4406 swap question

[oddball101]

Hey guys. My 4404 failed so I swapped over a 4406 manual Tcase.

The driveshaft (slip yoke) I have is 1.25" too short, but it bolted up. The slip yoke was long enough to still have a decent amount of length still on the output shaft. It really does recover some strength from the motor over the 4404.

Anyhow, something else I noticed during the test drive was a ton of white smoke about 5 minutes into the drive. The culprit is a mad leaking rear output shaft. The fluid spitting out of it and landing on my exhaust pipes. There's fluid slung everywhere now.

Can any of you tell me:

1. Is it most likely leaking due to 1.25 inches of insufficient length? -as in, does the shaft have to be a certain length to meet the inner seal?

2. I didn't replace the rear output seal (outer most rubber piece), could it just be that the seal is bad?

It leaks only during and after when the shaft is spins. Sitting still, before then and now when she's cold, there are no leaks.

So this is where I'm at.. Any help on the info would be much appreciated.

Cheers

 

[CDW6212R]

If it's throwing that much fluid out so quickly, it won't be just the outer seal. I would definitely change the seals though, and be sure to get the OEM style "extended" rubber boot kind. The cheap type without that extension let debris get to the shaft seal, and it doesn't live as long.

It sound like the shaft isn't quite long enough, but I don't know enough about that shaft and the output shaft needs.

 

[oddball101]

Ya, I get where you're coming from. I don't know about the shaft length requirement either.

When I replace the driveshaft, I will replace the seals as well this time. Just have to get a long driveshaft to have it cut down (again). The first one was cut to the size I specified. I just specified the wrong measurement with the truck lifted and wheels hanging down instead of at stock ride height. Such a rookie mistake. So stupid. I didn't even make that mistake the first go around. Blah

 

[boominXplorer]

If you over fill it the rear seal will leak. I would assume with the amount of fluid your using the rear seal is damaged.

 

[CDW6212R]

True, if the ATF is over filled it might not be the shaft. Double check the length that so many others have used with the BW4406, and again see how yours differs.

Buying one from a 4.6 Expedition I recall is where they all got theirs. Mine is also, but not installed yet.

 

[oddball101]

So looking at the slip yoke, it has about an inch of smooth surface before the splines begin, along with the single missing spline for relief. I believe the that smooth surface rides on an internal seal that sits like a donut on the output shaft, and that the slip yoke is just short enough to miss it. I will have no idea until I get to it to replace it. I am hoping I can replace what I need to (bushing?, inner seal?, outer extended lip seal) without having to remove its tailhousing.

My application is a bit different than the common setup. The driveshafts that are supposed to bolt up are the 5.4 4wd rear and 4.6 front, I think.. The concept being the use of the shorter rear and the shorter front in each application. In my ranger, I have installed a rebuilt M5R2 (about a half inch shorter) along with the 4406 Tcase. That effectively changes both lengths, but not that much. I may have picked up the wrong rear from the junk yard having gotten it mixed up with a couple others I was eyeballing.

Just dropped off the rear driveshaft this morning to be lengthened. Another $180 down the drain. He said the slip yoke, if it was from a different application, may be either to long, or the outer diameter may be off as well. I don't believe there is a difference in seals between the electric and manual version of the 4406 which I pulled the shaft from, so I went ahead and had it lengthened to match its original state anyway.

Also, because of the way the length of the 4406 housing extends further than the 4404, it changes the pinion angle slightly. So in this case, I went ahead and used the shorter 4r70w mount with my shortened tranny crossmember. I am also using a mix of f150 leafs with my explorer main spring on to with the f150 main spring with eyes cut off, keeping it SUA. These three variables also factor into and length difference, but really, it appears to sit at more of a stock ride height.

Gonna have to go buy the seals on my way back to pick up the rear shaft so I can test the seal fitment and make sure it is good to go. Then it'll be refilling the Tcase with Mercon V (2 quarts) until it drains (sitting on level ground) from the fill plug.


..This whole thing has really been an uphill battle for me since doing my manual conversion. Oh well. I'd still do it again, just a little smarter lol.

 

[oddball101]

Went to get the shaft, tested the replacement seal and it doesn't even come close to fitting. Apparently amidst all of the driveshafts I had sitting together, I go tit mixed up. So now I have a driveshaft that has been cut to length for the wrong slip yoke.. literally just threw away $200. So pissed.

Unless I can find a new seal that fits the 4406 and has an inner diameter that seals this slip yoke outer diameter of 1.683, I am royally screwed having to pay out for the new "proper" slip yoke, joint and cut-to-length-tube. He says the 4wd slip yoke OD is larger than the 2wd OD. I have no idea how this could be so messed up. Operator error really killed this one..

 

[CDW6212R]

Sorry to hear that, so many changes makes it harder to mate the right parts. Keep at it and go slow, be patient, you'll get it right.

 

[oddball101]

Note to anybody who does this.

1. Make sure you have the 30 base 31 spline slip yoke from a 4wd
-apparently others can look the same but will in fact have a thinner sleeve wall carrying the splines
-easy way to check, get a new seal and see if it fits snug or not

2. If you have to have yours cut to size, measure the natural length when vehicle is not lifted

3. Make damn sure you don't get your drive shafts mixed up
-they may fit the shaft, but the seal is a different story

**edit
4. For a ranger application, it is the f150 4wd short bed driveshaft that is supposed to work. Not sure if this is for a ranger regular cab or extended cab though. Please chime in if you know.

 

[CDW6212R]

Good points, as most buys of a used drive shaft are from a source obtaining it and telling you it's from such and such vehicle. My rear one is that way, I have yet to double check it.

 

[oddball101]

So the shaft shop gave me a break. Instead of paying $200 for the work he just did, then another 50 + 85 for the yoke and the joint, and then another 200 for the resizing of the shaft itself due to the new yoke, instead only asked for $250, then gave me $20 back. Said I had a good attitude (I really don't know where that came from). So all in all, my lesson is learned.

Point number
5. Don't bite the hand that feeds.

 

[CDW6212R]

Good to hear. Drive shaft labor has gone way way up in the last 20 years.

I was almost stunned when I was asked $180 for building my front shaft, using two that I brought him. I paid it since the shop was recommended to me. The shop I used to go to shut down when the road was moved etc, in about 2004. So I took the first suggestion I got, and drove to the new place to get the work done. Things change, prices go up...more than my salary does.

 

[oddball101]

Lol, no kidding. Well, as it stands, I am mega glad this all came through the way it did, lessons and all. She's running beautifully now.

It's a subtle difference but it's noticeable, especially in the top end. The tranny builder told me to be nice the first few hundred miles.

Also, I went fishing around for programmers snd found Lasota racing. Good stuff. Low and behold though, James Henson actually contacted me back and was still helpful. Even offered to assist in some areas. Real stand up guy considering he's no longer in the main stream of things anymore.

 

[CDW6212R]

That's great to hear, and James has always been helpful when I needed it.