Transfer case problem?

[mbleitz]

When in AWD in the rain, in the snow, and when floored, I get this bump, bump,bump,......But not in 4x4 hi,or low.It must be something to do with the AWD system.
Is there a clutch in there that engages the front end that is engaging too harshly,wrong fluid?
Thanks
98 xlt ,auto,137k, heavy duty torque converter,rebuilt trans.

 

[backroads]

Bump

 

[joecrna]

Sounds like normal functioning of the Auto (not AWD) transfer case. There is an electromechanical clutch that engages the front output shaft when the system detects rear wheel slip. You don't usually feel it engage though and there should be no noise.

 

[Four0Sport]

might want to look at the fluid in the t-case. old worn fluid can cause parts to not engage smoothly bc of the loss of friction in the fluid. make sense? it did in my head but i dont know if i typed it out correctly lol hope this helps.

 

[mbleitz]

Oops it's auto, not awd.It seems like the clutch is engaging too harshly when the front axle engages.I'll replace the transfer cace fluid with the right stuff first,and see what happens.
Any other ideas as to what it could be would greatly apperciated.
Thanks
M

 

[IZwack]

Here's one possible solution: dont floor it while in snow/rain . Seriously though, rotational speed differences in the drivetrain is going to kill your vehicle if anything all of the sudden "catches" or "gets grip".

 

[backroads]

Is there a clutch in the transfer case that is wearing out? I did some searching and found other people that had the same problem(popping or the bump noise) while under load in auto.It looks like a fairly common issue with these transfer cases after about 130000 mi.
I couldn't find anything on this site ,but it looks like a problem that will be rearing its head for a lot of people with explorers.

It should not be making this noise,if it is then something is starting to go,

 

[mbleitz]

Well I took it to a tranny shop, and the guy says the fransfer case needs to be rebuilt soon.After 2 tranny rebuilds and all the other things that have gone wrong with my ex.Along with terrible ratings explorers get especially the 2002's,its time to send this thing down the road before the timing chain tensioners go out ,and who knows what else.
It's Honda Passport time.

 

[tgfrench]

transfer case

My transfer case had the same bump problem. Ford wanted $2300 to put a new one in. I said F that and got one on ebay for 60 bucks, installed it in a weekend and it worked great for me in the last snow storm. My recommendation is find one at a salvage yard, ebay, or craigslist and do it urself.

 

[gijoecam]

Completely normal. Mine's done it since day-1. 165,000 miles later, it's still running.

 

[mbleitz]

Mine also does it from a stop from 3/4 throttle or more,it will make the bump bump noise.Maybe there's some slop in some part in the transfer case .The rear wheels must under load be turning a tiny bit faster than the fronts.Then the computer senses it and starts to engage the front driveline.If that is right than maybe it should allow for a little more differentiation in speed between the 2 axles.It would be nice to be able to adjust it.Make sense?
Sounds like another reason for the brown wire mod.Personally I would rather have a manual transfer case and hubs,much more reliable.