727 Extention Housing and Output Shaft may have bit it..

Engine, Transmission & Driveline

  1. Matt Gallant

    Matt Gallant New Member

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    So 2 years ago, my transmission let go and I kept putting off fixing it until now. I poured some ATF in to pinpoint the problem area and came across a cracked extension housing. My question is: it's a 1974 Monaco with a 440, what length of extension housing and output shaft do I need, and what parts/pieces should I order to go with replacing the housing? Bearings, seals etc..

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  2. thrashingcows

    thrashingcows Senior Member

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    Well that's not good...:( I would pull the tranny and tear it down, could be way more internally wrong then just a cracked tail housing.....they just don't crack for no reason. You weren't doing dukes of hazard jumps when this happened were you??? :wideyed:
     
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  3. Wollfen

    Wollfen Old Man with a Hat

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    It the output shaft needs replacing, you will have to pull the whole tranny anyway, so my thinking is you need to pull it first, tear the whole thing down and inspect it for any other damage internally. I know you didn't want to hear that, but it is the best route to go.
     
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  4. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

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    Your output shaft and planetary gears might also be damaged, the output shaft should be checked for run out as it may have been stressed enough to bend it. This type of catastrophic failure has a root cause someplace. As noted, check all the internals of the transmission. A broken motor mount will also sometimes stress the tail shaft enough to break it, so check the mounts as well. You should also consider a full rebuild of the transmission. You can reference the serial number on the transmission to order the correct parts. If the internals have been seriously damaged, you may want to consider finding another transmission as that would be cheaper to rebuild/repair.

    Dave
     
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  5. 73Coupe

    73Coupe Well-Known Member

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    727s are plentiful....it will be easier to go with a fresh plug and play unit + new TC. Change the u-joints while you're at it....
     
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  6. Matt Gallant

    Matt Gallant New Member

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    Thanks for the input everyone! I wasn't expecting any "good news" but I agree with all comments, perhaps just replacing the entire trans with a new one is the cheapest/best option. I'll also check my engine mounts as mentioned. Has anyone ever done polyurethane engine mounts? Wouldn't mind going that route if it's suggested
     
  7. Matt Gallant

    Matt Gallant New Member

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    Haha nope, just was determined to stay ahead of my friend in his Civic, it was a shallow victory hahaha
     
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  8. polara71

    polara71 Old Man with a Hat FCBO Gold Member

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    I had a catastrophic trans failure a couple years ago. Tail shaft blew apart. I needed to keep the numbers matching bell housing which I did. I bought another 727 and had the builder swap what was needed .
     
  9. thrashingcows

    thrashingcows Senior Member

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    A friend years ago had his driveshaft on his numbers matching 999 paint code 69 roadrunner drop from the rear axle and bounce around then came to rest wedged between the floor boards and exhaust, the poor trans came out in about 11 pieces. :(