312 Transmission issues (I think)

[tplace 5]

I have a couple of things going on with my 312-8.  I have a moderate grade that I mow and usually go up it in low 1st gear, recently it barely makes it up the hill, I also have to keep my hand on the shifter to make sure it doesn't pop out of 1st gear.  One other thing, when starting, I have to apply rearward pressure to the shifter while in neutral. Any advice would be appreciated.

[953 nut 68,735]

Bad Dog-point screw would do that.

 

[Ed Kennell 47,091]

13 minutes ago, tplace said:

go up it in low 1st gear, recently it barely makes it up the hill,

Is the engine dying?   In low range first gear at wide open throttle it is barely crawling and should be unstoppable.

[ri702bill 12,894]

10 minutes ago, 953 nut said:

Bad Dog-point screw would do that.

Bad Doggie - no Biscuit!

[Ed Kennell 47,091]

17 minutes ago, tplace said:

when starting, I have to apply rearward pressure to the shifter

Is the wiring to the seat safety switch pinched or worn in the tunnel? The four  Safety switches that prevent starting are the seat the clutch/brake pedal and the two PTO.

[tplace 5]

25 minutes ago, Ed Kennell said:

Is the engine dying?   In low range first gear at wide open throttle it is barely crawling and should be unstoppable.

No, the engine makes full power.

[WHX?? 57,877]

Drive belt slipping? but sounds like third gear may be worn from trying to shift on the fly. 

We were just discussing that. 

 

[Ed Kennell 47,091]

2 hours ago, tplace said:

No, the engine makes full power.

So you have a disconnect in the drive train. 

1. Belt slipping due to weak tension spring

2. Transmission input pulley slipping on the shaft

3. A hub slipping on an axle

4.The 1/8" roll pin that connects the clutch cross shaft to the lever on the lelt end may be sheared causing belt to slip

Edited 4 hours ago by Ed Kennell

[stevasaurus 23,811]

I am inclined to think the trouble is with your dog-point set screw.  A broken point or loose set screw would make for a sloppy shifter and not shifting the 1st gear all the way into 1st gear.  Check the set scew and replace that if needed.