V8 Down

[CDW6212R]

LOL, I know well what it takes to repair and replace the many 4WD parts in these AWD Explorers. I do wish it was more simple and reliable, but in prefer the ability of it, mainly the virtually never disturb the gravel or dirt/grass where I drive, a ton.

I've driven 2WD a ton on much better roads than I travel now, and I spun the RR tire literally countless times, the lack of grass at every mailbox was my mark. Now I really like being able to never spin the RR tire, but the fronts work hard every time I crank the wheels to turn around, on sloping driveways and some gravel. That's what is hard on the AWD TC, the front wheels fully left or right, and on a sticky surface, at more than idle.

Keeping the tires all identical, rotated, and fresh fluid in everything keeps most parts alive. My 98 Limited had black TC fluid when I got it, with no front DS, and 158k miles. Now after 4 TC fluid changes, and 195k miles, it's still too dark for my liking. The past owners obviously drove it quite a bit with mismatched tires, before they took the DS out. I'm amazed it's still kicking, I can tell no difference from my Mercury that was always flawless, clean TC fluid, and has 206k on it.

Care has a ton(ton ton ton) to do with reliability.

RandomNerd2000, you keep at it and that truck will be fine the way you take care of it.

 

[Centaurus5.0]

Are you saying the fluid in the 4404 is getting burnt from the excess heat generated from the harshness of your mail route?

I had an ex with a froze up 4404. Way too much resistance in the steering when turning it at full tilt. Tested it in a big parking lot by turning steering wheel all the way to one side and letting off the brake. It would not roll under idle power. I replaced it with a junk yard unit and replaced nothing else and the steering was MUCH more free and on the same test it would roll and keep rolling at idle with the wheel at max turn. I know they "seize" up, just don't know exactly why. Maybe the one I replaced it with was blown out?? On the other hand, I was helping a friend with his AWD rig and we had it up on jack stands trying to find something unrelated to the transfer case (can't remember now) put it in drive and only the back wheels turned?? Do all 4 wheels need to be on the ground to enact the power split? Front diff blown out? It didn't make any noises.. I dunno.. pretty spooky if you ask me. I need to know how it all works and definite signs if it does or does not. If it can still do a sideways 4 wheel power drift going around a corner on a snow packed road, I guess that it works good enough. I guess...

 

[CDW6212R]

I believe these AWD TC's simply resist forces that oppose the front wheels turning at the same speed as the rears. Up in the air I'll bet it's a 50/50 power split(front/back spinning equally fast). In normal operation with no real heat in the fluid or viscous clutch, there should be no big resistance to the front tires spinning faster(in all turns). But as the heat builds up, the VC resists more, like when mismatched tires are on. The growing or constant heat increases the VC efforts to hold the speeds the same. That's the only variance I can envision in the AWD TC.

People speak of varying power distribution, of 50-65% etc, I think that all came from advertising to wow buyers. The AWD simply wants the speeds of both output shafts to be the same. Too much forced variance(heat in the VC) will eventually kill it, we just don't know how much.

 

[RandomNerd2000]

I halfway can't wait to have this truck 2WD, when the front differential quit pulling, I didn't notice it in steering, but on the highway I got over 20 to the gallon, driving nice and straight at 65 was a breeze, the AWD really kills the MPG. I figure likely before it's over, I'll have my Eddie Bauer 4WD swapped, one must be careful there though because I've seen that turn into SAS swaps and rock crawlers.

 

[Centaurus5.0]

As per Ford:

Four-Wheel Drive Systems — All-Wheel Drive (AWD)

The all-wheel drive system utilizes a transfer case that is a two-piece aluminum, chain-driven, viscous-clutch type unit. This results in a system in which all-wheel drive is always activated. The all-wheel drive transfer case is automatic and has no external controls.

The viscous clutch is a torque distribution device. It is non-repairable. The internal construction of the viscous clutch consists of alternating plates that are connected to the front and rear outputs of the transfer case. The viscous clutch is filled with a high viscosity fluid which flows through slots in the plates. The resistance to shear causes the plates to transmit torque at the needed ratio. The ratio that torque is transmitted at is approximately 35% front and 65% rear.

Torque is transmitted through the input shaft to the planet carrier assembly. Torque flow continues through the gear ring to the rear output shaft. Torque also flows from the planet carrier assembly to the sun gear shaft, which is splined to the drive sprocket. The drive gear is connected to the driven sprocket by the drive chain. Torque continues through the driven sprocket to the front output shaft flange. The viscous clutch provides the connection between the gear ring and the sun gear shaft.

" the transfer case is a Borg-Warner make. It is the same case GMC used in the S15 Typhoon hot-rod. Usage indicates exceptional reliability.

