727 questions

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gtmopar

gtmopar

Phuckin A!
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Hey guys hoping someone can shed some light on a couple of questions. I'm switching over to auto from 4 speed and I'm not up on auto equipped cars. Found a real nice 727 at swap meet that I'm going to tackle a rebuild job on. The guy I got it from said it came out of a early 70's motorhome with a 360 but he wasn't sure what year. How can I determine what year it is so I can make sure I order the right year rebuild kit. He also said it had a weighted converter. I'm going to go with about a 2800 stall. Being that the old one was weighted what do I need to do about that? It's going to be a street strip use. What's a good rebuild kit. I want the toughest stuff because I'm abusive. Thanks guys
 
Look for the "PK" number on the pan rail under the selector area. List it here and someone will get back to you. What engine do you have?
 
Someone correct me if I am wrong but I thought I read somewhere that only problem is the tailshaft lengths. you would have to disassemble it and swap the shaft from a car 727 into them.
 
I have had 3 70s style motorhomes and they all had the standard 727 tailshaft on them....just gotta check...
 
I have a 727 and it must be out of a truck, the tail shaft is to long, have yet to find the right length of tail shaft for it
 
Not to worried about the tail shaft because I have to get a new driveshaft anyways. My main concern was the converter. I'll do a good inspection on it to see if I can find some numbers and post them to see what I came up with.
 
The problem with the short/long tailshafts isnt the length its the yoke attachment. On the short shaft its a bolt on yoke like on a rear end but long shafts have slipshafts for travel. As far as the convertor being weighted i dont think that will matter much. It was probably more for the engines benefit than the trans. I dont recall seeing any after market convertors listed as weighted or not so its probably nothing. Youll need to know if its a 12 or 14 roller sprag though. Not sure how to tell other than disassembly. Someone may know the signs of how to tell them apart visually
 
gtmopar said:
Not to worried about the tail shaft because I have to get a new driveshaft anyways. My main concern was the converter. I'll do a good inspection on it to see if I can find some numbers and post them to see what I came up with.
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As mentioned, the weights on the converter are there to balance the externally balanced 360 engine. If you use a 360 you'll either need a converter with weights or use a B&M or TCI flex plate that takes care of the balancing so you can run any neutral balanced converter. If the driveshaft connects via a slip yoke your ok. If it has a bolt on yoke it won't work in a car. I've seen both types in RV's.
 
dustinmoran91 said:
The problem with the short/long tailshafts isnt the length its the yoke attachment. On the short shaft its a bolt on yoke like on a rear end but long shafts have slipshafts for travel. As far as the convertor being weighted i dont think that will matter much. It was probably more for the engines benefit than the trans. I dont recall seeing any after market convertors listed as weighted or not so its probably nothing. Youll need to know if its a 12 or 14 roller sprag though. Not sure how to tell other than disassembly. Someone may know the signs of how to tell them apart visually
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I've never seen a 14 roller sprague in a 70's 727. I think they came out a lot later, like around 90. Only way to identify them is to take the trans. apart and count the rollers.
 
the early diesel three speed case has a 14 roller sprag but i don't know if it will retro into a older case. something to checkout when a guy has some spare time.
 
zijmer said:
the early diesel three speed case has a 14 roller sprag but i don't know if it will retro into a older case. something to checkout when a guy has some spare time.
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What years was that? I did a 89 Cummins 727 a couple yrs. back and it only had 12 rollers.
 
fishy68 said:
What years was that? I did a 89 Cummins 727 a couple yrs. back and it only had 12 rollers.
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i'am not sure. i'll check tomorrow. its been sitting around for years. i beleave it came from a 4x4. the sprag is in a plastic cage. it just drops into the case.
 
zijmer said:
i'am not sure. i'll check tomorrow. its been sitting around for years. i beleave it came from a 4x4. the sprag is in a plastic cage. it just drops into the case.
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Ok. If you got time that's fine. Was just curious. I've seen the plastic spragues listed. Don't think I'd trust them in anything perf. oriented, even low hp. Maybe there's something I'm missing??
 
mopardrt said:
I have a 727 and it must be out of a truck, the tail shaft is to long, have yet to find the right length of tail shaft for it
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Too long for what? The long tail shaft trans. trucks used is the same one that cars used. The only different 727 trucks used was a short tail shaft version with a bolt on yoke on the output shaft and used a 2 piece driveshaft with a slip yoke in the middle.
 
mopardrt said:
I have a 727 and it must be out of a truck, the tail shaft is to long, have yet to find the right length of tail shaft for it
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fishy68 said:
Too long for what? The long tail shaft trans. trucks used is the same one that cars used. The only different 727 trucks used was a short tail shaft version with a bolt on yoke on the output shaft and used a 2 piece driveshaft with a slip yoke in the middle.
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THIS

There is no such thing as a "too long" 727. All cars used the long shaft, which is a little bit longer than a 904, and will require a different yoke and shorter driveshaft.

IN FACT since the 727 installed is the same length as an A-833 4 speed, I've never understood why Mopar bothered with short shaft 4 speeds!!! in the A bodies
 
fishy68 said:
Ok. If you got time that's fine. Was just curious. I've seen the plastic spragues listed. Don't think I'd trust them in anything perf. oriented, even low hp. Maybe there's something I'm missing??
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hi, no, your not missing anything. its just the new way of doing it. 47/48re does the same. i would think if the oil got really hot it might melt the cage, but by then you would have more problems. anyways the number on the case is pk 4761867 1894 4158. hope someone can decode this. i thought i saw someone with a 16 roller bolt in sprag. ill try to find that again.
 
fishy68 said:
Too long for what? The long tail shaft trans. trucks used is the same one that cars used. The only different 727 trucks used was a short tail shaft version with a bolt on yoke on the output shaft and used a 2 piece driveshaft with a slip yoke in the middle.
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the only differance in extension houseings ive seen is the 1/2 ton truck dosn't have the two little tabs for the floor shifter bracket.
 
zijmer said:
hi, no, your not missing anything. its just the new way of doing it. 47/48re does the same. i would think if the oil got really hot it might melt the cage, but by then you would have more problems. anyways the number on the case is pk 4761867 1894 4158. hope someone can decode this. i thought i saw someone with a 16 roller bolt in sprag. ill try to find that again.
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That figures. Any way they can save a buck. Unfortunately I don't know where to decode newer stuff, only 86 on back. I imagine a dealer could do it. I believe A&A and Cope Racing Trans. (and probably more places that deal with high perf. torqueflite parts) sells a 16 sprague "ultimate sprague" as they call it. I haven't used one but think it's a drop in. Thanks for the info.
 
fishy68 said:
That figures. Any way they can save a buck. Unfortunately I don't know where to decode newer stuff, only 86 on back. I imagine a dealer could do it. I believe A&A and Cope Racing Trans. (and probably more places that deal with high perf. torqueflite parts) sells a 16 sprague "ultimate sprague" as they call it. I haven't used one but think it's a drop in. Thanks for the info.
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found that sprag. coanraceing of course. #coa-42801. $185.00 us.
 
six bolt would be better, but would it matter if your valve body had rear band apply in manual low?
 
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