Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Sign in to follow this  
mroman59

7117, sluggish or delayed hydrostatic speed?

Recommended Posts

mroman59
On my 7117, when I engage the forward hydrostatic lever, there seems to be a delayed response, then all of a sudden the tractor will take off and achieve set speed. I bought this tractor used, but I dont remember that being a problem or maybe I just did not notice it because it was new to me. Does that sound like any problem that anyone has had. The only linkage adjustment that I know of is for finding neutral. I believe my fluid level is correct. Thoughts appreciated.

Share this post


Link to post
Share on other sites
Al
Hi, This is a common problem. It is caused by binding in the linkage. First remove the cam roller on the front of the hydro unit, Clean the shoulder bolt off with solvent. next wipe the roller clean. Lube the bolt with white grease, put the roller on and reinstall. Next lube the pivot points on the frame of the tractor where the shafs on the cam pivot. Next lube the pivot point where the rod from the shift lever comes back from the shock absorbing spring assembly. What is happening is when the hydro lever is moved forward, the shock absorbing spring is compressed and the linkage behind it is binding, so the cam roller on the hydro barely moves. When you go a little bit the spring finally overcomes the resistance and the roller goes up the cam where it should be. Hence the delay. After lubing everything up, you may need to readjust the neutral settings. To do this, put the lever in neutral. Next check the roller is centered in the flat area between the forward ramp and the reverse ramp. If it is not, move the lever from forward to neutral and recheck roller position and repeat from reverse to neutral. If the shock spring is fully expanded and the roller is not returning to the same spot from both directions, Check for "play or slack" where the hydro lever and the arm inside the frame have slack. This slack is very common and is caused by wear in the rectangular hole and the flats on the shift lever. No amount of adjusting can fix this. Replacing these 2 parts is the fix. Part of the problem comes from the fact that the inside arm is only partly engaged on the shift lever and the contact area is shallow. This is done to allow the arm to be tightened to increase the holding friction of the shift lever. If the wear is just starting, the shift lever may be removed and the bushing in the frame removed and the "boss" on the frame ground down about 3/32 of an inch. This will allow the inside arm to go over the flats on the shift lever shaft about 3/32 further. This will move the arm to unworn areas. DO NOT TAKE TOO MUCH OFF THE FRAME OR YOU WILL NOT BE ABLE TO ADJUST THE FRICTION DISK TENSION. If this doesn't fix the slack, the arm and lever must be replaced. Once the slack is all removed. Go to the control rod behind the shock spring and if in neutral, the roller is not in the center of the flat area in the middle of the cam between the ramps. If not correct loosen the pivot between the control rod and the arm on the cam assy. Loosen the nut and move the pivot in the adjustment slot. After setting check roller position from both forward and reverse to neutral. If OK. "SAFELY" block up the rear of the tractor and check fwd to neut. and Rev to neut. Wheels should not turn. Open the engine wide open and recheck. If the wheels "creep", on the left side of the tractor there is a pivot on the shaft of the cam that is in the hole of the frame. This is a double nut assembly and you loosen the jam nut and turn the other one and the wheels should stop. It will take very little adjustment to correct neutral stop. After adjustment tighten the jam nut and recheck. Repeat until correct. CAUTION THE TRACTOR MUST BE SUPPORTED SO IT WILL NOT FALL OFF THE SUPPORT WHEN THE ADJUSTMENTS ARE DONE OR IT WILL RUN AWAY AND CAN RUN OVER YOU" Al Eden

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

×