Manual transmission choices / discussion

[oldndcctrucks]

NOTE: I posted this in the Brainstorming Forum but it looks like that one is too random. I apologize if posting here is a rule violation; Moderators please delete the thread in Brainstorming.

Good Day All:

I have a 1973 W200 with a 318LA engine and a NV-435 transmission.

I really want overdrive (OD); I have considered the NV-4500 as was recommended, but this will not be my first choice due to high cost and all the extra work changing the clutch mechanicals. Also, buying and disposing of a donor truck is added work and time. Finally, I would like to get rid of the deep “granny” 1st gear; I don’t need it as this truck will not be pulling heavy.

I’ve also considered regearing my diff’s but haven’t priced it; I will have to pay a shop for that, so I know it will be a few thousand dollars (not worth it).

The -435 I have needs to come out for rebuild.

So, I’m looking for thoughts on the NV-445 and A-833, especially from people who have had either or both in any of their trucks.

I’ve looked at both on the interweb and can see that the A-833 will be a lot of work, as well, due to the shifter being so far to the rear and the long tail housing probably necessitating moving the transfer case.

OR, can anyone recommend an aftermarket trans?

THANKS!

-Ken

[oldndcctrucks]

Well, Tremec is out! I just got a quote for a new trans with shifter and etc. for $4365 (after $300 discount!), shipped.

[Frank Irons]

Well the 445 will add another syncro and the 883 is a car transmission. The NP540 overdrive version would be my next choice, although they are rare. NV4 500 would be my choice.

Frank

[Desoto61]

This will probably not be popular, but what about the NV3500 or AX15? They were used behind the 3.9 V6 and 318 V8 in the Dodge Dakotas for many years, so they should bolt right up to your motor, but are not as strong as the NV4500 as they were meant for the lighter trucks and SUVs. So they won't hold up to the beating that the NV4500 will, but should be far more available and cheaper.

Otherwise I don't think you're going to like any of the options. The NV4500s are expensive and getting harder to find as they're quite old now too, and trying to adapt a trans from a Ford or Chevy will be similarly expensive to the Tremec with adapter plates and such assuming they even exist.

[712edf]

The NP540, even if a rare OD version, wouldn't be a step in the right direction. They are much bigger/heavier than a 435 & require their own special bellhousing/engine mount/crossmember, plus everything inside the bell. Just not worth the expense & most are geared lower than the 435.

The 833 probably isn't strong enough to last very long, depend on how you drive it. They handle power well but aren't designed for 4x4 trucks.

At least you have a LA engine which gives you a few options, much more than a B/RB engine would.

Bucky

[KRB64]

Well, Tremec is out! I just got a quote for a new trans with shifter and etc. for $4365 (after $300 discount!), shipped.

Then a Gear Vendors under/over is probably out too as it looks like it would be a little over $3K.
https://www.gearvendors.com/4x4dmanual.html
Unless you could ever find a used unit.

[oldndcctrucks]

Aaannnd… what about the Spicer 3035a?

I did call Novak about using an AX15, but the tech said they didn't have adapters or any way to do a divorced t-case setup.

[Desoto61]

Not sure why you'd need an adapter, just use the 2WD version, you'll have to have an intermediate shaft built, but that's true of basically any transmission and a divorced t-case. Now if the 2WD AX-15 is too long to fit without moving the transfer case or other trickery then I could see that being true.

I heavily looked into the Spicer for my Cummins conversion, the biggest downside for me was finding the right adapters to get it to bolt up to the Cummins. They seem to be small, durable, and have a decent OD, though there was a company offering a lower OD ratio, which was a big draw for me. The shift pattern is a little weird IIRC, but like I said, I just didn't want to spend the money experimenting with parts to make it all work together. Charles Talbert at M-series uses them in their conversions (though his adapter stack is secret sauce unfortunately, but that doesn't affect you).

[oldndcctrucks]

Thanks Desoto!

[Desoto61]

Unfortunately unless you can stay under the same manufacturer transmission swaps are the definition of that whole "good, fast, cheap; pick two". The clutch issues and shifter location are going to be a factor for just about any swap that was not meant for the truck.

For the Cummins guys the Ford ZF manual transmissions were another option. They're small enough to be used in front of the divorced transfer case, were used for truck duty, and are relatively simple, cheap, and durable.
The biggest downsides were that there were many different versions so finding the right one is important, and if I remember correctly their OD ratio was not that great, which depending on what your rear axle ratio and tire size is may not be an issue for you (a FFPW with 4.88:1 and a diesel wants all the OD it can get). Of course for you the bigger issue is if there's any way to get it to bolt up to a Mopar. I have no idea if such a unicorn exists or would be cheap enough to justify the swap.

It may be worth trying to swap out the transmission and transfer case for a later combined unit, just have to make sure you can find one with the right "drop" off the transfer case. Seems most manufacturers swapped sides at some point. You'll have to modify the front and rear driveshafts but you also eliminate the intermediate shaft, so it's kind of a wash.

[oldndcctrucks]

Sounds like a complete trans/t-case assembly is another good option.

The trip has been delayed a year to accommodate one of my daughters’ college progress, so I now have more time and an extended budget.

So, THANKS VERY MUCH to all of you who contributed to this discussion! There are a lot of good, thought- out considerations here.

I will post here through the completion of the job, although it won’t be finished until sometime around the middle of 2020.

-Ken

[Chewie]

Old post aside, I found a 93 w250 with 5.9 magnum, an NV 4500 and 241TC. Still passenger side drop, so it's a perfect canidate to swap into the crew cab if I don't go with a cummins swap..

[712edf]

That's somewhat surprising & a good find. Seems like nobody was opting for gas engines in the W250/350 by the end of that era.

Bucky

[oldndcctrucks]

Concluded:

I am keeping the NP435 and adding a Gear Vendor OD unit to the rear of the t-case.

When that happens, I will post the updates.