NV4500 Rebuild Questions

[scottystills]

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.

To give you an example I swapped out my 700 for a 465 last year. I made the mistake of trying the SBC flywheel and once buttoned up if felt like my teeth were going to shake out of my mouth. Here's the side by side. Diesel flywheel is on the left.







They both bolt up, but being an externally balanced engine the flywheel obviously made a huge difference.

 

[dyeager535]

I am still considering an NV4500 swap, but have little/no intention of getting rid of the front 10 bolt. The gains vs. a 465 are so miniscule that it's tough to justify it. If you have to have really low gears but still need OD for the street, there isn't much else as an option for a manual than the 4500 though to drive freeway RPM's down.

The easiest answer to run the NV4500 is to drill and tap the 4500 for the *one* bellhousing bolt that doesn't line up with the 465 bellhousing. Since three bolts line up, and the pilot bearing retainer is the same diameter as the 4500 you have, it's going to be pretty darn easy.

It's been done, there are pics online of it. Pretty sure I linked to the writeup on one of my posts here not that long ago. A hell of a lot cheaper and easier than trying to run either an AA bellhousing, or cobbling something else together.

At least by sticking with the 208, at a later date if you want to upgrade to the 241, you can do so and have no issues with shifter location. I'm pretty certain the 4500 will unfortunately push the t-case shifter back from the stock location. Wonder if there would be clearance to just lengthen the shift rod from the shifter vs. relocating it?

 

[campfire]

To give you an example I swapped out my 700 for a 465 last year. I made the mistake of trying the SBC flywheel and once buttoned up if felt like my teeth were going to shake out of my mouth.

Yikes!

That was exactly why I wanted to ask that question before I hit the local yards...

 

[campfire]

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.

I'm gonna see what the local yards have before I look at shipping something half-way across the country. I can get a whole 6.2 engine for somewhere around $300, so I'm hoping that a flywheel will be a relatively small fraction of that.


Hmm...ignoring the dual-mass flywheels, are the single-mass diesel flywheels all the same? Or did they change over the 20 years that 6.2/6.5 engines were made?

 

[kennyw]

are the single-mass diesel flywheels all the same? Or did they change over the 20 years that 6.2/6.5 engines were made?

I believe so, just look for the casting number listed in scotty's pic above. You may actually have a hard time finding a flywheel though. By the time GM started offering diesels, only 1 in 50 had a manual tranny.

 

[campfire]

The gains vs. a 465 are so miniscule that it's tough to justify it. If you have to have really low gears but still need OD for the street, there isn't much else as an option for a manual than the 4500 though to drive freeway RPM's down.

For a 350, I'd agree with you. But my engines don't like spinning quickly very much. And I have a weird (for this site) set of desired parameters in my builds. All 3 of them are intended to be daily drivers that will see light offroading use. So I'm looking for fuel mileage, reliability, and durability. Power/torque is a secondary concern.

My K10 has 3.08s, 29" tires, and a 700R4 transmission. Engine range is ~1250RPM at 55MPH and ~1600 at 65 (IIRC). I like that gearing. Enough power to take a 2-3% grade without downshifting (and unless I head North of here I don't encounter very many hills steeper than that in this region).

My Suburban has 3.73s, 31s, and a 700R4. It has much more available power than the K10, but unless I'm trailering I simply can't use it. Even when trailering 11,000 pounds (combined vehicle weight) it stayed in O/D on the road. Nice for trailering, but I hardly ever pull that much weight, and overall I'd rather have the mileage of the K10 than the power of the Suburban.

The M1009 with 3.08s, 31s and no O/D is worse yet (1800RPM @ 55, 2250 @65). Fine gearing for a 350, and not bad for a 6.2, but not what I wish to keep in a daily driver. I don't think any of the 6.2 engines sound healthy above 2000RPM, but with the lack of sound insulation in the M1009, it sounds downright terrible at highway speed.


So, a non-O/D tranny would be fine...if I could find gears more anemic than what I already have. But I've only rarely seen gears above 3.08. And I like sticking with common parts, living in a rural area with few parts-finding resources available.

 

[campfire]

The easiest answer to run the NV4500 is to drill and tap the 4500 for the *one* bellhousing bolt that doesn't line up with the 465 bellhousing. Since three bolts line up, and the pilot bearing retainer is the same diameter as the 4500 you have, it's going to be pretty darn easy.

It's been done, there are pics online of it. Pretty sure I linked to the writeup on one of my posts here not that long ago. A hell of a lot cheaper and easier than trying to run either an AA bellhousing, or cobbling something else together.

At least by sticking with the 208, at a later date if you want to upgrade to the 241, you can do so and have no issues with shifter location. I'm pretty certain the 4500 will unfortunately push the t-case shifter back from the stock location. Wonder if there would be clearance to just lengthen the shift rod from the shifter vs. relocating it?

Hadn't thought of that. Will have to do some research.

 

[82355]

I've mentioned it twice already.....

Martin

 

[kennyw]

I've mentioned it twice already.....

Martin

Yes, but no one wants to listen to you

 

[82355]

haha

Martin

 

[campfire]

I've mentioned it twice already.....

