New Grom clutch destroyed?

12112 Views 51 Replies 15 Participants Last post by messymathews90, 18 d ago

Leon

Discussion Starter · Aug 26, 2018

So my brother-in-law was trying to learn how to do a burnout in a parking lot yesterday and failed miserably. After about 5 minutes of trying he gave up, he then tried to drive it home and the bike wouldn’t go faster than 7mph. The bike sounded like he was driving at around 3/4 throttle in 1st gear. He said his second gear wouldn’t drive either. It’s a brand new 2019 bike with only 250 miles on it. Did he really destroy the clutch that fast? Also what’s the solution to this problem? Can we just change the friction plates and that will fix it? I have a Grom also and these are our first bikes, I wanna help him out so we can ride together again, but I have no knowledge on bikes. I am mechanically inclined, so if it’s a fairly easy fix I can try myself.

Also my other brother in law caught the whole thing on his go pro and we had a pretty good laugh at the in law who destroyed his clutch. The video left us in tears

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fourfiftyare

· #2 · Aug 26, 2018

I would imagine the clutch plates are smoked. If hes going to try and do burnouts and other hoodrat things, he might want to put some heavier springs in it also.

Reactions: 1

nd4spdbh

· #3 · Aug 27, 2018

lol.... good job, what was he doing sitting there slipping the clutch at WOT?

Clutch is burnt, get a new set of steel plates and friction plates, and while your in there get a billet clutch plate and some stiffer springs... and dont be stupid with the clutch like that. Im still on a stock clutch with 7k miles, 4k of which is with a bbk, and Im always clutching up wheelies doing stupid shit, but im still on the stock clutch (stiffer springs of course).

Leon

Discussion Starter · #4 · Aug 27, 2018

Yeah that’s exactly what he was doing, I believe he was supposed to be pushing down on this front shocks so the rear could break free?

Anyways, so the steel plates and friction plates come in a set usually if I’m not mistaken. So he needs those, and then the two other items he will need are stiffer springs and the clutch plate. 3 items total, will we need any special tools or sockets? I have the basics, but nothing made particularly for bikes.

I’ll tell him to do an oil change will he’s at it.

Added a picture of our bikes, mines the white one.

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Leon

Discussion Starter · #5 · Aug 27, 2018

Does anyone know of any videos showing step-by-step how to change the plates? I tried searching for videos and I can't find a complete video. Photogromer has a video but it's not step-by-step.

dubSolo

· #6 · Aug 27, 2018

Leon said:
Does anyone know of any videos showing step-by-step how to change the plates? I tried searching for videos and I can't find a complete video. Photogromer has a video but it's not step-by-step.

Yeah photogromer dont know shit for installing upgrades, barely a decent motovlogger lmoa...:haha:

Z-Gargae isnt much better but its something to give you an idea, they suck at informative install vids especially when things go wrong...

Good Luck!

Leon

Discussion Starter · #7 · Aug 27, 2018

Awesome, that’s a good video, do I need to be torquing to specs? Or can I do quarter turn after it’s tight? I can’t find torque specs anywhere, I saw 46 lbs/ft in the service manual but I’m not sure for which bolts

solidjohnny

· #8 · Aug 27, 2018 (Edited)

Its super easy to NOT fully seated the clutch pressure plate teeth (part 12 in the the above youtube video thumbnail). The best way to insure its fully seated is to assemble the whole clutch assembly in your hands and take a mental note of its assembled thickness.

You know its wrong when you go to torque the main nut and it takes a few too many turns to reach from hand tight to 46 lbs/ft - and you hear a pop. That's either the pressure plate (part 12) or clutch center (part 8) cracking.

Reactions: 1

3sexy5u

· #9 · Aug 27, 2018

Auto part Rotor Clutch Vehicle brake Metal

Be very careful even tightening the spring plate. My plate cracked like this without much effort.

