F-N-R Gearbox

[Willie1]

I saw another post inquiring about a parts breakdown or info concerning the Chinese F-N-R gearboxes that are on E-Bay, Amazon, etc. This is the box that has the long input shaft that a 30 series converter can be mounted to, and the short shaft for the output sprocket. The post was from a couple years ago and showed 1 pic but not really any info, and the post was locked so I couldn't see if there was any more info had gotten out there. So the question is - anybody have any info on these - internal pics, etc.? I have the sales info as far as the gear ratios and such - looking more for "2nd tier" info like a parts diagram, or pics if someone took one apart. Thanks, Willie

 

[Denny]

You would need to get that info from the seller or manufacturer.

 

[Willie1]

You would need to get that info from the seller or manufacturer.

I've easily seen 30 different "manufacturers" names on these units. There doesn't seem to be much tech support for them. They don't include any paperwork with them - I guess let the buyer beware. I have found every part on the outside - cables, shifter, mount, sprockets, etc., but no info for the parts inside. They must be reasonably sturdy, since while they are only rated for 11-13hp and 2300rpm I've seen a lot of them with 25-30hp, 4500rpm put through them and never heard of issues. I will probably put oil in mine, spin it in both directions for 10-15 minutes with a drill, and then crack it apart and see what's in it.

 

[Willie1]

I found this pic from the earlier article and was able to sharpen the image and see inside. Appears to have a chain drive for forward and gears for reverse. Counting the teeth for reverse reflects the listed ratio - can't see the forward sprockets to verify. Guessing there is a sliding coupler to engage F or R.
If this is the case I will try to replace the chain with a premium pre-stretched one.

 

[Denny]

I don’t know anyone who tried to beef up one of those boxes or how long they last.

 

[Budget GoKart]

beefing it should work fine and id just run bar and chain oil its thick and snotty and really cheap i run it in a mower transmission and my other more reliable mower runs used engine oil in the axle mixed with ball bearing grease

 

[Denny]

Or you could run John Deere corn head grease. Will not flow until moved.