JD450B timing gear

[np205]

Is is possible for the timing gear to move during injection pump removal/ installation?

When engine is at TDC, (pin in hole) pump shaft mark will not align with mark inside pump.

Cannot rotate pump enough toward manifold to align shaft tang inside of pump.

Cannot find any serial numbers on machine. (tag under seat is missing)

Engine has casting number T32342D under alternator.

Pump is JDB-S2802.

Thanks for any info.

[jdemaris]

Is is possible for the timing gear to move during injection pump removal/ installation?


Pump is JDB-S2802.

Thanks for any info.

No, the timing gear teeth cannot move out of place just from having the pump out.

That pump # is probably wrong. Closest match is the pump used on the last 450Bs and early 450Cs - it's a JDB435MD2802.

[np205]

Thank you for the reply.

Would have taken the nose and timing cover off to check.
Lot of extra work...

The pump also has a number of AR-51747.

Was there a change in the pump models during the 450B series?

I could not find a tag on the engine below the alternator displaying serial number.

[jdemaris]

The pump also has a number of AR-51747.
.

That Deere # on a pump (AR-51747) can be either a JDB435AL2442 or a JDB435MD2802. Both pumps are set up exactly the same (fuel delivery and timing advance curve). Both used on late 450Bs or early 450Cs.

The original block for late 450Bs or early 450Cs ought to be marked R122820 but some older models have R72972 #s. They have the large piston pins.

Your block is the 219 c.i. engine with the smaller piston pins, made before serial # 275,483.

[np205]

Thank you for the advice and info.

The previous owner had bought the current pump.

Will contact a dealer and buy the 2442 pump.

Obviously, there is some difference in the pumps as the 2802 will not align when engine is at TDC and shaft/pump marks on same side.
(toward engine)

A quick check with protractor looks like about 6-8° error.

Thanks again for all the help.

[jdemaris]

Obviously, there is some difference in the pumps as the 2802 will not align when engine is at TDC and shaft/pump marks on same side.
(toward engine)

No, both pumps are set up exactly the same. The timing mark is etched on by hand when the pump first assembled new, or when rebuilt. Both pumps, JDB435AL2442 or a JDB435MD2802 have the timing marked etched on at 138.5 degrees (when laid on top of a degree chart).

Even the older pumps there were used on the first 450s in the 1960s have the marks in the same place at 138.5 degrees.

[jdemaris]

Obviously, there is some difference in the pumps as the 2802 will not align when engine is at TDC and shaft/pump marks on same side.
(toward engine)

A quick check with protractor looks like about 6-8° error.

Thanks again for all the help.

6 to 8 degrees error at the pump is 12 - 16 degrees error at the engine/flywheel since the pump runs half engine speed.

Did you recheck the pump numbers you first gave? You stated a JDB-S2802 and there never was any pump by that number used on any 450 crawlers. The correct pump for a 450 that ends with "2802" is the JDB435MD2802 with Deere part # AR51747.

Pump is JDB-S2802.

[np205]

JD450B

Here are all of the numbers on the pump:

JDB-S2802
1486589 Serial
AR-51747 Model
2500 PSI

Engine number (under alternator) T32342D

Have tried to find serial numbers on the machine. (under the seat near the battery box?)

The pump looks brand new or (most probably rebuilt)
It will start and run for a second or so even with the pump timing error.


Thank you.

[jdemaris]

JD450B

Here are all of the numbers on the pump:

JDB-S2802
1486589 Serial
AR-51747 Model
2500 PSI

Engine number (under alternator) T32342D

Have tried to find serial numbers on the machine. (under the seat near the battery box?)

The pump looks brand new or (most probably rebuilt)
It will start and run for a second or so even with the pump timing error.

That pump number is just a shortened, generic number for a replacement pump. It was rebuilt to match the specs intended for your engine. The Deere replacement pump marked JDB-S2802 or JDB-T2802 is built to match the characteristics of the original JDB-435MD2802. Same pump is used on many Deere machines, e.g. - 3300 combine, 450B,450C, 450D, 4219D power unit, 2030 ag tractor, windrowers 2250, 2270, 2280.

That "2500 PSI" you're citing does not make sense. The pump does not have ANY pressure settings. It should be "2500 RPM" if anything, and that is engine RPM. Actual pump RPM is 1250.


The original pump was one of the two numbers I posted previously. The "435" stands for "four cylinder" and .35" diameter pump plungers.

Your engine is the small piston-pin 219, as I stated before. The casting numbers you posted indicate that.

If you engine starts and quits, timing is not your problem.

As to why your marks don't line up? Several possibilities. I can't guess without some history on how the engine got this way. If somebody had the timing cover off, maybe the gears aren't timed. If somebody had the injection pump apart, maybe the timing mark was put on the wrong place. Also, maybe you've got the incorrect pump driveshaft.

[np205]

Thank you for reply.

You are correct regarding 2500 RPM.
Mistakenly put PSI after 2500.

Cannot ask previous owner about pump as he passed on.

Have ordered SM2045 book.

Hope the book will have detailed instructions regarding assembly/disassembly of the pump.

Does the timing of 138.5° have a tolerance in minutes?
ie: 138° 30' +/-


Will look more at pump this weekend.


The loader arms had been down.
Made it hard to work on tractor.

During the short periods of time it ran, moved loader toward top of stroke and blocked the cylinders.


Thanks for all the help and advice.

[np205]

Removed timing cover.

Found pump gear 2 teeth off from correct alignment.

Aligned properly, injector pump marks now correct.

No keys sheared or teeth missing.