ZF5 decisions. expert advice sought after.

[dunk]

Just curious, do you know how much torque an S5-42's seen and been demonstrated to accept long-term, beyond the factory ratings?

Never ran my 460 on a dyno but DesktopDyno says:

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I've broken I think three S5-42 transmissions. They tend to break when shock loading them like barking 38s too many times on the 2-3 and 3-4 shifts, suddenly catching while spinning off road, tugging stuck trucks out. Always case or mount failures and always seemed to coincide with shock loading. Never broke one driving normally, that is accelerating briskly and shifting at ~1800 RPM. FWIW the last one in that truck was still going strong after 2 years of use/abuse. Trans failures did seem to increase after upgrading to 1350 joints, though ujoint failures sharply dropped off. I think the key is don't shock load them if you got an engine that makes torque.

 

[franklin2]

Well, I have heard you can even break the cast iron t19 if you rev the clutch and dump it on dry pavement with it in 4x4. Had a guy ask one time why it broke. But I think it did break something inside and not the case.

 

[Kevin 007]

Well, I have heard you can even break the cast iron t19 if you rev the clutch and dump it on dry pavement with it in 4x4. Had a guy ask one time why it broke. But I think it did break something inside and not the case.

I cringe at the thought of doing something like that...

 

[dunk]

Ha. Never sidestepped the clutch on a truck. 6k lbs with lots of rubber on the ground and lockers is enough that I consider that asking for trouble. Never had a T19 but I have had a few NP435s, beat 'em pretty hard and never broke one. Never done anything I'd consider outright flagrant asking for trouble or abuse though, just as I haven't with a ZF... Yet the ZF breaks regularly. I've considered an NV4500 may be a more prudent trans choice for overdrive, but still they're only rated at 460 ft/lbs... Not overly concerned with my IDI though as I don't think it'll be making that much torque any time soon.

 

[IDIoit]

im no stranger to beating the pavement with 31 x 12's but its usually in somthing i dont mind breaking seeking thrills.
since my truck weighs in at 6200 lbs, clutch dropping is kind of like biting an ear in a heavy weight bout.
my 7.3 will not ignite the tires like my 1600 pound/ 550 hp car, i wont even try it.

i have a south bend clutch conversion kit on is way.
should be here tuesday.
now all i need is transfer case gaskets and hope that everything i have read is correct and i wont need to change internals.