Hello Here is the image of the old starter, teeth are the same, solonoid appears to be the same but pos and neg terminals are reversed from the other starter solonoid. the teeth on the new starter and the teeth on the flywheel are a bit chewed up as they are not engaging (this is in response to a question posted on teresa's thread, earlier regarding the banging sound we were hearing when starting up new starter. We were asked to start a new topic so will post our intro next! Thanks for your help. Background of our issues are to be found on Teresa's thread, we will repost them here!
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi495.photobucket.com%2Falbums%2Frr315%2Fhappycamperbrat%2FRon%2520and%2520Kristen%25204106%2F002.jpg&hash=b99b3fb4686a49ee05168510e8c3c15e1fd425f4)
When did GM change to negative ground from the positive ground was it at the beginning of the 4106 or later in the run, weren't all 4104 GM positive ground ? thinking he may have bought a positive ground starter or maybe a 24 volt
good luck
Answer Cliffords point first! then ck to see if this starter gear is going into the flywheel further than the original starter.=the hard thump when enguaged
As far as I can think of, a starter motor wouldn't be polarity sensitive in any way that could affect engagement, could it? I believe that either solenoid terminal could be configured as "power" and "motor" without causing engagement issues.
A CW vs CCW rotation drive gear would have the opposite edge of the tooth beveled to lead during engagement, but the drive would also freewheel in the opposite direction.
Some motors require a spacer between the motor end and flywheel housing.
How 'bout a picture of the two starter's drive ends, side by side?
After confirming an exact match with the original motor, I would say that Ron and Kristin's next step would be to energize the installed starter's solenoid, without energizing the motor, to check the drive engagement.
Ted
Quote from: MDV Maria V on May 05, 2011, 10:03:38 AM
Thanks for the welcome! Ok, here is a mystery that we are hoping to solve...From Evernote:
Bus notes as of 5/03
Symptoms of exisiting bus issues: annendum as of 3 weeks ago
Start of bus was hard as if batteries were low. Amp meter on dash showed heavy discharge, as in pegged the needle on discharge side of guage at low RPM.
When motor was at high RPM, it was charging. Turned off bus, could not restart. Starter solonoid hit hard, would not turn over engine. Separated house and coach systems and determined house system not of issue but never reconnected two systems.
Very slowly and systematically went through electrical system looking for dead short, with voltmeter. Multiple minor issues found. Put in new set of brand new 8D coach batteries, still would not start coach. Roll started, fired right up, ran well, voltage meter still full discharge. Turned off bus, would not restart. After turning off bus and trying to restart, solonid does not click or make any sound whatsoever. Spent several days looking for and running down several issues:
1. ignition switch corroded and not turning off completely, minimal amount of power running through at all times
2. all switches on dash faulty, not performing properly or shutting off- corrosion
3. went over electrical system, eliminated all wires that were not being used. Re-sautered new ends on all wires in question. Found one wire with total dead short. When disconnected, rest of system appeared to not be shorting out
4. Put new starter in , old starter was bad. Wire with dead short disconnected..of unknown origin, location at service panel next to driver seat.
5. started bus, bus starts well, total discharge on meter, wire with dead short still disconnected-
with bus not running there was no discharage on batteries when wire with short was disconnected but total discharge when bus was started.
Next issue:
installed rebuilt starter originally in a 4106 w 8v71. Starter sounds like someone is randomly beating on it with 4 lb sledge hammer when engaged, stops when disengaged. Were there different starters for different busses? Without having counted the teeth, they appeared to be the same, rotation is correct...getting ready to tear apart again..aargh, so hoping for advise soon!
Sorry, I replied before I read the above from the "other" thread.
Now that I know it's an '06, with a practically inaccessible starter motor, I'll retract my suggestion of engaging just the solenoid. Instead, careful measuring will have to be done on the bench.So R&K, does the engine start now, but with a terrible "clanking" during crank?
