Berserker26
Member
Just a question on how to do this - seems counter intuitive to grease and loctite, can anybody advise how to go about doing this?
Widespread Giant motor creaking problem - time for a recall?
- Thread starter shark_jumper
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Kiwi_Giant
Member
The creaking caused by engine mount bolts appear to be a common problem with a range of Giant e-bikes. The fix is to remove each (3) engine mount bolts individually lubricate them with either a lithium or molybdenum based grease, refit and retorque to 22 Nm. You will need a T30 TorX bit, the nylock nut on the opposite side of the motor is captured in the engine casing and if you are careful will remain in place. I am an Aircraft Engineer and I am not sure why you would use loctite with a nylock nut as a nylock nut is a self-locking nut by design and will not loosen unless worn out.
1. The process is pretty simple, locate your engine mount bolts, using a T30 TorX bit undo & remove the first bolt.
2. Smear with grease, refit the bolt, the nylock nut & washer on the opposite side of the motor will hopefully remain in it's hexagonal cut-out (if not relocate it and support it whilst inserting the bolt).
3. Tighten the bolt to 22 Nm and move on to the next bolt.
1. The process is pretty simple, locate your engine mount bolts, using a T30 TorX bit undo & remove the first bolt.
2. Smear with grease, refit the bolt, the nylock nut & washer on the opposite side of the motor will hopefully remain in it's hexagonal cut-out (if not relocate it and support it whilst inserting the bolt).
3. Tighten the bolt to 22 Nm and move on to the next bolt.
Last edited:
Karm
Member
What is the deal with aerospace engineering? lol. Do you think a bike company is capable of sending rocket up in the sky? It's full of snakeoil.
Raeda
New Member
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- USA
I just bought a used 2018 Thoughroad GX E+. The motor was see-sawing. I took it off and measured it and the cavity in the frame in which it sits is simply too big. In my case, the holes in the motor casing had become egg shaped and there was nearly 0.5mm clearance between the motor mount bosses and the cavity on the frame.
I made plastic shims and stuck them in there, then cranked the living hell out of the bolts. With my shims, I only had to close a gap of 0.1mm. If you remove the chain ring(s), you can trim the shims afterward with a knife (though you may scratch the finish on the motor). I didn't have it, but if you use the thin Scotch double-sided tape to hold the shims in place, you're going to be just fine. As it was, the "tails" let me move them around to align the holes as well as check that they no longer moved once I tightened the bolts.
The picture may not make any sense if you've never taken the motor out - you're looking at the frame cavity from below. My shims are pink plastic.
In my opinion, a lot of people tend to add grease to a lot of things. It's great when you're mixing aluminum and steel as galling can occur. I've done it to get rid of creaking between my pedals and the crank. But it's a temporary fix in most cases. I didn't fix my pedal creak definitively until I added washers. If your motor is creaking, it's at least a bit loose, and if you can't crank the bolts anymore, it's because of this design flaw on Giant's part. Keep an eye on it if you've added grease because it definitely won't creak if you end up with a gap as big as mine!
Overall I love the bike, and although it's a three-handed job to put things back together, the long wiring harnesses are a blessing. Can't wait to wire some lights to this thing.
Please be careful if you ever remove the battery connector on the frame - it will go back in both ways and there's no way to easily check the polarity on the battery. The terminal with the red wire goes on the chainring side.
I made plastic shims and stuck them in there, then cranked the living hell out of the bolts. With my shims, I only had to close a gap of 0.1mm. If you remove the chain ring(s), you can trim the shims afterward with a knife (though you may scratch the finish on the motor). I didn't have it, but if you use the thin Scotch double-sided tape to hold the shims in place, you're going to be just fine. As it was, the "tails" let me move them around to align the holes as well as check that they no longer moved once I tightened the bolts.
The picture may not make any sense if you've never taken the motor out - you're looking at the frame cavity from below. My shims are pink plastic.
In my opinion, a lot of people tend to add grease to a lot of things. It's great when you're mixing aluminum and steel as galling can occur. I've done it to get rid of creaking between my pedals and the crank. But it's a temporary fix in most cases. I didn't fix my pedal creak definitively until I added washers. If your motor is creaking, it's at least a bit loose, and if you can't crank the bolts anymore, it's because of this design flaw on Giant's part. Keep an eye on it if you've added grease because it definitely won't creak if you end up with a gap as big as mine!
Overall I love the bike, and although it's a three-handed job to put things back together, the long wiring harnesses are a blessing. Can't wait to wire some lights to this thing.
Please be careful if you ever remove the battery connector on the frame - it will go back in both ways and there's no way to easily check the polarity on the battery. The terminal with the red wire goes on the chainring side.
davidsmartin
New Member
- Region
- USA
My crank started creaking late last summer. The lbs replaced the motor under warranty. Now it is creaking again after only 400 miles. I suspect that the issue is with the mounting bolts but the lbs folks are very skeptical -- they want to submit another warranty claim and replace the motor again. Does Giant issue service bulletins or anything to suggest that they should try greasing and tightening these bolts before submitting a claim to replace the motor? Or is there anything else I can point to that might convince the lbs to try this?
