Interesting Specs Page & Cat 931 Query
Posted: Wed Aug 26, 2015 1:08 am
Came across this page of old specs, flyers info, many old loaders & dozers on here
http://murphyused.com/specs.php Enjoy
Reading up on the 931, it seems there was a choice of the typical Cat 3F 3R powershift & a 3F 1R powershift. I knew the machine was built by Mitsubishi (under licence) & the machines destined for the Japanese / Asia market had a 'direct drive powershift - with inching pedal / clutch (as sub 100 HP Komatsu) The torque converter 3F + 3R was for western markets & supplied by Cat - When problems came with this (machine was withdrawn for a while) Mitsubishi stood by the Direct powershift which was trouble free. I knew nothing of the 3F + 1R at all. Also there was an optional accelerator or decelerator pedal, I never saw one with this.
I always felt this last was a feature lacking on the Cat Traxcavators as the D6C blade did have a decelerator. I know a driver going from say a 941 to a 125B or Case would shift direction at full revs & without braking - eventually killing the tranny. If you started on IH & Case powershift as I did you would be easier on it. I was only a youngster in the heyday of the 100/125B but the consensus of the older guys was that they needed an extra lower gear, as they had from memory Lo 3.7 & Hi 4.5 meaning a lot of slippage & heat when under heavy load. The Case lowest was about 2.4 dependent on which model. Generally on the 450A it was thought the low range 2 speeds was all that was needed when on site, just shift ranges if on a long travel, & only go to 4th if you kept the revs down to reduce track wear.
The thing regarding deceleration was that you needed some revs to work the bucket hydraulics but not too many when shifting direction. This is where the Komatsu inching pedal came in, nice tracking control & revs to work the hyds - oil immersed clutches should last the life of machine. Also the lack of a wasteful torque converter at part revs (fuel was an imported costly item to the Japanese) What do other old trackshovel drivers think was the best transmission set up???
http://murphyused.com/specs.php Enjoy
Reading up on the 931, it seems there was a choice of the typical Cat 3F 3R powershift & a 3F 1R powershift. I knew the machine was built by Mitsubishi (under licence) & the machines destined for the Japanese / Asia market had a 'direct drive powershift - with inching pedal / clutch (as sub 100 HP Komatsu) The torque converter 3F + 3R was for western markets & supplied by Cat - When problems came with this (machine was withdrawn for a while) Mitsubishi stood by the Direct powershift which was trouble free. I knew nothing of the 3F + 1R at all. Also there was an optional accelerator or decelerator pedal, I never saw one with this.
I always felt this last was a feature lacking on the Cat Traxcavators as the D6C blade did have a decelerator. I know a driver going from say a 941 to a 125B or Case would shift direction at full revs & without braking - eventually killing the tranny. If you started on IH & Case powershift as I did you would be easier on it. I was only a youngster in the heyday of the 100/125B but the consensus of the older guys was that they needed an extra lower gear, as they had from memory Lo 3.7 & Hi 4.5 meaning a lot of slippage & heat when under heavy load. The Case lowest was about 2.4 dependent on which model. Generally on the 450A it was thought the low range 2 speeds was all that was needed when on site, just shift ranges if on a long travel, & only go to 4th if you kept the revs down to reduce track wear.
The thing regarding deceleration was that you needed some revs to work the bucket hydraulics but not too many when shifting direction. This is where the Komatsu inching pedal came in, nice tracking control & revs to work the hyds - oil immersed clutches should last the life of machine. Also the lack of a wasteful torque converter at part revs (fuel was an imported costly item to the Japanese) What do other old trackshovel drivers think was the best transmission set up???