....the AWD functions like this: the transfer case has no driver input; i.e., no switch. Thirty-five percent of the torque is distributed to the front axle; sixty-five percent to the rear axle at all times. When wheel slippage occurs, the viscous clutch in the transfer case transfers more torque to the axle that has the most traction.....35% torque to the front/ 65% to the rear is a measurement under normal conditions. If the front end was affected by icy road conditions, where the transfer case clutch transferred the maximum torque to the front axle, the ratio could be 50/50 or even 65% (front) and 35% (rear). According to Ford Engineering personnel, AWD testing in off-road dirt/ sand conditions, the AWD performed superbly."

The base torque distribution ratio is set by the sheer qualities of the fluid as it flows through the slots in the plates inside the vc. Like torque convertors k-factor is set by the angle of the fins and the diameter.

Spooky mechanical voodoo...

It would be cool though it Torsen came up with a drop in replacement for the VC using spur/worm gears.

 

[Centaurus5.0]

..one must be careful there though because I've seen that turn into SAS swaps and rock crawlers.

Modding a rig can be a slippery slope indeed! Just like a simple K&N filter change can easily turn into a supercharged stroked small block project!

 

[RandomNerd2000]

I got offered a 347 ready to bolt in when I started V8 Eddie, do I want it? Yes, guy was offering a real bargain on a CRATE motor, still has it too, but then comes a truck that'll tear itself in half. Anyhow, I replaced the cooler behind the grille, as instructed. Noticed something, it's also factory, the hoses going to it (rubber) say 2011 though, so I was right. Anyhow, I drained the fluid, very very very very little metal came out, fluid was nice looking, not silverish or anything really, just a spec of metal here and there, just shy of perfect. I noticed it's REALLY heavy though, I used the one from my 99 and it was weightless compared to this, but the fluid drained was within a hair of the same amount from both.

 

[delexploder]

The parts stores sell pressurized cans of tranny cooler flush , works very well

 

[RandomNerd2000]

Considering I had the cooler and it wasn't but 3 bolts, I just changed it, took five minutes.

 

[Centaurus5.0]

You could still use that stuff for flushing out the lines, if you haven't already done it another way.

 

[RandomNerd2000]

The lines I just made a compressor fitting with a hose on the end to stick into the lines, took a bit of faniggling but there wasn't anything in there, apparently it all drains back or was in the cooler, dunno.

 

[RandomNerd2000]

Alright so, excluding the driveshaft, the 2WD trans is in. Few comments I have are, it can be done without taking the passenger side exhaust off, little tighter but worth it. My engine also sits too far back and slightly outward on the left side, that made for an interesting time when I installed the dipstick tube. Otherwise, it's a normal swap, it does NOT go in as easy as it falls out, and I am 100%, without question, investing in a transmission jack to do the Eddie Bauer when the time comes, doing it any other way is a literal sh*t way.

 

[CDW6212R]

Well done, take a break and rest the sore back and arms.

Did you use just a floor jack? I've done that a few times myself, I just bought one of the small transmission scissors jacks to help with my 5R55E. Hopefully it'll attach securely, the pan with the bulge on the bottom is dumb(Ford).

 

[RandomNerd2000]

Dual scissor jacks, the spares out what I think are GM vehicles, one at the front, one at the back, and blocks stacked underneath the pan as plan B. I'm going to get a trans jack now though, it's worth the investment, what one did you get? I know Harbor Freight has some that start at like $100.

 

[CDW6212R]

The one I have was from HF, about $75 with the coupon then. it seems sturdy enough, if the mounting to the pan will be strong enough.

 

[RandomNerd2000]

So I drove it today, I did manage however apparently to break the shifter cable, so I have everything but park and reverse (got cable today, out a 98 SOHC), it shifts like butter too, much better than the old trans, which considering the case and all off the old one had a 98 date on top in the casting, it probably had as many miles as the car itself. It's actually so much nicer it's got me sorta anxious for the 131K mile AWD one I snagged for Eddie, to see how it performs, and considering my experiences with low mile 4R70Ws, I'm gonna be happy, since that trans I took a sample of the fluid and there was nothing in it abnormal, just used trans fluid, that was a $100 score.

 

[CDW6212R]

That sounds promising. How does it drive without the AWD transfer case pulling some power out of it?

 

[RandomNerd2000]

I'm getting 21 to the gallon, and it's noticeably light, like a 2WD truck, I always liked how a 2WD Explorer drove. I've covered 100 miles now, been really happy with it, it's strong, the gears feel more "solid" if that makes sense, it's obvious it's a straight 2WD and not an AWD that became a 2WD.

 

[CDW6212R]

Very good, the gas mileage is nice to get also. Enjoy that new frisky feeling.

 

[RandomNerd2000]

Probably if I'm fair before it's over, I'll have a dedicated 4WD swap accomplished on the Eddie Bauer, once it's a running driving V8 AWD with no issues. So far I don't miss the AWD, it was decent but it's a take it or leave it, I'd rather have a 4WD system.