Oct 2011 5 Speed Teardown and Rebuild

I have been running the rebuilt motor on a test stand, but to install it in the car I want to get the 5 speed up to par.  I have a few transmissions, so I pulled one and started the teardown.

If you undertake a transmission use lots of photos, notes, and drawings.  When you crack it open it looks daunting, but the early transmissions had pressed together 5th gears that would separate and give you a 5th gear neutral.  Later boxes had splined gears to reduce this risk.

The shift forks are held on with roll pins, simply tap out.

The Roadster had early Borg Warner brass synchro's and later boxes had the Servo cast steal.  You can see the brass in this tranny.

Once the shift fork is unpinned, you remove that rods check balls and tap out of the center housing.

The center housing has retainers designed to hold the rods in position based on shift location.

Each rod has a pressure spring that pushes balls against the rods for position lock.

Center carrier of tranny, note the large drawing I made of each item as I removed, I simply placed them on their "map" spot.

These are the shift rods in order. You can see the indentions on the rods where the check balls push into based on gear/rod position.

I started the main shaft removal.  You need a set of quality circlip pliers as some of the rings are very heavy duty.

Verifying gears and synchronizers.  

Many of the vendors sell welded 5th gears and the two pieces are known to separate and create a neutral 5th gear.

Front gets large spacer and clip.

This is the double nut that must be removed it also has a lock plate as these are known to back out.

The transmission rebuild kit comes with all new seals and gaskets. Here the rear seal is being removed.

Everything is cleaned and pained and ready for assembly.  The shifter has a small seal in the tail housing.

Rear tail seal going in.

Ready.

I scratched the input tube with the seal puller, so a quick soft sanding cleaned it right up.

With everything laid in order I assembled and greased the mechanicals and readied for the cases.

Bell housing gets a new seal and gasket.

Last time I'll see the guts of this box, but the new bearings should last my ownerships (I hope).

Front cover on.  Lined up with bearings prefectly.

Tail section was a little tougher as the shift rod needs to engage on the shift forks correctly.

With tail section in place the driveshaft hub is secured, and shift receiver is pinned.

Torqued bellhousing to 16 pounds.

Before snapping the clutch fork in place I put a small dab of grease on the pivot point.

Clutch fork and new boot installed.

A little grease on the fork contacts and installed the throw out bearing.

DatsunParts sells stiffer shifter bushings.  The old rubber ones really had a lot of slop.

Shifter bolted in.

Fully rebuilt and ready to install.

This is the rebuilt engine I have been running on the test stand.  To install in the car, I need to put in a new clutch and replace with the rebuilt tranny.

Happy to say when I pulled the temp tranny the rear main seal area looked great.  I will torque the flywheel back on and install the new clutch/pressure plate.

With the engine on the hoist, I'm replacing the old soft motor mounts with new ones.

Transmission cross member got all new bolts and a new mount.

Lifted Engine from test stand and placed into its permanent home.

The breather was still available from the local Nissan dealerships parts counter.

Final step is to bolt the slave cylinder on.

New Clutch Slave Cyl in.  Will need hydraulics to adjust it later.

There is a 90-degree adapter that allows the tach cable to connect to the tranny in a parallel position rather than straight in.

Unscrewing the brass caps allows you to pull the gears, clean, and then reassemble.

Back together with a new zerk fitting, lubed and installed on tranny.

Will need to hook everything back up to run it as I did on the test stand.

Fun photo beside my 67 1600.