#6 nv5600
#16
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I hope its a good match for you.
I'm still mulling over why your 5600 kept failing. I know mine had regular gear oil in it and that's what killed it, they couldn't even get the mainshaft apart with an 80 ton press!!!
I wonder if it could have been non spec'd assembly lube or something that just cooked when run.....
I'm still mulling over why your 5600 kept failing. I know mine had regular gear oil in it and that's what killed it, they couldn't even get the mainshaft apart with an 80 ton press!!!
I wonder if it could have been non spec'd assembly lube or something that just cooked when run.....
#17
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My rebuild has about 80K on it, shifter tends to wiggle left to right in second, original didn't do this....
#18
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165K miles on mine. Bought it new in 2001. Changed the oil to Red Line @ 100K. It has been flawless. New clutch @ 165K. Actually, I cringe when I read these horror stories. In 2003 i met a mechanic who took the NV5600 repair course and he said it had some funny things to do that you would overlook if you were used to working on NV4500's.
When I researched the NV5600 i found it has a maximum weight rating, some combination of tow/haul that stopped at 26K pounds. ANY stress above that poundage would grenade the trans. I have been at the GCWR of 22K pounds a couple times.
My take on the trans is that it has very little deflection as the case is cast iron. No intermediate bearing needed. But it's a heavy sucker @ 360 pounds. I have a feeling that the heaviness is what killed it after so few years of production.
I have a friend who bought a cheap, used '04/NV5600 truck but he complained that the synchos were bad. I said, it has the wrong oil. He had the oil changed to the factory recommended oil and Voila! the trannie was back in business. I'm thinking the wrong oil is a common mistake.
Some time ago, when I was collecting medium truck transmissions, I found a possible replacement for the NV5600: a Clark 280VO, 5 speed w/ O.D., 5 ton, all synchro truck trans from a 1979 Ford F-700 4X4 Dump Truck. This is the rare O.D. model. Most of the other 200 variations on the Clark 5 speed are 1:1 in 5th. Only 295 pounds. Still has the divorced T.Case lever attached. Kind of a lightweight but with unbreakable grunt. ratios: 5.98/3.50/1.86/1.00/0.80/5.04R. 10 spline, 7" stickout, Ford gas engine b.h. pattern.
The tape is on there when I steam cleaned it. It's still sitting around in my garage holding the compressor from walking out the door. Yep, boat anchor.
jefe
When I researched the NV5600 i found it has a maximum weight rating, some combination of tow/haul that stopped at 26K pounds. ANY stress above that poundage would grenade the trans. I have been at the GCWR of 22K pounds a couple times.
My take on the trans is that it has very little deflection as the case is cast iron. No intermediate bearing needed. But it's a heavy sucker @ 360 pounds. I have a feeling that the heaviness is what killed it after so few years of production.
I have a friend who bought a cheap, used '04/NV5600 truck but he complained that the synchos were bad. I said, it has the wrong oil. He had the oil changed to the factory recommended oil and Voila! the trannie was back in business. I'm thinking the wrong oil is a common mistake.
Some time ago, when I was collecting medium truck transmissions, I found a possible replacement for the NV5600: a Clark 280VO, 5 speed w/ O.D., 5 ton, all synchro truck trans from a 1979 Ford F-700 4X4 Dump Truck. This is the rare O.D. model. Most of the other 200 variations on the Clark 5 speed are 1:1 in 5th. Only 295 pounds. Still has the divorced T.Case lever attached. Kind of a lightweight but with unbreakable grunt. ratios: 5.98/3.50/1.86/1.00/0.80/5.04R. 10 spline, 7" stickout, Ford gas engine b.h. pattern.
The tape is on there when I steam cleaned it. It's still sitting around in my garage holding the compressor from walking out the door. Yep, boat anchor.
jefe
#19
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Update on new G56
Well the wife and I just returned home from our trip .we headed south for a month there about .transmission worked great . We pulled some real steep grades on hwys 269 I5 and I8 .on 269 I pulled 38 psi boost for 20 minutes up one grade and the trans never even got to 150 at first I thought I forgot to hook up the temp gauge so I ran it in 6th for 1hr before it even came off the 140* Mark and in 5th it never got past 140*.I filled it with Delvac 50 so on cold mornings it was stiff but after a few miles that was over. Also the G56 I got is an early model and has the lower 6th ratio and for my use its perfect with my setup .the 5600 was a tad tall in 6th and .I was pulling 12500 this trip normally closer to 17k (towing in 5th) and averaged 9mpg with a strong head wind a 13mpg on the flat. Overall I'm happy with the swap and it shifts way nicer too. I definitely think the 5600 is tweeked internally causing the constant breakage. I will junk it because I really don't want it to end up being a problem for someone else. If anyone ever needs info on what's needed to swap pm me.
#20
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Working great
well thought I would just give an up date, it's been a while. The g56 has be working flawless after several thousands miles .realy like my truck again. Imho it is a lot more refined 6spd happy with the swap
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