Front Drive Shaft (4406) question

[Dono]

Okay, trying to make sense of the 4406 having the output shafts 1 inch over.
If we move the transmission over an inch, won't that increase the angles (side to side, since the front of the drivetrain isn't being shifted over also) of the drive shafts creating a bigger issue?
From a video gmanpaint posted, the angle on the diff side and the transfer case need to be exactly the same to cancel vibration. I'd say that this angle applies to up and down, as well as side to side.
I had no idea these angles were so critical.

If the front transfer case yoke is pointed up slightly, doesn't the front diff need to point up the same degrees also?

I do also start to get a vibration over 70 mph. It becomes a high frequency vibration that makes my mirror buzz, along with he rest of the truck. I'm not sure if it's as simple as tires needing balancing, or if I'm exactly where Ahodges is at. I have a feeling I'm where Andrew is,although I'm running single u joints on the back, and double cardan on the front.

 

[ahodges]

That is the exact same drive shaft configuration I am running now as well. singles in the back and a double on the transfer case end on the front.

 

[ilovemetjb]

Yeah, that is part of the problem. Years and memory don't always work together.

I want to try the expedition shaft, I think. Thanks for your input Evan!

Is that a better shaft I have a2000 explorer 4x4 and the front shaft is weak.

 

[Anticitizen1]

Has anybody ever resolved this issue? I have gone through 2 t-cases trying to find the issue, as well as balancing the front driveshaft with 2 sets of u-joints and no cigar. The vibration above 70mph is killer! Thanks guys

 

[boominXplorer]

Has anybody ever resolved this issue? I have gone through 2 t-cases trying to find the issue, as well as balancing the front driveshaft with 2 sets of u-joints and no cigar. The vibration above 70mph is killer! Thanks guys

What shaft are you currently running? Drop bracket lift kit or stock suspension in the front?

 

[Anticitizen1]

Sorry I should've elaborated better. I am on stock ride height suspension, Bilstein Shocks with Hellwig 1" chromoly rear sway bar, LT 245/75R16 tires. For my front driveshaft, I am currently running a 4.6 F150/Expedition front driveshaft with the conversion u-joint. Professionally balanced 2 weeks ago with new USA made u-joints and checks out fine, but I imagine there could be something about it other then being out of round or excessive runout that may not agree with MY truck specifically. Tried 2 different BW4406 T-Cases, haven't rebuilt either of them but the second one only had 134k with spiffy atf and nice tight shifts. Thanks for the help guys.

 

[ahodges]

My issue has never been resolved. I can tell you that in my case, the F150/ Expedition front drive shaft (1 u-joint on each end) made a far worse vibration that using the stock 91-96 front driveshaft with a conversion piece at the transfer case end for the double carden. Even with the double carden, mine vibrates noticeably above 70MPH and worse as I go faster. I am convinced the only way to eliminate this vibration is to run a true CV joint at the transfer case (like the AWD was originally on 1997+ models). I have checked everything else including the drive shaft geometry, and on paper nothing but CV's will cure the vibration. The trick is finding someone to make a custom drive shaft with a CV bolted to the 4 bolt pattern on the 4406.

 

[vroomzoomboom]

im not going to say i solved this problem for me, but somewhere, somehow it did get solved. i had bought a truck for the motor and trans to put into mine. it also had a 4406 swap in it. i know the transfer case had been rebuilt before i got it and had very little miles on it as well. in the end, i am using a double cardon rear drive shaft (double at the case, single at the diff) and a single for the front. there are two styles of front drive shaft. one has a sleeve on it, one doesnt. for what its worth, mine doesnt have that sleeve. i am also using a ploy trans mount, and i believe i angled the rear diff with 4 degree shims. however, i am also lowered, and it has never been off road, BUT when ever i race it, or am needing a data log with hard acceleration (or just feel like beating on the truck) it gets launched in 4x4 on dry pavement. it had been fine for the last two years, i am now noticing a slight, and i mean slight vibration now when about 60mph. i had also had the truck apart in the spring and when i put it back together had a vibration. i reclocked the front driveshaft at the diff side, and it went away.

