Transfer Case Technical Discussion

[mpeugeot]

You're right. I've had every type of locking hub or no hub there is since my 1945 GPW and really they are all fine. The automatics of the 80's and 90's were probably the weak link. With those on snowy days I'd 'preengage' them to avoid that violent first engagement at speed. I also preengage manual hubs before needing them. No problem running them engaged while in 2wd, even all winter. People should get over the idea that they need to be engaged/disengaged at every 4wd/2wd shift. I've never had an issue with the semi automatic hubs on a couple Ford Super Dutys. My LJ and current Bronco had/have no axle disengagement at all (just at transfer case) and work great. For some reason my BB with 4.27's is the only part time without FAD which is fine with me. It still averages 23mpg.

Same with my OBX in Sport mode 4A. Mileage is largely affected by speed/aerodynamic load, tire size/weight, and exhaust/parasitic engine loss... in roughly that order.

The 4A mode, if based on a bosch case, is roughly able to adjust the clutch pack at 50Hz. It's a fairly robust multi-disc wet clutch which is unlikely to fail under normal conditions. The electromechanical nomenclature means that an electric motor is adjusting the clutch pack with regards to engagement. There is an electric motor which turns a gear that either engages or disengages the clutch pack. When disengaged, the impact on fuel economy is negligible.

Sponsored

 

[Bmadda]

Great info. You do not loose 4wd, but if you start in 2wd does the loss of a WSS prevent a 4wd shift? My sons Tacoma would not shift into 4wd with a faulty WSS.

Also, regarding manually shifting the TC. I suppose I would remove the shift motor and rotate whatever it attaches to. Anybody tried this? Anybody know the "shift pattern"?

I did not test that scenario...the purpose of my test was to learn if the xfer case would in fact shift out of 4wd w/out driver input, because of a wss failure...this has been reported as fact on various youtube videos, and I am not calling anybody a liar...let's make that clear, however my results are what they are, and repeated several times. Now I would like to test the scenario you describe...however there are several possible permutations. A wss failure that continues to exist? or a wss failure that was intermittent and has stored a code? My thinking is if you get to the trailhead and the vehicle wont allow you to shift into 4wd...that sure sucks, but you have the opportunity to turn around and get it fixed, but losing 4wd while out there sucks way worse! Either way, i would prefer that 4wd works when I need it regardless. Maybe I can try it in the AM?

 

[Deleted member 32220]

I don’t know if it has been mentioned in these 6 pages…but take the three 10mm bolts out of the power window”ish” motor on the t-case. I think there is a 4th bolt on a 90 degree bracket, zip tie it out of the way, the markings for 2H N 4H 4L are molded right in the t-case then shift it like a big boy with vise grips. You line the shaft up with the markings. 4A is a solenoid based clutch system.

 

[dgorsett]

I don’t know if it has been mentioned in these 6 pages…but take the three 10mm bolts out of the power window”ish” motor on the t-case. I think there is a 4th bolt on a 90 degree bracket, zip tie it out of the way, the markings for 2H N 4H 4L are molded right in the t-case then shift it like a big boy with vise grips. You line the shaft up with the markings. 4A is a solenoid based clutch system.

Excellent!!

 

[Bmadda]

I don’t know if it has been mentioned in these 6 pages…but take the three 10mm bolts out of the power window”ish” motor on the t-case. I think there is a 4th bolt on a 90 degree bracket, zip tie it out of the way, the markings for 2H N 4H 4L are molded right in the t-case then shift it like a big boy with vise grips. You line the shaft up with the markings. 4A is a solenoid based clutch system.

4A is an encoder motor also, it's mounted on the front of the case instead of the rear. No way you could get vise grips in there, but looks like the right allen socket could do it. W/that motor not mounted tho, idk what keeps the linkage from vibrating into a different position, possibly neutral, wouldn't be something I'd wana do on the trail unless totally out of options. The part time xfer case looks way easier...here's pics, 1st the 4A:

Now the part time case. Looks like you could shift it w/a screwdriver, but how to keep it locked in position? Might be a strong enough detent to hold it in each position, but I doubt it!

