Terrible transfer case noise

[BanjoBend]

So my Dana 20 is making a horrible noise and in need of rebuild. what im wondering is if anyone can tell me what is wrong and if it would be worth it just to fine another t-case.

here are the symptoms. it only makes noise when the hubs are locked. when its in 2wheel with hubs locked it makes a noise that gets louder with rpms, it sounds like the chain is fluttering. when i put it into 4hi, the noise goes away but another one starts. it makes a horrible grinding sound when there is no load (not accelerating or decelerating, just cruising). i dont know for certain, but i think it makes the 4hi noise more when it is icy.

[Dennis Bernth]

The Dana 20 doesn't have a chain; it's gear driven. First thing is make sure all of the U joints are in good shape, a bad U joint can make you think the transfer case is about to blow itself into a million pieces. If it turns out to be the transfer case, it would probably be cheaper to find a good used one to swap in. Please note that this advice could change depending on your location; where I'm at, there are more rusty parts Scouts than running driving Scouts, so I've got at least a half dozen Dana 20's sitting in my storage trailer or tarped over outside. If rust isn't a problem and Scouts don't get scrapped, you might be better off to go through the one you have if the cost of a used one is getting close to what the kit costs. I've only sold one TC, and I got fifty bucks out of that, seems to be the going rate in my neck of the woods. For that money, no way would I do a rebuild that will cost two or three hundred bucks.

[BanjoBend]

gear drivin, boy do i feel dumb! ill put it up in the air tomorow and check everything again but everything seems to be fine. i found a used one at a wrecking yard near by and they say its in good shape. i think i might do that seeing that LKQ will deliver to our shop for free!

[Jay Tabor]

well yank the drain plug outa it, catch all the oil and [metal chunks] in a clean oil pan/bucket. and see whatcha got that aint oil . in the bucket.
then go give the front out put yoke a good shake and feel for looseness . .
do the same with rear output yoke.
if the yokes move up and down and in and out enough to notice, thens youse gots problems.
so do what Dennis says --swaperoo another'n inta the scout, or yank that one off and rebuild it..
i would say by the description your chain is loose . . even though it aint got a chain . . lessn of course some previous owner /abuser put one in and thats possible . .

its your front output shaft bearings by the sounds you describe.
you get you a reepair manuel and read up on fixing thangs, itll tell you what to do . .

[Scott Hickman]

Why don't you drop the pan and take a look inside?

[Doc Stewart]

If you don't find big chunks in that oil you drain, wave a magnet through it to see how much metal filings are in there.

[Gary Billings]

Do you have a lift or spring over?

Are your u-joints in good shape?

-Gary

[BanjoBend]

all u joints looked good, front and rear end inspected and look good. decided to pull transfer, no big chunks, some metal fillings. i think the bearings on the center shaft are to blame. ill find out tomorow when i tear the thing down

Do you have a lift or spring over?

Are your u-joints in good shape?

I have a four inch lift with five inch shackles. no u joint binding if thats where your goin, otherwise any input is appreciated.

[ihscoutfanatic]

i have a fully rebuilt d20 in mine and it makes the same noise while coasting. I found it to be the front driveshaft slip yoke of shot. That thing has a ton of play in it. need to have it rebuilt but not a priority since in texas we dont really need 4 wheel at higher speeds much

[Dana Strong]

Originally Posted by BanjoBend

So my Dana 20 is making a horrible noise and in need of rebuild. what im wondering is if anyone can tell me what is wrong and if it would be worth it just to fine another t-case.

here are the symptoms. it only makes noise when the hubs are locked. when its in 2wheel with hubs locked it makes a noise that gets louder with rpms, it sounds like the chain is fluttering. when i put it into 4hi, the noise goes away but another one starts. it makes a horrible grinding sound when there is no load (not accelerating or decelerating, just cruising). i dont know for certain, but i think it makes the 4hi noise more when it is icy.

I agree with the above, particularly about checking the fluid.

In high range, 2WD on the D20, most of the gears rotate but are not under pressure since the force only goes straight through to the rear output shaft. If the gears are badly rusted or or have broken/chipped teeth, their meshing could be making the noise. If that is not the cause, in 2WD, the front output shaft isn't 'connected' to the rest of the gears so any problem is likely in the shaft's bearings; it has one in front and one in back, the back one being used to adjust the endplay which should be something like 2-5/1000" (from memory). With hubs unlocked, the front doesn't even need to turn.
Having the front engaged in 4 Hi takes up the backlash and puts pressure on the gears which increased noise from bad gear contact. In 4 Low, the power transfer is through a different arrangement of gears and the noise will change.
BTW, 4WD on hard surfaces, even with some icy spots, is hard on the system and will cause torque buildup between the front and rear axles/drive shafts/TC output shafts so is only recommended if/when absolutely required.

[Posts 5, 6, 7, 8 and 9 weren't here when I posted this one (#10); if you look at the posting times, you can see they're out order. What happened here? ]