It sounds like one of the pinion gears is backwards. Do you hear clicks from both sides when you pull backwards with the transmission not engaged? The gears go on the axle with the open side facing the same direction. If one is reversed the wheel on the "wrong" side will lock in place and not spin when pulled backwards and you will hear clicks from that side when pushing it forward. Bk bk - the axle springs ca be ordered from www.greenpartsstore.com or through a John Deere dealer.

Tips when rebuilding Honda Mini FG100 Transmission: Before order any parts do the follow: - The brass drive gear is connected to the tines axle by spines only. So be careful how much you hammer on the axle to try and get rusted on tines off, it possible to drive the gear off the axle. - The primary reason this transmission fails is water intrusion. While low or old grease(it separates) doesn't help and will cause the transmission to fail after a long period time, it's normally allowing water into the transmission which can rust the worm gear and thrust bearing that really speeds up the failure. - Thoroughly clean and degrease worm gear. Look for rust and pitting, this is what normally kills the brass drive gear. Remember brass is softer metal then steel. If any rust or pitting forms on the steel worm gear it will just grind down brass drive gear. The rust and pitting acts like sand paper. - If worm gear has any rust or pitting this must be clean up and smooth out, otherwise a new brass drive will just get grind down again. A 1x30" bench belt sander works good for this, the last sanding should be with a 300 or 400 grit sanding belt. - Soak and clean the thrust bearing with a penetrating oil. Make sure the roller bearing and washer are turning and look fine, no pitting. The thrust bearing is just above the worm gear and below the brass bushing. - Clean drive shaft for worm gear to remove any rust. Any bench grinder and wire brush works great for this. - Check all bushings for excessive play and wear. - Thoroughly clean and check the tines axle rubber seals and worm drive top seal for wear. All to often water intrusion is caused by the tiller being left out in the rain and water run pass the top seal which result in rusting on the up end of the worm drive shaft, thrust bearing, and worm gear. - Check the top bearing for play and wear. It at the top of the drive shaft for the worm gear under the top seal and is a sealed bearing. - If the worm gear, thrust bearing, top and bottom worm gear bushings, top sealed bearing, or top seal are too worn or damage you have to purchase the full transmission rebuild kit($$$$$) - However if whole worm drive assembly looks good, maybe after a little sanding of the worm gear, then only the tiller tine shaft assemble is need to replace the damage brass drive gear. Double check the bushing, thrust washers and rubber seals for your tine shaft, if this look fine the Earthquake 4651 replacement tiller tine shaft assembly might work and save you some money but I have not tested this. Others say it the same tine shaft. However if you have any concerns about this or the bushing and seals Pete's Small Engine tine shaft kit includes the axle with drive gear, bushings, and seals. Modification: - I replaced the top grease fill bolt with a M6 grease nipple. This was the prefect thread size to make a solid connection. I did have to drill the existing thread out which do not match any standard nipple thread size to tap for M6 thread. I recommend doing this on a drill press so you can drill the hole a little offset so the nipple will not hit the tines axle dirt cap. - The reason for installing the grease nipple is to allow easy greasing but also to allow the transmission to be pressure fill with grease to avoid creating any air pocket for water accumulate if it finds it way into the transmission. I use the bottom grease fill bolt to check for water. Assembly: - I recommend popping the seal off the top drive bearing, removing the old grease with an air gun, and then packing in new grease with your fingers. Once done you should be able press the seal back into place. - Use thin gasket material not form a gasket silicone to seal transmission housing. Using form a gasket silicone with cause the tines axle to bind against the axle bushing and thrust washers, it's just not thick enough. - I recommend using Mystik JT-6 #2 Multi-purpose grease, it's extremely water resistance and extreme pressure grease. Very low oil separation rate. I have found tubes of Mystik JT-6 #2 Multi-purpose grease that over 20 years ago and the oil still has not started to separate.

It all depends: A 4 speed is less complicated, has fewer parts and clutches and has the potential of having heavier gears. The downside: It has only 4 gears; the spacing of the gear ratios may not be optium. The 4 speed probably is an older design and well developed. Four speeds have been used for years and were ok. The 6 speed offers better matching of engine output to vehicle speed, but has more parts. if the transmission case is about the same size as the 3 speed, this means that extra gears are stuffed into the same space as the 4-speed. The 6-speed may get better fuel mileage depending on many factors. Best choice depends on the engine and you did not say which engine you have. If you have a 'honking' big V-8 with a flat torque curve, a 4 speed should be ok. If you have a small v-6 or 4 cylinder, the the 6 speed is definitely better.

You might want to post this in Lawn Mowers, there are a lot of lawn tractor gurus in there. Not so many here in the garage. They must be out mowing. :-] Might need a clutch adjustment?