Destroying 4406s after more SOA lift

[rabbit91]

Been running SOA with an F150 pack for a few years now and the BW4406 for 5 years.

Recently I lifted my rear to a few inches higher than the front to compensate for my SAS and new rear bumper. I extended had my leafs rearched w/ new bushings, drive shaft extended with new ujoints, new ubolts, longer shocks. My driveshaft angles from top flange to bottom are within 2* but about 300miles after the lift my tcase developed a rattle while coasting at high speeds 40mph+ The sound is as if the chain is loose and becoming more loose

I swapped tcases and the sound went away only to come back within 300 miles again. I took the driveshaft back and had it rebalanced, which it needed. I Put it back in and the tcase still make the noise.

With the front shaft removed, it still rattles

With the rear shaft removed and driving in 4x4 it seems that the high speed rattle while coasting is gone.

My question is, has anyone lifted there 5L the same hieght and been able to run the slipyolk fine?

I'm swapping another 4406 in tomorrow but I'm worried about wrecking another one although this time the driveshaft has been rebalanced... still uneasy feeling

Upon opening the first case, everything looked fine inside.

Both cases I've had leaking from the output seal even after replacing that but wondering if that's a result of the driveshaft taking out the tcase rear bushing.

Any insight or questions are appreciated!

Since Photobucket isn't free anymore, I have pictures of the truck on Instagram: brad.olson

 

[Stealthbowl]

my guess at this is that its enough angle for the out put bushing get trashed could also be a worn slip yoke and just tossing this out in the universe are you sure that you might not need a longer driveshaft with the soa. i have seen it happen in the past with lifted trucks that the drive shaft with slip yoke looks long enough and "works" but it is slid so far back on the out put shaft that all the loading takes place on the very end of the shaft and buggers the bushing

 

[boominXplorer]

Running a double cardon shaft? I am on my second 4406 myself. I've never seen one not leak from the tailshaft though. Mine still leaks after new driveshaft flange, new brass bushing and new seal. I just chalk it up to being over filled and at the wrong angle at this point.

My truck is also a ranger with only 4" suspension lift in the rear so my driveline angles are nowhere as severe as yours.

 

[rabbit91]

Running a double cardon shaft? I am on my second 4406 myself. I've never seen one not leak from the tailshaft though. Mine still leaks after new driveshaft flange, new brass bushing and new seal. I just chalk it up to being over filled and at the wrong angle at this point.

My truck is also a ranger with only 4" suspension lift in the rear so my driveline angles are nowhere as severe as yours.

You definitely get better angles with the longer wheel base. How are you running a 4406 with a double Cardon? Hack and tap?

Been also looking into other tcases to run with rear flanges like a 271 but that's more like a plan C

Never had a leaking tail shaft until now, guess I got lucky...sorta

 

[Turdle]

Did the problems seem to occur after or before the Front axle swap?

 

[rabbit91]

Did the problems seem to occur after or before the Front axle swap?

After, I've had the SAS for 2 years now with my original SOA done 3 years before that. Zero problems then

 

[Turdle]

Ok hear me out.
The 4406 was only offered in trucks with fixed front diffs. I have often wondered if the added stress of the front axle moving around causes issues. For example, if the slip yoke were to get sticky and not slide well, it might push rearward on the front drive flange which isn't designed to encounter the rearward force.

If I am off base Forgive me. I asked in another thread but got brushed off.

 

[rabbit91]

I hear where you are coming from, another idea I hadn't thought of! I'll check the front slip to see how it feels and grease it to be sure

 

[boominXplorer]

I originally made a double cardon shaft when I did my v8 swap in my ranger but had vibrations since I didn't have enough lift to warrant the dc. I now have a single cardon and reset the pinion angle with almost all vibrations gone (never balanced my front shaft after building). Feels great all the way up to 70 mph.

You can find a double cardon rear shaft from from 97 and 98 4x4 Expeditions. The 2wd also has them but the slip is a different diameter and it won't seal.

