Dynatard Problem

[r600]

can anyone help with problems i am having with my dynatard.it's need worked since i have owned it .i know the solenoid's are earth to work (i think).i bridged the clutch micro switch(didn't know if it was working properly)i have no power at dash toggle switch(dont know if it works on earth?)maybe its a relay inside cab where all the fuses are can anyone help?thanks adrian

[Noid93]

I would first start at the solenoids.

1....Take the valve covers off, and with the engine running, push down on the top of one of the solenoids with your hand, if the engine labors, the flow of oil to the solenoid is good. Do the same to the other solenoid.

2....Jump power to the wires on the solenoids also. If the engine labors, the solenoids are working..(the solenoids on a negative ground system neeed to be charged with positve power to engage them)

3....Check for continuity between all the switches and components(micro switch on throttle and clutch) jump power one switch at a time to eliminate a bad switch

4....See if appling power to the dash switch engages the dynatard. If it does, then as you stated, there is no power at the switch. Check the wire going to the switch from the fuse panel

5.... The fuse pannel on a r600 is located behind the pannel directly in front of the passanger seat on the dash.(although they should be self reseting circut breakers)

That would be a start to diagnosing the problem.

[HK Trucking]

can anyone help with problems i am having with my dynatard.it's need worked since i have owned it .i know the solenoid's are earth to work (i think).i bridged the clutch micro switch(didn't know if it was working properly)i have no power at dash toggle switch(dont know if it works on earth?)maybe its a relay inside cab where all the fuses are can anyone help?thanks adrian

If it has a switch on the clutch pedal, then it's a Jake brake, not a dynatard.

The Dynatard did not need a clutch pedal switch because the actuating switch in the governor turned the Dynatard off when the engine dropped to idle and the governor pushed the rack open for idle fuel, so there was no possibility of the Dynatard "stalling" the engine, hence no need for a clutch pedal switch.

Dynatard and Jake brake circuitry is completely different.

That said, if there's no power at the dash switch, start there.

Check fuse or circuit breaker in that circuit, or look for a broken wire .

If still no power to the dash switch, run a new power wire to it from a fused source and abandon the inoperative power wire.

Check to see that the switch has continuity in the "on" position.

Work your way on down the line, check for power at clutch switch, throttle switch, and at the terminals at the Jake spacers between the valve covers and the heads. Make repairs as necessary to achieve this.

With dash switch on, clutch pedal up, and throttle at idle, you should have power all the way thru the system to the terminals on the spacers.

Once you get this far, then try the Jake with the engine running, it should work, if not, the wires inside the Jake spacers could be broken, or you have defective Jake brake units.

Last I heard, overhaul kits are still available for those Jake brakes.

[r600]

If it has a switch on the clutch pedal, then it's a Jake brake, not a dynatard.

The Dynatard did not need a clutch pedal switch because the actuating switch in the governor turned the Dynatard off when the engine dropped to idle and the governor pushed the rack open for idle fuel, so there was no possibility of the Dynatard "stalling" the engine, hence no need for a clutch pedal switch.

Dynatard and Jake brake circuitry is completely different.

That said, if there's no power at the dash switch, start there.

Check fuse or circuit breaker in that circuit, or look for a broken wire .

If still no power to the dash switch, run a new power wire to it from a fused source and abandon the inoperative power wire.

Check to see that the switch has continuity in the "on" position.

Work your way on down the line, check for power at clutch switch, throttle switch, and at the terminals at the Jake spacers between the valve covers and the heads. Make repairs as necessary to achieve this.

With dash switch on, clutch pedal up, and throttle at idle, you should have power all the way thru the system to the terminals on the spacers.

Once you get this far, then try the Jake with the engine running, it should work, if not, the wires inside the Jake spacers could be broken, or you have defective Jake brake units.

Last I heard, overhaul kits are still available for those Jake brakes.

BIG THANKS TOO BOTH NOID93 AND ALSO HK TRUCKING i have got them working.run new power to dash switch and they work. hk trucking is there anyway buy looking at the rocker covers to tell if dynatard or jake?i think it is a dynatard just someone has fit clutch switch(i know no point) . it doesnt sound like jake brakes?????does the terminal on the rocker cover have power all the time waiting for the no fuel signal????thanks adrian

[HK Trucking]

A Jake brake will have cast iron spacers about 2 inches high between the top of the heads and the rocker covers, a Dynatard does not.

A Dynatard has a relay under the right side of the dashboard (perhaps under the left side on an Australian truck?). The switch inside the governor housing grounds out this relay when the governor goes to the "no fuel" position, and the relay then energizes the Dynatard solenoids.

When the governor moves out of the no fuel position (idle, or throttle application) the switch breaks the ground connection, de energizing the relay, turning off the Dynatard, therefore no switch is needed on the clutch pedal. (As you said, someone may have installed a clutch switch for some unknown reason.)

As you can see there is a major difference in the circuitry between a Dynatard and a Jake brake.

The terminals at the rocker covers only have power when the engine brake is on.

