screw is C. Make sure you mark each screw's location a lot of different sizes.


Mine had 1100 hours and the cam gear failed, lost 7 teeth. I replaced the water pump and bottom crank seal, but not governor or oil pump gears (plastic, but looked great).


I also replaced the tappets/cam followers. Later I found new valve springs were recommended. I did not replace mine.


It ran fine for over a year, then was stolen in 2017

 

[L120]

Like you, I found that ignoring JD #'s and going straight to the MFG'r make model of the engine. If you have the time & patience to put a new rod in, that's admirable. If the engine is torn down this far maybe consider a shortblock. There are many small engines suppliers online.

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Nothing says you need to use a KAW or even the same HP as the old engine. Example: I replaced a 20HP B&S engine with a 27 HP B&S Commercial engine that has an oil cooler and many more rugged features. The only thing you need to verify is the shaft size and overall size if the engine to fit in the engine compartment. The bolt hole even aligned for my new engine.

 

[beenthere]

Started the tear down to get the 425 FD620D engine ready to pull.

 

[Gittyup]

I put a new Cam, water pump, oil pump, governor gear, push rods, and valve springs in my 425 a number of years ago. It was more work getting the engine out/in than actually doing the rebuild. I had the service manual, but really the JD dealer was the biggest help. They knew exactly what parts I needed and put the list together and I purchased directly from them. I suspect that is the best avenue for you too. Most dealers have done many of these cam jobs. I'm sure they can source the piston parts, block, and whatever you want. I think you can also buy this engine new from time to time on ebay.

 

[serefli1]

very interesting

 

[beenthere]

Have been poking along with this 425 engine FD620D, and today pulled the crankcase cover off.
Plan now is to just replace the plastic gear camshaft, the water pump, and the governor..

At an impasse now with trying to get the two Phillips screws out holding that oil screen in place in the bottom of the crankcase. For sure don't want to break one or both off and have to deal with that..

Before I pull out the camshaft, the plan is to hoist the engine upside down so the push rods and tappets stay in place. Hope that works as simple as implied. Any thoughts otherwise would be appreciated.

Have the engine sitting on my tool cabinet and found a plastic tray that just fits on top to allow cleaning the engine off before removal of parts. So far, the words of wisdom that the hardest part is removing the engine from the tractor holds true.

 

[Richard001]

Have been poking along with this 425 engine FD620D, and today pulled the crankcase cover off.
Plan now is to just replace the plastic gear camshaft, the water pump, and the governor..

In the photo you posted, that sure doesn't look like a plastic cam gear.

Before I pull out the camshaft, the plan is to hoist the engine upside down so the push rods and tappets stay in place. Hope that works as simple as implied. Any thoughts otherwise would be appreciated.

I will have to assume that you have removed the rocker arms to take any pressure of of the springs. Then your idea should work.

Richard

 

[beenthere]

Richard
I owe you big time... I just went out to the engine.. and stuck a magnet to that gear.. WHOA WHOA WHOA.. it is steel.

I've no history on this tractor prior to the 600 hours it had on it when I bought it. Given the serial number dating it to the plastic cams, and the low hours.. just presumed it still had plastic. Had I suspected plastic or steel when I took the water pump off, I had the opportunity then to put the magnet to the teeth before removing the crankcase cover but it never crossed my mind.

Now, the plan to button this thing up and move forward has taken a whole new direction... many thanks to you Richard.

Will keep you all informed but without the process of changing out the camshaft.. and I was kinda looking forward to doing it too.

bt

 

[Zebrafive]

For the two screws; the type of impact driver you hit with a hammer would be my choice of tools. Be sure to install a new crank seal.