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Hemi vs. HP 727 TF

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Neal Zimmerman

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Ok, this has probably been covered but here goes. Somebody gave me a big block 727 that had quit working. the pan rail number is 2801541 which traces to a 67-68 Chrysler/Dodge /Plymouth . I've taken it partially apart and it has 4 pinion planetaries front and rear. What else would distinguish a 440HP transmission over a standard 440 tranny?
Thanky
 
Does it have yellow paint on the end of the input shaft?
 
Yellow paint on the input is a hardened shaft. Though we run the normal run of the mill shafts at 900+ hp with no issue. Most BB 727 have 4 pin front planets. HD has 4 pin rear planets. Again we run 3 pin planets at high HP with zero failure. I've even seen 4 pin modified removing 2 pinions to use only 2 pinions. If a planet is going to fail it's usually the splines on the front planet. Other than that the rest will be number of springs in the front clutch, front servo, accumulator, KD lever ratio, governor and valve body calibration.
Doug
 
Doug, Im not questioning what you have seen. But how would just 2 pinions even work? There would be nothing to keep things centered up located, I would guess the planet and the sun gears would always be trying to collide. What was the trick there?
 
OOps , I forgot to mention that when I looked up the numbers it indeed said it was a 67-68 440HP trans. It has front and rear 4 pinion planetary sets, and a groove and yellow dot (barely) on the tip of the input shaft. according to my Carl Munroe book that was correct for HP and Hemi. Also the output shaft does indeed look darker ( kind of brown in a way) as he says the shaft should be due to extra heat treating. I guess I will dig in further as Munroe says it should have 10 springs in the front clutch piston as opposed to the more normal 9.
 
Neal Zimmerman said:
Ok, this has probably been covered but here goes. Somebody gave me a big block 727 that had quit working. the pan rail number is 2801541 which traces to a 67-68 Chrysler/Dodge /Plymouth . I've taken it partially apart and it has 4 pinion planetaries front and rear. What else would distinguish a 440HP transmission over a standard 440 tranny?
Thanky
Click to expand...
Just because the case has a number on it indicating it originally came in a 67-68 car does not mean whats inside is original. Through the years I built many and just used a case that fit the engine. No one knows whats inside until its apart.
 
pnora said:
Just because the case has a number on it indicating it originally came in a 67-68 car does not mean whats inside is original. Through the years I built many and just used a case that fit the engine. No one knows whats inside until its apart.
Click to expand...
This ^


Ive picked up 2 hemi specific 727s recently
1st a 1966 Unit had NONE of the hemi specific parts in it
2nd a 1968 unit appears to have at least the hemi front drum , But does not have the correct valve body
 
68-500 said:
Doug, Im not questioning what you have seen. But how would just 2 pinions even work? There would be nothing to keep things centered up located, I would guess the planet and the sun gears would always be trying to collide. What was the trick there?
Click to expand...
The sun gear centers it. The trans in my racecar was 2 pin when I traded for it. Came out of a NHRA 63 Max Wedge stock eliminator car. When I got it it was being used in a friends 64 Dodge Hemi car on the street. I didn't trust only 2 pins. Swapped to 3 pin. Been running 3 pin in my car for 13 years over 1100 passes. Car runs 9.0@3370lbs
Doug
 
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