Dkruse
Well-Known Member
seeking opinions on which trans is better for racing short or long tail shaft? Please explain why you think which trans is better. Thanks David
Which trans is better for racing short tail shaft 727 or long tail shaft
- Thread starter Dkruse
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69_340_GTS
Well-Known Member
The best one is the one that fits in your car. All the guts are the same and they all work the same. I suppose that if whether or not the trans fits in the car does not matter, use the lighter/short one.
d55dave
Well-Known Member
Pretty much..... the short tailshaft is better for vans and trucks because that is what it was designed for and bolts into. Likewise the long tailshaft is better for cars, same reasons.
The internal workings are the same. Most shorties have heavy duty internals as they are truck transmissions.
If you dont know, the long shaft transmissions use a slip yoke output which is simple to use in a car. All cars used slip yokes. The shorties had a fixed yoke and are designed to use with a hanger bearing and 2 piece driveshaft.
I dont believe that, other than one bad hack job conversion, I have ever seen a shortie in a car.
The internal workings are the same. Most shorties have heavy duty internals as they are truck transmissions.
If you dont know, the long shaft transmissions use a slip yoke output which is simple to use in a car. All cars used slip yokes. The shorties had a fixed yoke and are designed to use with a hanger bearing and 2 piece driveshaft.
I dont believe that, other than one bad hack job conversion, I have ever seen a shortie in a car.
Just like what d55dave said. The 727 short housing is a fixed yoke for the U joint, no provisions for a slip yoke, I don't think you have a choice.
Would be a weight difference between the two, with a long tailshaft trans requiring a driveshaft with the two welded yoke ends, a slip yoke, and the shaft tube. A short shaft trans would require a driveshaft with a reversed slip yoke, a seal, a male splined welded end, the shorter shaft tube, and rear welded yoke end. Obviously both versions use two u-joints. I've got a short 727 in my A100, drive shaft u-joint to u-joint is about 20", no carrier bearing, it's design is just as described above. A longer two piece shaft in a car would likely require a hanger/carrier bearing setup one would assume. Heavy duty trucks I deal with all have two piece w/carrier so I would say there's a good reason for that, stability and strength, definitely not weigh savings. For a car, using quality tubing and welded yokes with the long tail trans would seem the better setup. Just a guess.
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