The Grambo Trick - Version 2.0 (ACCT Adjustment)

388 Views 31 Replies 5 Participants Last post by O' Darkness, 15 d ago

O' Darkness

Discussion Starter · 17 d ago (Edited)

Before committing to replacing or repairing my ACCT's, or making the conversion to MCCT's (be it DIY or pre-made) I decided today to completely remove both of them and have a peek.

With the ACCT out and in my hands, I tightened the (front cylinder) tensioner screw all the way in, fully retracting the plunger. While doing this VERY slowly, I could feel just the tiniest bit of resistance about halfway through. Almost as if there was a little friction point that the spring might have bound upon. The rear cylinder ACCT also had this almost imperceptible bit of resistance about halfway.

So I submerged both ACCT's in clean motor oil inside of a clean tupperware container. (Don't worry, I wiped it out afterwards with a paper towel before I ate my Campbell's Cream-Of-Mushroom soup out of it. It DID taste a little funny, though...)

I flipped the container gently, so as not to create bubbles; a few times about every ten minutes for an hour. Giving the oil the opportunity to seep into every crevice.

Additionally, I turned the tension screw all the way in a few times while they were submerged.

When I replaced them onto the bike, I observed how far I could install them back onto the bolts before I was stopped by the compression guide. Slightly more than 1/4 inch. I simply turned that tension screw until I could slip one of the nuts on. It went much easier than I thought.

I should have taken pictures, but I'm pretty sure everyone here is rather familiar with how this went.

I hope this is useful and possibly helps someone in the future!

EDIT: Problem solved! No more clacking.

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Buddy

· #2 · 17 d ago

I was under the impression that you were to wind the ACCT to its retracted position and insert the little tool that you make to hold the ACCT then bolt the unit in place and then slowly release the tool so the plunger unwinds and rests on the guides am I correct

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O' Darkness

Discussion Starter · #3 · 17 d ago

Buddy said:
I was under the impression that you were to wind the ACCT to its retracted position and insert the little tool that you make to hold the ACCT then bolt the unit in place and then slowly release the tool so the plunger unwinds and rests on the guides am I correct

Completely unnecessary step. I just retracted the plunger with a tiny little flathead screwdriver. I held the ACCT in my right hand, used my left hand to turn the screw until that plunger was retracted, then slowly and carefully placed the ACCT onto the the bolt, the whole unit flush...

Once it was there, I spun one of the nuts on to hold it in place with my right hand, then released the tension. After that, put the other bolt into place and tightened it all up. Worked great.

EDIT: Buddy, I think that what you're referring to is the "preload" step if one is doing the TOC spring repair. I did NOT disassemble my ACCT's at all...

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Buddy

· #4 · 17 d ago

You’re right about the pre load . If you’re clumsy like I am I use the tool

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Thorn

· #5 · 16 d ago

O' Darkness said:
Completely unnecessary step. I just retracted the plunger with a tiny little flathead screwdriver. I held the ACCT in my right hand, used my left hand to turn the screw until that plunger was retracted, then slowly and carefully placed the ACCT onto the the bolt, the whole unit flush...

Once it was there, I spun one of the nuts on to hold it in place with my right hand, then released the tension. After that, put the other bolt into place and tightened it all up. Worked great.

EDIT: Buddy, I think that what you're referring to is the "preload" step if one is doing the TOC spring repair. I did NOT disassemble my ACCT's at all...

This is NOT ok, and you could be severely overtensioning your chain. The ACCT is not designed to compress to the right tension, only extend. I have only ever had MCCTs, but overtensioning leads to premature wear of the guides, stretching of the chain, and bogs down the engine. With the MCCTs you can increase/decrease the tension in real time as you listen to the engine, but with ACCTs you are relying on the spring to only extend the proper distance, then get held in check by the chain guide at just the right pressure, only moving forward as the chain stretches naturally.