I am running a front double cardon though. It's a must have if you don't have a fixed stock location front diff.

 

[boominXplorer]

Ok hear me out.
The 4406 was only offered in trucks with fixed front diffs. I have often wondered if the added stress of the front axle moving around causes issues. For example, if the slip yoke were to get sticky and not slide well, it might push rearward on the front drive flange which isn't designed to encounter the rearward force.

If I am off base Forgive me. I asked in another thread but got brushed off.

Good point. The front output bearing is mounted very very similar to a 1356 which has the ttb front suspension. It has a clip holding the bearing in and the output is pressed in. I don't think it should be a big concern but the case is made out of magnesium. I assume a full width axle may cause stress at an angle it wasn't designed for. If it fails I figure it would immediately be catastrophic and not just a symptom.

 

[Spudhut]

Since Photobucket isn't free anymore, I have pictures of the truck on Instagram: brad.olson

I have been using 'cube upload' for photos, its free and simple to use. https://cubeupload.com/images

 

[rabbit91]

Good point. The front output bearing is mounted very very similar to a 1356 which has the ttb front suspension. It has a clip holding the bearing in and the output is pressed in. I don't think it should be a big concern but the case is made out of magnesium. I assume a full width axle may cause stress at an angle it wasn't designed for. If it fails I figure it would immediately be catastrophic and not just a symptom.

That's what I figured too, if it was going to be a problem, it would happen shortly after a SAS.

All the problems I listed have happened after I raised my SOA more. Top of my spring plate to the frame I have 13" gap, hope that gives a better idea of the height

I originally made a double cardon shaft when I did my v8 swap in my ranger but had vibrations since I didn't have enough lift to warrant the dc. I now have a single cardon and reset the pinion angle with almost all vibrations gone (never balanced my front shaft after building). Feels great all the way up to 70 mph.

You can find a double cardon rear shaft from from 97 and 98 4x4 Expeditions. The 2wd also has them but the slip is a different diameter and it won't seal.

I am running a front double cardon though. It's a must have if you don't have a fixed stock location front diff.

Double Cardon with a slip yolk for the tcase? Thought I would have to go to a fixed output on the tcase and have the slip in the shaft

 

[Spudhut]

What about adding a slip type driveshaft from a Jeep Wranger in the front to help absorb the front axle movement and take the stress off the transfer case?

 

[boominXplorer]

That's what I figured too, if it was going to be a problem, it would happen shortly after a SAS.

All the problems I listed have happened after I raised my SOA more. Top of my spring plate to the frame I have 13" gap, hope that gives a better idea of the height


Double Cardon with a slip yolk for the tcase? Thought I would have to go to a fixed output on the tcase and have the slip in the shaft

Fixed yoke would be ideal but slip dc is readily available. Heck I'd sell you mine if you want to try it. You'd probably have to shorten it though. It's the black recently retubed one in the pic.

 

[rabbit91]

Fixed yoke would be ideal but slip dc is readily available. Heck I'd sell you mine if you want to try it. You'd probably have to shorten it though. It's the black recently retubed one in the pic.

View attachment 150903

Well f*ck wish I had know that I could double Cardon with the slip yolk before I had mine extended o

 

[rabbit91]

Fixed yoke would be ideal but slip dc is readily available. Heck I'd sell you mine if you want to try it. You'd probably have to shorten it though. It's the black recently retubed one in the pic.

View attachment 150903

Any chance you have the length on that?

 

[boominXplorer]

Any chance you have the length on that?

 

[rabbit91]

Sourced out parts to get my shaft made to a double cardon now I think I'll have to change my pinion angle to get it to point at the tcase. Nothing like rushing to get this all done before Oregon in less than a week...

 

[boominXplorer]

You got another shaft? You can't convert over a regular shaft, there's a center stub for the inner bearing to ride on.

Yes you'll have to adjust pinion angle toward tcase.

 

[Spudhut]

Hey @rabbit91, were you able to find a fix for this?