Best automatic transmission?

[Brody74]

Who makes the best tranny to drop in that has more gears than say my current C4?

 

[Broncobowsher]

You need to look at a 4R70W.
It will bolt to the existing V8 without adaptors.
Has a lower 1st gear.
Has a nice .70 overdrive
Has a lockup torque convertor.
Can take a lot of power right out of the box.
You put a nice little stand alone computer on is (Baumann makes it) and you can get it to shift at the right times.
The stock shifter can be adapted to work if you desire
There are a couple of ways to put a transfer case on the back. Anything from a solid but generally cheap NP205, use a ZF adaptor kit. Those work if you start with a 4WD transmission. You can also use the Advance Adaptors AOD to Dana 20 kit with a couple of extra parts. The AOD kit works because this is a far superior moderinzed version of an AOD. It is heavy duty enough that it is still being used in 1-ton E350 vans.

 

[blubuckaroo]

GM 700R4. It has lower first and second gears, and more overdrive. Sure you'll spend more on the additional engine adapter but these transmissions cost a lot less than the Ford versions of overdrive to begin with. It's a proven "stout" transmission and you'll find them behind a lot of Ford motors. Advance Adaprers can fix you up.

 

[broncnaz]

For what its worth the 700R4 only has a .16 lower first gear and OD is the same as the 4r70W.
You biggest differance is you need a $400 engine adapter for the 700R4 where the 4r70W needs a $500 computer. Of course the 700 r4 will need a t case adapter for either the np205 or D20 while the 4r70W only needs a adapter if you want to retain the D20.

All said and done I dont think you'll see much of a price differance between either setup.

Now depending on your current axle gearing and tire size pretty much all the OD trannys will require you to change axle gearing otherwise OD will be useless. I only say depending as we dont know what your current setup is. Most people are running stock gearing and larger than stock tires so regearing the axle is a must for almost everyone. So drop in is not always drop in and not always cheap.

 

[blubuckaroo]

In a discussion with my tranny shop, the owner told me, he saw it as a slam dunk for the 700R4. He installs them in Ford trucks. He says too many problems with both AODs and 4R70Ws. The 700R4s are also cheaper to buy and rebuild.

 

[broncnaz]

A lot of places I've seen charge the about same price for a rebuilt 7004r or a 4r70W. But yes the AOD and 4r70w do have there share of issues maybe more so than the 700r4 but the 4r70w is so much more versatile with add on computer. And there issues are not that bad. Most of the issues are due to lack of proper maintenance IMO.

 

[Ranchtruck]

One of my friends bought a 98 Explorer V8 brand new, it now has 250k on it. We changed the fluid and filter in its 4r70w for the first time at 220k, and we knew it because the dipstick lollypop was still in the pan. So even with lack of maintenance they hold up well.

I see a lot more chevy's in the junkyard with smoked 700r4's than fords with smoked 4r70ws. The AOD's may have had issues, but the 4r70w's fixed that.

I can see a trans guy recommending a 700r4 just because he's much more familiar with how they look inside, and which parts to upgrade to get them to last.

If your going fuel injection, then use the harness out of a 94-95 F150 with a 4r70w. Its MAF based EEC-IV and OBDI, but has the 4r70w controls built in. That saves the cost of a Baumenator if you were going fuel injected anyway.

 

[Brody74]

i dont plan on going fuel injected... i guess i could always throw on bigger tires to attempt to get more out of my 3rd gear...

 

[broncnaz]

Even with bigger tires its a fine line. To big a differance and lowend is crappy and it puts a big strain on the tranny. What gears and tires do you currently run? realisticaly 3.50 gears and 33in tires is about as big as I'd go even then the truck may feel doggy. unless the engine is setup for the lower RPM's.
Its a snowball effect. As gearing tire size and how the engine is built all go hand in hand. you can rarely change just one thing and have the effect you want

 

[blubuckaroo]

i dont plan on going fuel injected... i guess i could always throw on bigger tires to attempt to get more out of my 3rd gear...

Or you could just run it as is. 302s usually like to run a higher RPM anyway. The problem with bigger tires and a C4 is it's very high first gear. It's hard to put big tires on without it feeling poopy off the line.

 

[Brody74]

broncnaz... as far as i know the gears are all stock (i recently picked it up) and im running 33's and maybe looking to go as high as 35's but that would be as large as i would go.

 

[broncnaz]

Most likely it has 3.50 gears most v8 broncos with automatics came with 3.50's. There are a few people that run 35in tires with 3.50 gears and claim its fine. but I wouldnt it puts a lot more strain on the tranny and will have you needing a rebuild quicker. Along with it would be pretty doggy both lowend on topend. hit a hill below 60 mph and it would probably fall flat on its face.
As was said 302's dont mind reving running 2400-3000 rpm down the hiway is fine.

 

[Brody74]

well good to know, i always felt like the rpms were high, but if thats where she's meant to run it makes me feel a lot better! what do you think i should re-gear to to run 35's?

 

[Dave]

I've been driving a 4R70W on a couple of Explorers for years. They have been flawless and I like the way they shift. Haven't got my Bronco conversion on the road yet.

The stock Explorer gearing on the 5.0 / 4R70W is 3.73 gears with 31 inch tires. They cruise really nice at about 70-80 on the highway with decent mpg and still run pretty well on the trails in the Rockys without a low range (2WD). Probably a little faster than one would cruise with a Bronco. 4.11 with 31s or 4.56 with 35s would probably be a decent choice depending on your use. Never had any heat issues trail running or pulling fairly heavy trailers. Explorers have a pretty nice aux tranny cooler that is easy to grab at a U-Jerk-It.

 

[broncnaz]

The least gears I would run with 35in tires and a C4 would be 4.10 but 4.30 or 4.56's would be better but the RPM's will be a little higher probably only 300 RPM differance but you will notice the better power with the lower gears. If your going to regear then you really need to consider if you are going to do a tranny upgrade that way you if you go with a OD tranny you wont have to change gears again. Because if a OD tranny is in your future then I would go with 4.88 or 5.13 gears with 35in tires.

 

[blubuckaroo]

Maybe just keep the 3.50 / C4 and use 32" tires. They drive better anyway. The only reason for bigger than that is boulders & bling.

 

[G's Baja Bronco]

4r70w, you get teh lower first and second and the od, get the newest 4x4 trans you can find from a v6 (2 bolt starter) and it should mate to the np 205 w/o adapters.

BTW I like this: "If your going fuel injection, then use the harness out of a 94-95 F150 with a 4r70w. Its MAF based EEC-IV and OBDI, but has the 4r70w controls built in. That saves the cost of a Baumenator if you were going fuel injected anyway." good to know, depending on how my aod with 4r70w internals behaves I might go with this set up.

 

[reddawn222]

G,

Is the bell housing and bolt pattern the same on a 4R70W from a v6 and a 5.0 V8, say from an Explorer?

 

[G's Baja Bronco]

Yes, it is, as far as I know. I am certain the 2 bolt starter will work for our 302/351w's and the 3 bolt starter is for the modular v8's (4.6 5.4)

 

[KyleQ]

My 95' F150 has one in it and it was PERFECT for wheeling. I have 4.56 gearing and ran 32's and 34's without issue. I really miss how much power I had and how good it ran ;(