DIY Tool: Variator Wrench

eDan · Post by **eDan** » Fri Apr 27, 2012 11:48 pm

Sure you could buy a spanner wrench, or a strap wrench, but what's the fun in that?

There are undoubtedly many design variants, many of which I'm sure are better that what I came up with, but what follows is my version:

I wanted a static (non-adjustable), robust tool, one with two screws rigidly mounted to engage the variator. I also wanted to re-purpose components rather than buying new. I went to our local surplus store and decided on shelf brackets. Each bracket is 16" long, but is only 0.125" thick. I bought four. I would make my own laminate wrench!

Yeah, it's overkill, BUT my design had threaded fasteners, so I wanted as much thread engagement as I could get. The thicker, the stronger, the more threads, the better.

Having recently discovered JB Weld, I was eager to sandwich these together. With existing bracket holes I temporarily fastened them together with fasteners and small washers between each bracket to make space for the JB Weld.

Lamination Closeup

Once it was fully cured, I drilled and tapped two M5 holes at 80mm apart. I then drilled a 1" center hole for my 19mm socket. This is another reason to go thicker, because the center hole is large compared to width the brackets.

Center Hole Closeup

I did drill out the holes in my NCY variator just a few thou to get the M5 screws to easily engage. 80mm seems standard, so this also works with my stock variator. I wanted the tool to be flush against the variator and not bottom out on the M5 screws, so I added some washers to keep them at 10mm proud on the variator side.

Tool in Action

Total cost: less than $7. Each bracket was $0.95, about $2 for the screws and nuts and I already had the JB weld. I won't get an award for aesthetics, but it works.

Mousenut · Post by **Mousenut** » Sat Apr 28, 2012 12:01 am

What is the purpose of the JB Weld? Wouldn't it work without it?
What did you use to make the 1" hole?

Very sturdy looking compared to other DIY solutions I have seen.

eDan · Post by **eDan** » Sat Apr 28, 2012 12:13 am

Since I was tapping the assembly, I wanted the group of brackets not to float with respect to each other. That's why I chose to glue them together rather than clamp or screw them with other fasteners.

I could have had through-holes and had a nut on the variator side, but I was concerned about an exposed nut on the variator side because I wanted the tool to lie flush on the variator when torquing the nut down. I figured this way the tool would be more stable.

Like I say, it is overkill.

I used a step bit like this: Step Bit, but mine maxed out at one inch.

Old Crow · Post by **Old Crow** » Tue Jul 31, 2012 2:37 am

Lots of folks talking about how to get the variator nut off but few about how to get it back on and properly torqued. I guess most are using 12V impact wrenches and few also using witness marks. I like the torque wrench, so thanks for your post/photos.

bluebuddygirl · Post by **bluebuddygirl** » Tue Jul 31, 2012 2:50 am

Old Crow wrote:Lots of folks talking about how to get the variator nut off but few about how to get it back on and properly torqued. I guess most are using 12V impact wrenches and few also using witness marks. I like the torque wrench, so thanks for your post/photos.

My understanding has always been that you should never use an impact wrench for re-assembly.

Old Crow · Post by **Old Crow** » Tue Jul 31, 2012 2:57 am

Yes, I don't like that solution either. I'm particular and use a torque wrench when putting my car tires back on.

Post by **ericalm** » Fri Aug 03, 2012 12:16 am

bluebuddygirl wrote:
Old Crow wrote:Lots of folks talking about how to get the variator nut off but few about how to get it back on and properly torqued. I guess most are using 12V impact wrenches and few also using witness marks. I like the torque wrench, so thanks for your post/photos.
My understanding has always been that you should never use an impact wrench for re-assembly.

That's technically correct.

I'm particular about torque for my clutch and variator. The risk when reassembling is stripping the threads on the nut or, worse, the shaft.

CROSSBOLT · Post by **CROSSBOLT** » Fri Aug 03, 2012 8:34 pm

eDan, you are a genius! That is a good looking tool as well! Gave me some ideas.....

