NV4500 Rebuild Questions

[campfire]

Been thinking about a manual transmission swap for a while now. Here's what I have collected so far:

1986 M1009 Blazer with slightly-functional TH400 & NP208 and a 6.2 engine with hydroboost brakes
Clutch/brake pedal set with hydraulic master cylinder (but not from a hydroboost truck )
NV4500 from 1994 K30 (comes with bell housing and driver-side drop T-case)



What I need to collect:

Shifting lever / boot
hydraulic line between master & slave cylinder
slave cylinder
clutch disc

Questions:

1) What else am I missing from this list?

2) What options do I have for mating a transfer case? My NP208 should have too few splines on the input shaft (AFAIK). The t-case with the tranny (I believe it to be an NP241, but I have not verified this) drops down on the wrong side. I assume I cannot practically modify it to become a passenger-side drop (right?). Is finding a passenger-drop 30-spline input shaft transfer case my best bet? Do I have my spline counts right?

3) Why is it that I never hear, when folks are simultaneously swapping out tranny, t-case, and front axle, that they do a driver-side driveshaft? Is there some reason I have to keep the passenger-side drop? Why not just grab a driver-side axle and stick with the (free) transfer case already mated up?

4) What do I need in order to get a clutch coupled to my engine? I have no pressure plate (just the pilot bearing). Will a 6.2 auto flywheel accept a clutch setup?

5) Will I run into clearance issues with the external slave cylinder (protruding forward from the bottom of the bell housing on the driveshaft side)? My truck has no lift (although it is noticeably taller than the '83 and '84). It looks like it will crowd into the driveshaft space.

6) Will an NV4500 fit into a TH400 space (length and crossmember-wise)? I see the potential for changes in driveshaft length before I'm through...

7) Why can't I find a thread from someone who has done this already that actually shows how this swap fits/works? I know there are a bunch of you on here who have blazed this trail already, but I haven't found pictures or a detailed description yet.


And PM if you have an NV4500 shifter & boot you're willing to part with. I'd prefer the one that's marked L,1,2,3,OD,R instead of 1,2,3,4,OD,R (but not a biggie). Or if you're in Northern Wisconsin (all three of you) and have a manual-tranny t-case lying around.


No doubt there are other questions needing to be asked, but those are the ones that come to mind.

 

[fourxpete]

as far as the clutch set up to the 6.2 the auto flywheel will NOT work doesnt matter if gas or diesel auto flywheels total different design when i put a stick behind a 6.2 i used a clutch for a 6.5 external balance out of i believe a 93 or 94 i might still have it if needed

 

[dahreno]

I have a SM 465 and an NP 208 with A Centerforce dual friction clutch with an aluminum fly wheel that just came off a SBC in fantastic shape for sale.The problem is I'm in Reno Nv. Anyway, the clutch cost well over 800 bucks and I want 700 for everything.

 

[82355]

1. Lots of stuff I am sure.

2. A transfer case from behind a TH400 will have a 32 spline input. That transfer case will work with your NV4500.

3. Because there is no solid GM front axle with a driverside drop.

4. The pressure plate is part of the clutch. An automatic has a flex plate, not a flywheel. You need a flywheel.

5. Yes.

6. I am not sure, but should be close. I could measure both tomorrow.

7. The search function on this site sucks.

Martin

 

[diesel4me]

Far as I know a 6.2 needs a specific flywheel,its balanced differently and though one from a gas engine "might" bolt up,it wont work right,unless you have it balanced to the stock 6.2's specs,and since these diesels have enough crank breakage problems,its best to just get the correct one off a junker, or new from GM...

 

[campfire]

1. Lots of stuff I am sure.

I already knew that!

2. A transfer case from behind a TH400 will have a 32 spline input. That transfer case will work with your NV4500.

Thank you. That piece I did not realize (and I had my spline count wrong anyway... ). Are the bolting patterns the same for all 208/241 t-cases? I know that 205 cases are not all the same...

3. Because there is no solid GM front axle with a driverside drop.

Why not a driver-side D60 from a Ford?

4. The pressure plate is part of the clutch. An automatic has a flex plate, not a flywheel. You need a flywheel.

I figured as much. So the flywheel, pressure plate, and clutch disc would have to come from a donor truck (in a set). Actually, I wouldn't reuse a clutch disc. Unless it was VERY new...

