Tuesday, February 28, 2012

Happy Birthday Ol' Rusty!!

Ol' Rusty was first purchased on Feb 28, 1968 from Rye Ford, Inc. in Rye, NY from some folks that gave her a full, well-used life in the rust belt.   She was "restored" in 1984 and then pressed into service for another couple of decades until she finally was placed in storage until I answered an ad for a 1968 Ford Mustang convertible in January of 2008 and purchased her from her original owners and the rest, as they say, is blogged.

So, happy 44th birthday Ol' Rusty.  I hope to give you at least another 44.

The original invoice. February 1968

January 2008

November 2008

May 2011

You've come a long way, baby.

Sunday, February 26, 2012

C4 Restore for the Poor

About 4 years ago, I pulled my old C4 automatic transmission out of Old Rusty along with the engine, detached it, hauled it out back, and and put it on a pallet under a covered area next to my house... and forgot about it.  Every so often I'd go out there to dig up a part or pull weeds and spot it out of the corner of my eye and I'd feel a little twinge of pain in my gut.  This usually caused me to exit the area as quickly as possible and find something else to do.  Well, Ol' Rusty will be coming to take back her stall in a few days which means that she's going to want an engine and something to spin with it.  So, out I stumbled in the rain and mud and strapped the old blue oddity to my dolly and wheeled it into the garage.  Oh right... somebody painted it blue... blue... really?   My first thought was to drop it at some transmission shop and let somebody else deal with it.  Until I got a couple of quotes for the job.  $750 being the cheapest.  Ugh.  I could also have grabbed a rebuilt unit but that's just a crap shoot for years, casting codes, quality, etc.   Besides, I told myself I wasn't going to do the core trade-in thing after I lost my original alternator to NAPA the first month I had the car.  I want the parts to be original and this transmission MIGHT be although it'll be hard to prove without the tags.  At any rate, my only real option was to do it myself... as usual.  Sometimes, being cheap is a real burden. ;-)

I bought a master rebuild kit from Oregon Performance Transmission along with a low/reverse servo piston for the low-low price of $97 shipped (then they raised the price the next day to $112.. lucky me).  The kit includes all of the gaskets and seals, friction plates, intermediate band, vacuum modulator, a front and rear bushings, and miscellaneous other parts.  What else could I possibly need right?  I mean, it's a MASTER rebuild kit... right?  Well, not quite, additionally, you'll need a bushing set, a spacer set, and a low/reverse servo piston.

Now, I like just tearing into things and guessing my way through it's re-assembly as much as the next guy but a transmission rebuild probably shouldn't be one of those situations.  That leaves us with the question of, "Soooo... how do I do it?".  Well, there are lots of instructional aides in the world like a Haynes tech book called Ford Automatic Transmission Overhaul or other books like Transmission Repair Book Ford 1960 to 2007: Automatic and Manual.  There's also a video series by "Bad Shoe Productions" on rebuilding the C4 that's very popular.

I would have bought one of the aforementioned guides, I really would have except... I discovered that I already had a great guide in my greasy little hands, the 1968 Cougar, Falcon, Mustang Shop Manual.  Mine was a CD digital version of the manual distributed by Forel Publishing.  This is basically a copy protected PDF file scan of the original service manual.  However, being digital allows you to search the manual and print just specific parts (like the c4 rebuild guide, pages 224-245), staple it together and bring it into the shop to write notes on, mark off the steps, wrap in greasy rags, or whatever.    When you're done with it, toss it and your pristine original manual is none the worse for wear.  Also, you can't beat Forel's technical support.  The owner of the company called me on a Saturday to help me work through a problem I was having with the protected file printing on my printer.  Also, the service manual instructions for doing the rebuild are step-by-step and don't leave much of anything out for you to figure out yourself.  So, if you already have a service manual, use it.  If not, you should have one anyway.

And now, on to the rebuild.  As usual, this blog entry isn't meant as an instruction manual for rebuilding the C4 by itself.  It's meant to show you what a cracked-open C4 looks like along with some of the steps for doing a rebuild.  This will hopefully put you at ease with doing it yourself or convince you to take to to a pro. 

1/14/2013: I incorrectly used "engine assembly lube" (the white stuff) in the assembly of the transmission as show in this posting.  Not long after I posted this blog entry, I opened the transmission back up and cleaned the lube off of all of the parts and simply coated the parts in transmission fluid.

The before pic. It's blue... sheesh.

The input side, bell-housing in place complete with broken-off starter bolt.

Bell housing removed. The bell-housing bolts pretty much hold the front pump onto the case.  Once the bell housing is removed, the transmission is officially "cracked open"

I found I needed to drain out some more fluid.  This stuff just keeps leaking out no matter how much you've already drained.  It's like these things have their own little transmission fluid factories inside them or something.

Crusty old mounting plate getting pulled off.

I used my angle grinder cup brush to clean the old paint off.
I painted the case and THEN decided I was going to go ahead and do a rebuild.

The transmission, service manual printout, and master rebuild kit ready to go.  BTW, cardboard really does a great job of soaking up trans fluid.  Do this job on flattened out cardboard boxes.

The control valve assembly has been removed.

The low/reverse band struts being removed.  This band is basically a brake that wraps around the low/reverse drum.  The low/reverse servo makes it clamp when it's pressurized.

When you first start the rebuild, you'll need to take a reading of the input shaft "end play".  This end play is supposed to be between .008 and .042 inches.  Mine is at .082.  Ouch.

This is the intermediate/forward band.  It's like the low/reverse band but on the opposite end of the case and is actuated by the intermediate servo.  It clamps the reverse/high clutch drum.

Removing the intermediate band.  Just remove the struts, rotate it to align with the indention in the case, and it comes out.

Nothing special to get this out.  It's the forward gear train with the "sun gear"/input shell at the top.

The forward gear train unstacked and disassembled.

Starting to pull apart the reverse gear train.  First out is the planetary assembly.

Removed the reverse planet carrier and reverse ring.

Pulling the low/reverse drum. The output shaft retaining ring has to be removed first though.  After that, this drum comes out and the shaft would too if the rear extension housing were removed.

This wild-looking thing is the one-way clutch

Pull the center gear out and the whole thing falls apart.

This is the low/reverse end of the gear train disassembled.

Removing the extension housing.

Extension housing removed.  Exposes the output shaft which will just pull out with the governor (the aluminum thingy) attached.  Next you pull the distributor (the cast-iron thingy).  It's two tubes need to be wiggled out of their ports.

From the back end of the case after the distributor and parking gear (not shown, sorry) have been removed.

The empty case surrounded by it's guts.  Welp, that's it for me.  Transmission medic!!!  (just kidding)

The low/reverse servo piston and cover.

The old piston (left) next to a new one (right).  The rubber lip is bonded so you have to replace the whole thing.  Note the missing nut on the end of the new one.   It's okay, one less thing to adjust/torque.

New servo piston lubed up and installed in the low/reverse servo.

Pulled the intermediate servo.  Yuck!

New seals and cleaned up intermediate servo ready to reassemble.

This is the shifter lever being pulled.

New shifter lever seal.

On to the valve body.  It's ready to be separated.

The inside of the valve body.  Looks scary but it's really just 3 pieces with 2 check balls and a valve slug.

Upper, Lower, Separator plate, and gasket.  You could do a lot of dis-assembly on the upper part because there are several pistons and actuators in there but no seals to replace so I just left it alone.

New check ball #1 in the lower

New check ball #2 in the upper with valve slug just to the right of the check ball.

Valve body reassembled with new filter (came with the kit).

Next is the front pump assembly.  This stuffs into the end of the reverse/high clutch drum with sealing rings like a piston pushing against the walls.  Note the ring on top is "locked" and I've already unlocked the second ring (the last 2 have already been removed).  BTW, that yellowed nylon ring is "spacer #2".

The stator support (top) bolts to the pump housing (bottom).  Pull the stator support and you see the pump gears.

The pump gears just pop out and you can get to the pump bushing and seal.

I've replaced both the bushing and the seal here.

I've replaced the rings with new rings that came in the kit.

Testing the fit and pump rotation on the old torque converter

This is the forward clutch. Remove the snap ring and the clutch plates come out.

There's a piston in the bottom of the clutches.  Blow some air in a port and the piston pops out.

The piston with new seals next to the empty clutch drum.

New friction plates have to be soaked in trans fluid for 15 mins prior to install.

Dropped in the first friction plate (drive plate)

Dropped in the first driven plate

Assembled forward clutch with pressure plate and snap ring in place.

Reverse clutch disassembled.

There's an annoying spring retainer that needs to be pulled to get the piston out.  I used two clamps to put pressure on the plate so the snap ring could be removed.

The springs that hold the piston down.

Piston removed with new seals ready to reinstall.

Reverse clutch reassembled.

This is the governor that is held onto the output shaft with a snap ring.  It uses rings to seal in the cast iron distributor that it's inserted into.  New rings next to it.

The only part in the distributor that makes it worth disassembling is the filter (top left).

New rings installed on the governor.

During tear-down, keep the spacers marked and sorted to ensure you have them all and that you put them back where they belong.  There are 10.  #1 and #2 are responsible for setting "end play" (measurement taken at the top of this blog entry).   The bag contains the spacer kit.

New spacers matched up with their counterparts.

The governor was put back onto the output shaft.  The distributor and parking gear were bolted back onto the case, and the distributor is inserted into the top of the distributor.  Ring compressors not required.  They compress themselves.

This is the old bushing in the extension housing.   I was going to leave it be since I don't have any kind of bushing press but the wear was just too much and the bushing came in the kit sooo...

Old bushing next to new.

Starting the new bushing.

I found a couple of disks in my Harbor Freight seal driver kit that fit perfectly and made the install job work out very well.

Re-assembly started.  Output shaft installed.

Starting to reassemble the one-way clutch.  First install the springs.

Then fit in the rollers.

The low/revers drum in place with it's band wrapped around it.  Spacers lubed up.

Assembling the high/forward gear train.  Reverse/high clutch under the Forward clutch

Then forward ring gear.

Then planetary gear.

Then shell/sun gear.

All stacked up again.

And lowered back down into the case with intermediate band and struts back in place.  The new intermediate band came in the kit and had to be soaked in trans fluid for 15 mins prior to install.

There's a procedure for setting the end-play of the input shaft that involves selecting the correct #1 (larger) and #2 (small) spacers.  The small spacer is chosen based on a thickness that is appropriate to reduce the end-play value to within specs.  For me it was a .056 spacer with a .042 shim that I had to make from a machine bearing I bought at the local ACE hardware.  The larger spacer is not used in the calculation for end-play at all.  It literally takes up the space that the smaller spacer causes between the pump housing and the face of the reverse/high clutch drum.  It is not meant to fully contact the surfaces and act as a true spacer.  Note the yellow striped pump housing square cut ring that's inserted into a groove around the outside edge of the pump housing.  This transmission didn't come with one but the kit did so I used it.

The new pump gasket. I didn't use any kind of gasket sealer on any of the gaskets.

And here's the assembled transmission, the stack of discarded parts, and the bag of unused parts, presumably for a different type/year of C4.

I had to order this seal special from CJ Pony parts as the seal that came in the kit didn't have the long rubber extension.  I used a ring compressor to drive the seal in and it worked surprisingly well.

I screwed up and didn't install the secondary lever early on like I should have.  I solved this by removing the gear select lever that gave me enough clearance to insert the shaft and then reinserted the selector over the inner shaft.  Just save yourself the hassle by inserting this before you install the forward gear train.

This is the position to place the levers in before installing the valve body.

This is the underside of the valve body showing the selector setting for when the levers are set like the above picture.  The inner lever contacts that plunger to the right of the selector piston (the thing with the notch cut out of the side of it).  The pin on the main selector is inserted into the slot in the gear selection plunger.

Valve body and gasket in place.

Oil pan in place.

The bell-housing is then torqued on top of the pump.

One freshly rebuilt C4.

Finally, I reinserted the newly painted filler tube and put the C4 in it's place of honor next to the engine.
After all was said and done, I came out with an input shaft end-play of .027.  Not perfect but firmly within specs.

Note:  I didn't purchase or install a bushing kit.  I may regret this later but the internal shaft to bushing clearances didn't seem that far off (with the exception of the front and rear bushings that I did replace).  I don't have a press and I was afraid of doing more damage then I would cure.   However, I'd recommend that if you have the means to replace bushings without damaging them, get the kit.

Other than that, this rebuild was definitely doable by reasonably mechanically inclined beginner.  Transmissions seem complicated with their crazy valve-bodies and their stacks of gears that look like something in the engine-bay of a star ship but once you break them down into their sub-assemblies, things start looking a little less alien.  Oh yeah, and once you're done, you can do some air tests to give you a warm-fuzzy feeling that the thing will probably work again.  Mine passed. :-)