StumpSlinger
Well-Known Member
Looking for any info on this D7F sn 94n1131.
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D7F
- Thread starter StumpSlinger
- Start date
Nige
Senior Member
An early model D7F fitted with a D333C engine and a similar transmission to a late-model D7E.
The transmission was the weak point of the early D7F machines and was changed to a different style from machines starting with S/N 94N5192-Up.
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StumpSlinger
Well-Known Member
We're these one prone for trans failure? I would be the primary operator and would mainly rough grade/ push scrapers with it. Occasionally stump as well.
Nige
Senior Member
Here's the full SP on the early D7F machines. I think you're probably the only one who could decide if your proposed use for the tractor could put too much stress on the transnmission. (The words below are not mine)
"All D7E tractors were fitted with the 4-cylinder D339 engine that produced a maximum of 1200 rpm at full load. The transmission was quite happy at that rpm.
When the D7F was first introduced it was fitted with a 6-cylinder D333C producing 180 BHP @ 2000 rpm. The tractor used the same basic transmission as the D7E but with different transfer gears to slow it down because of the 800 RPM difference in maximum engine RPM. The problem was that the larger, heavier planetary assemblies of what was originally designed as a low-speed transmission didn’t like the higher RPM and this resulted in failures.
Additionally the D333C engine was significantly lighter than the D339 which led to complaints about these D7F tractors being lighter in the nose. Cat changed the transmission to the lighter D6C style; but with more plates and stronger transfer gears starting from S/N 94N5192 (1973). Also the D333C engine was changed for a 3306 engine from S/N 94N5660 (1973). As a result of these changes the D7F became a good reliable machine."
"All D7E tractors were fitted with the 4-cylinder D339 engine that produced a maximum of 1200 rpm at full load. The transmission was quite happy at that rpm.
When the D7F was first introduced it was fitted with a 6-cylinder D333C producing 180 BHP @ 2000 rpm. The tractor used the same basic transmission as the D7E but with different transfer gears to slow it down because of the 800 RPM difference in maximum engine RPM. The problem was that the larger, heavier planetary assemblies of what was originally designed as a low-speed transmission didn’t like the higher RPM and this resulted in failures.
Additionally the D333C engine was significantly lighter than the D339 which led to complaints about these D7F tractors being lighter in the nose. Cat changed the transmission to the lighter D6C style; but with more plates and stronger transfer gears starting from S/N 94N5192 (1973). Also the D333C engine was changed for a 3306 engine from S/N 94N5660 (1973). As a result of these changes the D7F became a good reliable machine."
StumpSlinger
Well-Known Member
Hard to say, I've run several 7Fs over the years not sure if they were early or later style. All seemed to be decent dozers. I would imagine reliability all depends on operator and maintenance.