| Author | Message | ||
| Larry Nelson (Larryn4106)
Registered Member Username: Larryn4106 Post Number: 95 Registered: 8-2008 Posted From: 50.83.99.205 Rating: N/A |
I always carry one and on this last trip I had to use it on my 4106. I am wondering what makes these simple devices go bad??? It (the one I removed) was TRYING to work, just couldn't cut the mustard. These are just a coil. I even reused my old plunger. Can they be redone at a motor shop? Or call Luke? | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 692 Registered: 2-2001 Posted From: 184.0.13.120  Rating: N/A |
Mine failed about 11 years ago. I took it to an electric motor shop & they rewound it. Been great ever since. I always wondered why they weren't air solenoids. If they were, they might leak but wouldn't ever burn out. A skinner valve & a small air cylinder with a return spring would do it. You'd need a little hole drilled in the line or fitting to bleed off the air when you let the switch go. Or an air relay valve that dumps when released would do nicely. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1596 Registered: 10-2006 Posted From: 76.192.5.151  Rating: N/A |
I found that our requirement to back a long block , in order to back into our yard in Fl, over heates the HOLD points and the spring then does not reset. The HOLD coil is not strong enough to engage the solenoid , only as designed Hold it. My solution , as noted , is a small hole in the center of the cover. After a long backup a push with a chop stick assures reset , and operation of reverse when next required . YES it is a PIA , but it does work 100%. FF | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 2163 Registered: 10-2003 Posted From: 71.58.71.157  Rating: N/A |
Remove the rear cover and inspect the point gap...When solenoid is fully in reverse, the points to the pull coil should be open; at that time the hold coil will be doing the work. Adjust the linkage bolt to obtain this gap. You will find that the linkage bolt has quite a bit of slop when adjusted properly.When I first fooled with mine, I removed most of that slop and started having trouble. After studying manual and adjusting gap properly, never had any more problems. Seems to me like that slop is necessary to get the solenoid in motion some before moving shift lever. | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 693 Registered: 2-2001 Posted From: 184.0.13.120 Rating: N/A |
I don't have to hold mine all the time I am in reverse. It only has to be held when putting the trans into reverse. I put it in first, push the reverse switch (shifter jumps when solenoid engages) and shift to "second" gear position (while holding the reverse switch) which is temporararily reverse. I let go & it stays in reverse. Shifting to neutral takes it out of reverse and restores normal shift pattern. I think if you have to hold it the whole time you are in reverse, something is wrong. When my solenoid failed, I had my wife go back & pull the lever for me. It stayed in reverse until shifted out to neutral. | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 1289 Registered: 8-2006 Posted From: 99.29.76.231 Rating: N/A |
Jim is exactly right, and something is wrong with Fred's bus, or his idea of how these solenoids work. They have a pull-in coil, and a hold-in coil, and an adjustable set of contacts. The pull-in coil is very strong, and will overheat quickly. The contacts are designed to de-energize the pull-in coil as soon as the shift mech is engaged, then the hold-in coil does just that as long as the button is held down. As soon as the shift lever is in reverse, the button should be released. The shift lever can be in reverse for an hour without hurting anything, because there is no current flowing once the button is released. V-drive, or T-drive, doesn't matter. Air would work fine as suggested, and it woudn't need pull-in, and hold-in, OR an adjustable set of contacts. We just won't talk about the coil in the solenoid valve! G | ||
| Tony LEE (T_lee)
Registered Member Username: T_lee Post Number: 84 Registered: 11-2007 Posted From: 66.135.68.100 Rating: N/A |
"Air would work fine as suggested" or, as I had to do for a couple of days, hook a rope to the lever and get the copilot to go out and pull it whenever I needed reverse. Surprising how few times you really need reverse gear. | ||
| Jack Fids (Jack_fids)
Registered Member Username: Jack_fids Post Number: 943 Registered: 1-2009 Posted From: 72.211.145.15  Rating: N/A |
My Wife drove her car for 3 years with no reverse & dint want me to fix it because "it was more work than it's worth, I rarely use reverse." My '06 operates exactly like jimBob's, although I'll be adjusting the Slack BACK into the linkage today after reading the above info, I've yet to experience a problem with the unit or it's operation... I do carry a spare tho. Always have a "Plan B" in your pocket ! The Air-Ram idea merits some further investigation & discussion... at first look it seems like a natural for a more reliable operation, AND I happen to have a 5 gallon pail full of 4-6 & 8 in. air-rams that Raytheon junked when they trashed a production line... | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1598 Registered: 10-2006 Posted From: 76.195.73.138 Rating: N/A |
