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NV4500? Is this cheap?

bigred88

bigred88

1/2 ton status
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The TC has been really slow to lock up lately in my 700r4, and I'd like to go to a stick, so if I'm going to pull the tranny I don't want to put any cash into the 700r4, I'd just rather swap over at that point. And I want an OD, so I'm thinking NV4500.

I admittedly haven't done all the needed research yet, I have none of the parts needed for the swap, and I'm not 100% sold on actually doing the swap. I was just looking on craigslist to get an idea of price, and most were listed for around $800-$1000, but one guy has a few listed for $400 each.

I'd want to rebuild whatever I get anyways- once the tranny is in there I don't want to pull it again, and I don't want any mystery as to the condition- so at that point cheaper is better. But he said they're from 2wd trucks- is it possible to switch them over? Is it worth it? He also says he has ones from 91-95 and 96-00 (I'm assuming there was a significant change in 96?).

Seeing how much cheaper they are than the others I've seen listed, I'm just wondering if this is a deal I should jump on and figure the rest out after, or am I inviting more stress and money by getting a 2wd transmission?

Also, if anyone has a link to a detailed automatic to nv4500 swap writeup, I would appreciate it if you could post it. I've been doing some searching, but haven't found anything that specific yet.
 
Thanks for the link. I still haven't found anything outright saying 2wd to 4wd can't be done, but it kind of sounds that way. I'll keep doing research, that just popped up and it seemed really cheap. Maybe that's why.

I've got a 350/700r4/3.73/31", the K5 is a dd/on the way too rare occasions that I can do it light wheeler. I do a fair bit of highway driving (daily 10 mile each way interstate commute, and two days a week a 30 mile each way all interstate drive), and it does get taken on the occaisional long distance trip. I don't think I'm willing to give up the OD- honestly if the NV4500 isn't doable I might just stick with the 700r4. I'll do some more reading into the sm465, because I know it's a lot cheaper/easier, but I just don't think it is the right fit for what I use the truck for.
 
Just to give you some numbers to help you make up your mind.

305/700R4/3.08/28.8" tires= 1510RPM@60MPH
305/700R4/3.08/31" = 1403@60MPH

350/465/3.42/33" = 2090@60MPH

350/465/3.73/31" = 2427@60MPH
350/465/3.73/33" = 2280@60MPH

First three combos are what I personally ran/run. Average freeway only MPG was/is 17MPG for all three.

Outside of massively changing cruise RPM (say by 1000RPM) I believe aerodynamics at speed are the real problem with economy. Higher RPM will indeed not help matters.

I despise automatics though, so you'd be hard pressed to find me saying to keep it that way, but I understand. :)
 
I'd much rather have a manual, but I've had this as an auto for 6 years now, so I'm pretty well used to it.

And I'm not expecting great MPGs, yeah, 5,000lbs and brick styling generally doesn't do great for that. Still, I'd rather not see too much of a dip.

Thanks for the numbers! I find it really interesting that your 3 setups were all a wash when it came to mileage. I would not have expected that. Maybe it is more weight/aerodynamics controlled than I was thinking.

I just ran these off grimmjeeper's calculator, so they may vary a little if you used something else, but:

700r4/3.73/31- 1698 @ 60mph
NV4500/3.73/31- 1819 @ 60mph
sm465/3.73/31- 2426 @ 60mph
sm465/3.73/33- 2279 @ 60mph

Even if I step up to 33s, which I'm not opposed to (but I would need a small lift at that point, more $$), I'm looking at ~450 more rpms at 60mph with a 465 vs a NV4500.

I guess I don't really know what that would look like in terms of mpg change- I mean, are we talking 0.5 mpg less? 1? 2? I don't know how that math would work at that point.

What concerns me is the numbers when you set the speed to 80mph, though. I don't often hit 80, but 70 isn't uncommon and if I'm driving across Kansas like I do from time to time, I don't really slow down to watch the scenery:whistle:. I'd be looking at 3234rpm with a 465 vs. 2426 with a NV4500. I think I'd be uncomfortable running it at over 3,000 rpms for a long period of time, and I'd need earplugs or a different muffler:D, or I would just need to chill out and slow down:doah:.

The 4500 just seems to compare a lot more closely to the 700r4 across the board for gearing, plus you get the low first. But then it costs more. Of course. Damn tradeoffs.:rolleyes:
 
Well if you aren't hard on it (sounds like you and I are fairly similar in usage), apparently the NV3500 may be an option. There is a thread a few posts back that talks about them. I thought they were all light duty pieces of junk, but it sounds like the later ones are pretty decent. Then again, the 3500 may come with it's own host of "problems" compared to the NV4500, but you'd have to research to find out what those might be. I tend to overbuild stuff for my use, but I don't like "fixing" things more than once either. I'd spend time/money on the 4500 over the 3500, unless the cost savings was massive on the 3500, and I was reasonably certain I got one that would hold up for a long time.

If you look at my signature, the 350 has IMO just about every "efficiency" change (for light throttle use) I can think of, yet it just equals the 305 for mileage. I didn't include it, but I had the exact same setup (same truck/drivetrain) but carbed then fuel injected as it is now, and there was no change in highway mileage there either. I spent a decent amount of time with the carb making sure it was dialed in, but nothing crazy.

