Can a mid-'90s 5 speed transmission be put in a 1977 Dodge W100 4X4; specifically one that has early '70s 3/4 ton axles, springs, and transfer case, and a 360 V8?If so, what "special" parts would be required to mate the tranny to the engine? Will the existing transfer case bolt to the tranny, or should a transmission/transfer case assembly be procured for the swap?The reason for thinking about the swap is to get the overdrive to offset the 4.1 gearing of the 3/4 ton axles.

With enough money and time it would not be totally impossible, but one needs to ask the quest as to why bother.Better options exist instead of attempting morph parts onto something that was never intended to be morphed...If you are seeking over drive then you might be further ahead to add a overdrive unit and be done with it.Check out Gear Vendors for one manufacturer...GEAR VENDORS OVER DRIVE UNITThey also make an under drive unit which allows you to drop your gear ratio on the axles to get better mileage when the power is not needed. When you need the extra power you stomp the under drive switch and you have a new gear ratio to work with.Either way much better than attempting to adapt a 90s transmission to a older engine/vehicle..

Gear vendors overdrives are pricey, over $3000 without installation, and only work in 2WD. Also, I'm not sure that the GV overdrive is compatible with the NP 205 transfer case in your truck. And you'd need new driveshaft.The problem is going to be matching the spline count and mounting flange on the transfer case. Advance adapters probably has the one you'll need in stock. You'll need to look for a manual transmisison 3/4 ton or 1 ton Dodge V8 powered 4x4 truck from 1994 to 2002, which should have the V8 version of the NV4500 5 speed.You cannot use the transfer case out of the donor truck, it will be driver's side drop, your truck is passenger side drop (front drive shaft). You could mate a late 80's / 1990-93 NV241 transfer case to the NV4500 (like the transfer case in my 1990 Ramcharger).Personally, I'd go with the NV4500 and adapter, keeping the 205 transfer case... as a cast iron gear drive case, it's fairly bulletproof. You'd probably still be able to keep your current driveshafts, depending on the difference in length with adapter between the NV4500 and the four speed that's currently in your truck.

HoJoPo wrote:Gear vendors overdrives are pricey, over $3000 without installation, and only work in 2WD. Also, I'm not sure that the GV overdrive is compatible with the NP 205 transfer case in your truck. And you'd need new driveshaft.The problem is going to be matching the spline count and mounting flange on the transfer case. Advance adapters probably has the one you'll need in stock. You'll need to look for a manual transmisison 3/4 ton or 1 ton Dodge V8 powered 4x4 truck from 1994 to 2002, which should have the V8 version of the NV4500 5 speed.You cannot use the transfer case out of the donor truck, it will be driver's side drop, your truck is passenger side drop (front drive shaft). You could mate a late 80's / 1990-93 NV241 transfer case to the NV4500 (like the transfer case in my 1990 Ramcharger).Personally, I'd go with the NV4500 and adapter, keeping the 205 transfer case... as a cast iron gear drive case, it's fairly bulletproof. You'd probably still be able to keep your current driveshafts, depending on the difference in length with adapter between the NV4500 and the four speed that's currently in your truck.From Gear Vendors site.."GEAR VENDORS makes specific adaptation kits for each model of transfer case. This is far more costly than other manufacturers who will have you move your transfer case because GM/Dodge/Ford all use the same patterns between the transfer case and transmission (thus one kit fits all). Simple for them but a host of engineering problems for you and the truck. By making specific extension housings to each model/brand transfer case GEAR VENDORS is able to have a better product with great engineering benefit to the final installation. Fact is, when you are in 4X4 there is very little desire to use GearSplitting and overdrive unless you are racing (and we do make the in-between kit for that purpose), it's 2wd where the benefits of overdrive and additional gears are most needed. All our kits bolt directly to the rear of the transfer case and are electronically locked out during 4X4 operation.No additional crossmembers and you retain the factory ground clearance instead of moving the transfer case rearward which puts it at or nearer the middle of the wheelbase where ground clearance is most critical. No lengthening of the front driveshaft which can create too long a shaft for today's highway speeds and engineering concerns of joint cancellation and driveshaft critical speeds. You get all the benefits of the GearSplitting performance and overdrive economy listed in the 2wd section (see your appropriate transmission under GM/Dodge/Ford 2wd) and the best auxiliary transmission you can buy. Call us at the factory for any questions on the product or installation or to arrange for installation at your local authorized dealer or preferred mechanic."Gear Vendors can be pricy but if you add up the costs of a "donor" transmission which if used would most likely need rebuilt, That would put you somewhere around $2K-$K right off the top. Then add in additional parts like adapters and such.Gear Vendors does more than overdrive, it basically allows you to SPLIT GEARS. A 3 speed becomes a 6 speed, a 4 speed becomes an 8 speed.My Dad has one, has in excess of 200K miles on it, works flawless.

