5:1 Pocket Bike Tranny

Is it chain or gears?
The gears would like oil.
the Chain a bit of grease.
I'm guessing you talking about the geared reduction, which reverses your drive.
A bit like this one, which likes a bit of gearbox oil.

AV,
Yes & Yes.
The case should be filled with a lubricant. There are bevel gears inside. I use a real thin grease '000' that I found at a lawnmower supply store locally. The gaskets are junk & some dont even come with a gasket. Mine came without the bolt (some do) so I unbolted the face bolts, opened it up added the grease & then resealed it. I have used 5 of these trannys so far & all have been great (except 1).
They are $29.99 on eBay (search pocket bike transmission or 43cc gearbox).
Sprockets are hard to find (especially for bmx chain). Dax used to sell them for $4.99 but must be sold out (gone from his website). Now a 12T 410 chain sprocket is avail on eBay for $23.99 (search dirve sprocket) yeah they spelled it wrong...lol
-Low-

Yeah,
You can buy the bolts there or online. They are M6 x 1.0mm metric bolts. Just measure the length needed & will vary due to custom mounting. Make sure the bolts are long enough to go into the engine cover a bit. Slightly longer works for me since I can always use washers under the bolt heads.
-Low-

lowracer said:

AV,
Yes & Yes.
The case should be filled with a lubricant. There are bevel gears inside. I use a real thin grease '000' that I found at a lawnmower supply store locally. The gaskets are junk & some dont even come with a gasket. Mine came without the bolt (some do) so I unbolted the face bolts, opened it up added the grease & then resealed it. I have used 5 of these trannys so far & all have been great.
They are $29.99 on eBay (search pocket bike transmission or 43cc gearbox).
Sprockets are hard to find (especially for bmx chain). Dax used to sell them for $4.99 but must be sold out (gone from his website). Now a 12T 410 chain sprocket is avail on eBay for $23.99 (search dirve sprocket) yeah they spelled it wrong...lol
-Low-

Click to expand...

I tried oil, but it leaked thru the junk gasket. I use lots of grease. Always split the gearbox, as every 5:1 tranny I purchased was bone dry.

I have a few pb trannies; some have bevel gears and some have straight cut gears.

I use 11-tooth T8F 8mm sprockets, which are plentiful and inexpensive on ebay or online.

The snap ring sells online for about $2.50, but they can be purchased at your local hardware store for about twenty-five cents.

Always keep a spare snap ring in your wallet. Side thrust is considerable enough to wear the ring down to the shape of a sharp wide fish hook.

Aside from that, it's a great transmission. I've had one front bearing and front seal fail, but that's it.

I'd look for the proper circlip, that won't stay there long.

A properly sized E-clip will work but might not be reliable.
The correct snap ring will work better. Shouldn't be too hard to find.

AV,
In your picture, is the clip not pushed on all the way?
It looks like if clicked on over the next riser, it would be very secure.
But, Ace Hardware carries the correct clips.
-Lowracer-

Your bolts are too long.
Try backing out the bolts a bit until it pulls. Then you know how many washers you need to put on under the heads.
-Low-

There are different clutch O.D.'s
Does your clutch match the tranny?

AV,
Some of these 5:1 tranny's can have more or less bell sticking out into the engine and could also require small washers between engine and tranny to space the bell outward (had that issue w/one).
-Low-

Bump.

AV, ever figure out what the problem was?

Cool, thanks for the info AV ^_^

Albula vulpes said:

5-7,

Were you ever able to get the GP460 to mate up with this tranny? I remember you were changing clutch springs at one time. Was thinking about getting a GP460 or a PF-4000. What are your opinions/ideas? Thanks

Click to expand...

Sorry I missed this query. I'm taking almost three years to respond.

Yes, the GP460 bolted directly to the pb tranny. It is extremely important NOT to overtighten the clutch bolts. The engine case at the mounting points is VERY thin. If you overtighten and damage the case, you're SOL. Also, the original clutch springs were designed for high-rpm engagement. I replaced the springs with aftermarket lower-rpm springs. Engagement slightly above high-idle worked well, although one of the three springs always tended to break. I also tried the pocket-bike clutch. It had very light springs and engaged slightly above high-idle. The pb clutch seemed to fit perfectly onto the GP460's tapered crankshaft, once you shaved the mounting crankshaft nut about 1/8".

The GP460 is an awesome, very powerful engine. I installed one on friction drive. It performed well on flat ground. However, no matter what size roller I used, it always ran out of power when climbing steep hills, especially long ones (It also had a habit of gouging divots into literally every inch of the rear tire). HOWEVER, when I bolted it onto a shift kit and proper gearing, it became a powerful hill-climber. It was VERY loud with stock muffler or even the Dominator pipe. Then I bolted on the SBP pipe designed for Happy Time engine. Although the exhaust port and head pipe were mismatched (rectangular port and round head pipe), the exhaust flange sealed very well. And lo and behold, the GP460 purred and screamed from idle to 8000rpm+ like a quiet little motorcycle. I swear I could hear the piston rings scraping the cylinder wall at idle speed. Notwithstanding the fact that the clutch springs were undependable, power was smooth and more abundant than my Tanaka 47R engine. Disappointedly, I broke a few clutch springs on my rides. The spring hook would slip out of its hole, break up and lodge itself between the clutch shoe and the drum. When this first happened, I'd call to have someone pick me and the bike up. Then I remembered how I'd driven my car home with a broken clutch, so I'd hobbled home on the bike the same way. Jack the rear wheel off the ground, start the bike, then roll the bike off the stand and hop on. When I came to a stop, the engine would lug down and die, and I'd repeat the rolling start. When I acquired the Tanaka 47R engines, I got rid of the GP460 engines. Voila, absolute dependability albeit a little more noise and less hp. Being a glutton for punishment, I MIGHT scrounge up a spare 460 engine. If I can find a way to keep the clutch springs from falling off their mounts, the 460 would be powerful AND dependable for my bike.