[Rob]

The terminals at the rocker covers only have power when the engine brake is on.

This statement got me to thinking, (dangerous thing you know) about how difficult it is to shift my Dynatard equipt V8 with the six speed transmission. It turns out the moron that I purchased the truck from wired up the Dynatard "hot" all the time. No wonder the engine struggled to idle smooth, and was very difficult to up, or downshift the transmission. It's always had a strange "Kackle" in the exhaust that sounds nothing like a "Jake Brake". With all wired/hooked up normal, and with the Dynatard working as it should, the beast is a different animal. I could get to like the six speed without too much effort. With the dash control switch turned to the "on" position, the Dynatard works quite well and really slows the truck. I've never pulled a load with it, but again it seems to work well. Shifting the transmission is quite a different experience too. The exhaust "rumble" sounds normal also.

The reason for referring to the seller as a "moron" is that this truck has been a "real piece of work" for his efforts and I was shorted two transmission PTO's that were paid for in the sale above the asking price for the truck. They were needed, and quite costly to obtain from another source.

The seller is a participant on this website.

Rob

[theakerstwo]

The terminals at the rocker covers only have power when the engine brake is on.

This statement got me to thinking, (dangerous thing you know) about how difficult it is to shift my Dynatard equipt V8 with the six speed transmission. It turns out the moron that I purchased the truck from wired up the Dynatard "hot" all the time. No wonder the engine struggled to idle smooth, and was very difficult to up, or downshift the transmission. It's always had a strange "Kackle" in the exhaust that sounds nothing like a "Jake Brake". With all wired/hooked up normal, and with the Dynatard working as it should, the beast is a different animal. I could get to like the six speed without too much effort. With the dash control switch turned to the "on" position, the Dynatard works quite well and really slows the truck. I've never pulled a load with it, but again it seems to work well. Shifting the transmission is quite a different experience too. The exhaust "rumble" sounds normal also.

The reason for referring to the seller as a "moron" is that this truck has been a "real piece of work" for his efforts and I was shorted two transmission PTO's that were paid for in the sale above the asking price for the truck. They were needed, and quite costly to obtain from another source.

The seller is a participant on this website.

Rob

I know what you feel i have being there and try not to let it bother me because you have to remember that he will pay for it some time and when the lord get thru with him he is going to wish he could look you up and make things right . Just think about that me and you have some one watching over us . glenn

[Rob]

Last evening I went to a friends/customers house that is a grain hauler and "borrowed" one of his bottom dump trailers that had a load on it for testing and what an experience this was; The trailer had nearly a full load of corn and the V8 pulled it really well to my surprise! Until this experience I'd never had a trailer latched into the fifth wheel so it was completely new to me. I found out in short order that my transmission mounting biscuits are shot as the the shifters really move to the right side under power and there is a noticable clunk as they rub the mounting bolts upon upshifting. Several years ago I purchased a transmission isolator kit from the Mack dealer I used to deal with and now if I can just find them........ The Dynatard works well and as it should. I've never driven anything with a "Jake Brake" so there is really nothing to compare it to.

I had Andy, (owner of the bottom dump) drive the truck if for no other reason to listen to him cuss a Mack and as anticipated, he did effectively. I found it irresisitable to not "badger" him about thinking he was a truck driver, as I could shift that transmission much better than he could. Fortunatly, it was a short run and I only lost a small portion of gear teeth but had a great time.

I'm going to send the nozzels into the shop for testing/rebuild as this truck really smokes black under a pull with 25 plus psi showing on the boost gauge at about 2250 rpm. The pyrometer was showing about 950 degrees but I wasn't into the throttle long enough to know if it was still going to keep climbing or not.

All in all, it was an exciting experience as this truck is going to be my daily driver if I can afford the fuel!!

Rob

[r600]

Last evening I went to a friends/customers house that is a grain hauler and "borrowed" one of his bottom dump trailers that had a load on it for testing and what an experience this was; The trailer had nearly a full load of corn and the V8 pulled it really well to my surprise! Until this experience I'd never had a trailer latched into the fifth wheel so it was completely new to me. I found out in short order that my transmission mounting biscuits are shot as the the shifters really move to the right side under power and there is a noticable clunk as they rub the mounting bolts upon upshifting. Several years ago I purchased a transmission isolator kit from the Mack dealer I used to deal with and now if I can just find them........ The Dynatard works well and as it should. I've never driven anything with a "Jake Brake" so there is really nothing to compare it to.

I had Andy, (owner of the bottom dump) drive the truck if for no other reason to listen to him cuss a Mack and as anticipated, he did effectively. I found it irresisitable to not "badger" him about thinking he was a truck driver, as I could shift that transmission much better than he could. Fortunatly, it was a short run and I only lost a small portion of gear teeth but had a great time.

I'm going to send the nozzels into the shop for testing/rebuild as this truck really smokes black under a pull with 25 plus psi showing on the boost gauge at about 2250 rpm. The pyrometer was showing about 950 degrees but I wasn't into the throttle long enough to know if it was still going to keep climbing or not.

