555 D ford backdoe shifting problem

[eKretz]

Oh boy, the back side is a little bit hairier, haha! I don't see any signs of damage with a cursory glance, but I'll check the relays individually and all the solder joints for any cracks tomorrow. Probably check out the pair of electrolytic caps for high ESR too. I broke diode D5 removing the potting compound, will have to order a new one to replace it.

 

[eKretz]

Got an idea for a complete replacement of this module that is pretty cheap and readily available today. Going to try it out and I'll report back.

 

[eKretz]

Victory! Just ran the machine for a couple hours with zero issues. Pulled a couple stumps, then hauled off the wood and graded back over with the loader bucket. Not a hiccup the whole time. I only had this set up in a temporary fashion at the moment to see if it would work. I happened to have a PWM DC motor controller with programmable soft start laying around the electronics bench. This particular model soft starts as soon as it powers on. Perfect for use with the signal from the shuttle shift stalk. Also can be set to display either voltage or amperage in use. Also nice.

I took the plugs from the original controller so it could plug straight into the harness. I set it up with a ganged ground to both solenoids, and the positive from the controller going to a 3-position toggle switch. That way I could set the toggle switch for sending power to either the forward or reverse solenoid, then engage the shuttle shift to forward to activate the solenoid and engage the selected clutch. I settled at a 2.5s soft start engagement time, that worked pretty good. I just ordered another controller, so in the permanent installation I'll have one controller for forward and one for reverse, that way the toggle switch will be eliminated and the shuttle will work just like it originally did. These will tuck up under the dash just like the original. They're rated for way more power than needed in this application so I'm hoping they'll be pretty hardy.

Speaking of which, the original control module is unavailable anywhere as far as I can tell. These DC motor controllers are available on eBay for around $25-$30 each. I'll probably order some spares.

 

[TractorTech]

Victory! Just ran the machine for a couple hours with zero issues. Pulled a couple stumps, then hauled off the wood and graded back over with the loader bucket. Not a hiccup the whole time. I only had this set up in a temporary fashion at the moment to see if it would work. I happened to have a PWM DC motor controller with programmable soft start laying around the electronics bench. This particular model soft starts as soon as it powers on. Perfect for use with the signal from the shuttle shift stalk. Also can be set to display either voltage or amperage in use. Also nice.

I took the plugs from the original controller so it could plug straight into the harness. I set it up with a ganged ground to both solenoids, and the positive from the controller going to a 3-position toggle switch. That way I could set the toggle switch for sending power to either the forward or reverse solenoid, then engage the shuttle shift to forward to activate the solenoid and engage the selected clutch. I settled at a 2.5s soft start engagement time, that worked pretty good. I just ordered another controller, so in the permanent installation I'll have one controller for forward and one for reverse, that way the toggle switch will be eliminated and the shuttle will work just like it originally did. These will tuck up under the dash just like the original. They're rated for way more power than needed in this application so I'm hoping they'll be pretty hardy.

Speaking of which, the original control module is unavailable anywhere as far as I can tell. These DC motor controllers are available on eBay for around $25-$30 each. I'll probably order some spares.

View attachment 837648

That is really what the original controller is, a PWM controller.

I saw that unit on the internet, bit from AliExpress. What site do you source yours?

 

[eKretz]

That is really what the original controller is, a PWM controller.

I saw that unit on the internet, bit from AliExpress. What site do you source yours?

I just grabbed them from eBay, myself. I think at the quantity I purchased (4) they were right around $20 each with free shipping.

 

[milkman636]

Great find. Love those Wago connectors too. I’m never going without them on hand again.

Do the PWM controllers have an input available that could be used to adjust the delay? Just thinking it would be sweet to mount a “sensitivity” adjustment knob on your dash to adjust the shifting delay based on the type of work and speeds you are operating at.

 

[eKretz]

Great find. Love those Wago connectors too. I’m never going without them on hand again.

Do the PWM controllers have an input available that could be used to adjust the delay? Just thinking it would be sweet to mount a “sensitivity” adjustment knob on your dash to adjust the shifting delay based on the type of work and speeds you are operating at.

Yeah those Wagos are very handy. I have a stash of them that I use all the time for electrical stuff. Handy for making meter probe extensions and long jumpers too.

The controllers have an up/down PWM adjustment that could be made on the fly with an added remote momentary toggle or something similar if you go inside and solder one in at the switch contacts. I'm not sure if it would work quite like you're thinking, but even if it did, it would be likely to wear out the clutches a lot faster if you slipped them much. And they are not an easy thing to replace in this particular machine, requiring an engine/transmission split. Probably better to just let the torque converter do the slipping. The built in interface on these can be set to start the "on" cycle from 0 to 80% minimum pulse width. It can also be set to limit the max pulse width once "on" also, and of course the pulse width can be adjusted up or down while in "on." Oh, and yes, the "on" time ramp is adjustable. From 0 to at least 10 seconds IIRC.

I originally bought the one I had setting on the electronics bench to use with a tool and cutter grinder that I've got in my small machine shop, for spin grinding cutting tools.

 

[milkman636]

I was thinking the optimum ramp time may vary. I was curious if a $20 controller would have a configurable input that could maybe be used for a proportional signal.

 

[eKretz]

No, you'd have to make or add something for that. Raspberry pi Ford 555?