Rebuild or Swap 727 transmission?

rattlenbang · July 08, 2014, 04:05 PM

Looks like I toasted the tranny on my 73 Empress. Combination of heat, traffic, very steep hill and fluid leak caused it slip and quickly burn out clutches. I'm considering rebuilding it, but the other option is to just find another 727 and pop it in. The chances of my getting a MH version with the brake is pretty much nil, so I was wondering if it's possible to just swap the tranny ends? Replace the tail of a generic 727 with the MH one with a brake?

pvoth1111 · July 08, 2014, 04:19 PM

usually tail housing swaps are a little more involved new tranny taken apart internal shafts etc swaped to the new one,,, I would just have your rebuild by a great tranny guy...with maybe some upgrades along the way....you can rebuild and seal the E-brake while your at it...you could pull it yourself and take it to get rebuilt....many good tranny shops have dynos they can run your tranny one test it adjust it and give it back to you and you know it works with no worries....

LJ-TJ · July 08, 2014, 05:08 PM

If you want to save yourself a lot of headaches, step one, check on Craig's List for a bolt in replacement and step two if you can't find one with the brake then just do a straight swap. You'll save yourself a lot of time,money and frustration. TRUST ME

tiinytina · July 08, 2014, 06:42 PM

Trust TJ... some mechanics are like PO's we rant about here.. what they say "they can do" and "know" how to do , is in many cases not even close proximity to reality... and and in the end 2-10x $ to fix what they screw up. These old gals are a special breed.... you might try http://www.uneedapart.com poke in what you need and junk yards all over the place will email you with what they have that matches etc... just an option.
Tina

rattlenbang · July 08, 2014, 08:32 PM

A local guy has a low mileage long shaft tranny...would that take up the space currently used by the brake unit? I'm not at all familiar with the different versions available. It would seem that a typical car tranny would be too short, given the space taken up by the brake unit. Of course that also means no e-brake...I really want to avoid the crazy cost of a pro rebuild, which would cost twice what I paid for the MH. I might consider doing it myself, although that's the one repair I have very little experience with.

rattlenbang · July 11, 2014, 08:10 PM

Found a rebuild kit for $155.00. Can't pass that up. This will be my first tranny rebuild. Should be fun.

pvoth1111 · July 11, 2014, 08:40 PM

155 for a kit seems high to me.....I would take it to a real trans pro and give em 800 and get a guarantee......good luck to ya....better get a book and read it....

Froggy1936 · July 11, 2014, 11:03 PM

That price for a rebuild kit is very good if it includes all the lined and steel clutch plates You cannot eliminate the parking/emergency brake So a rebuild is the best option . Get a manual and follow it replace all thrust washers/ torrington bearings replace as many bushings as possible especially frt pump Try it on the convertor after replacement to make sure it fits before installing frt seal Replace all clutch seals match them up to make sure you use the correct one in ea position there are a lot of very simular sizes but not exactly the same Use assembly lube or vaseline Before installing the valve body you can air check all band and clutch operations The manual should show air application locations Kerosine is a good solvent for cleaning With carb cleaner for stubborn areas Cleanliness is important Good Luck Frank

rattlenbang · July 12, 2014, 01:01 AM

That kit does include all bearings, bushings the front band and all clutch plates and all seals. The rear band is extra but doesn't usually need replacement. There is a whole series of videos on the basic assembly/disassembly (although it seems strange to start by removing the tailpiece first) at https://www.youtube.com/user/Autotransmissions/videos watching this gave me reassurance that it's not too crazy complicated. I also have the manual. I don't foresee any problems, but then I'm an optimist, like anyone else who goes on vacation in a 41-year-old motorhome.

Froggy1936 · July 12, 2014, 09:42 PM

That is a very good video and the kit also has everything you will need . Since you saw how easy it is to created the conditions that will destroy a tranny that has any weakness .you also should consider installing an auxillary oil cooler and a deeper pan for extra fluid . The Torqueflyte is one of the easier trannys to rebuild Frank

rattlenbang · July 12, 2014, 11:36 PM

ironically, it was an aux cooler that caused the tranny's demise. I was aware of an oil leak at the pan that I was going to get to soon, but meantime I was watching the engine oil level like a hawk. Turns out it was actually a leaking cooler line with tranny fluid running down the pan, picking up dirt and looking dark by the time it hit the ground. D:oH!

rattlenbang · July 14, 2014, 01:54 AM

Tranny is out. The brake cable seemed frozen in place so I had to pull it from the other end. [smg id=6679]

Rebuild kit.
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rattlenbang · July 15, 2014, 10:38 AM

As suspected, the rear clutch was toast. Actually,burned to a crisp.

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And here's the culprit: the clutch piston seal had fragged itself, preventing it from apply adequate pressure to the clutch disks. Amazing how a small, 50 cent part can take out a whole transmission.

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Stripe · July 15, 2014, 07:11 PM

How does one go about checking that part to see if it's good to go?

rattlenbang · July 15, 2014, 08:14 PM

Only with a tear-down, after which you might as well replace it. But many, many years ago I recall an old tranny tech telling me that transmission seals often go hard over time (symptom in my case was a delay in going into gear), and they can be helped a lot by adding seal softener to the tranny fluid. I thought I was looking at a rebuild, but a bottle of that stuff and my problem went away as long as I had that vehicle. It's the only "repair in a can" that I've ever found to actually work. So for our very old trucks, adding some seal softener might be a good practice to keep them on the road a little bit longer.

pvoth1111 · July 15, 2014, 08:26 PM

heat kills fluids kills seals kills transmissions

rattlenbang · July 16, 2014, 10:36 PM

After a mighty struggle, we got the transmission back in old Thunderbutt, and it works great. Needs a few adjustments still, but it shifts nice and solid; better than before (naturally). Total cost, $200 Ca for rebuild kit and fluids, and 2.5 days work. One less thing to worry about now. Only hitch was the output seal in the kit was for a yoke output, not the brake drum but the FLAPS had one on the shelf. Overall it wasn't a difficult job, but there sure was a lot of parts to keep track of, and having to makeshift a compressor for clutch springs and devising something to replace the inch-pound torque wrench for the bands.

Lots of parts!
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