D21 Differential

Been there done that. Low transmission/rear end oil levels (all one compartment) is for sure the death of a differential located that high in the drive line. A tractor used for moldboard plowing would have the highest failure rate possibility. Four new matching radial tires across the back and a lot of short turning would be stressful. A tractor that weighed more than 13K would also place the differential under more pressure. I remember a customer who once got one buried in the mud and rocked it back and forth and back and forth while jamming on the brakes side to side. Soon afterwards the differential was toast. What's the history of the tractor ???  I've always looked back to a D-17 or WD-45 and think of the hundreds upon thousands of hours some of those tractors had on a moldboard plow and NEVER had any differential issues.

Edited by DrAllis - 22 hours 10 minutes ago at 6:00am

One last thing that I forgot.......160 HP fuel setting versus 127.75 HP fuel setting also stresses the differential more.

210-220's used the same differential. They had a larger bearing on the ring gear side of the diff where the D-21 was same bearing on both sides. 210-220's were way heavier in the final drive/bull gear and axle size area. The wheelbase was even 4 or 5 inches longer because of the larger diameter bull and bull pinion gears.

I might have confused myself with the 4-pinion's on 190's and 200's. I know they had a bigger bearing on the right side, and for some reason I thought the 210/220 series did too.