Karl

Mousenut · Post by **Mousenut** » Fri Aug 03, 2012 8:46 pm

I bet you can crack a zombie with it pretty good too. That's always a plus!

schroeder · Post by **schroeder** » Fri Aug 03, 2012 8:47 pm

If you need an impact wrench to remove the nut, how do you tighten the nut on the variator without the impact wrench? It will just spin with out enough torque. What tool does one use?

eDan · Post by **eDan** » Sat Aug 04, 2012 3:13 am

Old Crow wrote:Lots of folks talking about how to get the variator nut off but few about how to get it back on and properly torqued. I guess most are using 12V impact wrenches and few also using witness marks. I like the torque wrench, so thanks for your post/photos.

Glad you like it. Give it a go and see what you come up with.

CROSSBOLT wrote:eDan, you are a genius! That is a good looking tool as well! Gave me some ideas.....

Well 'genius' is certainly overly kind. So many thanks! Be sure to post your inspired idea(s) when complete.

Syd · Post by **Syd** » Sat Aug 04, 2012 6:10 am

schroeder wrote:If you need an impact wrench to remove the nut, how do you tighten the nut on the variator without the impact wrench? It will just spin with out enough torque. What tool does one use?

eDan's third picture shows exactly that. the variator tool keeps the variator (an by extension the crank) from spinning, and the torque wrench tightens the nut.

eDan, teh tool is very long when the engine is out of the scoot. Is it still plenty long when the engine is reinstalled into the scoot?

Post by **jrsjr** » Sat Aug 04, 2012 4:34 pm

Syd wrote:eDan, teh tool is very long when the engine is out of the scoot. Is it still plenty long when the engine is reinstalled into the scoot?

Syd, I wondered the same thing, but then it occurred to me that, if it was a bit short, he could just put a wood block under the end of the tool and problem solved.

I like this tool design. I especially like the fact that the laminated construction actually helps keep the weight down. Very nice job!

mattgordon · Post by **mattgordon** » Sat Aug 04, 2012 5:04 pm

jrsjr wrote:
I like this tool design. I especially like the fact that the laminated construction actually helps keep the weight down. Very nice job!

Why is the weight of the tool a concern?

My variator tools, and other specialty tools stay in my toolbox in the garage.

FWIW thats substantially larger (and correspondingly heavier) than either variator tool I use for my GTS 250, or GT200L...but what's the difference so long as it's functional?

Just curious.

Post by **jrsjr** » Sat Aug 04, 2012 5:19 pm

mattgordon wrote:
jrsjr wrote:
I like this tool design. I especially like the fact that the laminated construction actually helps keep the weight down. Very nice job!

Why is the weight of the tool a concern?

My variator tools, and other specialty tools stay in my toolbox in the garage.

FWIW thats substantially larger (and correspondingly heavier) than either variator tool I use for my GTS 250, or GT200L...but what's the difference so long as it's functional?

Just curious.

Fair question! Riding in the Cannonballs got me in the habit of thinking about the weight of tools. On CBR 06, there was a guy who had a tool for breaking the bead on tires. It served the purpose well, but it was machined from a bench clamp that was made of cast iron so it was unbelievably heavy. That one tool probably far exceeded the carrying capacity of most scooter topcases!

eDan · Post by **eDan** » Sat Aug 04, 2012 6:47 pm

Syd wrote:eDan, teh tool is very long when the engine is out of the scoot. Is it still plenty long when the engine is reinstalled into the scoot?

Good question. I didn't have any picts of the tool in action on the scoot, so I popped off the CVT cover and took these:

Removing the variator nut

Torquing down the variator nut

In both cases (removal and torquing) the tool reacts against the ground. I put a piece of scrap lumber between the tool and the concrete to prevent scraping up the concrete. Under load the tool also 'seats' into the wood making it a bit more stable.

For removal the tool does get quite close to the center stand stud and spring with just the one 2x4. A second block or flipping the 2x4 on its side would give plenty of space.

In these setups the force pathway runs outside the scooter, so be mindful that it is possible, although unlikely, to lift/tip the scooter when removing and torquing the nut if supporting the pivot end of the torque wrench as I like to do. The danger is more likely to deform the tool's M5 screws or worse the variator as the scoot tips and the tool is over constrained than completely tipping the scooter over.