The pre-load is to ensure the proper tension in the spring throughout the ACCT's travel length. Without the pre-load it will lose it's ability to push the plunger effectively at the end of it's travel. In the instructions, after the preload, you are supposed to fully retract the plunger, hold it in place while tightening up the ACCT to the engine, then release the spring tension, allowing it to find it's natural position against the chain guide.

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O' Darkness

Discussion Starter · #6 · 15 d ago (Edited)

Thorn said:
This is NOT ok, and you could be severely overtensioning your chain. The ACCT is not designed to compress to the right tension, only extend. I have only ever had MCCTs, but overtensioning leads to premature wear of the guides, stretching of the chain, and bogs down the engine. With the MCCTs you can increase/decrease the tension in real time as you listen to the engine, but with ACCTs you are relying on the spring to only extend the proper distance, then get held in check by the chain guide at just the right pressure, only moving forward as the chain stretches naturally.

The pre-load is to ensure the proper tension in the spring throughout the ACCT's travel length. Without the pre-load it will lose it's ability to push the plunger effectively at the end of it's travel. In the instructions, after the preload, you are supposed to fully retract the plunger, hold it in place while tightening up the ACCT to the engine, then release the spring tension, allowing it to find it's natural position against the chain guide.

You obviously misunderstood me. There's absolutely no need to use that special tool to preload it. That was my entire point. I accomplished the same thing by just holding the tension with a screwdriver.

You also neglected to observe that there was NO preloading involved. That's only if one had replaced the spring. I did not.

I had the plunger retracted, put the ACCT back in place, then slowly released the tension of the screwdriver (and thus the plunger) until it made contact.

My method is correct. It worked perfectly.

Thorn

· #7 · 15 d ago

O' Darkness said:
You obviously misunderStoo

You obviously misunderstood me. There's absolutely no need to use that special tool to preload it. That was my entire point. I accomplished the same thing by just holding the tension with a screwdriver.

Sorry for misunderstanding.
"When I replaced them onto the bike, I observed how far I could install them back onto the bolts before I was stopped by the compression guide. Slightly more than 1/4 inch. I simply turned that tension screw until I could slip one of the nuts on." I took that to mean that as soon as you were able to get the first threads of the nut onto the bolts, you just tightened up the bolts without continuing to retract the plunger. When you responded to Buddy's question, which seemed like exactly the right procedure, you said "Completely unnecessary step". I don't even recognize the rest of your response, so I may have blacked out before reading further last night.

The rest of your post seems completely on-point, and you're totally correct that you don't have to make a special tool to lock things in place if you have the dexterity too hold the tension manually while getting the nuts finger-tight.

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O' Darkness

Discussion Starter · #8 · 15 d ago

Thorn said:
Sorry for misunderstanding.
"When I replaced them onto the bike, I observed how far I could install them back onto the bolts before I was stopped by the compression guide. Slightly more than 1/4 inch. I simply turned that tension screw until I could slip one of the nuts on." I took that to mean that as soon as you were able to get the first threads of the nut onto the bolts, you just tightened up the bolts without continuing to retract the plunger. When you responded to Buddy's question, which seemed like exactly the right procedure, you said "Completely unnecessary step". I don't even recognize the rest of your response, so I may have blacked out before reading further last night. The rest of your post seems completely on-point, and you're totally correct that you don't have to make a special tool to lock things in place if you have the dexterity too hold the tension manually while getting the nuts finger-tight.

Correct, and fair enough! Yep, I studied the diagrams as well to ensure that I completely understood the mechanical action before I even bothered to remove them.

That spring doesn't apply compression to the chain, it just prevents the plunger from unthreading(?) or unwinding.

As the chain loosens, the ACCT slowly "expands", for lack of a better word...

