Which 5 speed would you choose?

[jaluhn83]

No, not S47 vs S42, I meant more the 'well it works in a 500 hp gasser pulling truck so it must be tough enough for a turbo diesel'

 

[ZWilson07]

No, not S47 vs S42, I meant more the 'well it works in a 500 hp gasser pulling truck so it must be tough enough for a turbo diesel'

Oh yeah definitely not.

The way I look at it is, if you have a modified turbo idi and you beat on it or tow with it, then an s42 or s47 on borrowed time. Yes it may last a while but eventually it will wear out so just be keeping funds for a rainy day when it finally goes to build it stronger and be done with it.

 

[jaluhn83]

Heck, any trans thats beat on is going to fail eventually....

Going to disagree a bit with you - I think we have a pretty good record of turbo idi's pulling heavy with stock s42 trannies without major issues, and likewise the PSD guys have a pretty good record with the S47 and stock to modified psd motors.

S42 is rated to 420 ft/lb input, S47 to 470. A turbo idi probably isn't much over that, if at all. Now, if you're going to get really crazy with the motor or pull super heavy loads all the time it might be an issue, but I think 98% of us on here are fine.

Personally I'm happy I found the S47 with the setup I'm running, but more cause it gives that extra comfort factor then cause I really think it's that critical.

 

[ZWilson07]

Heck, any trans thats beat on is going to fail eventually....

Going to disagree a bit with you - I think we have a pretty good record of turbo idi's pulling heavy with stock s42 trannies without major issues, and likewise the PSD guys have a pretty good record with the S47 and stock to modified psd motors.

S42 is rated to 420 ft/lb input, S47 to 470. A turbo idi probably isn't much over that, if at all. Now, if you're going to get really crazy with the motor or pull super heavy loads all the time it might be an issue, but I think 98% of us on here are fine.

Personally I'm happy I found the S47 with the setup I'm running, but more cause it gives that extra comfort factor then cause I really think it's that critical.

Yeah you're right, for some reason I was thinking of RacinnDrummin's type of builds; I don't know why I was only thinking of them.

 

[racin460]

so after following this thread for a little . To answer the original question that was asked, id run what ever you can find at a decent cost. what do you prefer is more on experience of what you know about the transmission and your likes. So I went to all three trucks that I own and crawled under them and took a pic of the tags. this is my opinion. I have a 90 f350 ccsw 460 the trans came out of an 88f350 cab & chassis 4x4 the tag is crowded off iv pulled lots of trailers with it first gear is totally useless so low you cant use it if you do you have to shift before you let the clutch all the way out and the jump to second is so big that you miswell pull out in second and reverse is so high I have to use 4 low to back it up slow. I got a 90 f250 351w 2wd same thing the tag reads its an s5-42 total ratio 5.72-0.76.i feel you back up about 20mph. My project truck 93 f350 ccdrw 4x4 7.3l the trans came out of an 88 f450 sd the tag reads its an s5-42 total ratio 4.14-0.77 I haven't drove it yet because its my project truck im hoping that first gear isn't as low and reverse is a little lower than the 460 truck I pull with now.

 

[idiabuse]

Correct me if I am wrong, but I believe the one tranny is stronger(the close ratio) because there is less ratio in the 1st gear. In other words, both trannies are the same, same case, same guts. But the higher torque multiplication in the lower 1st gear of the one tranny, means they have to rate it at a lower input torque, because it has more advantage with the lower gear and could break something easier in the tranny.

I have seen this on the T5's in the mustangs also. The 4 cyl tranny in the SVO I had was the same tranny the v8's had, except it had a lower 1st gear for the 4 cyl to get going. Everything was the same except the ratio, and I am thinking because of this the reason the 4 cyl tranny was also rated lower.

Mustang T-5s are different, the difference is the amount of teeth.
More teeth for the 4cyl unit=thinner teeth=weaker unit. both main shaft and cluster have more teeth.
Input shaft on the 4cyl had a larger input bearing yet more teeth "thinner teeth"=weaker
Generally we don't touch the 4cyl boxes unless it is a full rebuild which is rare cause them guys R CHEAP

 

[FarmerFrank]

so after following this thread for a little . To answer the original question that was asked, id run what ever you can find at a decent cost. what do you prefer is more on experience of what you know about the transmission and your likes. So I went to all three trucks that I own and crawled under them and took a pic of the tags. this is my opinion. I have a 90 f350 ccsw 460 the trans came out of an 88f350 cab & chassis 4x4 the tag is crowded off iv pulled lots of trailers with it first gear is totally useless so low you cant use it if you do you have to shift before you let the clutch all the way out and the jump to second is so big that you miswell pull out in second and reverse is so high I have to use 4 low to back it up slow. I got a 90 f250 351w 2wd same thing the tag reads its an s5-42 total ratio 5.72-0.76.i feel you back up about 20mph. My project truck 93 f350 ccdrw 4x4 7.3l the trans came out of an 88 f450 sd the tag reads its an s5-42 total ratio 4.14-0.77 I haven't drove it yet because its my project truck im hoping that first gear isn't as low and reverse is a little lower than the 460 truck I pull with now.

To answer you i decided to go with the Diesel s47. i already have 2 gas s42 and one diesel s47. the lower reverse gear and the little bit faster first have my attention along with the closer gearing to 3-4 shifts