Hi all, I was going downhill at speed and my already noisy gearbox sounded like it started to really grind. Got it home and took out the motor and input shaft. The input shaft has all its teeth. The rear bearing needs to be replaced but it is full in tact and the front bearing is still in good shape. When I turn the hub there is resistance and some noise. Is it possible to rebuild myself? Is it worth buying a used one off eBay? Does anyone have an extra gearbox they want to sell?
I have the ride4fun motor and as far as I know the stock gearbox. It is also really hilly where I am in San Diego so would appreciate some help with what gear ratio would balance the speed from the r4fun motor and the need to climb the crazy hills.
I couldn’t quite see what you were trying to show with this set of pictures.
Down at the bottom of the gearbox you will find the pan/cover and a big rubber plug. Gently pry out that rubber plug and catch any oil that comes out. Inspect that oil for metal bits.
Stick a finger in there and gently feel around for metal bits and scoop out anything you find.
Show what you find.
Hopefully you didn’t destroy an intermediate bearing. At any time did it sound like popcorn?
Thanks for the reply! I was sharing the videos to demonstrate the sound it makes and also try to show the teeth on the ring inside. It did sound like popcorn. I’ll pop the plug and see what the find and report back.
Also, the motor is fine it’s only a year old from Ride4Fun to replace the blown motor.
Depending on what I find can I possibly rebuild this thing myself? I’ve seen Grant Wests video taking it apart. Outside of bearings which I’m sure I can source, the gears aren’t easily found. The kits ride4fun sell are as much as a used gearbox from eBay so I’m more than likely going to go the route if I can’t source parts less explosively
I didn’t bother opening up the old gear box. I bought a used 12:1 off eBay and installed it pretty quickly. I had some 1/8” rubber material that I used as isolator material and the new gearbox is super quiet. It’s running great.
One thing that is happening is it is leaking fluid from the tubing. When I installed it I filled it until the fluid just dripped out of the hole. I’m assuming it will eventually stop but does that leave my level too low?
I’m also going to pull the motor to make sure it isn’t coming through the bearing.
Any real concern here or should I just leave well enough alone.
Filled it from where you pull the plug on the cover
It came with some 90w in it. I couldn’t find 90w so I topped it off with some 85w gear box fluid.
The tube runs up high under the battery tray. I’ll rig up a catch bottle. The fluid coming out is black so I’m thinking perhaps I should drain completely and refill with all the same fluid?
Would running 5w 30 be better if I’m doing hills all the time?
I almost made that same mistake of filling up to the fill hole. Turns out that is way too much oil. Find the specifications and just put in the proper amount and the recommended weight.
The dealer told me if I would have over filled it, it would be blowing out the vent tube. Sounds like he was right.
I wouldn’t run a lighter than recommended weight oil. Some of us have gone heavier ie 145w to try to quiet the gears a bit. I just don’t think the gears would get the lubrication needed with a light oil. Just my 2 cents.
I would think the 3hp would appreciate coming from 10.3 to 12.44, especially if SDG is in the hilly parts of SanD.
Perhaps your use of anemic should be switched to asthmatic?
@SDGem - JJ brings up a good point. Your car will now pull the hills better, but be careful about going down some of those hills now. If you have a speed modifier in place (no speed limiter), it is real easy to over speed your motor.
According that math stuff- With 21 in tires (guessing), your motor hits 7k at 35mph.
Your old gears would go to 42 and you might be used to that.