Here are the 2 starters side by side for comparison
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi495.photobucket.com%2Falbums%2Frr315%2Fhappycamperbrat%2FRon%2520and%2520Kristen%25204106%2FRKstarters.jpg&hash=50a5a5472b89faa984cf0b9e44714275671b4e19)
Glad to see that the original motor didn't get away, that's good.
Do not surrender it until the cranking problem is solved.
I'm almost positive that the "flag" connector and solenoid configuration aren't a concern here.
I'm betting on a mismatch at the drive end.
Could we see the drive ends pictured side by side?
---
If this isnt a good enough pic, I can retake
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi495.photobucket.com%2Falbums%2Frr315%2Fhappycamperbrat%2FRon%2520and%2520Kristen%25204106%2F003.jpg&hash=7e9bf634f84ed025013dcae55876b1f37d6a6538)
From here, the drive gears look different. The flanges also look to be slightly different and "clocked" differently. The mounting flanges are just different enough that there could be mounting interference with some applications. But the big issue would be tooth count of the drives. Count the teeth, looks like a mismatch from here.
Instant and final starter failure is relatively rare. Since the engine seemed to have been cranking fine before the various electrical issue cropped up and drained the batteries, I'd be tempted to give the original motor a bench test with a known good battery.
Ted
Thanks Ted! I will tell them in the morning. I think they might be asleep now. But I think Ron said he had counted the teeth and they were the same.....
They may be the same, it's hard to tell for sure from the pictures, but in all likelihood some difference on that end of the starter is causing the problem.
good luck
Could the solenoid be kicking out and reconnecting? I had an old chevy do that and it ate the ring gear...Cable
Well, if it is the wrong starter........ umm, any idea where they could get another for less then $500.00? That was what Napa had quoted him.....
Buddy has so many electricity issues.....is he even sure the original starter is toast? Bench test it. I have quasi rebuilt a starter on the side of the road, redressed the commuter end, , dressed the solenoid contact points, lubed moving bits etc....took maybe an hour tops...has worked great since then....since he has an extra starter there he can scavenge brushes...solenoids/whatever from one to the other.
I think youre on to something there zub!
Electrical note wire guage white wire on new starter appears to be lighter than black wire on old starter. Cold cause low amperage problem and over heating of wire. Bob Not trying to pick just observing.
T, the MT 42 starter should cost 200 to 250 bucks tops is the there a rebuilder in your area ? sorry I don't have a lefty starter or I would send it to him I have plenty of the rights
good luck
An auto electric shop should be able to rebuild the original starter. I think I paid about $200. for that last year. They may even be more expert at seeing the difference between the two.
would a starter off a 4905 8v71 be what is needed
I wonder if all 8v71 starters are interchangeable if the direction is the same
what is your location state and city
Lonnie
Quote from: Lonnie timetogo on May 06, 2011, 08:32:00 AM
would a starter off a 4905 8v71 be what is needed
I wonder if all 8v71 starters are interchangeable if the direction is the same
what is your location state and city
Lonnie
I think so (in bus applications at least), except the nose cone may need reindexed. Jack
The starters are different according to the starter location on the bell housing a 8v71 righty can use 3 different starters not being a GM guy they could be the same starter location is the key for the right starter
good luck
That trip to the re-builder is a terrific one. I am a firm believer in "experts with experience". The beauty here is you might be able to use things like the solenoid, armature and body to swap over to your old parts and come out of it with no more invested than the charge for that at the starter shop.
I understand that the starter is criminal to replace so I guess this is the time to get a expert on site involved.
John
Im at work now, but will make sure Ron sees all this when I get home. Im in Ridgecrest, Ca http://maps.google.com/maps?q=4756+sydnor+ridgecrest,ca&oe=UTF-8&ie=UTF8&hq=&hnear=4756+Sydnor+Ave,+Ridgecrest,+California+93555&gl=us&z=16 (http://maps.google.com/maps?q=4756+sydnor+ridgecrest,ca&oe=UTF-8&ie=UTF8&hq=&hnear=4756+Sydnor+Ave,+Ridgecrest,+California+93555&gl=us&z=16) They are really nice folk and it's a pleasure having them, but I sure would like to see them get on the road in a bus that will get them home.
