Automatic behind a heavily modified and built SD33T

[RMP&O]

Hello,

I have a Nissan patrol with a very heavily modified and built up sd33t. I had planned to put an nv4500 behind it using the IH north kit, I even went as far as to buy the kit.

Now I am wanting to put an auto behind it. The 727 came behind the Scout sd33t right? How good is this tranny? Can it be built up a bit? What is gearing like in it? Is the 727 a floor shifter and if not can it be made into one fairly easily? Sorry if these seem like dumb questions....I am not familiar with this auto.

I would like to put a slightly built th700 behind my sd33t. But how possible is this? Would it just be a matter of machining up a one off adapter plate?

Thanks a lot for any help!

 

[kyleandhisIH]

hello,

I have a Nissan patrol with a very heavily modified and built up sd33t. I had planned to put an nv4500 behind it using the IH north kit, I even went as far as to buy the kit.

Now I am wanting to put an auto behind it. The 727 came behind the Scout sd33t right? How good is this tranny? Can it be built up a bit? What is gearing like in it? Is the 727 a floor shifter and if not can it be made into one fairly easily? Sorry if these seem like dumb questions....I am not familiar with this auto.

I would like to put a slightly built th700 behind my sd33t. But how possible is this? Would it just be a matter of machining up a one off adapter plate?

Thanks a lot for any help!

Many people don't like plugging the sd33 diesel into that particular transmission due to somewhat sluggish response from the wide shift relationships. I think my own 727's ratios are ~2.7x, ~1.7x, 1.00. A tailored torque converter probably helps the engine to get on top of the load, and if you're not a speed demon I don't think you'd have a problem with it. The last factor that determines wether you need a 727 is your intended area's topography - can such wide shifts cover the kind of driving you plan on doing?


The 727 utilizes a floor shifter in the Scout II's. I know you can find the column shift setup in late 60's GM pickups. I am not 100% sure, but I think you need to match the shifter with the transmission's shift shaft linkage to ensure proper synchronization and selection.


You don't need to worry about the 727's strength. That gets proven every weekend at the drag strip behind my house. Ultimately the transmission will give back what you put into it, and everyone seems to recommend the transgo tf-2 shift reprogramming kit. I believe this gives you a more solid 2-3 shift, among other things.


You say a th700 is in your sights. The r4 version can come with ratios of 3.06, 1.62, 1.00, and 0.70, and that's if my internet source is correct. This is both a lower first and higher second gear than the 727 offers, as well as a rather deep overdrive. The 727's last two gears (1.00 / 1.71 = 0.62) are a bit further apart than the 700-r4's, which could mean a bit more usable downshift in the 700-r4 at highway speeds.


I do not know how easy a machined adapter could be created for the combo, and I can guess that it'll be pretty expensive. It's definitely a route that would see more long-term satisfaction if the unit you use is robust and in shape, and if you can obtain the optimum rear-end gearing for cruise-speed power. Hopefully someone with more slushbox experience can chime in and fill in all my gaps.

 

[Michael Mayben]

hello,

I have a Nissan patrol with a very heavily modified and built up sd33t. I had planned to put an nv4500 behind it using the IH north kit, I even went as far as to buy the kit.

Now I am wanting to put an auto behind it. The 727 came behind the Scout sd33t right? How good is this tranny? Can it be built up a bit? What is gearing like in it? Is the 727 a floor shifter and if not can it be made into one fairly easily? Sorry if these seem like dumb questions....I am not familiar with this auto.

I would like to put a slightly built th700 behind my sd33t. But how possible is this? Would it just be a matter of machining up a one off adapter plate?

Thanks a lot for any help!

Converting the Nissan sd33t to use with a tf 727 is far more involved than a simple "adaptation".

First off, a correctly built 727 is far more than capable of handling any sd33t output. And that requires nothing out of the ordinary other than using the right parts for the build.

I'm not familiar with the patrol as far as what it uses for a transfer case setup...married or divorced? That factor would determine which version of a tf 727 you started with.

The t-407/4x4 option behind an sd33 in a Scout II used a married Dana/spicer 20. And...that particular transmission is specific to the sd33t application along with the amc 232/258 gasoline engine. The bellhousing pattern is the amc pattern and also places the starter on the driver side which is opposite compared to any IH sv (v8) engine application.

The sd33t installed in a Scout II uses an "sae"-pattern "flywheel housing"/adapter, along with a unique crank hub adapter and "spider" (rudimentary flex plate). The torque converter is also somewhat a dedicated unit (stall speed) for use behind the diesel.

In short...in order to mate your existing engine to a 727, you would need an entire "pullout" sd33t powertrain from a Scout II and use everything that is bolted to the rear of the block and the flywheel. And that would be for a married transfer case setup unless ya found a diesel Scout II in 2x4 trim (highly unlikely) for a donor. That trans would have a very short tailshaft ending in a bolt-on yoke for the u-joint/output.

 

[RMP&O]

Hey guys...I guess I should clarify,

my patrol is not used on the pavement much. It has full hydraulic steering and 40" tires along with many other mods that have turned it into basically a trailer queen. So I don't care at all about on road performance.

The patrol has a married t-case....that doesn't really matter either though as I am going with an atlas.

As far as short rear prop shaft. My wheelbase is 113", stretched from the stock 93". Rear suspension is a tri-4link so plenty of room. As far as bolt in, I didn't mean there won't be some fab work, obviously tranny mounts and so forth wil be new and custom fabbed. I meant by bolt in that I won't need to make a custom one off adapter plate.

As far as getting all the stuff from the back of the Scout sd33t. Not really a problem, it is available for a reasonable price from more than one Scout source. I have to use the Scout bellhousing at the least to go with the nv4500 any ways. It is a custom built truck, none of this is new to me!

The main uses of the truck is rock crawling and other types of off-roading. In the rocks the auto is just going to be much better. Plus some day I might compete in the truck, just for fun...but an auto will definately give me the chance to do something other than just finish in last place!

 

[Carl Wiese]

What you'll need to do is find an auto behind a sd33. The n/a diesel in the Scout had a option to come with the 727, the turbo models did not. Once you've got it I would suggest you find a Jeep round tailshaft housing and tailshaft that would mate to the Dana 300. When you rebuild the 727, you simple swap on the Jeep tailshaft housing and tailshaft and now you can bolt the atlas directly to the transmission, no need for another adapter.

As for the transmission itself, I'd build it no different then any other transmission I'd build for crawling. Heavy duty parts, rmvb and I'd let my wallet decide how crazy I wanted to be. You're really want to pay attention to what torque converter you've got in it. The stock diesel converter maybe a good place to start, but you May end up having one built for you by a professional to get the preformance you want. Good luck.