 

[Yamapro]

I absolutely can verify that a speed sensor fault, abs sensor, will still allow you to shift into 4wd but the problem is that it will not allow you to engage your lockers or one foot assist. I had all 4 wheel speed sensors throw a code when I was on Golden Spike in Moab last week. I was 8 hours deep in the trail and my lockers became inoperable. I was stuck! 4wd worked fine but without lockers I couldn’t get over obstacles. There definitely needs to be some research put into this by Ford! I desperately needed a override or force engagement on the lockers.

 

[Bmadda]

I absolutely can verify that a speed sensor fault, abs sensor, will still allow you to shift into 4wd but the problem is that it will not allow you to engage your lockers or one foot assist. I had all 4 wheel speed sensors throw a code when I was on Golden Spike in Moab last week. I was 8 hours deep in the trail and my lockers became inoperable. I was stuck! 4wd worked fine but without lockers I couldn’t get over obstacles. There definitely needs to be some research put into this by Ford! I desperately needed a override or force engagement on the lockers.

Mine only disabled the front locker...of course I had the rear already locked when I simulated the failure. Did yours cancel the rear locker on it's own? Or not allow you to select it after the failure?

 

[orion]

I absolutely can verify that a speed sensor fault, abs sensor, will still allow you to shift into 4wd but the problem is that it will not allow you to engage your lockers or one foot assist. I had all 4 wheel speed sensors throw a code when I was on Golden Spike in Moab last week. I was 8 hours deep in the trail and my lockers became inoperable. I was stuck! 4wd worked fine but without lockers I couldn’t get over obstacles. There definitely needs to be some research put into this by Ford! I desperately needed a override or force engagement on the lockers.

Good to know. Maybe splice in a backup switch to the lockers so that in this situation you can lock them. Bummer that we have all these gizmos relying on wheel speed sensors to function. I get it though, there are a lot of idiots out there that would destroy stuff if Ford didn't speed limit these things...

Maybe forscan can come to the rescue in some of these instances???

I think we need WSS's and Tie Rods in our truck when wheeling...

 

[Yamapro]

I just ordered inner/outer tie rods as well as all 4 speed sensors to keep in the truck!

 

[Yamapro]

Mine only disabled the front locker...of course I had the rear already locked when I simulated the failure. Did yours cancel the rear locker on it's own? Or not allow you to select it after the failure?

Neither locker was engaged at the moment it happened. When I attempted to engage them, the lights and dash showed they were on but when I tried climbing you could tell they definitely were not engaged.

 

[Felix808]

I just ordered inner/outer tie rods as well as all 4 speed sensors to keep in the truck!

Yep, I used my points for inner & outer tie rods. I'll probably pick up the wheel sensors as well. Looks like the 2 front are different & the rears are the same.

 

[Yamapro]

Yep, I used my points for inner & outer tie rods. I'll probably pick up the wheel sensors as well. Looks like the 2 front are different & the rears are the same.

Both rear abs sensors are the same but the front are side specific, I just ordered all four

 

[Bmadda]

Both rear abs sensors are the same but the front are side specific, I just ordered all four

I still wonder how you got codes for all 4? I find it hard to believe you damaged all 4 of them at the same time? Did you ever figure out which one was the bad one? and were the other codes set in error? I think there's still alot of room to improve this software. But hey, that's why we bring this stuff up right?

 

[Felix808]

I still wonder how you got codes for all 4? I find it hard to believe you damaged all 4 of them at the same time? Did you ever figure out which one was the bad one? and were the other codes set in error? I think there's still alot of room to improve this software. But hey, that's why we bring this stuff up right?

I was just thinking something similar. Can you identify which senor is bad? I would also wonder if it is just dirty or obscured & could be cleaned. There are no tone rings on the axles that I can tell. Curious as what it's sensing in the hub. Perhaps it gets obscured as previously mentioned & the error might come clean by cleaning it.

 

[Bmadda]

I was just thinking something similar. Can you identify which senor is bad? I would also wonder if it is just dirty or obscured & could be cleaned. There are no tone rings on the axles that I can tell. Curious as what it's sensing in the hub. Perhaps it gets obscured as previously mentioned & the error might come clean by cleaning it.

Tone rings are gradually becoming a thing of the past, the new style is magnetic strips. They do the same as tone rings, but are usually just a magnetic strip on the wheel bearing where the dust cover would have been. Don't know what Bronco uses yet...haven't had to mess w/mine, but it sounds like I better learn all I can!

Sponsored