Official '66 SP 400 buildup thread

I did some thinking, and thought that since so many of us have interest in the Switch Pitch 400 trannies, what we really need is to do a buildup on one. The tranny in mine works fine, although it has over 200,000 miles on it and has only been opened up to add a B&M shift kit and a selector shaft seal. And believe me, in my younger days I beat ther crap out of this tranny! It doesn't slip......the brakes barely hold the car back when I do a brake torque......(true testimony to the durability of this trans) :Brow:

I wanted to re-program it to shift at a higher RPM and install a later valve body with 2-3 part throttle downshift capability, something the stock SP valve bodies don't have. But then I was thinking......why fix something that ain't broke? o No:

So, rather than sacrilidge this original transmission, I have decided to rebuild a spare I have that's been resting in the basement for a long time. It is a model BR that was removed from a '66 Lesabre and was slipping when I removed it, so this really one needs rebuilding. And I also have a '67 BT parts tranny for any internal parts it might need. (I'm running a Nailhead so I will never use it anyway)

This way if something goes wrong here, I can always stuff old faithful back in my car. :laugh:

As I progress through this project, I will post photo's and ask questions to the guru's........I will install a later '73 BC valve body, with the later filter and pick up tube. I am also going to install a modified governor that will hopefully bump my full throttle shifts to around 5,500 RPM's.

I don't want shifts so harsh that it chirps the tires, but I do want them to be more firm than stock......enough that I can feel them.

The only tranny I have ever rebuilt before was a ferd c-4, it worked OK after I put the missing check ball back in that I forgot when I put it back together. :spank: (reverse was missing) This is going to be a challenge. :TU:

My first question is this......should I use the B&M seperator plate or modify the original one?

 

first of many photos

here's the first photo.......notice the heel print in the pan.......that's what identifies the SP pan. The filter is unique to this trans and matches the pan:

 

here's what the pan and filter look like from the inside:

 

Here's what the inside of the tranny looked like with the filter installed before I took it apart:

 

Notice how the valve body is missing the 3-2 part throttle downshift valve:

(it would normally be there on the right side in the photo next to the valve that's there.....it's just blank)

 

My '67 trans doesn't have one of these funky set screw thingies.......but both my '66 trannies do........the factory book calls it a 1-2 accumulator adjustment screw: (no proceedure is given to adjust it, it just says that it's set at the factory) ou:

 

here's how the electrical plug comes off on the inside........you need to do this in order to take things out:

 

In order to get the front pump out with the wire attached without cutting it, you need to remove the spade that connects to the downshift solenoid from the socket with a small bladed screwdriver: (notice the 6 checkballs in their sockets, I removed the valve body)

 

Adj.

Joe:

Just an FYI for ya, the Sessions book says to measure the height of that set screw with a micrometer prior to removal to put it back the same as it came out.

Jim

 

After grabbing the check balls with a magnet, I proceeded to remove the front servo:

 

Next, I removed the rear servo: (didn't break anything so far) p

 

Next I removed the vacuum Modulator......I photo'd it with the valve as it came out, I hear these can be re-installed upside down......this way I have a photo of how it should be: (dial ups suck......this is gonna take some time ou: )

 

Next I removed the governor........(I only wish it was that easy to remove George Pataki :laugh: ) LOL just kidding

 

Next I took out the speedometer gear:

 

Next I removed the tailshaft housing:

 

Next I removed the shift lever.......I don't think it would be a good idea to skip this step, you need to get it out in order to replace the "O" ring.........these are known to leak:

 

Any time I tried to get a front pump off a tranny, it was stuck in pretty good. This one was too.

The book says to do this with a slide hammer......I don't have one of those, so I threaded 2 long set screws into the case through the 2 threaded holes in the pump body.........then using 2 long bolts, I threaded them into the case against the set screws, pushing the pump out. 2 of the holes in the pump were threaded from the factory:

 

The front pump on a SP is special........notice the SP solenoid in the photo on the right side.........the pump on a non-SP is different and doesn't have this solenoid....... (you can't get this out without cutting the wire unless you remove the spade from the plug connecting it to the downshift/detent solenoid first as I showed in an earlier photo above):

 

Here's a wrenchin' tip........next I'll remove the guts, in the absence of a holding fixture, I just cut a hole in a pail to set the tranny on........tail side down:

 

Now for the real fun........one good rule here........if it don't come out, forget the BFH.......it's prolly held in with a snap ring. This input shaft came out first, it was the easiest part to take out......it just pulled out. The rest is held in behind snap rings.

This part is also unique to the SP trans......the screwdriver in the photo is pointing to the oil hole that makes the SP work. this shaft can be pressed out of the hub. The later non-sp units don't have this hole: