Saturday, March 10, 2012

(Trans) Mission: COMPLETE!

If you will recall, this transmission was already disassembled when I purchased it and I had to inventory all of the parts to figure out which ones were usable and which ones were AWOL.  I spent an afternoon in the garage with a caliper, a few different manuals and the internet trying to figure it out.  Once I had it all labeled and a wishlist written out, I ordered the parts and waited.  Well, they arrived and it is now time to assemble this steel jigsaw puzzle together.

Cluster gear and washers installed and being held in place with a temporary steel tube.

The first step was to gently persuade the new cluster gear into place.  The old one had one too many chipped teeth for my faint heart.  It is now a sturdy paperweight on the workbench.  On either end of the cluster gear sits some assorted brass washers.  I put a few dabs of grease on the washers in an attempt to hold them in place while I fitted the cluster gear into the box.  Then I used my faithful steel tube (that was used to punch out seals in the axles!) to hold the cluster gear and washers in place while the remaining parts of the transmission are to be installed.  Funny thing is, if I were to place the proper shaft through the cluster gear now, I would not be able to fit the remaining gears and shafts into their proper places.

Next step is to assemble the main shaft.  This consists of placing (in specific order) the retainer ring, two gears as well as the assembled synchronizer and another snap ring to hold it all in place.  Quite often it is the synchronizer that fails, thus shift issues when driving develop prominently with the second gear.  I think this is an issue with my "good" jeep and will be addressed (hopefully) during a future rainy day.  Anyhow, in my new small parts kit were replacement parts for the synchronizer so this transmission shouldn't have this problem.  I'm sure it will have its own set of issues, anyway.

Note the assembled main shaft in the lower part of this picture. 
Also scattered about, in somewhat organized chaos, are the remaining bits and pieces of the transmission.
The main shaft slides into the upper part of the transmission and sticks out of the rear of the case connecting it to the transfer case...which Jack will tell you makes the jeep go in 4-wheel drive...and he is correct, too!  With the main shaft in place, the input shaft can now be assembled and will slide onto the front part of the main shaft. 

There were a couple tricky parts for the input shaft.  The first obstacle to hurdle was getting all of the roller bearings in their proper place internally.  My friend, Greasy Bob, (not really, more like just the grease minus the Bob) came in handy here.  A little dab of grease and the assistance of needle nose pliers works miracles.  Thirteen little tube-like bearings have to form a perimeter for the main shaft to slide into.
The thriteen little tube-like bearings (on the right) need to be placed perpendicularly inside the input shaft (being held).

Disco tech:  Bearings in place.  Thank you Greasy (Bob).
Now it is time to slide the assembled input shaft (it has a larger bearing with snap ring, gear, and synchronizer blocking ring) into the front of the transmission box and mate it up with the already installed main gear.  This is the second tricky endeavor.  The shaft has to go in through the hole on the front of the transmission case, clear the cluster gear sitting on the bottom of the case, mate up with the main shaft (without knocking the thirteen little bearings down) and have the synchronizer blocking ring (brass rings on both sides of the synchronizer) in their required positions.  Over the river and through the woods with low lying branches at a full on trot/jog...because I don't run.  This took a few attempts, but it finally worked out.
Attempt No. 1:  no good.  The brass blocking ring on the right is not snug enough to the synchronizer assembly.  Turns out I did not have the synchronizer deep enough on the main shaft.  So that was why the snap ring didn't fit properly?  Huh.  Everything came out and the mistake was corrected.

This might have been attempt 7 or 8, but finally I got it right...I think.  Input shaft is at the top, output shaft is at the bottom.
Now, the entire case must be flipped upside down and the steel tube is to be removed and replaced with the proper cluster gear shaft.  The process is kind of like a magician pulling a table cloth out from underneath the settings.  The shaft must slide through the holes without letting the thrust washers fall to the bottom of the case.  If this occurs, it is back to step one...after disassembling it all!
First attempt:  flipped, removed, installed and locking plate in position for the final tapping. 
I actually may have read about this in the Kama Sutra book.

With the shafts in position, the next step is to install the shift rails.  Two actual shift rails which run along both sides (like a set of railroad tracks) and a smaller rail will be placed to hold the shifting forks.  Yes, dinner and a show, folks.
Skinny rail and two shifting forks in position.
Now it is time for the pair of shifting rails (the railroad part of the equation).  The fun part of this procedure is to put in AND keep in the tiny springs and poppet balls.  In a split second, the poppet balls can (and will) shoot out and fly all over the garage like a bb pellet on steroids.  Nice.  Happened twice.  Lost and then found my balls.
Both poppet balls are sitting on their respective springs next to the holes that they will be placed. 
Shift rails are in position to cover up the poppet balls. 
The shifting rails both run south to north (in the ablove picture) in the transmission box.  They have tiny grooves cut into them that will slide across the top of the poppet balls.  The springs will apply pressure to the balls which in turn will apply upward pressure on the shifting rails, thus helping to keep them in place and your vehicle in gear.  So, the tricky part is keeping the poppet and spring compressed while you slide the shift rail across the top of them.  A third hand would have been downright awesome.  A fourth hand could have patted me on the back, consoling me after shooting the balls across the garage.

When I was cleaning up the case before I began this assembly, one of the poppet balls were stuck inside the cavity.  I couldn't recall which one it was.  I guessed and inside this cavity I placed my new poppet ball and spring.  Well, it turns out that I guessed incorrectly.  It was the left hand cavity that had the ball stuck.  I know this because I place my new poppet ball in the right hand cavity...and the poppet ball in the left was stuck...again.  Well, it was a pain in the arse removing it with all of the gears in place.  However, with some clever finagling and duct tape, I was able to dislodge it without losing it.  I replaced it with another poppet ball and I instantly could feel the pressure on the rail.  This is good.
Both rails in place and poppet balls and springs are doing their job.
Cover, retainer and old throw-out bearing installed.  Extra parts in the background?!?
Now, one might ask, "Bo, why would you have painted your GPW transmission case Ford tractor gray and the cover with OD?"  And I would reply that I could not find any GPW markings on the cover, so it must be from an MB and MB covers were painted OD, not Ford tractor gray like the GPWs.  Also, please note that the cover and front retainers are setting in place.  I still need to install the required gaskets (in picture above) as well as replace the clutch throw-out bearing (big steel donut on the middle of the input shaft in the picture above).  As for the other extra parts pictured...I bought some duplicates...just in case!

Since you made it this far, wanna see something else?  Sarah says it is probably pornographic in my head...
This might have to be my "happy place."  Yes, they ARE building jeeps...back in the early months of 1942. 
Thank you to for finding this gem!
Now, onto that never-ending front axle.  The only things stopping me from finishing that project and installing it this weekend are my fantastic wife, my two kids and Tiger Woods PGA Tour 2012 for the Wii.  And not so much in that order. 

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