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Buddy

· #9 · 15 d ago

I understand how the ACCT functions the preload is to apply some pressure so that the plunger is able to hold the pressure when it’s fully extended the issue I do not understand is the AC CT cannot reverse and go backwards. I’ve taken them apart. I’ve operated them in my hand in order to back out they have to be broken, they only thread one way they don’t thread the other unless I’m not understanding I know there’s been a lot of conversation from respective members on the forum, but I think there’s a bit of mystery with regard to the springs function. We all understand the theory that the spring allows the plunger to put pressure on the guide and take up slack as it wears if the spring is weak it can’t hold pressure on the guide, but it also came back out. Can someone please explain this and enlighten me I think it’s a question of semantics here

O' Darkness

Discussion Starter · #10 · 15 d ago

Buddy said:
I understand how the ACCT functions the preload is to apply some pressure so that the plunger is able to hold the pressure when it’s fully extended the issue I do not understand is the AC CT cannot reverse and go backwards. I’ve taken them apart. I’ve operated them in my hand in order to back out they have to be broken, they only thread one way they don’t thread the other unless I’m not understanding I know there’s been a lot of conversation from respective members on the forum, but I think there’s a bit of mystery with regard to the springs function. We all understand the theory that the spring allows the plunger to put pressure on the guide and take up slack as it wears if the spring is weak it can’t hold pressure on the guide, but it also came back out. Can someone please explain this and enlighten me I think it’s a question of semantics here

There is no mystery at all. The plunger CAN retract, if one turns that tiny screw... Which (I think) is the entire point of "The Grambo Trick".. By twisting that screw, you compress the spring. Releasing it is thought (I suppose?) to sort of loosen it up a bit. This seems to be the case anyway, because I noticed an immediate difference in the resistance of the spring once I'd submerged the entire ACCT in fresh oil. I imagine that it's a good idea for oil to seep between the coils of the spring, ergo less friction.

As the chain becomes looser, the ACCT's plunger slowly extends because of that spring. There's just enough tension to allow it to do that. However, it doesn't retract or compress on its own. That's the entire point. If it DID retract or compress on its own, then tension on the chain would not be maintained.

Thorn

· #11 · 15 d ago

The grambo trick as I understand it is to turn the screw so that you're pushing WITH the spring instead of compressing it, forcibly extending the plunger further than the spring had naturally pushed it, and taking up the slack in the chain. This would help a weak spring or overcome unwanted resistance between the spring coils as mentioned. Interesting that there isn't enough oil seeping/creeping around in there to keep things fairly well coated. My MCCTs drip oil at an annoyingly constant rate (installed by PO, and I'm sure loctite would help, but I'm lazy).

O' Darkness

Discussion Starter · #12 · 15 d ago

Thorn said:
The grambo trick as I understand it is to turn the screw so that you're pushing WITH the spring instead of compressing it, forcibly extending the plunger further than the spring had naturally pushed it, and taking up the slack in the chain. This would help a weak spring or overcome unwanted resistance between the spring coils as mentioned. Interesting that there isn't enough oil seeping/creeping around in there to keep things fairly well coated. My MCCTs drip oil at an annoyingly constant rate (installed by PO, and I'm sure loctite would help, but I'm lazy).

I had to go back and re-read The Grambo Trick, and now I understand where the confusion originated. My fault, I guess. Turning that little screw counter-clockwise WOULD extend the plunger if there were ZERO resistance, i.e., slack in the chain.

But because of the design, if one were to turn that screw enough to force tension onto the chain, it would NOT retract on its own and now you'd have too much tension. I hope I'm expressing that correctly? I cannot imagine that enough force could be applied to that tiny little screw to overcome the existing pressure of the chain pushing back. What do you think?

Buddy

· #13 · 15 d ago (Edited)

I think its a bad design. Its billed as automatic cam chain adjuster. In fact it is a one way adjuster that once its extended either by slack in the chain or else user interference . I dont understand how it can back out by itself. The design is to increase length of plunger to place more pressure to adjust for wear. If it i. I s capable of backing itself out because of resistance that could spell disaster for failure. I ordered a new set of OEM ACCT from megazip all other suppliers i called said the ACCT were discontinued. I want to replace a set I have in my 1995 bike. I had used rebuilt TOC springs in my ACCT and i think there not working correctly. I was surprised that megazip had them OEM and are not NOS they were 74.00 each less 10 %. I will report here once i get them i will also so why the rebuilt ones in the bike now may be failing I will pull them and clean them and re-oil see if i can get them working they have the heavier duty springs in them .

