ZF6 speed?

[Niro]

just wondering how difficult it might be to swap a ford zf 6 speed into a 98 12 valve 4wd etc...

 

[FordCummins]

It would be doable. A new bellhousing adapter would be needed, and undoubtedly some driveshaft work, Im not sure if the Tcases would bolt right up or not. The clutch hydraulics would be easy enough if the truck is stick already. My only question is, why? The NV trannies would be bolt in, and arguably stronger. Assuming a 1 3/8" input shaft is used, and the upgraded clutch to 13. 25" (or whatever the big Dodge one is), the NV will never give you any problems.

 

[Niro]

the reason I asked is that I had called up dans (quad 4X4) and he told me the max torque on his trannys is 650ft/lbs



Im not looking for the 5600 because I heard its hard to shift quickly, Ive heard the ZF6 is bulletproof, so I just thought it might be an idea



my other idea was swapping a 12 valve into a superduty...

 

[LNeshem]

I disagree about the ZF being bullet proof? In my experience they are a bit on the fragile side. Also they are even slower shifting than a 5600. I would either run a 4500 that had a fully splined main shaft or the 5600. Just my 2 cents.

 

[Niro]

hey Im just going from what i read



I know tons of guys on this site with over 650ftlbs in their nv4500 and no problems



but Im scared about the dreaded 3rd gear breaking as well...



and like I said Dan from quad 4X4 who is basically the guru on these trannies told me that the max torque for it to be reliable would be about 650ftlbs...



this is with his torque king rebuild

 

[JUeckert]

there is a guy on the diesel garage,aswell as the cummins conversion web site that goes by the name of cummins superduty. he has the zf behind a commonrail,really likes it,and explains why he chose it over the 5600. personally i like both the trannies,but if i had to choose it would be the zf. lower first gear ratio,lower reverse gear ratio,and has not been discontinued. the 5600 in my dodge is crankier to shift than the zf in my 02 ford,but not enough difference to effect performance. memory servers me correct,the zf is rated to handle a little more trq also,but i know a coupl folk running 5600 trannys behind modded cummins engines with no issues.

 

[12V Ford]

I really love the zf-6 speed. Oo. I have one behind by 96 cummins in my 95 ford. The zf-6 and NV5600 are rated at the same GCWR of 26,000#, but I do think the zf is rated for more torque by the factory. I have been on zf's website and they also have the same transmission rated for 750# that is used in heavier duty stuff. You can get that one with a seperate bellhousing which would be cool if you could get a bellhousing to bolt right up to the cummins. Another plus is that they come with an oil pump that pumps to a transmission cooler radiator so they don't get hot. I think they shift faster than the NV and mine is liking the SBDD.

 

[firemanmarc]

You can get a ZF that will bolt right up. You get that heavier one you talk about that has a SAE #3 bellhousing, like that found on the Freightliner trucks... . Marc

 

[FordCummins]

Any more info on these heavier ZF6s that will bolt up? Id love to have a heavier ZF in my pickup. Any specs on this trans, or a model year that it came in a certain application? Thanks for any help.

 

[JRMora]

I disagree about the ZF being bullet proof? In my experience they are a bit on the fragile side. Also they are even slower shifting than a 5600. I would either run a 4500 that had a fully splined main shaft or the 5600. Just my 2 cents.

This is the same transmission in the F250/350? When I drove one around, I had a heck of a time getting from 1st to 2nd launching a load. I'd lose most of my momentum trying to find 2nd. With my NV it's a straight shot. I suppose if you're not going to use 1st a lot it isn't so bad. Maybe it was just the truck I was driving.



Juan

 

[FordCummins]

The 1st to 2nd shift is a bit awkward, but like you said using the 1st gear unloaded doesnt happen, starting in 2nd is what is recommended. My ZF6 with 220k on it, has a fairly loose shifter after all that time, and I still cant shift it fast, but I also dont try to. What Ive found on my truck, and our 05 F250 with a ZF6, is that just making a slow shift from 1st to 2nd is the best way to get it done. 1st just gets the load moving, then 2nd 3rd and 4th can really be used to get some speed built up.