Transmission Question

My jeepster has the original 225 dauntless V6 connected to the T-86 tranny that is shot. Engine runs strong but I will replace it soon. I need to get a replacement tranny and Earlycj5 member trickpatrick suggested i go with a 4 speed. I need to know which type/brand I should go with. Suggestions anyone? I need some help here as this is my first jeep and first resto. Thanks!

www.goincommando.wordpress.com

 

With the longer wheelbase of the commando, I would go with a t-18 out of a J-truck or wagoneer. These are pretty cheap and plentiful, and matched up with the Buick ring adapter from a early 400-turbo or one that originally came behind a Buick 350 it will bolt right up. These set-ups were actually the same length as the t-400 so that they could use the same crossmember and drivelines in both the manual and auto trannies.

 

You're saying you will replace the 225? With what engine? It might make a difference as far a transmission selection.

If you're staying with the 225, almost any truck 4-spd will work, with the T18 (Ford version) and SM420/465 swaps being the most common. You could even swap in a NV3550 5-spd from a TJ. Plenty of room in the Jeepster/CJ6 wheelbase as long as you keep it out of the clouds.

Daryl makes a good point about J-truck combos. Also keep in mind the TH400/D20 combo that came in Jeepsters from the factory. That is, if you're into automatics.

 

Thanks for the advice, Daryl.

 

Ok, gentlemen.......additional question......should i stick with the 225 or should i go with something like a 350...etc....? Is the 225 a strong engine?

 

IMO the 225 is a fine engine, and powerful for its size; no need to change it unless you want more displacement.

The small-block Buicks are excellent swaps into this chassis; 300, 340, 350 cid. Drops right onto the 225 motor mounts. All you have to do is move the radiator forward. Great with the TH400 in this chassis.

Nothing wrong with the 350 SBC, except that it's a harder swap than the Buick.

 

This begs the question.....do I, then, go with the TH400 or do i go with a 4-speed tranny? I don't at all mind going with the automatic, I just wonder what the jeep world's opinion is of having a jeep that has an automatic versus a manual. Thoughts,folks?

www.goincommando.wordpress.com :v6:

 

if you're gonna wheel it, I think the auto has disadvantages when it comes to long, steep, downhills...meaning I don't think you have the engine compression and gearing to hold you back as well as a manual transmission; I'm speaking in terms of engine idling here as you don't need to accelerate much in this situation.
with that being said, I have a manual trans.

 

I have always run sticks in my Jeeps (for wheeling) but my '71 Commando is getting a automatic (th350) and I am sticking with the Buick 225 V6. You cant beat them for power to weight. Not to mention they package alot easier than the V8.

And just for those asking why the Th350, becouse they take less HP to run that the Th400, and they weigh less. I'll be running a D300 t-case behind it. You can loose some of the engine braking with an Auto, but you can build them to hold the gear and get some braking.

I'll run it and see...If I dont like it, I am putting in a SM465 4spd.

 

I assumed someone with more experience than I would know this.

 

Driving an automatic in the rocks is a different, two-footed style of driving. You let the brakes hold you back and give the throttle enough speed to inch over the rocks and overcome the force of the brakes. You have the potential for a lot of control, and the torque-multiplication of the automatic can supply more power at low speed than you would have with a manual transmission. With a manual, you typically keep your foot off of the brake and clutch to move over an obstacle, feather the throttle, and let the gearing work for you.

So, with an automatic, you have the opportunity to have an effectively better crawl ratio without deep gearing, but you put more strain on the brakes, transmission and cooling, and use more fuel.

There's some automatic-specific crawler tech that I know exists but don't know well enough to comment on ... maybe others will. Certainly the factory TH400 is very durable and works well without a lot of mods, though I'm sure it can be improved upon.

I'd think that disk brakes would be a good upgrade for an automatic-equipped Jeep.

 

As mentioned above, long downhill grades can easily overtax drums and even disks when running autos. Ideally you could find a waggy, or J-truck and just pull the whole set-up for the swap. I just had a 65 J-truck follow me home with a Buick 350 and 400 turbo.

 

Looks like, for now, i am going to go with the TH400? It should bolt right up to the 225 right? will it be necessary to use an adapter or modification to make it fit? :v6:


www.goincommando.wordpress.com

 

It has to have the BOP pattern
Buick Olds Pontiac. or a Chevy with an adaptor.
It has to be switched to a 4x4 short shaft, and if you keep your Tcase an adaptor.

 

If it's out of your partster, which I'm assuming is a 71 or older, it will bolt right up. If so it will have the adapter and probably even the broken boss(es) where the mount bolts to R). Maybe you'll get lucky and it won't be broken. Plus you'll have all the other parts you'll need to make it work like drive shafts, shifter, etc.

 

Thanks, Pack! the partster is also a 67......i will get under it tomorrow to get a better picture of what i have in the partster.....i do know it has a solid TH400 and also another 225.....

 

Just a quick question. I have a customer that I am working with that wants to put a 4 speed sm465 in. I know it can be done with the 225 and the np205 tcase already installed in this modified vehicle. just need to know what year sm465 to be looking for.

 

I am not sure. But, Packrat and trickpatrick are both great resources. If you guys read this. Can you chime in on this question. :v6:

www.goincommando.wordpress.com

 

I'm not really up on adapting trannies, but Novak has some good information on the SM465 NOVAK ADAPTER. Thinking you'll be wanting the later edition though.

 

The 205 won't fit without cutting the frame.
Just too wide.

Should be a Dana 20 Tcase in it now.