2008 Tahoe LTZ. No oil. Added 2 quarts, dipstick still doesn't show anything.

[User_Name]

I did notice this, but there is no play, up, down, sideways, I did pull ups on it and nothing. This was the rear, at the transfer case, I believe... I'll have to check again.

 

[OR VietVet]

It is bad, play or no play, the grease seal at the left side of pic is split open and the u-joint is offset to the right, in the pic.

 

[User_Name]

Must be pretty low not to show, dump it out all out and start over. If the engine has an external oil cooler on the driver's side radiator tank, check the lines to see if any burst. After about 5-7 years, they start to weep and then leak and then let go and that takes a few years usually.

Just wanted to throw in, oil has stayed the same since I added 3 qts. Pressure has been steady 40+. Will do complete change tomorrow.. payday. No leaks

 

[User_Name]

It is bad, play or no play, the grease seal at the left side of pic is split open and the u-joint is offset to the right, in the pic.

Should this be where i start?

 

[Doubeleive]

So I -think- I know where the clunking may be coming from. I got under there, and I can literally push the front hog head up about half an inch. The mount bolts that the differential is attached to have play, so do the bushings where the mount bolts to frame.I have not used 4wd since I got the truck last friday, nor do I plan to ever, this was bought as a work truck, my tools aren't heavy. I'm fine with 2wd. That said, I took it to a mechanic, he wanted to sell me on motor mounts, but this is no motor mount I'm hearing, we agreed they are bad, but not the clunk cause. Then he said the sound is coming from the transfer case and said $2500 to replace. I am willing to replace a transfer case myself, and I will for sure replace the front hog head bushings and tighten mount bolts.



My question is, can I remove the front driveshaft, and drive in 2wd, to see if the clunking persists? If the clunking stopped, perhaps all I need to fix is the bushings/mounts. On the other hand, the mechanic did say that as long as you're in 2wd, there will be no load on the front axle, which makes sense.

I did check transfer case fluid, my finger could not fit in the hole to check fluid level, so I figured I'd add some anyways to see. I was able to fill it with probably 3/4 a quart of dexron6. Rest went on me and the ground. Not sure if it'll take more, I couldn't tell if it was leaking cause it was full, or if it was leftover fluid from the bendy funnel. Put the drain bolt back on. The clunking is still there. Maybe it's not as noticeable? I think I'm saying that because that's what I really wanted to happen. No it still clunks though, either way.

The clunking comes when I'm stopping, abruptly or slowly, about 10-15ft before the actual stop. It also comes when I go from P to D, 6/10 times. Same with reverse to D, maybe 3 or 4/10 times.

Pretty sure it's already in 1st gear when I hear/feel the clunk. Transmission shifts fine, up and down, it's just hard to tell if I'm in 1st when I hear the clunk, the long pipe headers with this engine have quite a rumble. Tbh, it drives/feels like my 67 mercury cougar, if it had power steering. I like that though. I don't want to give up on this truck.

Sorry for the book. I guess my question is, can I rule out if the clunk is caused by the failure of the front differential bushings, by removing the front driveshaft? In 2wd only ofc.

Thank you for every reply, yall are saints

the front diff mounts do go bad so that could be a source of a clunk for sure so could motor mounts, you can check those with the hood up and see how much the engine moves with brake applied and giving it gas in forward and reverse.
I doubt a transfer case would clunk and would more likely "grind" but you can drain the fluid use a seeve a see how much metal gets filtered out, chunks are bad, light silt in small amounts is normal, don't recall if the transfer case has a magnet drain plug or not

 

[OR VietVet]

Should this be where i start?

Change it and if it was me, I would do all of them, but I like to spend other people's money.

 

[Trey Hardy]

Just wanted to throw in, oil has stayed the same since I added 3 qts. Pressure has been steady 40+. Will do complete change tomorrow.. payday. No leaks

Should this be where i start?

Ps if your oil pressure fluctuates but no lifter tapping and oil level is good there is a PITA oil pressure sensor screen that gets gummed up I’ve changed 3 now and two for a friend and my dad
If you run into that issue you need a special socket for the sensor and a hand full of swivels and extensions to get back to it as it’s on the back of the intake

For the clunking I have the same issue I haven’t gone through the replacing everything to trace it out but from my inspections motor mounts and transmission mounts are good front diff is tight and bushings are good but I don’t know if the universal joints have ever been changed before and she’s got over 300,000 miles on her so I went ahead and got new joints front to back I just got to make the time and get a press to change them out

 

[User_Name]

It's hard to hold the phone and push the hog up with one hand, but this is just to give you an idea how much play there is. With two hands, it doubles.

 

[B-train]

It's loose at the fastener that holds the diffential! I could see space between the nut and bracket I think. Not the bushings from what i could see. Look at the video again.

Also, to the pic of the u-joint - that thing is TOAST. You can see the grease seal gone and every inch of it is coated with fine red powder called RUST that is working from the inside out. Pull the driveshaft and see how they feel. ANY play other than pivoting is bad, any tightness or limited movement is bad.

 

[User_Name]

It's loose at the fastener that holds the diffential! I could see space between the nut and bracket I think. Not the bushings from what i could see. Look at the video again.

Also, to the pic of the u-joint - that thing is TOAST. You can see the grease seal gone and every inch of it is coated with fine red powder called RUST that is working from the inside out. Pull the driveshaft and see how they feel. ANY play other than pivoting is bad, any tightness or limited movement is bad.

Would this cause a clunk, even if it isn't in 4wd?

It's loose at the fastener that holds the diffential! I could see space between the nut and bracket I think. Not the bushings from what i could see. Look at the video again.

Also, to the pic of the u-joint - that thing is TOAST. You can see the grease seal gone and every inch of it is coated with fine red powder called RUST that is working from the inside out. Pull the driveshaft and see how they feel. ANY play other than pivoting is bad, any tightness or limited movement is bad.

As far as the diff. Yeah, both have play. Should the bolts that touch the axle have a bushing? Or can I just tighten them?