Martin

Looking back through the thread I see that. But when you first mentioned it I must have misread it. I thought you were proposing to take the linkage from an SM465 bell housing and somehow transplant it to my existing bell housing. Being only slightly familiar with either bell housing, I figured there was a large risk of screwing up the linkage pivots and sending the bearing forward an incorrect amount. Or something like that. So I was thinking about it, but hadn't figured out a way to make it work.


I completely missed the underlying point that the whole bell housing could be swapped with a reasonable amount of effort.

Yes, but no one wants to listen to you

I will consider advice from nearly anyone when it comes to these trucks. I'm not only younger than my truck, I'm only 4 1/2 years into owning chevy trucks at all. I've done a lot of bodywork and routine maintenance, but I'm just starting to do serious drive-train modifications. So I think I can learn a lot from folks that have owned them for a while. Martin seems to have more square-bodies than I ever will, and his comments are insightful, showing a level of knowledge that I clearly don't have (maybe someday ). Thanks for your patience. That's why I'm on CK5 and not the hundred other truck sites out there.


His comments typically are also quite short.

 

[Hogback Fabrication]

If you have to have really low gears but still need OD for the street, there isn't much else as an option for a manual than the 4500 though to drive freeway RPM's down.

A 465 plus this is a good option a lot of people forget about

 

[campfire]

A 465 plus this is a good option a lot of people forget about

I don't think it will fit my needs, though. I already have the NV4500 (and I don't have a 465). Cost for a Ranger O/D unit is significant. In my area the 465 and NV4500 are both cheap ($200-300 for SM465, and the same for NV4500 if you're patient, $500 if you're not). Adding the O/D unit, IIRC, pushes the tranny/t-case further back from stock locations. And then I have another set of gears to drag around, increasing driveline losses (right?)

It'd awesome if this was primarily an off-road vehicle. I'm the kinda guy that would enjoy having 3 or 4 ranges instead of just 2. But for on-road driving I don't think it'd leave O/D mode very often.

Open to corrections if any of that is wrong...

 

[scottystills]

I'm gonna see what the local yards have before I look at shipping something half-way across the country. I can get a whole 6.2 engine for somewhere around $300, so I'm hoping that a flywheel will be a relatively small fraction of that.

Best of luck, not sure what you'll be able to find down there. Up here though it was hard to come by that flywheel, and everywhere that had them new wanted $2-300 for them. Nuts to that.

I ended up getting a full 6.2 w/ 2wd sm465 for $400 or something around there and just took the flywheel out of it. Come in useful to snag odds and ends off of. Who needs a junkyard!

Though my neighbours might disagree...

 

[campfire]

Bringing this thread up to date:

I have done a small amount of local looking, and I've had several sbc flywheels in my hand, but not a 6.2 flywheel as of yet.

Autozone carries them new for $140
Autozone also carries Duralast clutch kits for $115 Interestingly enough, it comes with a lifetime warranty while the performance clutch kit (at twice the price) does not.

Anybody have feedback on Duralast clutches? Or any other brand to recommend?

I have stumbled upon what I believe to be a mechanical-linkage SM465 bell housing (with the pivot linkage sticking out of the driver-side hole). I've been told that a slave cylinder can be mounted externally at the end of the pivot linkage, but have no idea what that would look like. I am skeptical to say the least.

I am further confused by pictures of hydraulic SM465 bell housings like this one where the slave cylinder appears to be in the same passenger-side-bottom spot that the existing NV4500 bell housing utilizes. How do those bell housings work if the NV4500 one won't? Are these bell housings from driver-side-drop trucks?

 

[campfire]

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.

What all hardware do you have? I may not wanna ship the flywheel across-country, but I don't have the bell housing end all figured out either (slave cyl and whatever linkage is required).

 

[myhichevy4x4]

What all hardware do you have? I may not wanna ship the flywheel across-country, but I don't have the bell housing end all figured out either (slave cyl and whatever linkage is required).

The only hardware I have are the flywheel and pressure plate bolts. If you want pm me your email or cell and I can send some pics of exactly what I have.

 

[82355]

I am further confused by pictures of hydraulic SM465 bell housings like this one where the slave cylinder appears to be in the same passenger-side-bottom spot that the existing NV4500 bell housing utilizes. How do those bell housings work if the NV4500 one won't? Are these bell housings from driver-side-drop trucks?

This is from a newer body style truck (1988-1998). It is of no use to you.

http://coloradok5.com/forums/showthread.php?t=316899

Martin

 

[campfire]

This is from a newer body style truck (1988-1998). It is of no use to you.

http://coloradok5.com/forums/showthread.php?t=316899

Martin

Casting number on the bell housing I already have is 464697 (mechanical linkage).

I see setups such as this offering to attach hydraulics to such:

http://www.novak-adapt.com/catalog/clutch/kit_hcrc.htm

But I'm not sure what the difference between this and the OEM setup is (aside from being easier to find). I'm not eager to use a non-OEM (Autozone-available) slave cylinder, but I'm not sure where else to find that bracket. For some reason I don't feel like fabbing this one. Prolly because I don't have a donor truck to inspect...

Anybody have one of these brackets lying around (or know where to find one)?


Their tech article on setting up a clutch has been informative for me. I guess I've lucked out several times in the past.

 

[82355]

For that kind of money, you should be able to find an OEM hydraulic bell housing.

Martin