NV4500 swaps and clutch pedal specific questions

[RickTheEngineer]

Howdy everyone, I know that swapping a NV4500 is pretty popular when going to manual on squarebodies, but let's take a moment to discuss the specifics on an overlooked topic. What exactly is the easiest way to get that clutch pedal into your truck? What did you buy? Can you keep the original GM brake and throttle pedal? (I'm keeping the hydroboost system of course). From what I heard these cabs have a detent on where a clutch master would have mounted? If you have pics, that would be great.

Also, let's not worry about other running gear questions, I'd just like to know how hard it is to add that pedal in, and what you did if you did it!

Cheers!

 

[The FLU farm]

I can't see why parts off a regular K-5/10/30 wouldn't work in a CUCV. After all, they're practically identical.

 

[Recovry4x4]

It really depends on which 4500 you use. Different inputs may require a different bellhousing. A Dodge gas 4500 only requires a spacer plate to install. If one goes that way, they can use hydraulic or mechanicl pedals. As far as available pedals, the clutch and brake pedal are an assy. 85 and later will have a hydro clutch. The other concern is wether the pedals came out of a vehicle with vac booster or hydro. The brake pedal is different but can be modded to fit.

 

[Obijuank5]

easiest way that i know of is to use 85+ pedals with oem gm master cylinder and internal slave cylinder with a new line made. suggest some lift for slave to driveshaft clearance. most off the shelf gm components. literally bolts together. dont know much about the external nv4500.

second would be same pedals with oem master cyl and slave cyl with advance adapters bell housing.

 

[blueblaze]

After I did a 700r4 swap and finding it not that great with the O/D gear being too low. I did the Nv4500 swap. I could only find a set of pedals from a vacuum booster truck. But the brake pedal had two holes punched out for the pin far as I could see. One hole for the vacuum brakes and one for hydroboost. I cut the pin off and rewelded into the other position on the pedal. Before I did it I compared the pin locations from the pin on the automatic pedal set and it was either the same or really close. I can't quite remember now. If you do only end up finding vacuum booster pedals, you will have to cut or knock out two of the firewall mounting studs on the pedal assembly as the hydroboost set only has two studs. You can see this in the first few pics how the pedal assembly bolts through the firewall on a hydroboost truck. In the fourth picture I've circled a cover and spring that needs to be transferred from your auto brake pedal to the manual set as the vacuum brake pedal has no return spring. The last 2 pics show the before and after of the pin location for the brake push rod.

 

[blueblaze]

As for the clutch line, I was using an external '93 nv4500 as I wanted the low first gear and wanted nothing to do with the internal slave issues. I used an earls adapter on the factory 85-91 chevy master with a stainless ptfe line. I used the factory style external slave with an adapter that goes to the an style line. All of this stuff is easily found online. Also the master cylinder hole punches are present on the firewall as pictured and the factory res just attaches to the wiper motor hardware. The line between the res and master must be EPDM rated hose. Or the brake fluid will disintegrate it and make your fluid black and full of bits of rubber real fast. Ironically EPDM hose is the same as the washer hose found on our trucks and they give you more then enough to cut off a section for the clutch line.

 

[blueblaze]

Also lastly, if you do use an external slave nv4500, you will need a lift. I have a 2.5" skyjacker kit and under certain conditions the front shaft would hit the bellhousing which made me cringe. So I put on a set of 5.5" shackles which is 1.5" longer then stock along with going to 1/2" bolts from the factory 7/16" and I've had zero issues since. The shackles did double duty. They lifted an extra .75" and tilted the pinion down which got the shaft further away from the bellhousing and it leveled my truck out. Also this increases your caster a bit so now my steering wheel corrects itself better with the larger tires and has less wander. All things to think about.