Friday, November 11, 2011

Ford Flathead Transmission --Clean, Gaskets, Bearings

This trans isn't going to be a big challenge.  Because lucky for me this transmission was in good shape.  This one is going into the Model T.

It is a 3-speed, typical flathead tranny, late case; part number 78-7006.  But it is a 1950 truck transmission, and because of that it has some upgrades that makes it a good one for me.
I bought the trans attached to my first flathead, way back in 2003 and saved it all this time. 

It is an open-drive, with a sliding yoke instead of a closed torque tube.

That's the speedo sender sticking off the top of the tail housing.

It also has the light-duty truck gears, only found in these transmissions.  But they are in fact heavier-duty then popular passenger car gears.
It has a 27/16 tooth count main gear, it's a gears set that can't be mixed & matched with any other gears.

Taking the gears out for the first time, they all seem to be in good shape.  The bearings inside the main lower gear of this later transmissions has the loose pin roller bearings, rather then the caged type.  So I had to make sure I don't loose any.

You can see he pins falling out the front >>>>

I've stored this trans for years, I really should have drained it.  There was about a cup of water hiding under the oil,  But I have a feeling I let it get rained on a few times.

Luckily, no harm done.

My biggest worry was these pits in second gear.  But Jim Gordon assured me, they are a quite a minor defect and I should ignore it.  Jim has much info on transmissions, and he's happy to share it.

Compare the new & old trust bearings.

Jim is also best source for all flathead & trans parts I know in the LA area.  He own and operates Specialty Ford Parts in Rosemead CA --I'm just so glad it's there sometimes!
I bought all the parts I needed to freshen my trans up; gaskets, seals & thrust bearing.

There are also other sources like
Some decreasing and ta-da!  Like new again.

The case & gears now clean, it is time to put in the gears.

Remember those loose pin bearings in the main gear.  Well you need something like this: heavy transmission assembly grease.  It's really the only way to keep the pins stuck in place when sliding in the main gear shaft again.
Here is that main gear shaft I'm talking about.  That is its retaining pin at the end.  Use it as a handle to help slide the shaft in again.

The main gear has to be sitting on the bottom of the case to disassemble the gears and also at reassembly.
Getting this shaft in and out may be the hardest part of building a Ford trans.  It couldn't all be as easy as cake, could it!

I wouldn't forget to replace the front seal or I might be sorry later.

Reference material may be helpful, but honestly the only way to really learn is take it apart yourself.

These transmissions couldn't be easier to work on.  And frankly, it's pretty fun doing this kind of stuff.

Before that top goes back on for the last time, I'll make sure I have the shifter's arms in the gear slots, and a new gasket to seal it.

 And it's just about done --ain't she a beaut!  A little more wire brushing perhaps and it's ready for paint.