TECH – Toploader Transmission Takedown


Gas Pony Jack is a old friend and new contributor to Cars Illustrated, plus a true do-it-yourselfer…so check out this story of his quest to know the insides and outs of the infamous Top-Loader trans and what it take to get one back to perfect working order on a budget – the Janitor

When shopping for a new gas pony for the street, every fuel-blooded American knows one of the requirements should always be a third pedal.  Automatic muscle cars are great, and they get the job done, but this time around, we are talking about that thrill of stabbing at a clutch while jerking away at a shift lever.  This project Stang fit the bill; it was indeed a stick car – but only three gears to choose from.  The Toploader 3-speed is great, shifting smoothly and giving no problems whatsoever.  The meaty heft of the gears allows you to shift with confidence knowing it can take whatever power the engine can throw at it.


But that absent 4th gear leaves a big hole to be filled.  Nobody has ever composed a song about or otherwise glorified a 3-speed manual.  No, the much beloved manual transmission craves for all four and so, for afirst gen Mustang, that means a different Toploader. The notable Toploader 4-speed.  The hunt was on again, but this time with sights set on a unit with an H pattern and a lockout reverse.  Something that could be rebuilt while keeping a tight budget in mind.  Something that could give the satisfaction of a hands-on resurrection.  Having not yet added transmission repair to the list of “did-it-myself”, this was the perfect opportunity for a learning experience.

With a little time and patience the right box for the job popped up in Issaquah, Washington.  It was a three hour drive each way, but it was a good deal and avoided expensive shipping.I loaded more music than Elton John’s record collection and tossed a plastic tub into the back of our dreary commuter car and blasted off to gather my parts.

One of the wonderful things about a Toploader is that it is as simple as cracking the top on a can of soda to do a quick and easy visual inspection of the gears themselves.  A great view of the gears, synchronizer hubs, shift sleeves, blocker rings, shift forks, and more can be had by merely popping off the top cover, whichtl2 isn’t obstructed by any gear shift levers or rods.  If any of these crucial parts are majorly worn or broken,that could lead to an expensive rebuild.If you’re in the market for a rebuildable manual transmission, keep in mind that replacing the non-consumable parts like a cluster gear or main shaft can grenade a tight budget.After inspecting the tranny carefully to make sure it wouldn’t need any key components replaced, I concluded that it would only need a simple rebuild kit.  Perfect for this project.

Job number one was to get the new heap of grimy cast iron blown apart for closer inspection and cleaning.  Thankfully this yielded no surprises.  Other than a few synchronizer hub teeth that used to have a little more bite to them, everything looked great.  So first things first, the main case and tail housing got a bath.  The same tub I transported my project in became a hill-billy parts washer.  Like Betty Crocker gone mad from sniffing too much nitro, I created my own ‘proprietary’ blend of cleaning solution; start with a gallon of carb cleaner, add a few dashes of paint thinner, and a splash of lacquer thinner, then a spritz of brake cleaner for the bouquet and a nice aftertaste.

After the parts took an extended vacation at their own personal spa, they were ready to emerge from the primordial goo to be tl3scrubbed and rinsed.  As always, a good helping of elbow grease always produces the best results.  This is a good time to really give them another close inspection looking for any cracks or damage that may have been hiding under the sludge.  Get up close and personal with your parts.  You’re asking a lot from them!

Once everything is ready for reassembly is when the fun really starts.  A little Google-fu can lead you to a standard parts kit that comes with excellent instructions and everything needed to complete the job.  The best thing about tackling a task such as this is that it provides so many great learning opportunities along the way.  Questions like “How do they get all those needle bearings to stay in place during assembly?” are answered with a simple tube of sticky grease.  “How do the synchronizers get lined up during a shift?” With little shift dogs so simple it makes you wonder why you ever thought rebuilding a manual transmission would be mysterious or difficult.  While following along and completing the rebuild you will want to inspect and detail every part; filing burrs or buffing edges where needed, giving those synchro hubs the bite back to their teeth, manipulating the pieces, working them, polishing them, understanding how they move and mesh together, feeling and ensuring that every action was as smooth and as crisp as the OEM had intended.  Or better.

The finished result is a beautiful and silky 4-speed which has now racked up several thousand miles of hard driving.  It can be driven confidently and without a second thought knowing that it has been built to your standard, your  level of detail, because as the old adage says; If you want it done right, you better do it yourself.  So when the tree goes green and you are fiendishly yanking and shoving the stick like a Big Daddy Roth cartoon character with that devilish grin on your face, nobody else will know if it is the pure joy of driving a manual transmission, or the satisfaction of knowing it was a job well done – Gas Pony Jack





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