NV3500 to NV4500 moved from the 88-98 Forum...need advice

[bad68bowtie]

My buddy has a '98 Z71 with a 5.7 and an NV3500 backing it up. He's been hearing a lot of racket from the transmission as of late (the truck has a little over 165,000 miles on it) and has been trying to prepare for it to go out on him. He and I were talking about it and figured it wouldn't be a bad idea to swap in a NV4500 when the 3500 finally kicks the bucket, if it's possible to do so.

So my question is, does anyone know what it would entail to swap in an NV4500 in place of an NV3500? Did the two transmissions use the same transfer case? We were figuring that unless there's a bunch of crap to deal with to make the 4500 work, the money and time would be better well spent to go ahead and step up to the 4500 as opposed to just rebuilding the 3500.

Any input y'all could provide would be much appreciated, thanks.

[bad68bowtie]

Anyone? I admit it is kind of an off the wall question.

[DirtyLarry]

I suspect the transfer cases are the same (NP241) with the same spline count as well. 1 ton trucks with NV4500 transmissions used a Borq Warner tcase but not sure of the spline count. Chances are the trans cross member may need to be slid forward or backward a bit as the transmissions are probably different lengths which would also mean the driveshafts length could be different.

Depending on what year of NV4500 bell housing you use may depend on which kind of slave cylinder you will need. The earlier NV4500’s had an external slave while the later ones (1996 and later, I think) have an integrated slave with the release bearing just like what would already be in his ’98 now.

I had a ’98 Z71 ECSB with a NV3500 years ago. Actually bought it brand new. Manuals in the late 90’s were pretty rare.

[Dieselwrencher]

You could possibly get one from a 94-02 Dodge as well as long as you get one from a gas engine truck. I'm not positive, but I was told the output shaft for the NV3500 and NV4500 are the same. But I'm not 100% on that.

[cobinder]

I'd look at advance adapters site, good source of info

[bad68bowtie]

Cool. Thanks for the input guys. I guess the plan right now is gonna be to check some of the local wrecking yards to see what they have available and go from there. I reckon searching through some service manuals probably wouldn't hurt either.

DirtyLarry- Yeah, when my buddy was looking for his truck he insisted that it be a manual. He searched for a long while and finally found this one in Indiana for a decent price and drove it back here. I don't think I've ever seen one listed around here that wasn't a 305 or 4.3.

[newagecustom]

I have a 2000 new body style with a 4.8l v8 4x4 and a nv3500 that i am having problems with. I have been thinking about this too but i have been told the 1/2 ton transfer case will not work with the nv4500.

[woodwright]

I think there is a lot more options with the 4500. Check with Advance Adapters. I know you can mate them to a 205 as well.

[skchevota]

You want an nv 4500 from a chevy . If you use the dodge version, you have to use a bell housing from a company like advanced adapters which is like $500.
Then the out put has a diferant spline, and the clocking is a bit differant on the t case mountiong holes.
Get one from a chevy, with the factory bell housing, your t case will bolt right up, you might have to move the x member as stated, and mabey some drive line mods. The only reason to use a dodge vertion is if you are installing in an older chevy and have a pasenger drop t case. The chevy version has the slave cyilinder on that side and can cause drive line clearance issues. In your case, you will be just fine.

[Russell]

Just keep in mind that the gear spacing on the NV4500 is less than ideal. I'd sooner rebuild an NV3500 and continue to run it in a DD than to install an NV4500. I've put plenty of miles on 3500s in the past, and never had a lot of trouble. Only one I've ever had fail on me was the transmission in my old 96. The PO had it rebuilt shortly before I purchased it and filled it with 80w90. The transmission uses a 5w30 weight oil with an additive package, so it started making bad noises soon after I brought it home. Made noises for a good year / 10 000 miles before the syncronizers finally packed it in prompting a rebuild.

If you decide you do want to make the swap, it is more straight forward than you might be thinking. Most NV3500s are indeed 27 spline instead of 32 spline, but not all of them. I have an NV3500 from a 04, and it is definitely 32 spline. The shifter is in the same location as the NV4500, and both transmissions are nearly identical in length. Both use the same switch for the reverse lights, and if you purchase an internal slave NV4500, it uses the same master and internal slave cylinders as the NV3500 does. The clutch spline count is the same, as is the depth of the pilot bushing penetration by the input shaft.

[bad68bowtie]

Originally Posted by Russell

Just keep in mind that the gear spacing on the NV4500 is less than ideal. I'd sooner rebuild an NV3500 and continue to run it in a DD than to install an NV4500. I've put plenty of miles on 3500s in the past, and never had a lot of trouble. Only one I've ever had fail on me was the transmission in my old 96. The PO had it rebuilt shortly before I purchased it and filled it with 80w90. The transmission uses a 5w30 weight oil with an additive package, so it started making bad noises soon after I brought it home. Made noises for a good year / 10 000 miles before the syncronizers finally packed it in prompting a rebuild.

Hm, that's an interesting point you make. This may be a dumb question, but anyone know what a ballpark figure on the cost of rebuilding an NV3500 would be? I was showing this thread to my buddy and some of the decision making may come down to the cost of either option.

[Russell]

They are not an easy transmission to overhaul, and plenty of shops simply are not equipped to do so. The last one I had "overhauled" involved me purchasing a new one from the transmission shop to the tune of $2000. After turning in my old core they re-paid me $800, so it wound up being a $1200 replacement. Keep in mind that is in Canadian dollars, and you can usually add a good 20 - 30% on anything that I buy / have done up here vs the cost in the USA, not to mention the difference in currency values.

An NV4500 would cost only a few hundred bucks more, but it isn't the end-all to all O/D manual transmissions. It has plenty of weaknesses (particularly with the 5th gear), and again, it drives like a mid 80's SM465 with an O/D gear tacked on to the top. NV3500 drives much nicer, and is a true 5 speed transmission (NV4500 is more of a 4 speed)

I suppose it all boils down to how you drive the truck, and what your purposes are. If you have a daily driver that doesn't haul much more than passengers around, and isn't powered by a overly powerful engine, an NV3500 is plenty adequate, despite it's reputation. NV4500 is does great in trucks that are abused offroad, used to haul heavy loads, or is powered by something that'll just shatter the lighter transmission.

[bad68bowtie]

Russel, thanks for all the information. I guess we'll see what happens in the coming months. To me I'm getting the feeling that maybe rebuilding the NV3500 is the better route, but it isn't my truck (or my money, thankfully ). I'll try to update this as things happen for future reference if it can help anyone else.