2630 flywheel timing bolt hole, with broken pin?

[chickenfriend]

Here is a picture of a 2630 flywheel showing the timing pin hole.

The chamfer seen is 2mm deep, and then there is 1mm of depth after that for the actual hole.

Is there a piece of timing pin bolt broken off in the hole?

I'd like to know how deep this hole is supposed to be.




 

[Tx Jim]

It's been a long time since I looked at a flywheel but I'm fairly confident there's something stuck in timing hole.
 

[chickenfriend]

Thanks.

I finally decided to drill out the hole about 3-4 more mm, enough that a bolt will go into it enough to be perpendicular and index the flywheel to the frame sufficiently.

I used a drill size just under 3/8"

My neighbor has a 2030. When I get a chance, I 'll probe the depth using the housing cover hole, or if he ever has to replace his starter, I'll measure it directly.

At this point, the hole is good enough to get a TDC reading, so that is taken care of.

I am not sure how much any of the pin left in the flywheel is going to affect the flywheel balance, probably not anything to worry about, I never go over 2100 rpm.
 

[chickenfriend]

Yesterday, I did get a reply back from John Deere (which I should have been more patient for).

Here is the information they sent me. Perhaps there are one or two people out there that this may help:

"This tractor shows 3 flywheels, but the timing pin hole dimensions are the same on all of them as below:

.368 Drill .120 [3,05] Deep

.550 [13,97] x 120 degree csk"


The .368 drill is between 23/64" and 3/8". Originally, I thought is was a 3/8" drill, but that is a little too big. Why I assumed that was because a 3/8" bolt is the largest size that will fit through the pin hole in the flywheel housing.

I don't have the original bolt-pin that secured the timing plate to check the diameter (because it was sheared-off).

I assume the .120 is the depth, which is not very deep, only 3mm, about what my hole was originally, I think. So maybe it was ok, afterall.


The chamfer on the hole is by a .55" drill with a 120" countersink.

Typical lesson learned here is not to assume anything (I seem to re-learn this regularly).
 

[tim s]

I was kinda thinking it was about the right depth so that if it was turned with the pin in it would push it out and away from the flywheel. A guy that worked with me at the dealership hit the starter on a 4230 with the pin in the hole, it bend and stuck, he had to split the tractor to free it...
 

[chickenfriend]

Yes. I was thinking the same thing, knowing what I do now.

Perhaps they had a good reason not to make that hole no deeper than necessary; and with a little bit of play with the pin in the flywheel housing, it was more likely that the pin would be pushed out if accidentally left in.

It just didn't seem to me that 1mm was much of an insertion depth into the straight hole, and I had a local John Deere mechanic tell me the depth was about 3/8", he thought.

I don't have the original pin, but if the end is rounded ( I think it was) or tapered, it is possible it also fits the chamfer region, too, and in that case, the pin could have a 3/8" diameter, indicating I was thinking the wrong way about it.

If I need a substitute pin, I use a section of brass or cheap steel, and not something like grade 8.
 

[tim s]

The original pin was soft, the big thing is not to forget and crank the engine with it in...it's a locator, not a lock. I've god a 2030 out side waiting to come in..I'll look at it closer when I split it..
 

[chickenfriend]

[Tech 7]

My timing pin (JDE81-4) measures 0.338" if that helps
 

[chickenfriend]

That's good to know. Thanks. I'll add some more information, too.

The original fastener for the cover plate, which was thread on one side and timing pin on the other, has superseded to a plain 50 cent hex bolt, as it appears in the parts catalog.

The turning tool is still available as ServiceGuard SPX tool, and can only be ordered through a John Deere dealer. It is tool JD-281A (my old shop manual calls it JDE-281). Last I checked a couple of years ago, it was 99$.