"I think if you have to hold it the whole time you are in reverse, something is wrong." Correct! I do not hold the button down , the hold coil does hold in the reverse position till shifted . The purpose of the hold coil it to have the ability to stay in reverse , otherwise there would be just a Pull , with no hold required. FF | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 500 Registered: 12-2000 Posted From: 72.187.35.208  Rating: |
Fred, I think you misunderstand the way that circuit works. The purpose of the hold coil is simply to reduce the high current needed to operate the solenoid. If the circuit worked as you suggest, then you would either have to hold down the switch or there would have to be an alternate voltage source to the solenoid. Once you release the switch, there is no voltage there to operate the holding coil. It is not necessary to keep the coil energized in order to stay in reverse. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1600 Registered: 10-2006 Posted From: 76.195.73.138 Rating: N/A |
It is not necessary to keep the coil energized in order to stay in reverse. Correct , the hold coil is only 10A and the operate is 50A . The hold coil is required to lower the amps as the driver shifts from neutral, into first than pulls into "second" (Da Book procedure). The hold points sticking seems to be my problem as the pull circuit will not operate if the hold is in position.. | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 696 Registered: 2-2001 Posted From: 184.0.13.120 Rating: N/A |
Fred, Pretty hard to troubleshoot from a laptop. But it sounds to me like this may be related to the correct travel & play in the linkage. It may be that the solenoid armature needs to move backwards a bit when de energized to "pop" the points apart. If they are HOT & stay together, they would be more likely to stick. Now, as with all of us GM bus guys, the silver or other coating on those 40+ year old points may be gone, allowing the softer brass or copper to weld. If it were me, I'd look at the points condition, then at the travel. I know the solenoid has a return spring in it too. Is it there and in good shape? | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 2164 Registered: 10-2003 Posted From: 71.58.71.157 Rating: N/A |
Fred, did you remove that rear cover(two screws) and check the points condition and that they open when solenoid makes it's full travel?. Also wouldn't hurt to use a #8 gauge wire to operate it. You already know how to dress points if they are still in good condition. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1601 Registered: 10-2006 Posted From: 76.195.73.138 Rating: N/A |
The unit is new , and with the engine ideling the Voltage is 13.4 , just what the V reg is set for. Seems to be a lack of spring in the point arm. Dressing the points might help , but the simple method I use works just fine. A non conducting spring might work too. FF | ||
| Jack Fids (Jack_fids)
Registered Member Username: Jack_fids Post Number: 947 Registered: 1-2009 Posted From: 72.211.145.15 Rating: N/A |
2 small Phenolic washers, 1 on either end of the spring maybe...? | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 2166 Registered: 10-2003 Posted From: 71.58.71.157 Rating: N/A |
if you don't remove the cover and adjust OR check that the points gap to specs,you can not adjust the slop in the linkage so it will work properly consistently. That slop is more than you might think. The cover is easy to remove. It has a felt gasket and two small screws. Only thing in there is the points. nothing is going to fall out. "Be sure transmission control linkage is properly adjusted. Place gearshift lever in 1st speed position.Disconnect wire from terminal and remove cover from solenoid. Inspect contact points.If points are burned or pitted, replace or dress with a fine cut point file. Operate reverse lever, while observing contact points. As lever moves solenoid plunger,the points must open when plunger reaches end of travel.When current is supplied to solenoid, both coils are energized,and cause magnetic pull on plunger, but when points open, the circuit through the pulling coil is broken and only the holding coil remains energized. Damage to coils may occur if points do not open at end of plunger stroke. If necessary to make an adjustment, loosen locknut and remove clevis pin, and turn clevis while holding link assembly. Install clevis pin and tighten locknut, then recheck action as indicated above. Re assemble wire conn. and cover. Start engine and check operation." Per da book 4905. 4104,06 similar. When mine acted up, it worked fine when cold, but wouldn't when trans warmed up after driving several miles. Replaced solenoid with new from Luke. Same problem. Got the book out and followed directions- end of problem. Linkage didn't have enough slop in it to open points. Had a nice solid sound once adjusted. If the adjustment isn't right, even a new solenoid will cause issues some or most times. You can't tell if it is adjusted properly without removing that cover. Watch you don't drop the screws and a screw holder helps to reinstall them.Maybe slop isn't the right word; several threads showing between lock nuts.First time I saw that linkage, I thought someone jury rigged a substitute bolt for connector, but they all use the same setup. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1602 Registered: 10-2006 Posted From: 76.192.0.125 Rating: N/A |
"Watch you don't drop the screws and a screw holder helps to reinstall them" Swopped over to SS Alan heads so its easy to have the screw stay on the tool while installing. FF |
