clicking noise from transfer case?

[bzinsky]

Hi Everyone, first post, been looking around the site for various tips and tricks on my truck. I love the site and found lots of great info. Anyway, my truck is a 1997 4 door tahoe lt.

There is a strange metal-metal clicking noise coming from the truck. The click frequency sounds as if it is driveshaft related. I used to only hear it slightly in reverse, didn't pay much attention to it. All of it sudden it started happening while going foward, constantly. It sounds as if its 3-4 times faster than the tire rotation. I drove maybe 200 miles while hearing the noise.

I finally got a chance to get under the truck. I rotated the drive shaft back and forth and there was some play. I hear a similar noise coming from the 4wd transfer case. The u joints looked pretty solid, I couldn't budge them.

There appeared to be a good leak as well...

Maybe it just needs fluid? I haven't the slightest idea where to add the fluid though.

Does anybody have any insite on this issue? Hopefully I don't need a new transfer case. Looks like a pain in the ass to replace

On a site note....what does OBS mean?

 

[SunlitComet]

Old Body Style. The '90's unit. remove shaft and replace the end seal.

 

[denali00]

i think i got bout the same issue, but ive driven a good 700 miles w this, im goin to check the tcase for low fluid here after the truck cools off..what kinda damage can happen if fluid is low and how fast can damage occur..any input wouold b awesome

also notice small amount of rotaional play in the front driveshaft, is this normal, back is tight, back just needs new seal and i hope fluid refill!! dont wanna have to replace tcase

 

[bzinsky]

Old Body Style. The '90's unit. remove shaft and replace the end seal.

So you're clearly the forum old fogey that only has time for short winded responses.

I appreciate the help but i have a few unanswered questions.

DId i damage the t-case?
How do i add fluid.
How do i replace the end seal? Any writeups?

 

[taylorjm]

lol, old fogey...at 39...lol

You might want to apologize to sunlitcomet....he's an expert on just about everything that has to do with these trucks. He's someone that's good to have on your side. Plus he's a really nice guy, very helpful, kind, generous, and goodlooking. (hopefully I scored some brownie points with that comment!)

 

[bzinsky]

lol, old fogey...at 39...lol

You might want to apologize to sunlitcomet....he's an expert on just about everything that has to do with these trucks. He's someone that's good to have on your side. Plus he's a really nice guy, very helpful, kind, generous, and goodlooking. (hopefully I scored some brownie points with that comment!)

"forum" old fogey. Could be substituted for veteran. It was more of a compliment than anything. i want to fix this today so any advice on how properly replace the seal would be appreciated

 

[SunlitComet]

Sometimes I am just busy or very tired from work. I really can't say anything about possible damage but for a '97 unit that does not look the dexron III which is what should be in there. on the left back end of of t-case you will have a drain plug on bottom and a fill plug a little higher. drain and examine what is in there. and when you fill it up you have reached the full mark when it dribbles out the fill plug. do that before you tackle the seal unless it is outright drooling out of the seal.

 

[19992dr4x4]

Had the problem and it's a easy fix. As there are many opinions on this site here's mine. Put GM Auto Trac II fluid in the T-case and fill the yoke with GM "Special" grease...that's what its called. I had a prob in that same area and chased it for about year until 2 weeks ago and did what I just said and my truck drives smooth as butter!

 

[SunlitComet]

Let me make this point very clear.

ONLY USE AUTOTRAC II IF YOU HAVE A NP8/NV246 AUTO 4WD SYSTEM AND DO NOT USE IN VEHICLES '97 OR OLDER!