Anyone here get rid of a 700R4 for an NV4500?

[Boscolingus]

Currently have a 1988 K5 with a fragged 700R4. I have been toying around with the idea of swapping in an NV4500 based on simplicity, and the overdrive as compared to the SM 465.

I know of the parts offered by Advanced Adapters, HiTech Gear, and others but is there someone else by chance that has a complete kit that might even cover everything down to the drive shafts ( I have been told there will be length issues with the swap ).

Current transfercase is a 241. Was planning on keeping it simply because it's there. However, if switching out the transfer case nets a more complete parts package then Im all for it.

Those with experience with this swap, please, POST AWAY

 

[Boscolingus]

anybody?

 

[tRustyK5]

I don't think there is a 'kit' for what you want to do...but it's not hard to do the swap using factory pieces, and a few aftermarket bits.

The T-case will bolt right up if you swap the 27 spline input gear for a 32 spline input gear. Swapping the input gear is pretty easy with the T-case out.

Bellhousing I recomend the Advance Adaptors bell. It's not perfect, it's made for a Jeep with a small block so it's machined for a Jeep slave which is a POS. They do make an adaptor bracket so the GM slave will bolt right up and work with the provided clutch fork though.

The clutch master, line and pedal assembly are all stock parts you can find in an '85 or newer GM pick-up. It is a bit painfull to swap the pedal assembly out, but it's not rocket science. I ended pulling the whole steering column out which made it a lot easier.

One of the factory tranny/T-case crossmembers should work...maybe even the one you already have. I did a doubler behind my NV4500 and ended up fabbing a custom crossmember.

Shifter hole will need to be cut, T-case shifter should stay right where it already is. You may need to alter the linkage a little...or it may adjust enough.

Driveshafts are pretty easy...they just cost money. You'll have to measure em up after everything is in and shorten/lengthen as needed.

Crossmember and view from underneath.

Top view

HTH

Rene

 

[BL1TZKRIEG]

so do all 241s need to be swaped to a 32 spline input ?
sorry for the hijack

 

[tRustyK5]

Well, the NV4500 has a 32 spline output...so whether it's a 203, 205, 208, 241 it'll need a 32 spline input. The planetary T-cases (208 and 241) are very easy to swap inputs. 203's and 205's are a bit more trouble.

Rene

 

[Boscolingus]

Sweet, these are some details I'm looking for!

 

[bp71k5]

Any more pics of that crossmember? I'm almost at that stage with my conversion. I can see the mounts for the 4500 and the 203, but how did you mount/brace the 205?

 

[tRustyK5]

The 205 is mounted off the back of the 203

I will likely build some sort of 205 support down the road. The truck isn't going anywhere or even being driven right now and I still have a shop to build.

Rene

 

[Boscolingus]

so even with swapping in the correct input shaft to the np241, would I realy be gaining anything or would it be best to just use a 205 or 203 as far as strength and longevity are concerned?

 

[tRustyK5]

The 208 and 241 are both decent transfer cases. They have great gear reduction (2.61:1 and 2.72:1 respectively). Their drawback is the cast aluminum case, and in the 208 a diffcult time trying to eliminate the slip yoke.

I went with a doubler (203 range box, adaptor kit and complete 205 behind that) because I like to crawl in the rocks.

I'd say keep the 208 or 241 you have and just skidplate it with something sturdier than the factory stuff. If you have the 241 add a slip yoke eliminator kit ( http://coloradok5.com/jbconversionssye.shtml )

Rene