US Gear Decellerator

[jaluhn83]

I believe I had a source for those, let me see...... Remind me if I don't get back to you in a few days.

 

[jaluhn83]

Assuming you actually meant a US Gear dual range unit, the switch is likely one of these:

http://products.pollakaftermarket.com/viewitems/precision-ball-switches/cision-ball-switches-normally-open-sealed-terminal?

I'm trying to narrow it down further but have to do some measuring.

However, those switches are *not* critical to operation of the unit. All they do is sense the gear selection for the 2 indicator lights on the selector switch on the automatic version. Manual trans does not even use these since you have a positive position switch. The only thing that you need to run the box is the 2 wires going to the shift motor and a ground.

 

[OLDBULL8]

Assuming you actually meant a US Gear dual range unit, the switch is likely one of these:

http://products.pollakaftermarket.com/viewitems/precision-ball-switches/cision-ball-switches-normally-open-sealed-terminal?

I'm trying to narrow it down further but have to do some measuring.


However, those switches are *not* critical to operation of the unit. All they do is sense the gear selection for the 2 indicator lights on the selector switch on the automatic version. Manual trans does not even use these since you have a positive position switch. The only thing that you need to run the box is the 2 wires going to the shift motor and a ground.

Hey, jaluhn83. That is exactly the switch I need. Thanks a lot. Ya, I'll have to pull the broken one out and measure it up for thread size Etc.

 

[jaluhn83]

Very interesting and quite ingenious setup. I will keep this information in mind if I ever get my hands on a US gear exhaust brake, as I likely won't go full-auto w/ its box and all. Instead I will probably use a pair of relays (a 70amp and a 30 amp, in a Crown Vic ABS relay box), and make the smaller relay self-latching. Put a momentary switch on dash, push it in and count to 3 and release - the pull solenoid should have done its thing, and the hold solenoid relay is latched on. To disengage the hold solenoid, wire in the idle validation switch between main power and relay pull coil power - throttle on breaks continuity and relay unlatches. And the back pressure switch will definitely be used as well, it's a great tool to have available.

Was thinking about this and I think you can do it even simpler -

Need 2 on/off switches, one pushbutton switch and a stater relay.

Wire one on/off switch to a ignition wire. Switched lead of that switch goes to 2nd on/off and push button. 2nd on/off switched lead goes to the 'hold' coil on solenoid. Switched side of pushbutton goes to relay which is connected to battery + and 'pull in' coil of solenoid. If you want a clutch/throttle pedal disable add a normally closed switch on either (or both) pedals.

Turn on 1st on/off switch to turn on or off the system. To turn the brake on turn 2nd switch on (energizes hold coil) then push push button switch. Turning off either on/off switch disables brake. The reason for 2 on/off switches is to isolate power to the system so that accidentally bumping the push button doesn't try to close the brake.

Could do it with just one on/off too, just wire the push button to the switched side of the on/off.

 

[laserjock]

I've been thinking about an exhaust brake after driving my brothers Dodge with one. It's real nice traveling through the mountains even empty. What is the consensus on this US gear unit? I haven't really seen anything else that will work directly on the IDI's. Are there other options? Operation doing home made controls would seem to be pretty simple. I could probably whip up a controller from a PLC to do the same job the stock one did just not wireless... well.... I'd have to learn some more stuff to do it wireless anyway.

 

[jaluhn83]

I really like mine. Bought it used and haven't had any issues in 5+ years. Mine does leak a bit from the butterfly shaft bushings and makes a nice hissing sound but that's a minor issue.

The only thing I wish it had is variable braking like a real brake. There's been a few times when I'm in 2nd going down a curvy mountain road and the exhaust brake is too strong and pulls it almost down to idle, but without it she starts going too fast - wish I could set it for about a 50% level.... yah I know, life sucks.

I've found it to be pretty much priceless for mountain driving. Very rarely will I need to use the service brakes going downhills and I typically run 12-15k gross and we have pretty decent hills out here. Not going to stop you on a dime or anything but it works well to keep the speed in check.

 

[pontoonrob]

I really like mine. Bought it used and haven't had any issues in 5+ years. Mine does leak a bit from the butterfly shaft bushings and makes a nice hissing sound but that's a minor issue.

The only thing I wish it had is variable braking like a real brake. There's been a few times when I'm in 2nd going down a curvy mountain road and the exhaust brake is too strong and pulls it almost down to idle, but without it she starts going too fast - wish I could set it for about a 50% level.... yah I know, life sucks.

I've found it to be pretty much priceless for mountain driving. Very rarely will I need to use the service brakes going downhills and I typically run 12-15k gross and we have pretty decent hills out here. Not going to stop you on a dime or anything but it works well to keep the speed in check.

thats exactly why I like mine, even without hills it will slow down the big loads( especially my 6 ton fifth wheel) on level ground. I have to drive very carefull without it operating.---Rob

 

[pontoonrob]

Was thinking about this and I think you can do it even simpler -

Need 2 on/off switches, one pushbutton switch and a stater relay.

