NV 4500 2wd to 4x4 conversion

[Woody1962]

I’ve got a 97 Z71 with the 4L60E and a push button NP243 case. I just purchased a 97 C2500 with an NV4500 ( newer style ). I plan on swapping wiring harnesses and the complete dash and column as well as the swing pedals and shifter assembly from the donor truck as well as all related clutch parts. My two main questions are : how hard is it to remove knock outs in the firewall and floor board for the conversion to manual ? My second question is on the NV 4500 2wd to 4x4 conversion. I know I have to change the main shaft and the tail housing over 5th gear and I know I will have to use a 32 spline input on the T-Case ( have already purchased an NP 241 out of a K2500 to get the manual with correct input spline as well as the shifter and interior trim ),. How hard of a conversion is the nv4500 ? I’ve watched videos on you-tube explaining the process and have purchased a few tools ( law jaw puller and bearing separator) to try my first manual transmission disassembly and assembly, or would I be money ahead to buy the parts needed ( approx $250 on eBay ) and have the local tranny shop do the conversion ? Price quoted was $300 plus parts. I’m also buying the cast iron vs aluminum tail housing for this application. Any help or feedback from anyone who has done the nv 4500 2to4wd conversion appreciated.

 

[Erik the Awful]

I'm in the process of putting an NV3500 in my C1500. I imagine the NV4500 probably uses the same size hole and shift boot. If your truck didn't come with a manual, there is no hole in the floorboard... yet. Last weekend I scrounged a shift cover plate, but not the boot. Here's the measurements I got from the truck in the junkyard:

The hole is 5.5"x5.5".
If you measure across the transmission tunnel where it's fairly parallel, it's 15" including the upper radius, but not the radius to the floor.
The hole needs to be 5" from the left side of that 15", and 4.5" from the right side of the 15".
The hole needs to be 4" back from the upkick at the front of the transmission tunnel.
The corners of the hole are 7/8" radius (measured from the shift cover plate).

Also remember that at some point you're going to want that manual transmission steering column and gauge cluster.

 

[Woody1962]

I’ve pulled the carpet and pad in my Z71 and it has the knockouts. I’m sure I’ll have to cut them out but the impressions are there in the metal. I have the shifter, boot and ring from the donor truck. My firewall also has knockouts for the clutch master and the manual swing pedals. Through 97 they used either a manual or standard in the K series trucks. The manual was an option. The C series is a different story. My biggest thing is converting the 2wd NV 4500 to 4wd. They use a different length main shaft and the 4wd is a straight vs tapered shaft on the output end like a 2wd. The 4L60 and 4L80 are the same way. The 2wd versions use a tapered tail shaft because of the slip yoke driveline where with a 4wd trans the transfer case bolts direct to the trans and uses a straight spline output shaft to couple with the T-case.

 

[Woody1962]

I’ve pulled the carpet and pad in my Z71 and it has the knockouts. I’m sure I’ll have to cut them out but the impressions are there in the metal. I have the shifter, boot and ring from the donor truck. My firewall also has knockouts for the clutch master and the manual swing pedals. Through 97 they used either a manual or standard in the K series trucks. The manual was an option. The C series is a different story. My biggest thing is converting the 2wd NV 4500 to 4wd. They use a different length main shaft and the 4wd is a straight vs tapered shaft on the output end like a 2wd. The 4L60 and 4L80 are the same way. The 2wd versions use a tapered tail shaft because of the slip yoke driveline where with a 4wd trans the transfer case bolts direct to the trans and uses a straight spline output shaft to couple with the T-case.

I should reiterate that I have never done a rebuild on a manual transmission before so a basic newbie except what I read or see in videos explaining the procedure.

 

[Erik the Awful]

I’ve pulled the carpet and pad in my Z71 and it has the knockouts.

Sweet! I wish I had that. There's an impression, but it's not cut.
View media item 32099

 

[Ironjet]

Hole saw and a long drill bit for the clutch master,
Jigsaw for the floor, although the impression seemed a touch too big for the trim ring and boot