Dana 28 TTB / Dana 35 TTB Specifications

[RazorBeam]

In the Tech section, it mentions the transition to the SLA D35s on the later model gen 1 Ranger and Explorer. The BOM list shows the Explorer as having NON DISCONNECT (SLA IFS) from '95 on. I have a set of modified '94 Explorer TTBs and I like to the '97 Explorer style as a starting point. I'm trying to figure out if they will work in a '97 Explorer.
So, here are my questions.
1. Does the SLA come in the '95 and newer Explorers as suggested by the BOM list?
2. Does the drive shaft turn a different direction on the SLA model vehicles?
3. Does the SLA D35 Differential bolt into the '94 D35 TTB?
4. If 1 and 2 are 'yes' and 3 is 'no', can a '84 Bronco II Transfer Case be bolted to the '97 transmission to use with the '94 D35 and TTB (assuming the engine is a 4.0)?
Thanks for the help

 

[4x4junkie]

1. = Yes
2. = No
3. = No
4. = No (well ok, yes the case will bolt up to the trans, but no you're not using a '94 frontend in a '97 Ex without some really major fab work).

Hope that answers your question.

(the Ranger got the SLA IFS in '98, three years later than the Ex did).

I've seen people graft the '95-'01 ('03 Sport) frontends onto '91-'94 Explorers (I think the rear tails too). That's probably the best way to go if that is the look you're after but want the TTB suspension.

 

[adsm08]

I do not understand the point behind questi on number 4.

The transfer case is not going to be what determines the direction of drive shaft rotation.

Postin' from teh Galaxy

 

[4x4junkie]

I think it was a hypothetical in case #2 was 'Yes' (probably confusion stemming from the term "Reverse Rotation" as applied to front axles... The driveshaft is not what rotates in reverse, it only refers to the front axle's innards relative to a rear axle)

 

[RazorBeam]

Hope that answers your question.

Thank you, it does answer my questions and crushes my dreams at the same time... nice work, but it had to be done.

The transfer case is not going to be what determines the direction of drive shaft rotation.

I took the term "reverse rotation" to mean that the rear drive shaft on a '95 rotates in the same direction as the rear drive shaft on a '94 and that the '95 front shaft (SLA) rotates opposite from the '94 front shaft (Non-SLA). Thinking perhaps that if the transfer case used gears in direct contact (shitty design) or some more convoluted design, instead of the chain link drive in the Borg Warner (real good for handling loads); I might be able to change the front drive shaft rotation by putting in a Borg Warner transfer case. I didn't realize that they had switched to the double A-arm design on the Exploders that early. If they had kept the TTB with the D35 SLA, that would have made things too easy.

The driveshaft is not what rotates in reverse, it only refers to the front axle's innards relative to a rear axle

I'm going to have to find the exploded view of this to see what you mean.

 

[RazorBeam]

Looking at the counterclockwise twist of the teeth on the ring gear in the exploded view on this...

http://www.therangerstation.com/tech_library/pdf_documents/Dana_Ford_35.pdf

... and the clockwise twist of the teeth on this ring gear in the exploded view, it looks like the front drive shaft of the SLA rotates opposite of non-SLA.

http://www.therangerstation.com/tech_library/dana_35_sla.shtml

So the BW4405 and BW4406 seem to be the ones used it the later SLA versions and they use a planetary assembly (good design) between the front drive gear and the front shaft.

http://www.therangerstation.com/tech_library/pdf_documents/LiteDuty_Trans_TCase_Guide.pdf

It looks like the planetary gear set is part of the assembly to engage and disengage the front drive shaft. The older BW1350, like I have, just uses the chain to drive the other gear and just leaves the shifter half way between shifts to get a 2WD position.
So, it looks like the SLA does turn the other way around. Still sucks that the suspension mounts aren't similar enough for a swap.
Thanks

 

[4.0B2]

reverse rotation front axles work b/c the pinion is above the centerline of the ring gear... as opposed to the lower pinion on the standard front axles.

High Pinion axles are reverse cut
Low Pinion axles are standard cut

it's not about which way the driveshaft is spinning, it's about where the pinion engages the ring gear, either above or below centerline of it.

wait, now I'm confused lol... reverse rotation; is that the same as reverse cut?

 

[RazorBeam]

Reverse cut does not mean reverse rotation. I was mislead by the Coast/Drive distinction much like our friends at pirate 4x4 warned.

"E – Drive. The convex side of the gear tooth*
F – Coast. The concave side of the gear tooth*

* Don’t be mislead by the terms “coast” and “drive”, as the ring-gear can be driven by the pinion on either side of the teeth. Which side of the teeth will depend on if the gear-set is standard or reverse spiral and whether the vehicle is going forward or in reverse."

http://www.pirate4x4.com/tech/billavista/Gear_Setup/

But the planetary gear set in the SLA transfer case makes me think that the front drive shaft rotates backward, by comparison to pre-SLA drive shafts, so that the concave side would be coast and drive sides would be convex on both the SLA and non-SLA. The drive and coast sides can be either side, but having the convex side on the drive side is usually quieter, depending on the ratio.

 

[4x4junkie]

Note that the ring gear is to the passengerside of the pinion on both the SLA or TTB. This would mean the pinion has to turn in the same counterclockwise direction (looking from the pinion side of the diff) to drive the vehicle forward.

As 4.0L said, the difference is only in the gear teeth, not the direction things rotate... The shape of the gear teeth is reversed so that it drives forward on the convex side of the gear teeth when used as a front axle, which adds about 30% more strength in that direction vs driving on the concave side.

Note that SLA & TTB Rangers also use the same BW1354 T-case.

Why Ford went from a reverse-cut to a standard-cut frontend is beyond me, but that's what they did (seems a lot of manufacturers flip & flop back & forth in both directions on this, Chrysler (Jeep) is another one that can't make up their mind).

 

[RazorBeam]

Thanks Junkie, I missed the ring gear placement in my thought process.
So, have you been in one of the BW4405 or BW4406 T-cases?
Now I'm wondering what the planetary gear set up is used to accomplish in those two T-cases.

 

[4x4junkie]

You're probably looking at a planetary differential to allow full-time 4WD operation (AWD).