ZF6 Install

[superduty4x4]

Most people do not consider their girlfriend as a load that needs to be hauled, so what do you consider "SUPER large"?

BWAHAHAHAHAHA!!!!!!!!! I just sprayed my screen and keyboard with coffee.
LOL wned:

I just did a clutch on a ZF6 and didn't even think to look at the adapter. I'm going out to measure the ZF5, then I'll measure the ZF6 later, that's much needed info for a swap.

The ZF6 is definitely significantly larger (and apparently a lot stronger), but I'm not sure it's any taller from the center line as far as requiring floor pan modifications, I could be wrong. Several people have done this not sure if any of them are here.

I can't recall anyone having gone from a ZF5 to a ZF6 needing to mod the floor pan, the guys that swap their auto for a ZF6 usually run into issues.

 

[strokin'_tatsch]

I've driven several ZF6 trucks and I have to say that I like them better than my ZF5. The gears are closer together, definitely get a load moving easier, and final drive(OD) is better also. Like Chase already said, the ZF5 cruising down the highway puts you at pretty high RPMs. With 3.55s, mine cruises at more RPMs than an E4OD with 4.10s. The ZF6 also has a larger input shaft than the ZF5. For those of us that plan to run bigger power, we all know that the ZF5 input isn't the best for a 500+hp truck. If it wasn't such a PITA, I would switch to a ZF6 all day over my ZF5.

 

[Karbman]

I have a zf5 and my wife has a sd with a zf6. I like them both, but I prefer the zf5. Simply because I don't have to do as much shifting. There's no need to get technical. Different strokes for different folks is what I say.

 

[superduty4x4]

I've driven several ZF6 trucks and I have to say that I like them better than my ZF5. The gears are closer together, definitely get a load moving easier, and final drive(OD) is better also. Like Chase already said, the ZF5 cruising down the highway puts you at pretty high RPMs. With 3.55s, mine cruises at more RPMs than an E4OD with 4.10s. The ZF6 also has a larger input shaft than the ZF5. For those of us that plan to run bigger power, we all know that the ZF5 input isn't the best for a 500+hp truck. If it wasn't such a PITA, I would switch to a ZF6 all day over my ZF5.

PITA??? You've got the 2 wheel peel model, it should be a super simple swap for you.

 

[strokin'_tatsch]

PITA??? You've got the 2 wheel peel model, it should be a super simple swap for you.

Swaps are almost never as simple as they might seem. :lookaround:

 

[Big Bore]

Swaps are almost never as simple as they might seem. :lookaround:

Yea, but not having to deal with a transfer case and front yoke issue makes it at least half as easy. LOL

 

[strokin'_tatsch]

Yea, but not having to deal with a transfer case and front yoke issue makes it at least half as easy. LOL

To tell the truth, a ZF6 swap may be in my future if the 5 won't hold up to launching on slicks. We have one guy already that has broken an input shaft w/ 350hp in a crew cab 4x4 dually while racing from a roll. So, I'd say I have a pretty good chance of breaking it after the parts on the shelf start making their way on the truck. LOL Hopefully being lightweight will work for me and keep the ZF5 together b/c I'd rather not do the swap if I don't have to.

 

[Big Bore]

Damn thats weird, mine was running around 350 and I used to wind it up and dump the clutch with massive wheel hop etc and I was actually shocked it didn't break something.LOL

 

[strokin'_tatsch]

Damn thats weird, mine was running around 350 and I used to wind it up and dump the clutch with massive wheel hop etc and I was actually shocked it didn't break something.LOL

I do that in mine also and trap speed puts mine right around 400hp, dyno says 380hp. His CC 4x4 dually is quite a bit heavier than my regular cab 2wd though. @ 6400lbs, I don't think it has enough traction to hurt the transmission yet. LOL

 

[morefuel]

I figured out the OD final drive and the 1st final drive with the different gear ratios.
zf5 Has a .76 OD and a 5.72 first
Rearend OD First
3.55 2.698 20.306
3.73 2.835 21.336
4.11 3.124 23.509

zf6 Has a .72 OD and a 5.79 first
rearend OD First
3.55 2.556 20.555
3.73 2.686 21.597
4.11 2.959 23.797

Hopefully that helps you all.

 

[Big Bore]

zf5 Has... a 5.72 first

No, that is a gas trans, diesel ZF5 1st is 4.14 and 1,2,3 are all different between the two, which makes all the final drive ratios different.

