GL1800Riders Forums banner
Status
Not open for further replies.

Failed ADG

10K views 47 replies 17 participants last post by  Ted in ncal 
#1 ·
Here's a look at the inside of my failed Alternator Driven Gear assembly. This is out of an 01 with approx 111k. It was noisy as hell and ridden that way by the previous owner for approx 600 miles. Sounded like the bottom end of the engine was full of rocks when the rpm's dropped below11-12 hundred. You can see where the springs actually wore grooves into the halves when the keepers failed and the halves moved apart. Pulled the engine, clutch and rear cover. Replaced the ADG and then reassembled. The toughest parts of the job were removing the output shaft nut and making sure the the hoses wires and cables were all correctly routed on reassembly. Using the OEM Honda manual and special tools made it doable for me and I have to thank my local Honda dealer for letting me borrow the tools to get this done. Left them a hefty deposit just in case. Now it's quiet and ready to go. Except for the snow problem we've got..
 

Attachments

See less See more
1
#6 ·
No. The special tools were owned by the dealership. Two very large tool boxes full. Lots of money tied up in them. I think it would be prohibitive for each mechanic to own his own set.
Good on your dealer to loan you the tools needed to complete the job yourself..When I turned wrenches for shops,I had to buy all my tools if I wanted to work..My tool man loved me.I would of loved the shop to pay for Just the specialty tools needed,never mind what was in my roll-a-way that I still have..lol

Your ACG looked like mine when mine let go.


Only difference I didn't ride mine after I heard mine come apart like the PO did on yours.There is no place for all the pieces to go when the clip breaks.But it sure does sound like a empty paint can in there huh..lol

Mine was done under the Extended warranty..


Good job getting it done yourself :thumbup:,Some are shy to get to the air filter..lol


I take it you bought the bike this way and repaired it yourself??
 
#7 ·
Rocky;

When you say there is no place for the pieces to go when the clip turns loose; isn't there some piece that is prone to fall into the tranny like the proverbial monkey wrench in the gear, but hopefully entrapped in the pick-up screen or case bottom? Or maybe its just the gear set associated with the alt drive itself?

This is one of those jobs you hope not to have to do. I wonder if failure rates increase for all bikes with extended use; that is, is this flaw a universal characteristic of GL1800s made prior to some modification date. Or, is it an assembly quirk where someone on the line put the circlip on backward, ie, with the rolled margins toward the thrust side of the shaft?

prs

prs
 
#8 ·
Rocky;

When you say there is no place for the pieces to go when the clip turns loose; isn't there some piece that is prone to fall into the tranny like the proverbial monkey wrench in the gear, but hopefully entrapped in the pick-up screen or case bottom? Or maybe its just the gear set associated with the alt drive itself?

This is one of those jobs you hope not to have to do. I wonder if failure rates increase for all bikes with extended use; that is, is this flaw a universal characteristic of GL1800s made prior to some modification date. Or, is it an assembly quirk where someone on the line put the circlip on backward, ie, with the rolled margins toward the thrust side of the shaft?

prs

prs
Prs.Yes/no..The ACG is held in place by two bearings with just a few thousands of play between the bearings when it's in it's one piece state..

You are correct in thinking that when the Clip breaks it does "drop" it's pieces down past the other Gears in the rear of the engine..
Here is the pieces you speak of in my case that were sucked up in my oil pick up screen.


Now I'm not claiming to be a metal expert,But I'd think these pieces were made of a softer metal than the Gears in the back of the engine.??

When looking at my cases split.It was clear that these pieces didn't float around in the oil,(as one might think?) but sank to the bottom of the cases and seeing how the pick up screen is so close to the bottom of the cases.it was clear as to why they were sucked into the pick up screen and stayed there until the cases were split to look for them..
If they weren't.The mechanic (I use that word loosely) would of been able to fish them out,without needing to split the cases..

So No they couldn't hurt any tranny gears at at that point they were on the bottom of the cases and were out of harms way..

The only damaged gears I saw in my case were the gears in the rear of the engine,and they were just the related gears to the ACG,once it came apart,and it's half's were touching the neighboring gears to "rub them" if you will,to make then shiny so to speak..
 
#9 ·
I think that this flaw exists in all the pre-2006 alternator driven gear assemblies. My new replacement from Honda looked no different than the one I pulled out. Except it was still together. The half moon keepers that hold the ADG halves together float in their grooves and are held loosely in place by a soft stamped sheet metal retainer cap under a circlip. The keepers actually rattle around in there under the retainer cap. My theory is that with repeated visits to redline, the banging of the keepers against the soft sheet metal retainer cap slowly distends it and allows the half moon keepers to eventually escape. The ADG halves move apart slightly and the springs no longer provide any dampening. Instead the metal dogs of the halves just begin to pound on each other at low rpm when rotational acceleration and decelerational forces are most pronounced. The keepers, once they escape, fall to the bottom of the rear engine case cover. Hopefully they make it past the gears in the rear cover without getting chewed up. Luckily the keepers are softer than the gears. Once the keepers are in the bottom of the rear case, the possibility exists for them to migrate into the bottom of the crank case/transmission. If when you pull your rear cover, you don't find your keepers, then they probably made it through the little oil return hole in the back of the main case and are now in the bottom of the engine. That's when you decide whether to split the cases and go looking for them. In my opinion, they are not worth looking for. The main crankcase is deep. The shift drum rides high and the transmission gears ride even higher. See the attached pics. There is virtually no way those little keepers are gonna get sucked up past the shift drum into the trans gears. The oil pump pickup screen rides very low and the keepers will most likely end up trapped in the screen like Rocky's and spend the rest of their days trapped safely out of the way. I don't think it's necessary to split the cases to find them. But as usual, you have to make your own call.
 