5. Yes.

How can this problem be resolved? I assume that my bellhousing won't easily accept alternate locations for the slave cylinder (). Any other options? I don't particularly want to jack the truck up at this point, but I have seen lift kits used to create clearance (IIRC). Again, I can't easily find any links.

6. I am not sure, but should be close. I could measure both tomorrow.

That would be helpful. I'll take a tape to the NV4500, but the Blazer's offsite at the moment.

7. The search function on this site sucks.

That I am aware of. I'm hoping that one of the experienced guys will chime in with "Here, see my build thread," or something like that.

 

[82355]

Look for a hydraulic clutch setup for an SM465. I have seen where people drilled new holes in the bell housing, and used bolts and nuts to hold it together.

Martin

 

[kennyw]

Ford driver's drop D60 from 1978-79 can be used very easily.

You only need a used flywheel, I would get a new clutch disc and pressure plate.

 

[kennyw]

Also, the donor drivers drop NP241 will not have a mechanical speedo. You will need to get parts to change that our convert to an electric speedo.

 

[Smokinthehippies]

You would be money ahead selling the driver drop 241, and buying a new 241 vs spending the grand it would take to buy a ford Dana 60. Because you and everyone else doing a swap or SAS are looking for the same axle. The t cases can still be had for about 3-500$.

All 208s & 241s use the same bolt pattern. Just get the right spline count and you're good.

 

[82355]

Yeah, it's not like a Ford Dana 60 they sold for two years, and is super desirable is the easiest thing to find, and for no money......

Martin

 

[campfire]

Oh definitely. Given my driving habits (>95% on-road), I'm not even looking for a D60 of either type. I know I'm not typical of builders on this site, but I'd rather keep the matching 10-bolts in the three trucks than invest more work into swapping them out. Even with $500 D60 axles floating around this area commonly. The front axles are so rarely used. Back axles, on the other hand...

 

[campfire]

Sorry to derail my own thread. The important questions are the ones dealing with "what do I need to buy/do to get my perpetually-dead truck on the road?"

The (paid-for) 208 transfer case already installed in the truck is by far the most attractive option for me. It definitely fits the truck.


It looks like the slave cyl. issue is going to take some research. I wish the search engine on this site was more help. [bangs head against wall]


Where is the [bangs head against wall] icon anyway?

 

[campfire]

Took measurement of the NV4500 tonight. The gearbox (from back of bell housing to seam between transmission and transfer case) measures approximately 20.5" long. With 1994ish bell housing (slave cylinder extending forward on passenger side), total length is 27" from front of bell housing to seam between transmission and transfer case.


And the NP241 looks a lot heavier than the NP208...

 

[swettysblazer]

Took measurement of the NV4500 tonight. The gearbox (from back of bell housing to seam between transmission and transfer case) measures approximately 20.5" long. With 1994ish bell housing (slave cylinder extending forward on passenger side), total length is 27" from front of bell housing to seam between transmission and transfer case.


And the NP241 looks a lot heavier than the NP208...

For what it's worth, I can bench press my 241 into position with a little bit of oomph

 

[jkeys0218]

Try using Google to search the site. Just type in what you want to search for then
type

site:coloradok5.com

You can use Google to search any website that way.

 

[campfire]

What are the requirements for the flywheel? Is there a difference between the 6.2 flywheel and a normal sbc flywheel? If so, what? Dieselforme has me curious.

I have found a guy selling a pile of 350 engines and this:
"Gm truck clutch pressure plate, friction disc, and flywheel $50"
http://greenbay.craigslist.org/pts/4618207109.html

It sure would be convenient if they were compatible...

 

[82355]

Took measurement of the NV4500 tonight. The gearbox (from back of bell housing to seam between transmission and transfer case) measures approximately 20.5" long. With 1994ish bell housing (slave cylinder extending forward on passenger side), total length is 27" from front of bell housing to seam between transmission and transfer case.

Have you looked into using an SM465 bell housing?

And the NP241 looks a lot heavier than the NP208...

It can't be by much.

Martin

 

[myhichevy4x4]

I have a used flywheel, clutch, pressure plate, and all hardware that I just took off a 1997 6.5 diesel with NV4500. Not sure if that will work for you but I would let it go for $100 plus shipping. Shipping would prob kill you though that flywheel is heavy.

 

[kennyw]

I shipped the last flywheel I had to Sweden... the U.P. shouldn't be too bad.