Toro 106-3956 Rear Wheel Drive Transmission Assembly

Snap rings were tough to get out if you got the right tools that makes the job easier I rebuilt my whole RWD lawn MowerPulls like brand new now

Appears to be OEM part. Looks exactly the same as the original. I'm very happy with the part and it shipped quickly. Saved me a few hundred bucks.Installation: Mine is a 2008 Toro model 20067First remove the old axle. I think the easiest way is to remove both back wheels. There is a belt cover that has 3 screws, one in the middle that actually keeps you from removing the belt. You'll at minimum need to remove that one.I had to transfer the pulley from the old transmission. Getting it off the old involved removing the 4 screws and cleaning out the old nasty grease (in my case almost dry). There's hex nut inside so you can remove the pulley's nut. I was able to use vise grips to hold the axle when I put the pulley on the new transmission.Really, really make sure you keep track of the washers and spring clips order on each side of the axle as you remove them (I didn't so it cost me a lot of time). The diagrams you'll find on the internet aren't great to identify how to put them back on. The spring clips aren't a real standard type, so you may need to use a screwdriver to pop them off. There are 2 spring clip/snap rings on each side, don't lose them. I used channel-lock type pliers to put them back on.Be aware that there is a rocking key in model 20067 on each side that has a small spring under it and will likely pop out as you remove the pinion gears from the axle. The keys are about 1/2 inch long D-shaped pieces of metal and easy to misplace. The spring under the key is also pretty small, so keep track of them both on each side. When you put them back in, the curved side goes inside the groove, flat side is out/up.The pinion gears can be used on either side of the axle, they're stamped with an "R" and "L". You just have to put the "R" out on the right side and "L" out on the left side.Check your drive wheels, mine were in great shape so I just put them back on. If yours have beat up teeth it would be a good idea to replace them.Good luck and keep track of the order of the washers.

Item came days before promised which is awesome. Only had to push the mower for one weekend when I expected to have to do it for two. OEM part. Couple hints others have mentioned. It does not include the pulley so you have to pull off the old one and put it on the new part. The easiest way to remove the old one is to take the back off the old transmission, pull out the axle, then use a 22mm socket to hold the pinion while taking off the pulley nut. To install the pulley on the new transmission I was able to do it by using a vice grip on the long axle while holding the transmission body and tightening the pulley nut. The two holes that hold the belt guard on the transmission are not threaded but the metal is soft and I chased the bolts down the holes before installing the transmission and that worked great. My 13 years old mower runs like new again. Be careful with the pinion gears at the end of the axle, lots of parts. I used a piece of paper to lay the parts all out in the correct order to make install easy and make sure I kept them the same when reinstalling.

As others have stated, you need to reuse all the existing springs, clips, and washers - as well as the gasket between this unit and the belt pulley, so be very careful when disassembling to keep all parts organized.I was accidentally shipped part "106-3955" instead of part "106-3956" - both these units look IDENTICAL - so I didn't notice until AFTER I'd completely put the system back together and had a mower that wanted to push backwards instead of forward. "...55" is the transmission used in the FWD models rather than the "...56" part used in the RWD models. So, BEFORE you do any of the disassembly, hold the unit in front of you with the gearbox on the left. If you turn the top shaft clockwise, the axle should be turning as if it is rolling back toward you (top toward you, bottom away). If it turns the other way, you have the FWD version of the transmission. (This seems backward, but there is a gear transfer in the wheel assembly that reverses the rotational direction so that the wheels roll forward when the axle rolls back, so you want the axle moving in the opposite rotation you'd want the wheels rotating.)The seller made good by shipping the correct replacement out, but it's enough of a pain disassembling and reassembling this thing without bending or losing anything, that you definitely don't want to have to do it more than once by not checking the part first.

Everything fit and everything worked. That said, some instructions would have been nice. See Youtube for some help. It would also have been nice if this transmission was designed to last more than 5 years. It appears to be just like the original, which, in this case, is a bad thing. (I could at least hope for an improved design by now.) Less expensive than a new mower, and better than turning my self-propelled mower into a push mower (barely). If you like fixing mowers for fun, this is perfect. Else, this takes a little longer than I liked to replace, and requires taking apart the new transmission to swap the drive pulley on the top. Sort of a pain to do, but saves a few bucks and keeps a mower out of the scrap yard, or you cussing the lack of propulsion every time you mow.

When the product came I looked at it and every thing looked rite I installed it and the result was it drove like when it was new.very very happy

Parts Tree want's $110 for the same transaxle. This one will not fit a Lawn Boy 21" self propelled rear wheel drive push mower. However the gearbox is an exact replacement. The shaft on this one was 5" too long. I installed new wheel bearings, swapped the gearbox and gears and slide them onto the old shaft. Maybe 10 min of work and viola, "NEW" transmission. Mower runs as good as it did when I bought it 10+ years ago. Great value.

Used on toro 20041 rwd