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turpinator

· #10 · Aug 27, 2018

Leon said:
Awesome, that’s a good video, do I need to be torquing to specs? Or can I do quarter turn after it’s tight? I can’t find torque specs anywhere, I saw 46 lbs/ft in the service manual but I’m not sure for which bolts

Download this so youve got it all.
https://www.dropbox.com/sh/w33hejgpui3q74s/AADPASwHBprHbHw-F695l8vna?dl=0

You could also just take it back to the dealer and claim ignorance to why its not working. lol.

Semi related, ive got a box of friction plates sitting in my closet, slightly used? I think they are the barnett plates. You can have them for whatever the shipping is.

also, when installing the plates, line up the paint marker on all of them, the different color (blue?) goes to the outside.

WV_Grom

· #11 · Aug 27, 2018

turpinator said:
Download this so youve got it all.
https://www.dropbox.com/sh/w33hejgpui3q74s/AADPASwHBprHbHw-F695l8vna?dl=0

You could also just take it back to the dealer and claim ignorance to why its not working. lol.

Semi related, ive got a box of friction plates sitting in my closet, slightly used? I think they are the barnett plates. You can have them for whatever the shipping is.

also, when installing the plates, line up the paint marker on all of them, the different color (blue?) goes to the outside.

I never could understand why the paint tabs had to be aligned.

I have never aligned them. I see no reason too, the plates are all the same.

turpinator

· #12 · Aug 28, 2018

WV_Grom said:
I never could understand why the paint tabs had to be aligned.

I have never aligned them. I see no reason too, the plates are all the same.

Its just to make it easier during assembly. i guess i could have specified that.

If you dont make something easy or idiot proof to assemble, someone is going to complain or do it wrong, then its the designer's fault. Tiny stuff like screen printing lines 1/4" from the ends of hoses or putting datum tape for routed hoses/wires/etc really help out a ton. or even up/forward arrows.

Reactions: 1

Leon

Discussion Starter · #13 · Sep 2, 2018

Thanks to Turpinator, we got friction and steel plates in, just waiting on a Chimera clutch plate and 30% stiffer springs.

Leon

Discussion Starter · #14 · Sep 3, 2018 (Edited)

So we took apart the clutch today and I’m a bit worried. I was expecting to see the friction plates have little to no ceramic (or whatever that part is) but it looks almost new still. The steel plates are black, maybe that’s the damage and the reason for the clutch sliding?

I’m a newbie so I don’t know, but I’m hoping the new steel and friction plates will solve this issue.

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3sexy5u

· #15 · Sep 3, 2018

Yes, black means burnt. The pads don't completely disintegrate, they get "Glazed". You'll notice your oil you drained also has a black tint to it now.

In actuality, you only need new friction plates, as the steel plates don't get damaged.

Reactions: 1

David

· #16 · Sep 3, 2018

WV_Grom said:
I see no reason too, the plates are all the same.

The two outer (?) stock friction plates do have different part numbers compared to the three middle plates, no idea what the difference is though.

On a side note OEM parts are super cheap in the US! Here a friction costs more than double, a stock head is 450€, stock crank 560€, cylinder (without piston...) 360€...

phillybuilt

· #17 · Sep 3, 2018

OpusNectar said:
Yes, black means burnt. The pads don't completely disintegrate, they get "Glazed". You'll notice your oil you drained also has a black tint to it now.

In actuality, you only need new friction plates, as the steel plates don't get damaged.

Opus hit the nail right on the head.

However, you can possibly warp the steels if they have been slipping/burning for long enough. It's good practice, and peace of mind to replace everything at once.

Reactions: 1

Leon

Discussion Starter · #18 · Sep 4, 2018

Yeah I replaced the steel and friction plates. Just wondering why it was slipping even though there was still a lot of the ceramic material on the friction disks. I was expecting it to be bare.
Someone mentioned that’s from it glazing.

nd4spdbh

· #19 · Sep 4, 2018

WOWOWOW, you did a good job on that clutch..... i havnt seen black steel plates like that in a LOOONG time.

Reactions: 1

m in sc

· #20 · Sep 4, 2018

right? those got hot.

i always da sand or blast the steels on a wet clutch , makes a huge difference (as long as they are still flat).

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