So, I can remove, rebuild, and reinstall the clunky old 4 speed transmission, along with the gear vendors kit, to get an 8 speed transmission that I neither need nor want, or I can replace the clunky old worn 4 speed with a 5 speed to get the overdrive I want...Price-wise, it seems to be a toss up...Or, for about the same amount of money, I can upgrade to a '99 to '01 Dodge 1500 extended cab SWB, 360/automatic, and have a more "civilized" ride...Or, I can forget the whole thing and keep the ratty old '77 Dodge Power Wagon, complete with noisy clunky 4 speed...If installing the 5 speed were a little simpler, I would go for it.The Gear Vendors is out of the question. While it will give me the overdrive I want, it will also give me things I do not want. "electronically locked out..." I have an intense dislike for modern electronics, especially those that control gearcases!At the moment, it looks like keeping the ratty old truck is the best bet. I'll just keep tinkering with the electrical system, get the gauges working, change the speedometer, and drive it!Shucks, I might even recharge the air conditioning next spring!thanks for the thoughts. It gives me something to think about on the cold winter nights to come...

mowermech wrote: "electronically locked out..." I have an intense dislike for modern electronics, especially those that control gearcases!:RIn that case, you might want to remove all the electronic parts from your PC and perhaps try computing with a bunch of mechanical gears and see how that works..Seriously that is a real silly outlook on life.I have several very antique autos, not one stitch of modern day electronics and I can tell you this.. They are FAR from being "reliable", I would not want to have to rely on them as my one and only means of transportation.I have logged several MILLION miles on many modern day vehicles and I can tell you that they have been much more trouble free than my 40+ old vehicles...

Transmission change | Good Sam Community

HoJoPo
Explorer
Nov 10, 2013
Gear vendors overdrives are pricey, over $3000 without installation, and only work in 2WD. Also, I'm not sure that the GV overdrive is compatible with the NP 205 transfer case in your truck. And you'd need new driveshaft.

The problem is going to be matching the spline count and mounting flange on the transfer case. Advance adapters probably has the one you'll need in stock. You'll need to look for a manual transmisison 3/4 ton or 1 ton Dodge V8 powered 4x4 truck from 1994 to 2002, which should have the V8 version of the NV4500 5 speed.

You cannot use the transfer case out of the donor truck, it will be driver's side drop, your truck is passenger side drop (front drive shaft). You could mate a late 80's / 1990-93 NV241 transfer case to the NV4500 (like the transfer case in my 1990 Ramcharger).

Personally, I'd go with the NV4500 and adapter, keeping the 205 transfer case... as a cast iron gear drive case, it's fairly bulletproof. You'd probably still be able to keep your current driveshafts, depending on the difference in length with adapter between the NV4500 and the four speed that's currently in your truck.
Gdetrailer
Explorer III
Nov 10, 2013
With enough money and time it would not be totally impossible, but one needs to ask the quest as to why bother.

Better options exist instead of attempting morph parts onto something that was never intended to be morphed...

If you are seeking over drive then you might be further ahead to add a overdrive unit and be done with it.

Check out Gear Vendors for one manufacturer...

GEAR VENDORS OVER DRIVE UNIT

They also make an under drive unit which allows you to drop your gear ratio on the axles to get better mileage when the power is not needed. When you need the extra power you stomp the under drive switch and you have a new gear ratio to work with.

Either way much better than attempting to adapt a 90s transmission to a older engine/vehicle..

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