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School me on NV3500 transmissions...

campfire

campfire

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I've been contemplating an auto-to-manual tranny swap for quite a while now. I have most of the pieces required for an NV4500 swap, but this year's trip out to Colorado & Wyoming has persuaded me that I'd like my expedition truck to have 5 actual gears instead of 4 (NV4500) or 3 (SM465).

The downside is that, aside from driving one such 1/2-ton truck, I don't know much about these transmissions. Integral bell housing, 32-spline output shaft with 6-bolt round pattern. Today I came across this picture and was surprised to find an external slave cylinder.

00A0A_eOysNCxKmP2_600x450.jpg

Looks a lot like what came on my NV4500. Is this normal for these? For some reason I had thought they used internal slaves. :dunno: And is there a difference between the 1/2-ton and S-10 NV3500 trannys?

Aside from the slave blocking access to the starter motor, does this slave position conflict with the front driveshaft? How is this interference resolved?

Does anyone have a thread detailing how this box fits in a square-body?

I have much to learn. Let the schooling begin! :popcorn:

00A0A_eOysNCxKmP2_600x450.jpg
 
An s10 trans more or less wont fit. You would have to run a smaller tcase because they have a 5 bolt mating pattern.


The NV3500 is grossly underrated. They vary in strength from the early not even a real nv3500 years that break when you look at them to the later internal slave models that numerous guys had no issues with behind 500hp Joe Gibbs S/C'd 4.8 trucks.

My best advice is suck it up and run an internal slave unit simply because all the worthy transmission strength wise came with one. Theyre best in LS engine trim but the 96+ ones arent bad either. Also the LS ones bolt right up to a small block. Theres no funky bell depth changes they made a different flywheel to make it work.
 
Stomis said:
An s10 trans more or less wont fit. You would have to run a smaller tcase because they have a 5 bolt mating pattern.


The NV3500 is grossly underrated. They vary in strength from the early not even a real nv3500 years that break when you look at them to the later internal slave models that numerous guys had no issues with behind 500hp Joe Gibbs S/C'd 4.8 trucks.

My best advice is suck it up and run an internal slave unit simply because all the worthy transmission strength wise came with one. Theyre best in LS engine trim but the 96+ ones arent bad either. Also the LS ones bolt right up to a small block. Theres no funky bell depth changes they made a different flywheel to make it work.
Click to expand...

Ok. My trucks are all 6.2-based, so excessive power will not be happening, though torque rating is higher (prolly more relevant for this discussion).

Why is a different flywheel required if the bell housing matches? :dunno:


Stomis said:
The NV3500 is grossly underrated.
Click to expand...
Are you saying that the tranny can't handle the power, or people think too lowly of it? :dunno:
 
People think too lowly of it and it is not rated for as much input torque as it can hold. Russell ran a late model nv3500 behind a 6.2 in a blazer very successfully for years.
 
I've got an NV3500 going into one of my trucks. If you have got the parts to do an NV4500 swap, a NV3500 is no different. Both will probably require driveshaft mods (depending on what you are replacing).

The 3500 shifts much nicer and is more daily driver friendly, not that a 4500 is bad either. As said, the early ones are made of glass but the later ones aren't that bad. I wouldn't go pulling a ton of weight with one or dumping the clutch at 5k either, but for daily driving and moderate off roading it should hold up just fine.
 
For an expedition build, I think you will be plenty happy with the nv4500. A few weeks ago, I ran about 30 miles of backcountry Mtn. roads. Expect for washes and downed trees (where low comes in nicely), I hardly left 2nd (3rd). I have not felt the need for an extra gear except towing heavy in the hills on highway , where 2/3 (3/4) split is too wide.
 
As mentioned, NV3500’s are great driver transmissions but that is about it. They have no low range, which is a major minus if you plan to actually wheel with this rig. If I recall, 1st gear was like 3.09:1 or something stupid high like that whereas, a NV4500 would be 6:34 or 5:61 for later models. The other thing to keep in mind is GM did not offer Z82 trailering packages on any trucks that used the NV3500. So with that, they were only rated to tow the GM minimum of 2,000 lbs. That alone leads me to believe the NV3500 didn’t fare well in durability testing for what trucks are intended to get used for resulting in them being neutered to only 2,000 lb. low rating.

