Replacing the Input Shaft Bearing, Input Shaft Seal, and Linkage Seal on a D-Series Transmission
The D-Series cable (L3) trannies are getting old, and it's hard to find one that doesn't leak these days. A lot of them make noise too, usually due to a bad input shaft bearing. The bearing will cause a whining noise when the clutch is relased, common on old transmissions. Anyway, my transmission certainly needed new seals, but I wasn't sure about the bearing (it wasn't making noise). Since I didn't want to take the tranny out more than necessary, I did the bearing as well. My first time, it took less than one hour to complete, so I did a friend's the following week. The ones in the pictures are his, we found that the bearing had broken in the first one and we couldn't get the outer race out, so we installed the parts on a spare I had.
Materials and Tools
10mm, 12mm, 14mm sockets with extensions
8mm allen wrench
snap ring pliers
flat head screwdriver
slide hammer bearing puller
input shaft bearing (Honda part #91002-PS0-003)
**this P/N is for the 90-91 Si tranny, if you have something else, CHECK WITH HONDA BEFORE YOU ORDER
input shaft seal (Honda part #91216-PL3-005)
linkage seal (Honda part #91215-PL3-005)
bearing puller slide hammer thingy
you need 15, 20, and 21 from this diagram, under "MT CLUTCH AND DIFFERENTIAL HOUSING"
Opening it Up
I'll assume we're starting with the tranny out of the car, if you need help doing that, use the write up for removing the transmission
. First thing you want to do is unscrew the 8mm allen plug in the clutch housing near the starter hole, it's the only one in there. Now turn the whole thing over and set it on a bench face down. Remove the plug at the top with a 3/8" ratchet. Remove the 12mm bolts that hold the two case halves together, you may need to remove the mount bracket and stuff to get to these.
Now on to the hardest part. Look in the hole at the top of the case, where you pulled out the plug. You'll see a snap ring around a bearing, in a groove. To get the cases apart, hold the snap ring open while pulling up on the outer case, this is a LOT easier with a friend helping. You may need to pry it if you can get a screwdriver between them, or knock it loose with the rubber mallet. If you're having trouble, or just want to do it the easy way, put a socket on the differential, under the fill bolt. Now screw the bolt in, it will push the case up a little bit so you can pry it. There you go... the case should be off!
stef's tranny on the bench
the snap ring you have to expand
12mm bolts holding the case together
upper case removed
You should set aside a clean place to lay out the parts you remove here. Keep everything in order (including orientation) and clean!
The first thing you want to do is remove the reverse idler shaft and gear. Just pull up on the shaft to remove it, and the gear will be left there to remove as well. Now unbolt the two 10mm bolts holding the selector thing for reverse and remove that. Remove the 12mm bolt on the shift assembly near the forks (see picture). Now you can pull the gear stacks out. This is (again) a good place to have a helper. Hold both stacks together with the forks and pull up while your friend pries the bottom loose (gently) with a screwdriver. The whole thing will come out, try to keep it together. Lay the stacks down together, taking care not to loose pieces (the bearing at the top of the mainshaft likes to jump off). Now you can pull the differential out (just pick it right up). Remove the two bolts on the rod that goes out to the linkage (the one with the seal we're replacing). The one in the middle of the rod has a ball and spring, don't loose them. Once you have them out, slide the rod out the hole, out of the case.
Time to pull out the bearing and seals. I used a slide hammer puller tool on the input shaft bearing, some people knock it out from the other side with a hammer and an extension. Either way, get it out, the bearing is around the hole where the mainshaft (input shaft) sits, going into the clutch housing area. Once you have that out, you can pry the old seal underneath it out with a screwdriver. The seal is fairly hard, just bend one side of it inward and it will be easy to take out. The seal on the linkage can be removed using pliers and twisting as you pull on it.
reverse idler gear and selector...
you have to remove this 12mm bolt
remove the gear stacks...
and set them aside
the two bolts (facing up) holding the shifter rod
the spring and ball assembly under the bolt on the right in the previous picture
on stef's tranny, the input shaft bearing looked like this, with no trace of the missing balls . Yours shouldn't be that bad, the balls should all be in there. We ended up using another case at this point because the outer race was stuck in the case.
pulling the bearing
the magnet in stef's tranny, you can pry it out easily with a flat head once the stacks are out.
the magnet... looks like we found the missing metal balls...
Installing New Parts
Putting the new parts in is pretty straightforward. Use the old seals/bearing and a mallet to tap the new ones into place. The bearing will have some resistance at first, then it will fall back into place once it's far enough in. You may want to replace your magnet as well (I didn't), at least clean it.
Reputting it Back Together
As always, assembly is the reverse of removal
. Install the shifter rod before the ball/spring bolt, taking care to line up the ball socket at the end of it. Drop (ever so gently drop) the diff back in. While re-installing the stacks, have a helper line the forks up as you lower it slowly down, and don't forget the two washers under the mainshaft! Replace the 12mm bolt and then reinstall the reverse assembly, and you're done.
Clean the mating surfaces of the two pieces of the case, and apply a thin layer of RTV. Put the top case on, you might have to wiggle it a little to get things to line up. As the snap ring and bearing get close to each other, expand the ring and keep pushing down until it's held open by the bearing (it might not sit in the groove yet). Put in the 12mm bolts that hold the cases together, and tighten them down, wipe up the RTV that comes out the sides. Now check the snap ring around the bearing, if it's not in, put the tranny on its side and give the input shaft a love tap, it should seat the snap ring. You can reinstall the 8mm plug and the large 3/8" square plug as well now (and you should be done!).