Wednesday, April 8, 2020

Five Speed Rebuild, Part II

In today's episode, I get almost all the way down to the bare bones of the transmission.  Starting with a clean case...


Man, that was disgusting stuff.  ATF plus parts cleaner equals pink slime.

On to the fun part... The Haynes manual recommends that you use adapter plate KV32100300 to mount the gear assembly for easier service.  Since I don't have adapter plate KV32100300, I used the next best thing; a 2x4.

Disassembly is a pretty detailed but simple series of steps.  The manual is pretty good at describing how things look and the order of disassembly, though my transmission appears to have a couple of minor deviations.

First thing: Remove the thrust washer and note which way it goes.  The side with the little dots goes inward.  That lets oil move around and keep the washer from wearing.  It seems to work...

Next step: Pop out the pins that hold the shift forks to their rods with Fork Rod Pin Punch ST23540000.  I seem to have misplaced that tool; I used a punch that I ground down to fit.  There are three, and the pin for the R/5 shift fork is a little shorter.


Next, remove the check balls and their springs.  The retainers screw out: two on the top and one on the side.  The one on the side is a longer retaining bolt.  The balls come out when you remove the shift fork rods.

There are two circlips that act as a stop for the 3/4 and 1/2 shift fork rods; they come off.

Once the circlips are out, the fork rods can come out too and the forks just lift away.

Before proceeding, remove the two interlock plungers.  These sit in between the fork rods to keep you from shifting the transmission into an impossible state.


With that done, we have just a couple of gear trains.

Now the fun really begins, starting with removing the rear mainshaft bearing.  I bought a bearing puller just for this.  (Well, and I know I'll need it for another project.)  Easy peasy.  But before the bearing comes off, the circlips in front and behind have to be removed.  The front one comes off; the rear one gets shoved back so you can put the puller on the bearing.


This is where my transmission deviates from the manual a bit.  The manual states the next step is to unstake the mainshaft nut and remove it.  ("Unstaking" means to remove the dent applied to hold the nut in place.)  However, my transmission has no mainshaft nut, just a collar and thrust washers.  The counter shaft (so named because it rotates counter to the mainshaft) has a staked nut.  So I removed the collar and thrust washers, unstaked the counter shaft nut and removed that.  In this photo, the mainshaft is in the background and the counter shaft idler gear in the foreground.

Then I removed the idler gear, followed by the 5th and reverse gears.  The manual says 'together', but they came off individually and I see no reason they had to be together (for my transmission; maybe that is part of the deviation I noticed).

There is a circlip that retains the synchro, which in the below photo is buried under gunk but is there.  There is also a spacer on the main shaft that goes with the package.  Note that there is a very small ball bearing that retains the needle bearing for the R/5 synchro; don't lose that!


I then removed the needle bearing and its inner race.  This was particularly disgustingly caked with the remains of ATF.


I'm starting to build up a disassembled gear train...

Now the mainshaft bearing retaining plate can be removed.  This takes a star hex drive, which I happened to have thanks to a random trip to Home Depot.  To get leverage, a vise grip does the trick.

At this point, it's down to removing the circlip for the bearing and gently driving the main shaft out with a soft Big Hammer.  As the shaft frees up from the case, the counter shaft will also come out--you have to catch it or you'll be unhappy.  But the whole mainshaft just pops out of the plate.


The last item to remove is the reverse idler gear.  The manual states to pull the gear off, but I found it just as easy to remove the entire assembly on the shaft, which is held in place by a circlip and friction.

The result of all this work is impressive.

I figured I'd take a look at the R/1 synchro to see how worn it was.  I am quite surprised to find very little wear on the teeth that contact the baulk ring (the gear contacting the baulk ring is what slows things down so the gears mesh).

I said I got almost all the way down to bare bones.  I got everything out, but now the rest of the mainshaft remains.  It doesn't look all that horrible as long as I take enough pictures to remember where everything goes.

But I definitely have more cleaning to do.  Yuck.

Next time, I'll finish disassembly and get everything nice and clean.  Then the excitement of testing whether I remember how it goes back together can start!

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