If you are looking at 80MPH, I don't think transmission gearing is going to make a hill of beans difference. Somewhere I've got a chart showing the HP needed to move one of these trucks at various MPH's, and as we all know, it's exponential. Anything over about 55-60MPH and you are just throwing money away.

Many of the trucks came with drivetrain combos that put them into the 3000's at cruise, but while I may not think it would be a real issue to run at that RPM constantly, I don't want to listen to the motor turning that fast, nor the wind noise either. I normally limit myself to 65MPH just so I'm not listening to it quite so much. Plus at ~17MPG, I'm not looking to buy more fuel than I have to!

If you stick with stock wheels and 33x10.5R15 (BFG AT or MT's), you don't need a lift BTW.
 
The 3500 can survive. Assuming your old enough to know that 3000 rpm launches are for the young and dumb. My friend has one in his mud truck, 38in tires and a 350HO and his has been just fine. But he doesnt abuse the hell out of it either.

A 4500 would be ideal, if you can find one thats not all banged up and such. But dont rule the 3500 out.
 
I was the one interested in the NV3500. I think you would be a good candidate for one. I don't believe you really need the overkill that an NV4500 would be in your situation. Also, when I swapped from a TH700R4 to an SM465 in my 1988 V10 Suburban, I really didn't notice much of a mileage change.

Martin
 
Im semi tempted to swap a 4500 in mine, or use all my wiring and the 4L80E I have kicking around and do it. Choices choices.
 
Yeah, 80mph is going to kill efficiency with anything, I was just more concerned with the high rpms at that point. And it's rare that I'd be going that fast, but I don't want to make it obnoxious to do so.

I've seen the NV3500 come up a few times, too, but I had pretty much made that same assumption. I'll look into that a little more, too. And yeah, 3000rpm launches coupled with truck tires (and my 10 bolts!) always seemed like a bad idea. I prefer my truck functional and in one piece.
 
I think the terrible gear spread is more the issue with the sm465 than the outright lack of OD. But its really the OD in the nv4500 that lets you use deeper gears and make the gear jumps less noticeable.

I for one can tell you Id never build an sm465 into anything other than a trail rig again. The nv4500 is worth the money and when I go to build a work truck down the road it might even have a nv5600 behind the 4bt.
 
Where did ya find them for only 400 bucks... hell at the price Id buy all them... I gave almost 900 for one of mine, and it come from Texas... The other I only gave 200 bucks for, and was able to drive the truck, then pulled it in the guys garage and pulled it out...

Im needing a spare one or two to keep around..
 
I think the price on these things is coming down. They've been out long enough that they are starting to get into the realm of the 465...they've been out of use long enough (at least with GM) that people aren't as interested in them. Not to mention the utter dominance of automatics in the marketplace.

I saw a complete TPI setup for $300 a couple weeks ago at the swap meet, I remember when seeing one for $500 was a great deal. I'm really beginning to believe that these trucks/this vintage of vehicle is starting to peter out in popularity with the masses, and the dwindling availability is going to result in less people getting into them in the first place.

Now the 5600, that would be pretty sweet I'm sure, I better go take a look at the specs on that thing again, it's been awhile. :)
 
bronc3buster842001 said:
Where did ya find them for only 400 bucks... hell at the price Id buy all them... I gave almost 900 for one of mine, and it come from Texas... The other I only gave 200 bucks for, and was able to drive the truck, then pulled it in the guys garage and pulled it out...

Im needing a spare one or two to keep around..
Click to expand...

Some guy had two listed on the St. Louis craigslist, but they were both 2WD, and from what I've read I don't think it's possible to convert that to 4WD. I read conclusively that you can't do that with a 3500, but couldn't find anything that said that outright with a 4500, so...:dunno:.

I did briefly get all crazy and start looking at what it would take to drop a ZF S6-650 in. Then I came back down to earth when I realized that would take a lot of fab, and remembered I don't know how to weld.:doah::haha:

With the warmer temps the tranny seems to be behaving better, so I don't think I'm as pressed to do this soon as I was thinking, so I think I'm just going to keep my eyes peeled at the local junkyards and see if I can score a NV4500 core for cheap and rebuild one.
 
The rear extension housing is different between 4x4 and 2WD. But, unlike other trans, it is a much larger and more involved piece- there are gears inside the housing. Here is a page with some specs and a parts breakdown:http://www.offroaders.com/directory/products/NV4500-exploded.htm

Also, this is the difference in the pre-'96 and post '96 GM trans. Looks like GM went with the Dodge bolt pattern on the trans side of the bell housing:

Bellhousing Bolt Pattern:


  • GM 1993-1995 10.078 across the top, 10.394 across the bottom, 4.685 vertically
  • GM 1996 + up 10.078 across the top, 9.738 across the bottom, 6.043 vertically
  • Dodge (All) 10.078 across the top, 9.738 across the bottom, 6.043 vertically
I've been looking to swap my 700R4/208 combo to a NV4500/205, so I've been trying to do some research as well.
 
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