Attachments

#10 ·
The oil pump pickup screen rides very low and the keepers will most likely end up trapped in the screen like Rocky's and spend the rest of their days trapped safely out of the way. I don't think it's necessary to split the cases to find them. But as usual, you have to make your own call.
I agree with you on finding the missing pieces,knowing now where they ended up..(Mine were stuck in the oil pick up screen.)

Here is the Pick up screen rides about 3/16 off the bottom of the case.


Of all the GL1800 that were produced.Not very many have had this ACG failure issue per the number of the wings produced since 01.
I liken it to the frame cracks near the passenger boards..Some have cracked,But it's not all of them..

I don't think running up near the red line has anything to do with it.My bike had 15K when I bought it-It had 37K when the first one let go.I now have 74K and have been at the red line more times since 37-74K Then I ever was at 15-37K..

I attest the ACG failure to "The luck of the draw"
 
#11 ·
I think that this flaw exists in all the pre-2006 alternator driven gear assemblies. My new replacement from Honda looked no different than the one I pulled out. Except it was still together. The half moon keepers that hold the ADG halves together float in their grooves and are held loosely in place by a soft stamped sheet metal retainer cap under a circlip. The keepers actually rattle around in there under the retainer cap. My theory is that with repeated visits to redline, the banging of the keepers against the soft sheet metal retainer cap slowly distends it and allows the half moon keepers to eventually escape. The ADG halves move apart slightly and the springs no longer provide any dampening. Instead the metal dogs of the halves just begin to pound on each other at low rpm when rotational acceleration and decelerational forces are most pronounced. The keepers, once they escape, fall to the bottom of the rear engine case cover. Hopefully they make it past the gears in the rear cover without getting chewed up. Luckily the keepers are softer than the gears. Once the keepers are in the bottom of the rear case, the possibility exists for them to migrate into the bottom of the crank case/transmission. If when you pull your rear cover, you don't find your keepers, then they probably made it through the little oil return hole in the back of the main case and are now in the bottom of the engine. That's when you decide whether to split the cases and go looking for them. In my opinion, they are not worth looking for. The main crankcase is deep. The shift drum rides high and the transmission gears ride even higher. See the attached pics. There is virtually no way those little keepers are gonna get sucked up past the shift drum into the trans gears. The oil pump pickup screen rides very low and the keepers will most likely end up trapped in the screen like Rocky's and spend the rest of their days trapped safely out of the way. I don't think it's necessary to split the cases to find them. But as usual, you have to make your own call.
Thanks for the rundown on this, but can I assume from your comment above that Honda fixed this problem with the 2006 and up bikes?

hoverlover
 
#14 ·
Thanks for the rundown on this, but can I assume from your comment above that Honda fixed this problem with the 2006 and up bikes?

hoverlover
The ACG for 06-up bikes had a different part number due to the 06 bikes having a bigger Alternator (for NAV/80 Watt stereo amp/comfort package etc).it had nothing to due with having Honda fixing the ACG..

I'm betting the only difference between the two parts is the half that sticks out of the rear case to accept a thicker OD Alternator output shaft into the Rear of the ACG...It just doesn't make good business sense to build a totally different unit that does the same thing in this case.

In fact there have been a few 06 up bikes who did have the ACG failure as well.So no one is exempt from a ACG failure.
 
#15 ·
Boy, that sure sounds like my '01 with 90K miles. The "engine was full of rocks" noise I hear occurs mainly when the engine is cold and the transmission is engaged and more specifically when the engine might be lugged like slowing for an intersection turn and accelerating then after completing the turn.

How is this specifically diagnosed?
 
#16 ·
I'd say a valid preliminary test would be to remove the alternator and check the female spline of the Alternator Driven Gear where the alternators male spline fits in, for any perceptible rotational slop. It should be absolutely tight and have no rotational movement in either direction. On mine I could spin it back and forth a good 10 degrees. If it's tight, then I believe Honda also has a test where a torque wrench can be used to test the integrity of the damper springs. But if you've heard the noise and then pulled the bad ADG before, then there is no real mistaking the sound.
 