O' Darkness

Discussion Starter · #14 · 15 d ago

Buddy said:
I think its a bad design. Its billed as automatic cam chain adjuster. In fact it is a one way adjuster that once its extended either by slack in the chain or else user interference . I dont understand how it can back out by itself. The design is to increase length of plunger to place more pressure to adjust for wear. If it i. I s capable of backing itself out because of resistance that could spell disaster for failure. I ordered a new set of OEM ACCT from megazip all other suppliers i called said the ACCT were discontinued. I want to replace a set I have in my 1995 bike. I had used rebuilt TOC springs in my ACCT and i think there not working correctly. I was surprised that megazip had them OEM and are not NOS they were 74.00 each less 10 %. I will report here once i get them i will also so why the rebuilt ones in the bike now may be failing I will pull them and clean them and re-oil see if i can get them working they have the heavier duty springs in them .

It CAN'T back out. I think you're still a little confused...

What CAN happen is that it can stop EXPANDING. This is most likely caused by:

1. A weakening of the spring.
2. An unexplainable binding of the spring, which could possibly be caused by:

Insufficient lubrication
A bent shaft
Unknown various gremlins.

Buddy

· #15 · 15 d ago

I have looked at the ACCT as they come from the factory and there is no screw> What there is a slot that you can put a screw driver in or use the metal tool that comes with new ACCT. When you order OEM replacement ACCT they come with the small tool ( tab as described in manual to make one yourself } that is used to keep the plunger retracted and then after you install them you pull tool tab out slowly and then allow it to unwind till it seats on the guide. There is no actual screw there are crosshairs slots that allow you to insert the tab as mentioned or small flat head screwdriver.

Buddy

· #16 · 15 d ago

I agree with you it can't back out not designed that way. I have been sayin this all along . The weak spring would cause it not be able to extend the plunger and or a binding in the mechanism from contaminants that interfere with the springs travel .

O' Darkness

Discussion Starter · #17 · 15 d ago

Buddy said:
I have looked at the ACCT as they come from the factory and there is no screw> What there is a slot that you can put a screw driver in or use the metal tool that comes with new ACCT. When you order OEM replacement ACCT they come with the small tool ( tab as described in manual to make one yourself } that is used to keep the plunger retracted and then after you install them you pull tool tab out slowly and then allow it to unwind till it seats on the guide. There is no actual screw there are crosshairs slots that allow you to insert the tab as mentioned or small flat head screwdriver.

I beg to differ, Buddy. This is indeed a screw:

Font Auto part Engineering Gas Cable

That green arrow is the slot for a flathead.

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Buddy

· #18 · 15 d ago (Edited)

I agree with you there is a screw at the bottom of the barrel but when you look at it from the top there are crosshairs for either screwdriver or the tool. Its semantics but you are right. The screw looks pretty robust at the bottom of the barrel and the slot that allows you to turn it is strong enough to adjust .

dirtrack650

· #19 · 15 d ago

Please clarify why the ACCT can't back out? Heat+vibration+wear+weak spring= opportunity to back up. I'm not saying it stays retracted, even a millimeter or two would cause engine noise.

Spockster

· #20 · 15 d ago

2

I wondered if the fluctuations in the chain could cause a weak ACCT to loosen up even more.

Like if the chain was loose then became tight during the engine cycles if the constant on/off pressure could cause a weak ACCT to retract.

I've got two options, a set screw or $20 mccts.

The TOC is well built and has a large bolt size on the adjustment, but it's pricey.

There's a new contender for pricey, new design I saw on eBay, it's $88 each. Same mcct mechanically, just has an oddball shape for the body.

Font Auto part Electric blue Aluminium Circle

Or even $99, can polish this one.
.
.

Font Nickel Auto part Engineering Nut

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