Nice, I love the ingenuity!
They added spacers from the factory to my Revolt E+ at the motor mounts. This was a big issue.
Good point on connectors. An even easier and surefire way of getting the connector positioned right is to mark the connector and bike where the connector fits to with a marker-not visible and effective in case it's assembled with a different colored insulation!
davidsmartin
New Member
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- USA
So Giant told the lbs that they would not cover another motor under warranty. The shop then took out the motor, found nothing amiss, reassembled it and the problem has gone away. They are still skeptical that the problem could have been with the motor mount bolts, but that is what the evidence suggests.
davidsmartin
New Member
- Region
- USA
After a couple hundred miles the creaking has begun to return. I found this in the Giant Service Manual:
| Yamaha have designed a sideways play of 1 mm in the bottom bracket axle Of Sport & Life motors to reduce strain inside the motor. This is a feature, not a flaw. |
Does that suggest that the creaking is just an annoyance and will not cause any damage, if the bolts are tight and the noise is caused by a lack of grease inside the mount?
On my Explorer E-3 it appears that I could remove and grease the two rear bolts fairly easily but to remove the front one requires removing at least the battery mount and perhaps more. So I have not tried it yet.
04fuxake
New Member
By “bottom bracket” they probably mean the actual axle that the cranks mount to. We’ve been talking about the motor mounts on the frame.
That being said, if the creaking is in fact from the axle, then it would suggest there is nothing to be done.
If the creak can be isolated to the axle then it's time to start negotiating for a new motor before the bearings fail !
I've lost count of the number of creak causers on my 2018 full e pro, but none came from the motor itself.
There have been variations on motor mounting bolts, plastic guards, suspension linkages / bearings , a hairline crack in a seat base, even the dropper post. I've had front wheel bearings sound like they caused a creak from the motor region, and even a pedal bush!
What I don't understand is why my other brands of bikes don't carry on like this. My Specialized levo sl is silent with 2500 km on the clock - carbon frame or better suspension bushes ?
Interesting find David. I don't think the designed free-play they refer to is responsible for the creaks we get on our bikes. Personally, I wouldn't leave a creak in the BB area. There's a lot of force being transmitted down there and bad things happen quickly when play develops. Ovalised motor mounts and flogged out crank tapers are two good examples. I've removed, greased (mix of copper/wheel bearing grease) the motor mount bolts twice in 6000km, and crank bolts require re-torqueing every few dozen rides. Not too arduous a maintenance schedule, both are easy to rectify and a quiet bike is a happy bike.
Raeda
New Member
- Region
- USA
davidsmartin
New Member
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- USA
I found the service manual here:
https://www.emtbforums.com/community/attachments/service_manual_2020_v1-0_en_lores-pdf.31116/
There were some other links in this post:
electricbikereview.com
https://www.emtbforums.com/community/attachments/service_manual_2020_v1-0_en_lores-pdf.31116/
There were some other links in this post:
Repair Manual for Giant/ LIV bikes
Anyone know where to buy one? Especially online? Or a parts manual with diagrams?
electricbikereview.com
davidsmartin
New Member
- Region
- USA
My good news is that after I greased the three bolts and reattached them my creaking stopped!
My bad news is that when using my torque wrench to tighten the bolts, I broke the T30 bit. Three times. Even though I tried to support the bit and keep it at the right angle, by the time I was getting to 30 NM of torque, obviously I was not keeping the bits straight enough. Does anyone have suggestions about how to avoid this problem? Should I just use an impact wrench and trust that I won't tighten it so far that I will damage the bike?
My bad news is that when using my torque wrench to tighten the bolts, I broke the T30 bit. Three times. Even though I tried to support the bit and keep it at the right angle, by the time I was getting to 30 NM of torque, obviously I was not keeping the bits straight enough. Does anyone have suggestions about how to avoid this problem? Should I just use an impact wrench and trust that I won't tighten it so far that I will damage the bike?
arcom
Active Member
Should I just use an impact wrench and trust that I won't tighten it so far that I will damage the bike?
30 NM is 22 ft/lbs. For me, I can pretty much nail 20 ft/lbs by feel, without the aid of a torque wrench. Snug, but not gorilla snug. I think the important thing is to get them all the same. I would not recommend an impact wrench.
30 NM is 22 ft/lbs. For me, I can pretty much nail 20 ft/lbs by feel, without the aid of a torque wrench. Snug, but not gorilla snug. I think the important thing is to get them all the same. I would not recommend an impact wrench.
davidsmartin
New Member
- Region
- USA
Thanks. What tool do you use? A big screw driver? A battery powered drill/driver? I am having bad luck using wrenches.
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