Too much fluid in AWD t-case?

[nrschaaf]

Hello all. I was trying to hunt down a whining noise in a friends '00 X 5.0 AWD today and when I cracked the fill plug on her t-case the fluid came rushing out. I was doin it on a gravel driveway so it got sucked up too quick to get a good look at it, I was thinking maybe water infiltration and I don't wanna mess with it again untill I have a chance to get it on a lift but I was wondering about one thing. Is it possible that the input seal could have gone and the trans fluid is running into the t-case maybe under hard acceleration? If I don't find water in there I'm gonna be at a loss to explain why or even how that much fluid would be in there.

 

[SoNic67]

AWD case has two plugs. One higher (fill), one lower (drain). Did you try top one? Remember that the hot fluid has bigger volume, let it cool first!

 

[nrschaaf]

Yeah. It was the top one. It wasn't hot, but it wasn't cold either just took it down the stree and back to hear the noise. It really expands that much?

 

[gavin]

I really don't think fluid from the transmission could get in to the t-case; the tailhousing where the t-case bolts to the transmission would have to fill up first, before the fluid would even be able to get past the t-case intput seal.

there's a higher chance of t-case fluid "leaking" into the tailhousing.

if water did get in the t-case, the fluid would look milky

 

[Turdle]

Hmmm,
possible scenario:
T case was filled by previous owner with rear jacked up, when you cracked it you were facing slightly uphill???

 

[nrschaaf]

Yeah, I thought it was a long shot that trans fluid could get it. Unfortunately the driveway I checked it in sucked it up to quick to get a good look at it, but what was left in my arm wasn't milky, very dark to be honest. It also sealed really thin. It does make sense that the other owner could have had the back jacked up. It has a TT and warrior shackles now but she bought it not only was it stock height, but it was on smaller tires. I'd imagine he would have needed to lift it to get under it. I'll have it on a lift tonight so hopefully I'll have some answers.

 

[SoNic67]

Just drain it all...

 

[nrschaaf]

That's what I'm gonna go for. I don't believe she has the manual for her truck, does the 2000 use Mercon trans fluid too? I've only done my '97 so I just wanna be sure.

 

[gavin]

That's what I'm gonna go for. I don't believe she has the manual for her truck, does the 2000 use Mercon trans fluid too? I've only done my '97 so I just wanna be sure.

yeah.
thte BW4404 uses Mercon/MerconV

 

[nrschaaf]

Excellent, thanks guys.

 

[nrschaaf]

So I drained what looked to be a mixture of some brownish trans fluid and lots of water from the t-case and flushed it with some kerosene. Now that it's got fresh fluid in it the noise did not go away. I checked the front diff and it wound up taking a quart so I was hoping that was it, but yet again the noise persisted. After taking the front driveshaft out the noise finally gave up. I noticed a lot of rotational play in the front end so I think it's pretty clear this axle is gonna need to be freshened up.

 

[Turdle]

How does the cv end of the drive shaft feel? Look closely at the small rubber boot for a split-you may have to flex it to see. Move it around while compressed, check for rotational play.

You might grease the cv up real good with a nipple fitting, there is a small hole on the end of the cv ball. Then stick it back in and see if the noise quits or changes. Quite often the front drive shaft is the noise maker. It can make a grindy, rattling chain type noise. Real scary.

 

[gavin]

How does the cv end of the drive shaft feel? Look closely at the small rubber boot for a split-you may have to flex it to see. Move it around while compressed, check for rotational play.

You might grease the cv up real good with a nipple fitting, there is a small hole on the end of the cv ball. Then stick it back in and see if the noise quits or changes. Quite often the front drive shaft is the noise maker. It can make a grindy, rattling chain type noise. Real scary.

it's even worse when you have to drive 30 miles home and can't go faster than 30mph on the highway because of the noise, vibrations, and horrible grinding

 

[nrschaaf]

So I finally for a chance to check her driveshaft out and it seamed fine. I slapped it in my truck real quick to see if it made noise and it was all clear so that's kind of a good sign. Though it woulda been better than rebuilding the front axle. I am curious about something though. I know my truck rolled when I left the front driveshaft off it and Ive seen the threads saying that it will happen. Her truck doesn't roll at all with it just in park. Could that be a sign of issues with the t-case? I mean it did have a good amount of water in it for who knows how long.

 

[gavin]

possibly?
I assume you're comparing your truck with her's on the same slope?

while it's certainly possible the viscous coupling froze/seized up, I'm not sure how common of an issue that really is.

FWIW, I was able to push my truck, in P, without the front driveshaft installed, on a fairly level driveway.

 

[drdoom]

I have a 4404 on the bench right now, had some rinky dink 3" vent tube on it, water in there seems to have damged the front output bearing. Shavings in there too.

 

[nrschaaf]

Pretty much. I even took it a step further and threw a tow strap between our trucks to see if I could make it move. I couldn't. I suppose it'll be a good idea to have someone check out the t-case as well.