All in all, it was an exciting experience as this truck is going to be my daily driver if I can afford the fuel!!

Rob

rob,my dynatard relay has 4 terminals can you tell me where on your truck they go(tell me if i am right-30 positive power all the time /86 power from dash switch/85 earth to fuel pump/87 to dynatard sol?)thanks adrian

[Rob]

rob,my dynatard relay has 4 terminals can you tell me where on your truck they go(tell me if i am right-30 positive power all the time /86 power from dash switch/85 earth to fuel pump/87 to dynatard sol?)thanks adrian

Hi Adrian, I don't know off the top of my head about the routing of the wires. The electrical print I have and sent a copy to you is for a Caterpillar engined truck so it does not list Dynatard as it is Mack only.

From memory: Terminal 30 is constant DC voltage, and terminal 86 is postive DC voltage to the coil relay. I also believe that terminal 85 is ground, or earth. If the convention is correct when terminal 85 is grounded, postive DC voltage will be applied through terminal 87 will supply the voltage to the solenoids.

Rob

[Packer]

Hey!

If any one following this thread, or any one who knows someone following this thread, has a Jake rocker arm assembly (just need one) or the base only for a Jake brake, please let me know.

I bought a Jake set-up for a 673/237 two valve and only got one 'Correct' rocker arm base.

Didn't know I had the odd one until too late, and now I'm on the look-out for one.

I do have a Dynatard to part with if anyone is looking for one.

Thanks,

Packer

[mudslut28]

Rob dont worry bout being able to find the insulators. I buy them pretty regularly for my 2...best to buy the whole kit. Much cheaper that way. If I can find one of the boxes I may even be able to give you the part #.

[Rob]

Rob dont worry bout being able to find the insulators. I buy them pretty regularly for my 2...best to buy the whole kit. Much cheaper that way. If I can find one of the boxes I may even be able to give you the part #.

Hey there, thanks for the help. I was able to open the "cold storage locker", a.k.a. my brain, and found both kits. I had actually purchased these prior to owning either of the R models I now have, and thought they would work on a B model but they are physically smaller for that series.

The part number for the complete kit of needed pieces is 204SX216. This is the complete kit including all bolts, washers, biscuits, and locknuts. I paid $22.97 for each kit on 7/27/2000. Probably a little more now.

Rob

[HK Trucking]

Hey there, thanks for the help. I was able to open the "cold storage locker", a.k.a. my brain, and found both kits. I had actually purchased these prior to owning either of the R models I now have, and thought they would work on a B model but they are physically smaller for that series.

The part number for the complete kit of needed pieces is 204SX216. This is the complete kit including all bolts, washers, biscuits, and locknuts. I paid $22.97 for each kit on 7/27/2000. Probably a little more now.

Rob

Rob, when your under there replacing the trans mount insulators, carefully inspect the mount brackets that attach to the bellhousing, and also the mount brackets that attach to frame.

I've seen a lot of instances where the top corners (where the bolts attach it to the bellhousing) are cracked or broken off, especially on the right side.

I've also seen instances where one or more of the mount bolts pulled the threads out of the aluminum bellhousing, so check for that scenario too.

The fact that the shifters are moving an extreme amount relative to applying or removing throttle is a classic symptom of broken mounts, especially if that truck was abused by the previous owner.

[Rob]

Rob, when your under there replacing the trans mount insulators, carefully inspect the mount brackets that attach to the bellhousing, and also the mount brackets that attach to frame.

I've seen a lot of instances where the top corners (where the bolts attach it to the bellhousing) are cracked or broken off, especially on the right side.

I've also seen instances where one or more of the mount bolts pulled the threads out of the aluminum bellhousing, so check for that scenario too.

The fact that the shifters are moving an extreme amount relative to applying or removing throttle is a classic symptom of broken mounts, especially if that truck was abused by the previous owner.

Hi Herb, I was under the truck this afternoon and inspected the area(s) you advise. Fortunately, there is no fatique or damage of which you mention that I seen, and all bolts were tight and present. On the driver's side of the truck, the rearmost insulator rubber, (lower) is virtually non existent, with the forward insulator severely cracked and deteriorated. The upper insulators were also deteriorated severely, but there.

Sometime this next week I will try to find time to install the new mount kit. Maybe this will stop the chattering upon releasing the clutch pedal when loaded. I would think that with everything mounted securely things would not have any movement.

Rob

[mudslut28]

Glad ya got it taken care of Rob! Herb I have been through the broken mounts, insulators and even the insulator bolts coming loose if you have heard of that. The biggest pain I ran into on the 6 speed in my old truck was losing the threads in the side of the tranny where the hanger bolts to it. You can run it with 3 but it is nearly impossible to keep them tight. Another thing that will cause it right before things get really big is loose bellhousing bolts. Believe it or not I have seen a couple of trannies break completely free of the motor... Talk about a mess...lol. It wasnt my truck but it was a good lesson just by watching to always use new bolts and clean the threads out extremely well..lol.

Nice to look back at this stuff now and laugh but it sure didnt seem funny at the time