To avoid this, there may be an inclination to rest the tool against the clutch bell, thus keeping the force pathway within the scooter engine assembly. I don't recommend this. There's no need to load up the clutch assembly with a side load and risk damaging the bearings.

Another option I suppose is to grip the torque wrench in one hand and the variator tool in the other and torque away. Personally, I like to support the pivot end of the torque wrench with my free hand, especially when using an extension, to support the out-of-plane load and prevent the socket from tipping off the nut.

Also notice in both my 'lazy' setups that I would apply force a down on the torque wrench or the breaker bar, using my weight rather than reorienting the tools 180 degrees and pulling up and getting a work out.

jrsjr wrote:Syd, I wondered the same thing, but then it occurred to me that, if it was a bit short, he could just put a wood block under the end of the tool and problem solved.

I like this tool design. I especially like the fact that the laminated construction actually helps keep the weight down. Very nice job! Very Happy

jrsjr, you beat me to it! Yep, just some wood blocks. I never thought about its weight at all. I weighed it at 2 lbs 8 oz. It's heavier than my breaker bar, which is 1 lb 11 oz. Also, it's about 5/8" thick.

schroeder · Post by **schroeder** » Sat Aug 04, 2012 7:40 pm

I see how this tool would work nicely, but what tool can you buy that will do the same thing.

Post by **ericalm** » Sun Aug 05, 2012 10:06 pm

schroeder wrote:I see how this tool would work nicely, but what tool can you buy that will do the same thing.

http://www.scooterwest.com/items/?_page ... 0-GY6/8921

BootScootin'FireFighter · Mon Aug 06, 2012 2:48 am

ericalm wrote:
schroeder wrote:I see how this tool would work nicely, but what tool can you buy that will do the same thing.

http://www.scooterwest.com/items/?_page ... 0-GY6/8921

ditto... fits nicely in the bottom of my tool bag.

Skootz Kabootz · Post by **Skootz Kabootz** » Mon Aug 06, 2012 2:51 am

ericalm wrote:
schroeder wrote:I see how this tool would work nicely, but what tool can you buy that will do the same thing.

http://www.scooterwest.com/items/?_page ... 0-GY6/8921

Gotta get me one of these for my stock variator. But really I wish someone would make one for the Dr. Pulley variator. Anyone know of one?

Tocsik · Post by **Tocsik** » Mon Aug 06, 2012 3:17 am

Skootz Kabootz wrote: Gotta get me one of these for my stock variator. But really I wish someone would make one for the Dr. Pulley variator. Anyone know of one?

Ditto to that!
If there was a strap wrench that clamped-on like a vise grip wrench, and had a more grippy surface than the rubber strap, that would do the trick.

You could just put a piece of pipe on the handle to make it longer and brace it against the floor like eDan does with his wrench.

Skootz Kabootz · Post by **Skootz Kabootz** » Mon Aug 06, 2012 3:29 am

Tocsik wrote:
Skootz Kabootz wrote: Gotta get me one of these for my stock variator. But really I wish someone would make one for the Dr. Pulley variator. Anyone know of one?
Ditto to that!
If there was a strap wrench that clamped-on like a vise grip wrench, and had a more grippy surface than the rubber strap, that would do the trick.

You could just put a piece of pipe on the handle to make it longer and brace it against the floor like eDan does with his wrench.

I've thought of that too. I think I saw it done in a YouTube video or something. I just haven't found a strap wrench that is big enough or strong enough yet. So I just continue using my impact wrench. Happily I have a weak little 12v plug in emergency impact wrench. So I don't think it is quite as brutal as one of the bigger industrial strength ones.

schroeder · Post by **schroeder** » Tue Aug 07, 2012 2:05 am

Will the tool pictured from scooterwest work on the clutch bell also? Does the clutch need to come off to put the new belt on or can you just remove the variator?
I am not much of a mechanic, but would like to try to change the belt myself, hence all the questions. Any help would be appreciated.