Sloppy Motion Control 1075

[pfrederi 17,866]

Working on my neighbors 1075.  The motion control is very loose and sloppy.  He has to hold the lever all the time or it will go to full speed.  This was the first year of Wheelamatics and the motion control mechanistic was not that great.  Friction was created by two small springs pressing on the two tension plates that hold the plastic cam in place.  They are as tight as they can be.  Problem is compounded by 50 years of wear on the cross shaft and the nyliner inserts. The nyliner inserts are still available but given shaft wear I doubt that even new ones will solve the issue.

 

  By 1968 they had modified the design to include a heavy spring and cone assembly to create adjustable friction. I have 5 Chargers with that setup and you can adjust it to make it work well.

 

Looking at the mechanism other than the width of the side rails on the cam control arm and the need to add a hole on the left side of the hood stand I do not see why I couldn't put in the later style mechanism. I would get a control arm for the later model from A to Z I have the cross shaft spring and cone assembly.  Note in the picture the wider frame is from a C series Sunstrand, the handle has different bends.  The wider frame is needed for the bigger hole to accept the spring and cone shaft.

 

Bottom line has anyone done this or tried and found something that wouldn't let it happen??

[squonk 41,324]

I had the same issue on my 1075 Paul. As I increased the throttle, the belt would create a pull on the idler pulley forcing it down. The shaft the pulley arm is connected to was binding on the motion control pulling it forward. New tension springs, cam plate and a little lube where the shaft passes through the motion control cured it

[pfrederi 17,866]

Thanks  Will try that first...

[pfrederi 17,866]

Dug into the unit.  Turns out the the cross shaft (#182) had chewed through the nyliner on the right side and had worn a deep groove in the bottom of it.  There was also some wear at both points it passed though the motion control lever (#174).  Hit the deep groove with the mig then ground and filed it back to mostly round.  The other wear points were to shallow to try that.  Settled for new nyliners at all points.  Had some left over from my GT-14 project. Also figured out the belt was the wrong size it was only 71" got a new 72"  and replaced the plastic motion slider. Much improved but I had to almost fully tighten the slider springs too keep the motion control from moving on its own.  He is going to try this for while if it does not work out will have to see about converting to the spring and cone system

 

 

[squonk 41,324]

Paul. Another thing I did was I got a couple of new screws that were slightly longer with allen heads instead of the slots. I also added a small flat washer under the heads to provide a little more tension before the springs bottom. The allen heads allowed me to get the bolts good and snug.

[pfrederi 17,866]

1 hour ago, squonk said:

Paul. Another thing I did was I got a couple of new screws that were slightly longer with allen heads instead of the slots. I also added a small flat washer under the heads to provide a little more tension before the springs bottom. The allen heads allowed me to get the bolts good and snug.

I did use new hex head screws.  If it still slips will look at washers...