YOU ARE NOT WIRED CORRECTLY!
My ecpert just reminded me of the way the starter works. First, the way an automobile worls. The solinoid engages the bendix and connects the starter motor to B+. The solinoid stays connected and "working" throughout the start. This bus thing is designed to use the solinoid to engage the bendix and then when the armature gets engaged THE B+ FOR THE SOLINOIOD IS INTERUPTED and the B+ for the armature gets connected to the solinoid to KEEP the bendix engaged. If the starter solinoid wiring gets reversed then the "GROUND" is used to keep the starter engaged.....that won't work. That massive starter, when miswired like this, will "chatter".
The FIX. Solinoids are not themselves polarity sensative but they need to be in the circuit correctly. Look at your old solinoid/starter and carefull match that wireing config to your "new" starter. This is a common mistake and easily corrected with wireing properly connected. You have the correct wiring in the example of the old starter.
This info comes from a starter rebuild shop and is filtered through me. Any one should be able to get the same story from any shop.
Good luck,
John
You can verify this "theory" by connecting the starter to a battery and shorting the solinoid engage terminal to "Bat". HANG on as the thing will try to leave the premises. If it wired incorrectly then it should chatter. Try the old one too. They should react the same and be wired the same.
I think you are fixed.....good luck,
John
Update this am: Old starter when jumped, solenoid only throws sparks, no movement. New starter when bench tested, functions properly; first bench test procedure was to disconnect all three bolts and back starter away from fly wheel. Reconnected battery cables at battery connections- did not remove any cables from starter for this test, only pos and neg at battery. Starter engaged and ran smooth and strong with no load. All measurements and apparent visuals between two starters would appear that they are the same starter, turn the same direction, only apparent difference is different solenoid. Now under impression that this is possibly a relay issue to solenoid, causing chattering under load and am regoing over all cable connections to assure that they are clean and properly connected. Ron will put starter back in, test and if cables are not the issue, will test by jumping past relay. Will report back soon, thank so much for helping!
You have a wiring problem some place the engine starts and for what ever reason it is engaging the starter while the engine is running that is what is chewing the bendix drive up and causing the discharge on the gauge George will help you figure it out when he gets there and if you think it is a relay make your self a jumper and by pass the relay but I don't think that is the problem.I would also check the flywheel and be sure it hasn't come loose the old style 8v71 are bad about breaking the bolts if not updated to the 2 extra bolts in the crank end
good luck
On aside..... how did you know by looking at these pics it was left hand rotation and not right hand? Im still confused by how to tell the difference.....
The twist for the right hand, left hand deal is on the armature shaft inside the starter you need to pull the nose cone to see that
good luck
Thanks for the explanation ;)
Answers to replies both on this thread and Teresa's- will try to keep it all on this thread from now on for archived issues.
Starter does not grind; when starting, it hammers very hard until engine starts and the key is let off, then hammering stops. Does not hammer when key is in run position or make any sound whatsever, only sounds when key is in start position.
The new starter is wired exactly like old starter. If it is not right, it has been like that since purchased two months ago. Negative is grounded directly to bus body. There is a connection from bus body to engine. Starter is grounded directly to bus body. Positive runs from batteries to connection block, from block, one cable runs to starter, smaller cable runs to front of bus. From starter, cable connection goes directly to alternator. Wire from relay goes to solenoid.
RE: relay, could be relay, we did find one burned up going to tail lights, another that went to old horn. Starting issue may possibly be a bad relay chattering, causing hammering in starter.
Yes, we have roadside assistance with AAA. I would suggest that anyone planning an Alcan trip get the full protection!
Yes please on connecting us with the GM group who is going to AK June 1. We will already be home one way or another, by then. We may be looking for a place to store her for the summer, if anyone has any ideas about that. She was meant to be a stateside bus, anyway!
