Transmission swap; NV4500, G56 or ZF6
10-29-2009, 04:27 PM
#16
Well I will throw my $0.02 in here. Before I had my 1st Gen I had a '01 F250 with the 7.3L and the ZF6. I loved that combo and if I can ever find that truck for sale again I will buy it back no questions asked. It was a very short throw into the gears and the power splits were very nice especially when towing or running. 2nd (which FoMoCo calls 1st because they call "1st" Low Gear) seemed a little too high for towing starts but for everyday driving it wasn't bad. I wasn't putting gobs of power down as I was running a MBRP, Edge Evo programmer, and occasionally stacked a 10k mod on for good measure. With that said, the transmission was rebuilt at 72k miles not because it failed, but because when I put in my ceramic clutch I had chatter and had a trannie shop look at it...they said that there was some scoring on the input shaft and the synchros were worn. That repair cost $1200 and that was a cash money under-the-table friend price. I was told that the synchros are synthetic and are about $100-150 each. The transmission does have ports for auxiliary cooling and I *think* they also have a pump to circulate the fluid. Oh and the shift pattern is like this:
R-2-4-6
L-3-5
R-2-4-6
L-3-5
10-29-2009, 06:13 PM
#19
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10-29-2009, 06:38 PM
#20
Having the shift pattern like that also makes it easier to maneuver when hooking up a trailer by yourself or trying to negotiate into a parking spot. The only thing I disliked about the transmission was it seemed like th reverse ratio was too high...but I like a deep reverse so maybe it was just me.
10-29-2009, 10:22 PM
#21
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I have located a couple of newer g56s and zf6s. Since I have yet to see a zf6, any one have any dimensions on one?
Will the 205 transfercase have the same bolt pattern as a zf6?
Will the 205 transfercase have the same bolt pattern as a zf6?
10-30-2009, 12:16 AM
#22
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A little more info.
From what I understand the GM ZF6 has the 29 spline output but, it is very rare and the stock bellhousing does not fit over a Cummins flywheel. If it can be found, would need a Ford bellhousing.
The ZF6 in Fords have a 24 spline output if it came from a 7.3 and a 34 spline output behind the 6 liter.
From what I understand the GM ZF6 has the 29 spline output but, it is very rare and the stock bellhousing does not fit over a Cummins flywheel. If it can be found, would need a Ford bellhousing.
The ZF6 in Fords have a 24 spline output if it came from a 7.3 and a 34 spline output behind the 6 liter.
Ive driven a few 6 speed gm trucks - they shift real funky and not very smooth.
My buddy had one and nuked it a with a 60hp chip
10-30-2009, 07:55 AM
#23
The GM ZF6's all have dueal mass flywheels. My cousin had a '04 Dmax 4x4 with the ZF and though he loved it, the trannie was shot with about 50k on the truck. Don't know if it was the whole trannie or just the clutch but he traded and got an Allison. I drove it a few times and the trannie didn't seem to shift any different than the one in my F250. They do take some getting used to since the throws are shorter and the points are narrower.
10-30-2009, 02:04 PM
#24
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I just drove my first G56 in an 05. Very smooth and much closer than a Getrag.
I was just thinking for racing the 2nd 3rd shift is the hardest to make which is why the ZF6 looks appealing.
A guy on Comp D just ran a 11.92 @ 113 in his 05, 6000lb, ZF6, triple disc Duramax.
I was just thinking for racing the 2nd 3rd shift is the hardest to make which is why the ZF6 looks appealing.
A guy on Comp D just ran a 11.92 @ 113 in his 05, 6000lb, ZF6, triple disc Duramax.
12-08-2009, 12:15 PM
#26
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G56 gear cluster swap
I am disappointed with my G56 overdrive ratio. Until this thread I was not aware that there were different gear ratio's for the G56. Mine is a 2006 behind the last 5.9 Cummins. Will the gears and cluster from the 2007.5+ g56 transmission (with 0.74 overdrive) fit into my gear case and on the existing shafts? Any support in locating a source for this gear set would be appreciated.
03-01-2010, 10:29 PM
#27
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Don't know about the cluster swap.
Dan at Midwest transmission could tell you.
I now have a G56 on the garage floor.
Since the G56 uses a 2 piece case and the bellhousing is cast as part of the front case, it weighs 198 lbs.
Identical to my Getrag with a bellhousing. Getrag is 181 without.
These G56s are light for a 6 speed.
Dan at Midwest transmission could tell you.
I now have a G56 on the garage floor.
Since the G56 uses a 2 piece case and the bellhousing is cast as part of the front case, it weighs 198 lbs.
Identical to my Getrag with a bellhousing. Getrag is 181 without.
These G56s are light for a 6 speed.
03-02-2010, 01:08 AM
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I did some research into this as I was planning on using a ZF6 for my 1st Gen Cummins Crew project until I admitted my knees are shot. As stated, the GM version does have a 29 spline output, but I think they were only produced for a few years. The bellhousing is too small for a Cummins clutch. The Ford bellhousing is big enough, and they have an internal oil pump for a cooler. My solution was going to be using a GM mainshaft and gears in a Ford case. Not cheap, but it would have suited my needs perfectly and would have been more than adequate for my intended use. Another problem is the alignment of the transfer case mounting holes in rear flange. All Fords are driver's side drops, so they are clocked differently, but that's nothing a welder and drill couldn't take care of. I'm not sure, but I think the ZF6 is bigger than an NV4500, so the tranny tunnel might need to be massaged, too.
03-02-2010, 06:59 AM
#30
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NV4500HD - if you go this route and have to rebuild the tranny I would suggest you visit Quad 4X4s web site. They have a fix/redesign of the infamos 5th gear problem.
G56 - I was over at Rips (Source Automotive) when they had a G56 out with a cracked bell housing off of a Dodge used mostly for towing. I was asked to look at it because there did not appear to be any way to seperate the bell housing from the tranny. I couldn't see any way to seperate the two. I found out from Rip that that was attached internally to the transmission - not necessarily a major problem.
ZF6 - was lower tow rated than the auto tranny in Fords. Thats all I have heard about it - good or bad.
Just my .02 worth.
Bob
G56 - I was over at Rips (Source Automotive) when they had a G56 out with a cracked bell housing off of a Dodge used mostly for towing. I was asked to look at it because there did not appear to be any way to seperate the bell housing from the tranny. I couldn't see any way to seperate the two. I found out from Rip that that was attached internally to the transmission - not necessarily a major problem.
ZF6 - was lower tow rated than the auto tranny in Fords. Thats all I have heard about it - good or bad.
Just my .02 worth.
Bob