The units with the external slave were 1988-1994 units (Getrag for the early ones) then in 1995 they went with the integrated slave/release bearing (as did the NV4500). One problem you would run into swapping one of these in to a square body would be the hydraulic hose as the hose at the slave is attached via push in connection with a roll pin. The square body specific master cylinders use a threaded connected at the m/c (and slave). So that would mean you would have to either concoct a fashion to use a GMT400 slave in a square body (which could be a hassle to figure out the geometry to connect it to the clutch pedal) or figure out a way to make your own hydraulic hose.

I don’t think NV3500’s are horrible transmissions, I just don’t feel they are up to par for 4x4 duty. Hell, I ran one behind a 454 for a year before an auto swap in a ’93 2wd Sportside project and I just inhered another 2wd NV3500 this past week from a buddy that I plan to bolt behind the TBI 5.7L that came out of the Polar Bear Suburban for some future 2wd project. Again, not bad transmission…..just not sure they are worth the time and effort to swap into a 4x4 but then again, I am getting pretty turned off by how finicky the damn NV4500’s are too. Might just go with a built 4L80E on the next project or the next time of my NV4500's chits the bed again.
 
You're in Michigan correct? I have an early nv3500 or possibly getrag. It's out of a 91 half ton four wheel drive. I'd sell it cheap if you're interesting.
 
They sell adaptors for the slave cylinder hose issue. I use one on mine and was able to get it to work easy enough.
 
Mikey von said:
For an expedition build, I think you will be plenty happy with the nv4500. A few weeks ago, I ran about 30 miles of backcountry Mtn. roads. Expect for washes and downed trees (where low comes in nicely), I hardly left 2nd (3rd). I have not felt the need for an extra gear except towing heavy in the hills on highway , where 2/3 (3/4) split is too wide.
Click to expand...


Do you have a 6.2?
 
82355 said:
Link?

Martin
Click to expand...


Hooking up the internal or external slave is absolutely non issue. All you need is two GM quick disconnect to -4/-3 fittings and some -4 line. I made mine in the street truck in about 10 minutes.

Fitting seen here.

20140103_173233_zpsadc3abc0.jpg



Larry said:
As mentioned, NV3500’s are great driver transmissions but that is about it. They have no low range, which is a major minus if you plan to actually wheel with this rig. If I recall, 1st gear was like 3.09:1 or something stupid high like that whereas, a NV4500 would be 6:34 or 5:61 for later models. The other thing to keep in mind is GM did not offer Z82 trailering packages on any trucks that used the NV3500. So with that, they were only rated to tow the GM minimum of 2,000 lbs. That alone leads me to believe the NV3500 didn’t fare well in durability testing for what trucks are intended to get used for resulting in them being neutered to only 2,000 lb. low rating.

The units with the external slave were 1988-1994 units (Getrag for the early ones) then in 1995 they went with the integrated slave/release bearing (as did the NV4500). One problem you would run into swapping one of these in to a square body would be the hydraulic hose as the hose at the slave is attached via push in connection with a roll pin. The square body specific master cylinders use a threaded connected at the m/c (and slave). So that would mean you would have to either concoct a fashion to use a GMT400 slave in a square body (which could be a hassle to figure out the geometry to connect it to the clutch pedal) or figure out a way to make your own hydraulic hose.

I don’t think NV3500’s are horrible transmissions, I just don’t feel they are up to par for 4x4 duty. Hell, I ran one behind a 454 for a year before an auto swap in a ’93 2wd Sportside project and I just inhered another 2wd NV3500 this past week from a buddy that I plan to bolt behind the TBI 5.7L that came out of the Polar Bear Suburban for some future 2wd project. Again, not bad transmission…..just not sure they are worth the time and effort to swap into a 4x4 but then again, I am getting pretty turned off by how finicky the damn NV4500’s are too. Might just go with a built 4L80E on the next project or the next time of my NV4500's chits the bed again.
Click to expand...



NV3500s are 4:1 first gear in a fullsize and 3.5:1 in an s10.

4:1 first gear might not be granny but its nothing to scoff at when it comes to getting big tires rolling. That being said Ive towed numerous cars with mine and its terrible.
 
Stomis said:
Hooking up the internal or external slave is absolutely non issue. All you need is two GM quick disconnect to -4/-3 fittings and some -4 line. I made mine in the street truck in about 10 minutes.
Click to expand...

So . . . . . . link?

Martin
 
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