Wire one on/off switch to a ignition wire. Switched lead of that switch goes to 2nd on/off and push button. 2nd on/off switched lead goes to the 'hold' coil on solenoid. Switched side of pushbutton goes to relay which is connected to battery + and 'pull in' coil of solenoid. If you want a clutch/throttle pedal disable add a normally closed switch on either (or both) pedals.

Turn on 1st on/off switch to turn on or off the system. To turn the brake on turn 2nd switch on (energizes hold coil) then push push button switch. Turning off either on/off switch disables brake. The reason for 2 on/off switches is to isolate power to the system so that accidentally bumping the push button doesn't try to close the brake.

Could do it with just one on/off too, just wire the push button to the switched side of the on/off.

Ha' too bad you live 1700 miles away. you make it sound easy to fix.---Rob

 

[jaluhn83]

It is. I'll see if I can make some diagrams.

 

[Garbage_Mechan]

I have one of these under the bench, actually looking for a 4" one for the PSD truck too. I was thinking the exact thing with the pull in / hold in coil situation. I was thinking of an industrial timer relay for the pull in, set to say 3 seconds so when the throttle closes it powers the pull in coil for 3 seconds but maintains power on the hold in. I have some experience with these solenoids using them for throttle advance on mechanical diesels for PTO operation. Also Muncie has a series of PTO's that use on to pull in hold in the gears! The experience with the Muncies was failure of the little timer box, but it was mounted outside the cab and poorly made. Muncies solution was to replace the timer box with a rocker switch that had all in one switch off, on and momentary on so it worked pretty much exactly as described above with the toggle and push button. This switch is still available. I want to be able to have the exh brake come on with closed throttle so the timer is neccessary to me. Loving this discussion, hoping I can contribute!

 

[79jasper]

actually looking for a 4" one for the PSD truck too.

The PSD truck in your signature??
If so, why 4"???

 

[RLDSL]

I have one of these under the bench, actually looking for a 4" one for the PSD truck too. I was thinking the exact thing with the pull in / hold in coil situation. I was thinking of an industrial timer relay for the pull in, set to say 3 seconds so when the throttle closes it powers the pull in coil for 3 seconds but maintains power on the hold in. I have some experience with these solenoids using them for throttle advance on mechanical diesels for PTO operation. Also Muncie has a series of PTO's that use on to pull in hold in the gears! The experience with the Muncies was failure of the little timer box, but it was mounted outside the cab and poorly made. Muncies solution was to replace the timer box with a rocker switch that had all in one switch off, on and momentary on so it worked pretty much exactly as described above with the toggle and push button. This switch is still available. I want to be able to have the exh brake come on with closed throttle so the timer is neccessary to me. Loving this discussion, hoping I can contribute!

We crawled under that thing today to figure a bypass manual switch out. . Looks fairly basic as far as the pull coil to close the flap, but what exactly is the purpose of teh hold coil terminal? and are both terminals needed charged to activate the unit ?

 

[laserjock]

I've never worked on one of these specifically but it sounds like a latching solenoid system. The pull in coil is a larger coil that requires a fair amount of current to actuate and move the flap. The hold coil is a smaller coil that holds it closed (I'm guessing against spring pressure) until it is released. The reason for doing this is the larger pull coil will produce a lot of heat because of the power dissipation across the coil. If you leave it energized to hold the flap shut you will burn the coil up. The smaller coil generates less heat because its lower power hence it can stay in longer periods of time and not burn up. As mentioned above, I can see the operation being energizing both coils to actuate the brake then turn off the pull in coil once the brake flapper is closed so it doesn't over heat solenoid coil and burn it up.

Hope that helps. If I'm wrong, I'm sure someone will correct me.

 

[jaluhn83]

I've never worked on one of these specifically but it sounds like a latching solenoid system. The pull in coil is a larger coil that requires a fair amount of current to actuate and move the flap. The hold coil is a smaller coil that holds it closed (I'm guessing against spring pressure) until it is released. The reason for doing this is the larger pull coil will produce a lot of heat because of the power dissipation across the coil. If you leave it energized to hold the flap shut you will burn the coil up. The smaller coil generates less heat because its lower power hence it can stay in longer periods of time and not burn up. As mentioned above, I can see the operation being energizing both coils to actuate the brake then turn off the pull in coil once the brake flapper is closed so it doesn't over heat solenoid coil and burn it up.

Hope that helps. If I'm wrong, I'm sure someone will correct me.

You are correct. Pull in coil takes ~55 amps, hold coil takes ~2.

There's a pretty stiff spring inside the solenoid that returns the butterfly to open. Pretty amazing setup when you think about it - it take close to 100# of force to push that plunger in against spring pressure, yet little more power than your interior light will hold it there.

 

[RLDSL]

OK, that all makes sense, that thing was really wham banging with some current to it.
so we just need to rig a 2 stage switch then It can evenbe two seperates with setting teh hold first then triggering the pull with a momentary and that would set the thing