Planned to drive through Oregon, John, thanks for coverage!
Ron says thanks so much, you all "rock"~ KRISTIN
DO THIS NEXT...... Bus in neutral. connect a wire to the B+ term on the starter....strike connect/ momentary contact the other end of that wire to the Re or SW terminal on the starter solenoid. If it chatters you have a bad starter or it is not wired correctly internal. If it starts fine then it's between the switch and the starter. If the starter is OK then put in a switch in the engine compartment that is called a "rear start" switch. You are supposed to have one of those anyway but be sure it is a momentary contact switch so it shuts off when you release it.
From this point I think the trouble shooting of the starter is complete. Wiring? Lots of stuff.
I am pretty certain I can give you my space to store the bus. $50/ mth. or part. Rick's starter rebuild shop is on the premises. He rebuilds starters and alternators but doesn't work on vehicles. I can help you work on it but I am getting long in the tooth so heavy lifting is kept to a min. But, between the three of us we should be a certainty to succeed. This is only a option and not a request. I don't know what path you are taking north and the fuel difference might pay for a shop.
And again, good luck.
John
you correct me if I am wrong but in one of the posts you said the charge (amp) gauge pegs on the discharge side after starting if that is the case the starter is staying engaged because the starter will draw over double the amps the alternator will produce if it was a dead short the fire dept would be there
good luck
update and thanks so much for all the suggestions!
Wiring is most definitley correct, all terminals have been thouroghly cleaned, both pos and neg. starter has been bench tested prior to reinstallation, soon to occur. Bench test: starter solenoid on new starter, doesn't chatter, engages very solid. Starter spins freely. Old starter solinoid now engages very solid, old starter does not turn. I can turn old starter manaully but not with DC power. Have determined starter is not miswired and works correctly
Hi Folks,
Not being a GM man I am not sure of bus voltage but you said that you got a new "set" of 8Ds which would imply more than one and a 24 volt electrical system but the new starter solenoid was stamped 12V. Is the electrical system 12 or 24 volt?
12v
most likley the starter relay. had similar problem, just switch wires to ac relay if you still have it.pat.
Update for the archives:
They took the new starter apart to check the brushes. However the new starter's bushings were fine. In taking this starter apart though, they found a stripped screw. That tiny little screw was causing lack of good contact and thus the hammering sound.
With the help of my Uncle George Todd, they ran down several other issues with the electrical system. The reverse, lights, charging, etc. all seems to be working right now. Mostly it was bad grounds.
While Uncle George was here they also went over the slack adjustment to the brakes and the brakes are said to be safer now.
Hats off to your uncle Georage he seems to be a very good uncle to have. I really enjoyed talking with him. I am glad the folks are on their way home The OP should have his name posted some where they flat took these folks to the cleaner. Tony
Papatony
To me it doesn't seem like the previous owner deliberately misled, it just sounds like a typical old bus scenario. Once Uncle George was on the case, it sounds like a few minutes of accurate diagnosis and then repair of routine minor maintenance issues solved the problems.
Ted
Ted,
Well said. Not being there I tend to agree. Had I had this experience and this difficulty I quite imagine I would be looking for "Devils" as well as fixes. :( :'( Good thing he has agility and energy going for him.....my goose would have been cooked.
John
The upside! what a education!! he might not think so now but he has something no one can take away from him :and security if something else comes up. Just might be able to say-Aw that's nothin just do this and lets go best of luck and good bussin Bob
Hi guys I guess you are wright these guys have been around a long time. Its just if I had sold my bus going that far I would do every thing I could make sure it was right. Happycamperbrat brought up a good point about keeping a record of the changes we have to do for some one in the future. I had to do a lot of work on the wiring, and I'm going back right now and record it. Sooner than later some one else will have to deal with it. Hats off to all the folks who helped this couple. I bet we will have two new members soon. Tony