zf-5 speed limitations?

93fordturbo

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How much hp and torque can a stock zf-5 speed handle. Putting a cummins in eventually and want to know how much i can build it up without building anything else up. So i guess what i am asking is.... how much hp and torque can the rest of my truck handle without having to be rebuilt? thanks guys
 

tractorman86

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Personally I am a little dissatisfied with my zf, the syncos aren't the greatest, I had all kinds of problems with tranny mounts so I built a lower crossmember and used two factory mounts and it broke the mount pad off of the tranny.
 

Dieselguy123

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It depends on if you have a zf5-42 or zf5-47, The 47 are from the OBS powerstrokes 94ish-97ish. I think the 42 Stands for 420 ft lbs of torque and the 47 is for 470 ft lbs of torque. I am not positive on that but someone who knows for sure will chime in. Also The 5-47 has a deeper first gear.
 

Diesel_brad

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I have personally seen a ZF5 s42 hold 500 hp and over 1000 ft lbs tq. At least 50k miles, and it was a tow rig

the zf5 s 47 is rated even higher
 

towcat

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in 980k logbook miles on my F450, I have went through three ZF trans. average gross wt. 15-17k lbs.
in my '92 CC dually, with a avg gross of 10k lbs, I've run it up to and held at 104mph for half a day. finally got caught 30mins outside of ElPaso by DPS.
 

franklin2

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Apparently the factory was not too confident in the zf. They put that overload clutch in the original dual mass flywheel. They didn't have that with the t19.
 

Diesel_brad

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Apparently the factory was not too confident in the zf. They put that overload clutch in the original dual mass flywheel. They didn't have that with the t19.

It was just to keep the noise down, that is the ONLY reason for the DMF
 

MUDKICKR

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Personally I am a little dissatisfied with my zf, the syncos aren't the greatest, I had all kinds of problems with tranny mounts so I built a lower crossmember and used two factory mounts and it broke the mount pad off of the tranny.

sounds like it might be a motor mount issue
 

franklin2

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It was just to keep the noise down, that is the ONLY reason for the DMF

Not true. There are two sections to the DMF. One section oscillates back and forth with the springs, the other smaller section down in the middle cuts loose if there is too much torque applied.
In the picture below, the smaller friction units on the left are the overload part of the DMF, the larger friction units on the right are the noise reduction friction parts of the DMF.
You must be registered for see images attach
 

tractorman86

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sounds like it might be a motor mount issue
The original mount problem probably was because I found on loose motor mount from when my shop swapped my engines. But I put new motor mounts in shortly before I did the crossmember.The lift and 35s don't help but I do end up playing quite a bit. That's why I want to put a 6speed with a divorced 205 in it
 
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The ZF-5 is know to be a very strong transmission. I agree that the transmission mount is a weak area, but overall a very bulletproof box
 

82F100SWB

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There are Cummins guys swapping ZF 5 and 6 speeds in now, while they tend to have syncros on the weak side, and the shift feel isn't the greatest, they do handle power, even better than the NV4500/5600.
The all famed NV4500 is only rated at 450 ft/lbs input torque, and it lives pretty well behind CTD's, they do break though.
 

Diesel_brad

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Not true. There are two sections to the DMF. One section oscillates back and forth with the springs, the other smaller section down in the middle cuts loose if there is too much torque applied.
In the picture below, the smaller friction units on the left are the overload part of the DMF, the larger friction units on the right are the noise reduction friction parts of the DMF.
You must be registered for see images attach

Thats odd. Never seen the smaller pieces of the DMF in the 10 or 15 I have seen come apart, just the large springed ones
 

franklin2

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Thats odd. Never seen the smaller pieces of the DMF in the 10 or 15 I have seen come apart, just the large springed ones


If you take it all apart for the "Lucky Mod" you will find it way down in the middle of the unit.
 
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