 

[Anticitizen1]

Interesting thoughts guys! I may try that reclocking technique and see if it yields any results, and will be sure to let yall know. I just find it extremely odd that some Exploders have no problems whatsoever the first time around, and some seem to be cursed for life haha. I know for sure the rear end appears to be fine as I can get up around 100 mph with little NVH with the front shaft out, slap in the front shaft and its shuddering like all hell above 70 mph. Fuel Economy also seems to drop 1.5-2 MPG with that front shaft installed, which worried me as well that there may have been a serious mechanical issue. I may also try just pulling a second DS from the Junkyard and stab in a conversion joint and put it in, just to isolate the issue and see if maybe a different shaft yields different results.

 

[ahodges]

I have the exact, I mean exact same scenario as you. I haven't confirmed the lower fuel economy 100% but I have had that same suspicion for a while now. I've re-clocked the drive shaft, tried different ones, and had them balanced. I'm going to push hard for a CV style drive shaft very soon. Hoping I don't need to have custom machine work done.

 

[roscoe 0202]

one suggestion although not cheap get hold of tom wood's custom driveshafts at 4xshaft.com or 877-4x-shaft.i know he has built some custom shafts that made a car driveable.
roscoe

 

[boominXplorer]

I'm running a double cardon front shaft with 4" superlift and I don't notice any front driveshaft vibration but at the same time my truck doesn't go much faster than 70mph safely since it has no sway bars. I drive it 65-70 mph all the time and it's smooth drivetrain wise.

 

[Anticitizen1]

I'd definitely be interested in knowing how that cv style driveshaft turns out, I'm going to keep tweaking and doing the Sherlock Holmes work to try to fix this issue.

 

[ahodges]

I called Tom Wood's already. They don't do CV's at all, just double cardans.

 

[Anticitizen1]

I've never taken apart or looked at the exploded view diagrams of the BW4406/BW4405, but does anyone know if the CV joint on the 4405 can be loaded into a 4406 case? Similar production era and design, there might be a possibility there and then build a driveshaft to fit.

 

[CDW6212R]

I've never taken apart or looked at the exploded view diagrams of the BW4406/BW4405, but does anyone know if the CV joint on the 4405 can be loaded into a 4406 case? Similar production era and design, there might be a possibility there and then build a driveshaft to fit.

That's interesting if the CV joints are strong enough.

Mine not yet used, is also a DC front shaft I had made. I've looked at the front angles many times and wondered if the TC output shaft is parallel with the front pinion shaft. The angle of the two shaft is the biggest key for eliminating drive shaft vibrations. I would first try to adjust those to be parallel. The front diff, those all have three bushings in their mounts, and at this age many of them are wearing out. I think my rear one in the bracket is worn on my 98, I ordered four of the front ones, those are identical. The rear only comes with the bracket, which is a too much $190 price.

The trans mount on the cross member is a weak link with the BW4406 installed, that may be a big source of change of the output shaft angle.

 

[ahodges]

Don, I've tried to adjust the angles with little success. You can't significantly change the pinion or TC angle by raising or lowering the trans mount or the torque arm mount on the front diff (I even have one I modified and you can't change it enough to matter). The TC and the front diff pinion are not parallel and from my measurement, they couldn't have been from the factory either (hence the reason the factory started using CVs). The angles are way, way off of what they "should" be. Look under a new F150 once; they have a CV on both ends of the front drive shaft.

Anticitizen, I have wondered that same thing about the 4405 vs. the 4406 but I don't have a 4405 anymore to try it. I dismissed the thought because I looked up the parts diagram of each case and the bearing part numbers are different, but that doesn't mean everything. It would have been nice if I hadn't sold my 4405 and the stock CV front drive shaft; I could have experimented for free.

 

[Anticitizen1]

Welp gentlemen, I currently have a 4406 and a 4405 currrently sitting on my shop floor along with an AWD CV driveshaft, I think I'll be doing some evil genius scheming and might just rip those suckers apart and see if on fits into the other. If so, then all that would appear to be left would be to adapt or manufacture a matching driveshaft. I will certainly keep you guys posted what I find, I may try to dig into this sometime this week.

 

[ahodges]

Awesome! By the way, I think that your AWD CV driveshaft might fit right in there if the 4405 output shaft fits in the 4406. The splines will probably pull out another 1.5" but it would work for testing purposes. If we need to have a custom driveshaft made, I bet we could just have the diff end modified to work. My fingers are crossed!

 

[delexploder]

I solved that problem with manual hubs , no spin no vibration lol