4WD 4R70W Length?

['84 Bronco II]

I've spent way too much time trying to find the answer to this question and I am hoping someone here knows or has one they could measure for me. I want the length from the bell housing face to the transfer case mounting face. Specifically one with the Windsor/Essex bell housing in case the Modular bell housings are a different length.

I am trying to figure out which transmission I want to use for my buggy project I am in the planning/parts collecting stage for. I will be running a 5.0L and probably an Atlas, so I am trying to make the decision between a C4/5 and a 4R70W. I am also curious if anyone has an accurate weight for a 4R70W. I've seen around 150Lbs thrown around in several places.

 

[arse_sidewards]

Is this for your Ultra4 buggy?

 

['84 Bronco II]

Is this for your Ultra4 buggy?

Nope, recreational crawler. I finally pulled the trigger on a Bent Fab CH2 chassis and already have the engine and axles, but still need to figure out the tranny and transfer case. I already have a Dana 20 and BW1356, but a BW1356 isn't really suitable for a buggy application and as I found out with my 4600 build, an Atlas is cheaper than trying to build a Dana 20. Not to mention, the one guy who sells Dana 20 gears is a complete piece of work to try and deal with.

 

[Covecrawler]

The 4R70R in my explorer, behind a 5.0l looks to be 28” or so.

 

[Ummduh]

I have one in my garage out of an explorer, I can get you whatever measurements you want aside from specific t case measurements.

 

['84 Bronco II]

I have one in my garage out of an explorer, I can get you whatever measurements you want aside from specific t case measurements.

I assume it is the AWD/4WD version (31 spline output)? If you wouldn't mind confirming the length from the bell housing mounting surface to the transfer case mounting surface at the tail housing, I would appreciate it. Bonus points if you can get me an actual weight on it. I can post up the same measurements and weight for a C4 for comparison.

 

[Ummduh]

Honestly I couldn’t quote you splines and junk, I haven’t thought about this in 5 years now. The trans is out of a 2000 v8 explorer that was awd.

27.5” from output flange to bellhousing face

146 lbs mostly bare without converter. Pan is drained completely, the only fluid left in it is whatever was above the vb.

Converter is another 46 lbs but it is of unknown drain, and it’s out of a 2000 v6 mustang.

 

['84 Bronco II]

Honestly I couldn’t quote you splines and junk, I haven’t thought about this in 5 years now. The trans is out of a 2000 v8 explorer that was awd.

27.5” from output flange to bellhousing face

146 lbs mostly bare without converter. Pan is drained completely, the only fluid left in it is whatever was above the vb.

Converter is another 46 lbs but it is of unknown drain, and it’s out of a 2000 v6 mustang.

You're the man

I'll try to get the same info on my C4 posted this weekend so this thread will hopefully be useful to others.

As for my application, Tim at Bent Fab says the biggest trans and T-case combo the CH2 was designed around are a 4L80 and Atlas. The 4L80 is 26.25" long according to Novak, so a 4R70W might be too long then. Looks like I am on the hunt for a C4 then.

 

[arse_sidewards]

Can't you just make up for it by not running a monstrosity of a transfer case?

 

['84 Bronco II]

Can't you just make up for it by not running a monstrosity of a transfer case?

Maybe, but I'd really have to see once I get the chassis together and start trying to stick parts in it. However, I think I'll most likely end up running an Atlas since it is more cost effective than building up the Dana 20 I have or sourcing and building a Dana 300. The assembled Dana 300 from Midnight Metalworks is pretty bitchin' but it is $800 more than the Atlas I bought for my 4600 rig

 

[ParadisePWoffrd]

If you want to run the 4r70, I would not sweat 2". That length could change depending on what outputs/yokes you ran on the transfer case.

 

[arse_sidewards]

What engine? I bet if it comes down to it you can find 2" you don't need in the accessory drive.

 

['84 Bronco II]

If you want to run the 4r70, I would not sweat 2". That length could change depending on what outputs/yokes you ran on the transfer case.

The issue isn't the driveshaft lengths as much as how far back you can shove the engine to maintain proper balance and upper link clearance. The longer the drivetrain is, the further forward the engine is going to have to be which is also going to force the front axle further forward. This is going to affect the balance and CG location, which in turn affects suspension geometry.

What engine? I bet if it comes down to it you can find 2" you don't need in the accessory drive.

5.0L and probably going to run an Explorer serpentine setup which I believe is about the most compact accessory drive setup you can run.


I also got out today and took some measurements and weights on my C4 for the 4600 Bronco. It is a Pan fill C4 with a 164 tooth bell for reference (from an Early Bronco). The transmission and converter didn't have any fluid in them as well.

The bell housing is 6.25" face to face and weighed in right at 10Lbs.

The Case was 11 1/16" long and weighed 83Lbs (W/ the dipstick tube, picture on the scale with the bellhousing & perspective is off)

The factory Bronco C4 to Dana 20 tailhousing was right at 7.5" and weighed 24Lbs (26Lbs W/ the factory 28 to 6 spline adapter coupling, again the perspective is a little off in the picture of the scale). Advance adapters sells a 27 spline output shaft with a 2.90" aluminum tailhousing for the C4 but they also sell a version of the Atlas that bolts up to the Bronco tailhousing.

I also weighed the completely drain factory toque converter, and it came in at 25Lbs.

So here's where I am at with the transmission options:

C4

Pros​

• 24 13/16" Long with factory Bronco tailhousing or 20.2" long with Advance Adapters 50-2905 tail housing
• Only 119Lbs (with factory cast iron Bronco tailhousing, probably 100-105Lbs with aluminum short Advance Adapters tail housing)

Cons​

• Harder to find; not many show up in the junkyard these days
• Worse factory gearing (2.46 1st) and no overdrive; Dynamic low gear set (2.9 1st, 1.6 2nd) is an additional $900

4R70W

Pros​

• Plentiful in the junkyard
• 2.84 1st gear and .70 overdrive

Cons​

• Long; 27.5" and no way to decrease length
• 146 Lbs and the converters may be significantly heavier

My current build plans are 42" tires and the '07 Superduty axles I already have, which can only be geared down to 5.38, so I don't need an overdrive. However I think I will eventually want to go rear steer, and if I do I will want to run 9" based fabricated axles (maybe portals too if I win the lottery). In that case I would likely run 6.50 gears (lower with portals) and and overdrive would probably be nice to have at that point.