97 mountaineer BREAKING FRONT DRIVESHAFT!! | Page 2 | Ford Explorer Forums - Serious Explorations

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97 mountaineer BREAKING FRONT DRIVESHAFT!!

I think that driving without the front drive shaft might kill the viscous coupling in the AWD differential (the BW4404 it is NOT a transfer case).
So, next time when you need that limited slip provided by VC, you will have a seized diff all the time (transfer case type, bad for highway use). I think it might seize the VC due to overheating - the high differential in rotation speeds between rear output and front.
 



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I think that driving without the front drive shaft might kill the viscous coupling in the AWD differential (the BW4404 it is NOT a transfer case).
So, next time when you need that limited slip provided by VC, you will have a seized diff all the time (transfer case type, bad for highway use). I think it might seize the VC due to overheating - the high differential in rotation speeds between rear output and front.

huhhhh? have you ever taken one apart? the input shaft connects directly to the rear for a 1:1. if you took the front shaft out the coupling should last forever because it is on the front output (when you take turns the front shaft can differentiate from the rear) and when you dont have a front shaft the front output spins freely. when i had the 4404 i ran without the shaft for 6 months. no ill effects.

again i say the viscous coupling is there on the front so you dont get axle windup in turns like a true 4x4 would on dry pavement.
 






I think that the VC is not just on front. It is between front and rear, locking them when there is a difference in rotational speeds. Like a limited slip differential. You can see the satellites on top.

http://www.explorerforum.com/forums/showthread.php?t=218430

P1000537.jpg
 






I think that the VC is not just on front. It is between front and rear, locking them when there is a difference in rotational speeds. Like a limited slip differential. You can see the satellites on top.

http://www.explorerforum.com/forums/showthread.php?t=218430

P1000537.jpg





so what your saying is, when there is a difference in shaft speeds it locks? since front and rear shaft speeds are different when tight turning that would mean when you take a turn on high traction pavement the shafts would lock and wind up the driveline. that makes sense.....:rolleyes:
 






The difference between rean and front axles on curves is zero. There is only a difference between left and right tires.
And anyway, it won't lock at small differences - the rear diff is the same way.

In order to lock, the fluid inside the VC needs to warm up past a certain temperature, when it thickens/change of phase - becomes almost solid. That takes a few seconds and certain speed difference to produce that necessary heat. If it is heated just a little, will still be liquid. Warm liquid.
 






so what your saying is, when there is a difference in shaft speeds it locks? since front and rear shaft speeds are different when tight turning that would mean when you take a turn on high traction pavement the shafts would lock and wind up the driveline. that makes sense.....:rolleyes:

I understand your thinking here, however while turning the front wheels will rotate faster than the rear wheels, because they travel a greater distance. The AWD will only activate when the fronts turn slower then the rear. And as stated the LSD (or open) diff will make up any difference, as it is intended to do.

OK i would like to know what's truly up with my front driveshaft because I have been off roading several times since the time that i was sure it flung its lubricant out of the cv joint. So shouldn't the going on several trails have killed the front driveshaft?

Normally around these parts we waste time wondering why parts did break, instead of popping brain cells on why they didn't. Give it time grasshopper, you will soon be satisfied if you really want something to break.
 






the awd case on these is purely mechanical, unlike the 4405. there is no need for the rear to slip for the front to kick in, power is there all the time at a 65/35 split...
 






The AWD is permanent because is a differential permanetly engaged. It will lock the center ONLY when the difference in speeds between front/rear AXLES is high for a certain time - like when your front or rear wheels are on snow). Otherwise is a 35/65 split (normal driving).
If it was like you assume - VC only on front axle - then how do you explain that the rear would work with the front axle removed?
For example - if you suspend a wheel on a non-locking/limited split differential, than the other wheel will not turn. The suspended wheel will turn with double speed. In your case, the front "empty" flange will spin with double the speed and the rear will not budge.

And if you say 4404 it is not a differential, then explain why are those satellites (part #320) present in the 4404 and what that annulus is doing there (part #322)? More about that: http://en.wikipedia.org/wiki/Differential_gear#Epicyclic_differential
If you see, the rear shaft come from the 225 that is connected inside the annulus 322. The front shaft is connected via the 83, 18, chain 90 and gear 63 to the INSIDE part of the VC (#64). The outside of VC is connected inside the annulus 322, therfore directly to the rear shaft.
So liquid inside VC - the shafts spin independently via the differential and chain. If liquid solidifies inside VC, the front and rear shaft are solid connected (the chain ratio is 1:1 and the epicyclic ratio give the final ratio beween the shafts torque/power).
Input shaft goes inside the sun part (#65).
tc_bw4404p1.jpg

all_apart3.jpg


Last from me: Even if I am wrong, I would not run my AWD without the front shaft. Becaus eonce you remove the shaft and the VC is fried, you cannot put another one back in, will bind. If the VC doesn't fry running hot for months in row, then it is a great pice of engineering.
 






My shop guy who's been in business for 35 years drove his '97 Ex AWD for years w/o the front drive shaft...no ill effects. never drives off road, and parks it in bad weather...he's got 4-5 other cars/trucks to choose from...:D
 






Did he ever try to put back a front shaft in, to see if it had "no ill effects"? If not, then it does not count as valuable info.
 






huhhhh? have you ever taken one apart? the input shaft connects directly to the rear for a 1:1. if you took the front shaft out the coupling should last forever because it is on the front output (when you take turns the front shaft can differentiate from the rear) and when you dont have a front shaft the front output spins freely. when i had the 4404 i ran without the shaft for 6 months. no ill effects.

again i say the viscous coupling is there on the front so you dont get axle windup in turns like a true 4x4 would on dry pavement.

No it doesn't. If that were the case they wouldn't drift in park with the front driveshaft removed. The transfer case has a center differential that works just like the differential in an axle. It uses the VC to limit the slip of that differential, and in the event of too much slip it will lock. The reason you can drive with the front shaft removed is because the VC is locking. It drifts in park because it's slipping, but not enough to lock it.
 






Did he ever try to put back a front shaft in, to see if it had "no ill effects"? If not, then it does not count as valuable info.

i did. had it out while making a custom one that wouldnt explode with the 4'' superlift and once that one was in i wheeled the **** out of it for a year till the 4406 went in..
 






Did he ever try to put back a front shaft in, to see if it had "no ill effects"? If not, then it does not count as valuable info.

AAMOF, he did...now he drives it on rain/snow days with no mechanical problems....soooo is this elevated to valuable info, now? :rolleyes:
 






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