#17 ·
I'd say a valid preliminary test would be to remove the alternator and check the female spline of the Alternator Driven Gear where the alternators male spline fits in, for any perceptible rotational slop. It should be absolutely tight and have no rotational movement in either direction. On mine I could spin it back and forth a good 10 degrees. If it's tight, then I believe Honda also has a test where a torque wrench can be used to test the integrity of the damper springs. But if you've heard the noise and then pulled the bad ADG before, then there is no real mistaking the sound.
jwit, thank you for posting the great info about replacing your alt drive. :congrats: on fixing it yourself.

I have an 01 with 30,000 miles on it that has a clatter or rattle at around 2000 - 2500 rpm under light engine load with the engine hot. It is quiet at idle and below 2000 or above 2500 rpm. This does not match the noise that others, including you, have described, but there are other posts such as http://gl1800riders.com/forums/showthread.php?t=151967 that describe the same noise as mine. I bought it with 24,000 miles and never noticed the noise until I had it for a while. It has not gotten any worse over 5,000 miles, but it has never went away either.

I am contemplating doing as you did :eek:4: (no extended warranty), but had never thought about pulling the alternator and checking for play in the drive first .... duh.

Assuming my problem is the alt drive, my main problem in doing the work myself will be the special tools :tools1: needed for the job. I don't think there are any dealers in my area who would loan me these tools.

From reading the shop manual, it looks like there is a special holder for the output shaft, a holder for the clutch basket, a wrench/socket for the clutch basket nut and another for the output shaft nut. Is that correct? Are there any of these tools you think you could find a work-around for?

Thanks again for sharing your work with us.
 
#18 ·
You really should have the right tools. I'm sure you can buy commercial deep well sockets for the output shaft nut and the clutch nut. You could even pull your own drive shaft and use it as a shaft holder. But the triangular clutch holder would be tough to replicate.

Another problem is with the output shaft nut. The Honda socket tool is hollow and has an arm welded on the side to accept a breaker bar. The shaft holder fits on the shaft through the center of the socket tool. But even with the Honda tools I could not get the output shaft nut off. I finally settled for drilling it in several places to weaken it. Then returned with the Honda tool and it finally broke under pressure. Not easy. If you do choose to drill it, you have to be very careful not to trash the output shaft in the process, or fill the output shaft bearing with metal shavings.
 
#20 ·
I could be wrong but I believe the original problem with these failures was the clip being installed backward at the factory. The clip has a sharp edge and a slightly rounded edge due to the way they are stamped out. If the clip is installed backward the rounded edge will crawl out of the slot on the shaft and let the ADG split apart. The clip should be installed with the sharp edge away from the ADG.
 
#22 ·
You can see that Honda even changed something in the 06 up ACG's..
I was told by Honda that something was changed in the ACG in my 04,But the Customer service nor the Tech Dept has any knowledge of What or Why a piece was changed in a part that is superseded.They only see what we do,a new part number for a time,then only the single part number as in what is shown below in the 04 AGC part number.

HondaGEAR ASSY,ACG DRI for 2006 Honda GL1800
13430-MCA-A61
Replaces part number 13430-MCA-A60
$357.60

HONDAGEAR ASSY. (28T) for 2004 HONDA GL1800A
13430-MCA-780 $301.39
 
#23 ·
I could be wrong but I believe the original problem with these failures was the clip being installed backward at the factory. The clip has a sharp edge and a slightly rounded edge due to the way they are stamped out. If the clip is installed backward the rounded edge will crawl out of the slot on the shaft and let the ADG split apart. The clip should be installed with the sharp edge away from the ADG.
t-dude: Your memory is a bit foggy, like mine, huh? Up above I dun wint'n sed:

"I wonder if failure rates increase for all bikes with extended use; that is, is this flaw a universal characteristic of GL1800s made prior to some modification date. Or, is it an assembly quirk where someone on the line put the circlip on backward, ie, with the rolled margins toward the thrust side of the shaft?" But, I am not at all sure if that circlip placement was discussed in relation to this same problem or not (I 'think' it was). I also 'think' it may have been Stu Altman who brought-up that detail. I can tell you from first hand experience, that a reversed circlip will eventually jump out of its groove in an impact or vibration prone application.

prs
 
#26 ·
jwit, thank you for posting the great info about replacing your alt drive. :congrats: on fixing it yourself.

I have an 01 with 30,000 miles on it that has a clatter or rattle at around 2000 - 2500 rpm under light engine load with the engine hot. It is quiet at idle and below 2000 or above 2500 rpm. This does not match the noise that others, including you, have described, but there are other posts such as http://gl1800riders.com/forums/showthread.php?t=151967 that describe the same noise as mine. I bought it with 24,000 miles and never noticed the noise until I had it for a while. It has not gotten any worse over 5,000 miles, but it has never went away either.



.

This description is exactly what mine does. 08 with just over 6,000 miles, has been doing it since it was new. Above 2400 RPM, or with any load on the engine, it goes away. Dealer says not to worry about it. Still under warranty (bought it new in June 09), I don't know whether to just ride it til it breaks, or go back and insist on them trying to fix it. Your thoughts?
 
Status
Not open for further replies.
You have insufficient privileges to reply here.
Top