Since my is an 02, it does not have the transmission control module. To get the truck to start all I had to do was jumper the purple/white and yellow wires that went to the big plug on the neutral safety switch. Before I did that I flashed it with a manual transmission tune and it started right up with no codes.

Clutch engages and disengages as it should.

 

Now that I finally have it in and running I figured I would try to summarize what I figured out when I attempted this.

One of the reasons I did this swap is I would end up with a better choice of gears for less money than trying to build my 4L80E with a low gear set from TCI. It turned out the NP263HD has the same input shaft as the NP246/243/241. There is a 27 spline shaft available, but I have not seen a 29 spline shaft and not sure if a 29 spline for a 246 would work. (apparently there is a 29 spline available for the 241/243/246 because they were installed in Dodge trucks too). If anything I would need a stronger transfer so I chose to install a rebuilt NP263XHD from a diesel. That increased my costs by about $1200 including the new slip yoke it required.

Drive shafts were $300 plus another $120 for new Spicer u-joints. I could have gotten the u-joints cheaper, but since I bought them from the drive shaft shop they installed them. Well worth $10 per joint in my mind.

The fluid the ZF6 takes is $40 a gallon and it takes about 6 quarts and nobody had it so I ordered it from Zoro Tools. From everything I read GM uses a fluid called Transynd and Mobile Delcon synthetic ATF meets the same TES 295 standards.

On a 2500HD without a body lift, you could probably squeeze the tranny in, but it would be much more difficult. When I had it all bolted in, the factory foam seal was about two inches from the tunnel, less in some spots.

On the bright side, there were already holes in the frame, 2 inches behind the ones the gassers use, drilled for the crossmember so no mount fabrication was required.

There is a bulge in the tunnel where the shifter is obviously supposed to come out. Do not cut out the entire bulged area or your factory shifter boot will have nothing to screw to. Might be obvious for most when they see it, but it bears mentioning.


I took the entire trans cable out by disconnecting it from under the dash. You have to plug the two inch hole in the floor board if you do this, or not if you don't see any deep water.

The 6.0 starter used on 4L80E seems to work fine on the NFW 1050 flywheel. I did need to use a 1/32 shim, but one has to expect that with a $60 flywheel.

So what I thought was going to be $2500 turned into $3500. Another option was a rebuilt NV4500, but then I would have to buy a bell housing and the price would be right back where I started with less strength. At the end of the day it's good to have the stronger transfer case too, but had I known that was required in the beginning I might not have pulled the trigger on the swap. Just goes to show that there is a lot more to this stuff than is evident when you read it. It was a calculated risk for me and I'll try to post one more time once I have some miles on the truck.

 

I was hoping to be able to figure out the wiring on the neutral safety switch to trick the PCM into thinking it was in neutral every time I pressed the clutch, but don't have time to mess with it any more and just put the old neutral safety switch back with the selector in the neutral position. The ignition is still jumpered so even if the switch fails, the truck still starts. The only thing it allows is the transfer to shift into low.

 

been reading alot on this, where are you guys finding the zf6? or did you buy remans and just eat the core cost? smartparts auto has them for 1800 or so plus 500$ for a core? anyone heard of them? considering the cost to build an 80E with the lower gears and a new converter. you still probably saved a little coin or broke even, and now you got options.

i may attempt this on my 2500hd i have an 06 6.0 truck. from what i can see i will still need a different input shaft even with the hd T case?

 

Hello. I have a 1989 Chevy Silverado I wanted to keep my T5 But not sure it is the best option. I do a little towing with my truck. Not Alot. I like top end Miles per hour anda okay fuel economy. Please give me options and guidence. robrizzo@yahoo.com. Bolt on product and be as thrifty as possible. please advise,
Thank You
Rob

 

What is your concern with your t5 and towing. If you do a little towing and theres no problems then what are you looking to accomplish? If there are concerns then a NV4500 would be your be solution. 6 speeds are simply not necessary except for hi torque diesels, but again the nv4500 are used behind them as well and have been used for 20 years.

 

Hi I'm new to the forum and I've been reading this thread for a while.... I am planning on doing this swap on my 2003 sierra 1500. In the near future I am going to put 37s on my truck. With the 4L60E I would need to upgrade from 3.73s to 4.88s. But with the ZF6 would I need to change them? I only ask this because the 1st gear in the ZF6 is a lot lower than the 4L60E.... Any help would be greatly appreciated!

 

Bump...

 

I got mine off ebay, but I had to troll for a few months to get a good deal.

 

NV4500 is next best thing to ZF6. Not sure if NV5600 (used in Dodges) is doable. All of them offer about the same overdrive so mileage will be similar. By the time you buy a bell housing the NV4500 is almost as much as a ZF6. I would have stuck with the 80e if I wasn't racing, but when you might want to look into a 4500 if your T5 goes.