4020 crankshaft and flywheel

Craig C · Posted: Sat Feb 05, 2011 4:40 pm Post subject: 4020 crankshaft and flywheel

I am trying to figure out a riddle on a 4020 cranksaft. We are restoring a 4020, that was in the basket when we got it. Here's the tractor numbers T213R 149690R on the rear housing. The crank we are using is a new one that came from our dealer. It has one dowel pin and six bolt holes. It appears to be a replacement crank for a 4020 late. The fly wheel we have is a Part# R40727 with two dowels and four bolts. This is a desiel syncro tractor. The JD online parts catalog didn't give enough detail identify what I need. I am hoping that all I need is a late 4020 flywheel. Can anyone be of help.

rexhellwig · Posted: Sat Feb 05, 2011 4:59 pm Post subject: Re: 4020 crankshaft and flywheel

I reserve the right to be wrong, but Deere hasn't made any 4020 replacement cranks with 4 bolt holes in at least 20 years. They are all six bolt these days.

The four holes in your flywheel will align with four of the holes in the crank. You are supposed to install set screws in the other two holes to prevent engine oil leaking into the clutch housing. I install these set screws with Loctite and slightly disturbed threads.

You don't need six bolts unless you are building some super-duper hot-rod. If you are, you shouldn't be using a Deere flywheel.

Craig C · Posted: Sat Feb 05, 2011 5:15 pm Post subject: Re: 4020 crankshaft and flywheel

I thought that might be the case, but I wasn't sure. I put it up there and it looked like every thing would line up. It felt like the flywheel would be very tight on the crank, but a little more cleaning and it should pull up on it. This is just a classic restoration project. We actually went to great lengths to have the original block repaired, so that the block number would be an early like the tractor is. Thanks for the help.

rexhellwig · Posted: Sat Feb 05, 2011 5:44 pm Post subject: Re: 4020 crankshaft and flywheel

Sounds like you have a little work ahead of you.

- and maybe some $$$! :)

Take a few pics along the way and post them when you are done.

tim s · Posted: Sat Feb 05, 2011 5:50 pm Post subject: Re: 4020 crankshaft and flywheel

To add to what Rex stated, don't tighten the allen screws clear in, just a little past flush and let the loctite take over. On some older 4020 flywheels you need to turn a bit out of the center to get them to fit the crank center and let them fit up against the flange.

Bob · Posted: Sat Feb 05, 2011 6:40 pm Post subject: Re: 4020 crankshaft and flywheel

Even 4630's use only 4 bolts!

Don't WORRY, be HAPPY!

tim s · Posted: Sat Feb 05, 2011 6:43 pm Post subject: Re: 4020 crankshaft and flywheel

That's true and I have seen a few of them shear them....

Bob · Posted: Sat Feb 05, 2011 6:55 pm Post subject: Re: 4020 crankshaft and flywheel

Yep, I gotta agree with you on that Tim, just one I've dealt with though!

Tx Jim · Last edited by Tx Jim on Sun Feb 06, 2011 4:48 am; edited 1 time in total

According to JDparts.com this part # should fit your 4020 SN 149690
19H3385 CAP SCREW 4 1/2" X 1-1/8"
Part Number: RE63292
Replaces Part: AR26431
Part Price: 3,070.00 USD
Core Value: (600.00 USD)
End Price With Core Return: 2,470.00 USD
Description: CRANKSHAFT,DYNAMICALLY BAL ASY/PART

The photo for part # RE63292(marked R26560) in parts shows 2 dowel pin holes and 4 bolt holes. No where does it mention 6 flywheel bolts required.

I also looked up 4020 >SN 201000 and it only lists 4 flywheel bolts 19H3385 CAP SCREW 4 1/2" X 1-1/8"
Part Number: RE53422
Part Price: 2,470.00 USD
Description: CRANKSHAFT ASSEMBLY (PARTS)

Craig C · Posted: Sun Feb 06, 2011 4:50 am Post subject: Re: 4020 crankshaft and flywheel

So you are saying that more than likely we will need to chuck it back up in the lathe and cut the center until it fit? When I held it up there I though that the surface rust was holding it off. Are all 404s four bolt? We have never had the perma clutch off our 4230, but we have had plently of 466 flywheels off and they were all six bolt. Thanks.

tim s · Posted: Sun Feb 06, 2011 6:43 am Post subject: Re: 4020 crankshaft and flywheel

Yes that's probably what you will need to do, most of them have a slightly smaller center hole,just enough to keep them from setting onto the newer crankshaft, I think all 404's were 4 bolt, I'm sure your 4230 is 4 bolt.

Tx Jim · Posted: Sun Feb 06, 2011 6:48 am Post subject: Re: 4020 crankshaft and flywheel

Craig C
What is the part # on the crank you bought??

Craig C · Posted: Sun Feb 06, 2011 7:17 am Post subject: Re: 4020 crankshaft and flywheel

Machining the flywheel is not a problem, however I do have a question. Does JD have a six bolt flywheel that will fit that replacement crank? The dowel was sheared from the old crank and was stuck in the 4 bolt flywheel, so it looks to me that six bolts would be better if we could find one. We aren't building this tractor to use on the farm other than light hay work, but it could make it to the local tractor pull come June. Will the stock clutch take more torque than the four bolts, or is it the other way around? Thanks for the help sounds like you have been where we are at on this thing.

Kent Petersen · Guest Report to Moderator

you say you had the block fixed i hope that dont mean welded i have seen several that were welded and they all cracked right out side edge of weld welders tell me the cast is aolloyd and will not hold a weld

Mike M · Posted: Sun Feb 06, 2011 7:22 am Post subject: Re: 4020 crankshaft and flywheel

Wonder what's up with the core value ?

Is that a reman crank # ?

I think I heard about some brand new Deere engines the buyer was getting charged a core value. Why is Deere messing around with cores on NEW parts ?

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