 

[Buffalo444]

I figured out the OD final drive and the 1st final drive with the different gear ratios.
zf5 Has a .76 OD and a 5.72 first
Rearend OD First
3.55 2.698 20.306
3.73 2.835 21.336
4.11 3.124 23.509

zf6 Has a .72 OD and a 5.79 first
rearend OD First
3.55 2.556 20.555
3.73 2.686 21.597
4.11 2.959 23.797

Hopefully that helps you all.

Based on the numbers the zf6 wins hands pretty easily. If that extra gear REALLY bothers you that much I suppose its worth it to get a zf5 instead.

 

[Big Bore]

Based on the numbers the zf6 wins hands pretty easily.

Except his numbers for the ZF5 were way off, when the actual numbers are used the ZF6 is even better.

Rearend OD First
3.55 2.698 14.70
3.73 not available
4.11 3.124 16.97

zf6 Has a .72 OD and a 5.79 first
rearend OD First
3.55 2.556 20.555
3.73 2.686 21.597
4.11 2.959 23.797

 

[Big Bore]

Here is a link to Gear Vendors site with a complete breakdown of the trans ratios. I posted it earlier but seems a repost is in order.

http://www.gearvendors.com/4x4fmanual.html

 

[Buffalo444]

Except his numbers for the ZF5 were way off, when the actual numbers are used the ZF6 is even better.

Rearend OD First
3.55 2.698 14.70
3.73 not available
4.11 3.124 16.97

zf6 Has a .72 OD and a 5.79 first
rearend OD First
3.55 2.556 20.555
3.73 2.686 21.597
4.11 2.959 23.797

Touche, but wouldn't it be the zf5 IS offered with 3.73's behind it (they had the zf5 for e99's) and 3.55's not available for the zf6 (I do not recall and OBS zf6)

Which even be that standard, a zf6 behind a 7.3 with 3.73's has a better reduction in OD than a zf5 behind a 7.3 with 3.55's... and 1st/low isnt even a contest...

 

[Big Bore]

Touche, but wouldn't it be the zf5 IS offered with 3.73's behind it (they had the zf5 for e99's) and 3.55's not available for the zf6 (I do not recall and OBS zf6)

Which even be that standard, a zf6 behind a 7.3 with 3.73's has a better reduction in OD than a zf5 behind a 7.3 with 3.55's... and 1st/low isnt even a contest...

There are SD's with 3.55's and ZF6. Not sure what you mean by OBS not being offered with ZF6, that is a given. I don't know about the 3.73's and ZF5 in OBS, but the Gear Vendor site does not list that ratio, I'm assuming there is a reason for that.

 

[morefuel]

My bad on the first gear ratio but then I believe with the 4.14 first gear ratio the zf5 has a .77 OD. I wasn't sure whether or not we had the wide ratio or the close ratio trans.

 

[Buffalo444]

There are SD's with 3.55's and ZF6. Not sure what you mean by OBS not being offered with ZF6, that is a given. I don't know about the 3.73's and ZF5 in OBS, but the Gear Vendor site does not list that ratio, I'm assuming there is a reason for that.

I did not know that. I could never find a axle code for a 3.55 SD axle so I didn't think there were any. And everyone keeps hemoraging at me that there were zf5's behind e99 diesel (not this site, another) so I'm guessing it would have to have been appicable.

Btw I'm not trying to argue, I'm just trying to learn here and sharing what I've been told.

Those Gear Vendor units, I hear they are kinda weak. Any truth to that?

 

[Big Bore]

I believe with the 4.14 first gear ratio the zf5 has a .77 OD.

All ZF5 have .76 OD

I wasn't sure whether or not we had the wide ratio or the close ratio trans.

We have the close ratio because of the narrower power band.

 

[Big Bore]

I did not know that. I could never find a axle code for a 3.55 SD axle so I didn't think there were any. And everyone keeps hemoraging at me that there were zf5's behind e99 diesel (not this site, another) so I'm guessing it would have to have been appicable.

Btw I'm not trying to argue, I'm just trying to learn here and sharing what I've been told.

Those Gear Vendor units, I hear they are kinda weak. Any truth to that?

Somewhere earlier in this thread someone discussed their SD with 3:55's. It's also listed on Gear Vendors site. I'm not saying GV is the last word, but they are qualified expert source in the gear ratio field.

I have no idea on the strength of the GV but I always thought it was supposed to be very strong. I have no intention of running one because it cant be used in 4x4 and my truck spends most of the winter on icy roads in 4x4. If I had a need for a splitter hauling loads, I would need it just as much in winter. I have heard in the past that the now discontinued US Gear had some strength problems.