1974 John Deere 450B track loader.

Bought this track loader not running. The JD450's engine had died while clearing some trees. The machine, service manual, and an extra backhoe bucket were purchased for scrap price. Undercarriage was runout except for drive sprockets. The powershift transmission was about the only part of the tractor that had no problems. This JD450B was well used, but decided to undertake repairs and get it running.


The Stanadyne injector pump had failed and was reason JD450B quit. Fortunately, the previous owner had purchased a brand new injector pump. They had tried to install the new pump, but couldn't get the engine to run. The problem was engine timing. The injector pump timing marks would never line up when flywheel was at TDC. Removed the front nose, radiator, main hydraulic pump and timing cover. Found injector pump gear and one balance shaft out of time. Rebuilt water pump during this repair. All parts from John Deere dealer for water pump were less than $50. Timed everything according to service manual, reassembled, bled fuel lines and the 4-219 engine fired right up.
Transmission is powershift type, works well in all 4 speeds hi/lo and reverse. Backhoe is quick attach. Has the rotary swing motor. Backhoe is slow, but strong.

Ergonomics were not a priority when the JD450B's hoe was designed and built. The hoe operator is perched up on the "captain's chair" and becomes a clear target for every limb, tree trunk or whatever the hoe's arm can reach. Real men used these backhoes, no type of head protection whatsoever unless you wore a hardhat.


Steering clutches (9 friction discs), pressure plate, release bearing, pilot bearing and brakes on both sides were replaced.
Pictures show various views of work as it progressed.

Drilling out cotter pin holes with frozen pins was about the most time-consuming task. Sandblasting clutch baskets before assembly helped when installing steel separator plates. Be sure to put one friction disk behind the snap ring on clutch hub. Clutches on right side of this tractor had been assembled incorrectly at some point before I owned it. Someone had put all 9 discs in front of the snap ring. This explains why right side always slipped under a load.

The top brake return spring is difficult to attach if service manual instructions are followed. Spring was attached to brake shoe half, the other end was put in eyelet before bolting top cover on.

The JD service manual gives instructions how to adjust clutches and brakes. Found these instructions were not the best method due to wear in steering linkage. Release bearing clearance was set at 1/4". Brakes were adjusted after being first tightened and then backed off for proper clearance. Brake timing was adjusted so the pressure plates were fully disengaged before brakes would begin to apply. Took a few times of adjusting to get brakes appling at correct time. After running tractor for a while, noticed steering is slightly more responsive when traveling in reverse than forward gears.

Very happy with the results.

Although the JD450B is a smaller sized crawler, it has ample power.
Its compact size and fuel economy make it a good choice for smaller land clearing jobs. Next project will involve changing chains, pads, tension seals, and rollers.