Tcase on its way out?

[Erickk120]

So Started noticing this clunk lately its almost as if you are going into 4low when I cycle between R and D and vice also its the same sound when I gun it at high speed. I had another thread but it was regarding a vibration that started recently. Also noticed the rear tcase started leaking shortly before all of the clunking and vibes started. This is coming from somewhere in the front tcase and not from the slip yoke. Or at least thats where I heard it. I also have front driveshaft play up and down. I just havent had enough time to investigate due to work. Hopefully I will have time halfway through this week. Any ideas would be appreciated, although I will probably end up tearing it down to get to the root cause, here is a sound clip. Its more of a bang than a clunk.

Thanks

 

[wjburken]

So Started noticing this clunk lately its almost as if you are going into 4low when I cycle between R and D and vice also its the same sound when I gun it at high speed. I had another thread but it was regarding a vibration that started recently. Also noticed the rear tcase started leaking shortly before all of the clunking and vibes started. This is coming from somewhere in the front tcase and not from the slip yoke. Or at least thats where I heard it. I also have front driveshaft play up and down. I just havent had enough time to investigate due to work. Hopefully I will have time halfway through this week. Any ideas would be appreciated, although I will probably end up tearing it down to get to the root cause, here is a sound clip. Its more of a bang than a clunk.

Thanks

Transfer case or differential?

 

[OR VietVet]

Several mentions in several threads about the chain getting loose or pump rub problems and rubbing a hole in the transfer case. I know about this and watch and listen for mine all the time. That may be the culprit here. Or bearing play, lots, to allow the play you mentioned.

 

[Erickk120]

Transfer case or differential?

Most likely Tcase I removed the front shaft, tried shifting ans same noise. I will remove the rear and try that see if anything changes to isolate it to the tcase.

 

[Wylie_Tahoe]

Easy to eliminate u-jount as the source first. You can also feel the slop in the ring/pinion while checking the u-joints. Motor/trans mounts.

 

[swathdiver]

Might be time for some new bearings and races, you can order a rebuild kit and overhaul the whole thing to potentially minimize downtime.

 

[Erickk120]

Might be time for some new bearings and races, you can order a rebuild kit and overhaul the whole thing to potentially minimize downtime.

You might be right, I took the rear DS off and engaged 4wd, tried switching gears and there wasnt that loud clunk, I thought about the rear end but it seems to be coming from the Tcase, sounds like there is some slack somewhere inside it, Developed a vibration from 65-80 mph after I started hearing the noise and Tcase leaked just before it too. I still havent had time to take it out, since I've been working on getting a ford 8.8 finished by tomorrow, so that has taken my free time, but I will keep it updated once I get to it, Been neglecting the fat hoe.

 

[rockola1971]

You are probably hearing the chain slack of the stretched out chain smacking the inside of the case and its probably too late to save it. You will most likely need new case half or both. Which is a great time to put in new bearings, races and seals along with clutches if you have auto 4wd or you can just get a core and rebuild it.

 

[Erickk120]

Little update, Took my Tcase out, found a lot of ATF in the adapter, I believe 4l60's in 4wd config dont have a seal at the back of out output shaft. I would say I easily had below half a quart of oil inside the adapter, no idea if that is normal although, I did overfill my tranny last time, if any of you would chime in. Tcase fluid looked brand new blue, so no cross contamination, seal is good in tcase.

Now as far as the Tcase I took it down and turned the input that connects to the tranny, turned it by hand and it also engaged the front ds output, so I'm now wondering if the reason my tcase was clunking was because it has been permanently stuck in 4wd, without me realizing it, and the only thing saving it from potentially blowing up has been the front actuator not being engaged at the front.

I know early 246's were supposed to be engaged, or atleast spin the front ds, with the clutches barely engaged, but I thought it was discontinued in later years, mine is an 04.
and I know the 246's are different for 02 and later.

At this point I debating whether or not to do the 241c manual swap, I pretty much have everything including the new front D/S but I still need to do the 4lo mod, to be able to get 4lo working, the vss should be straight forward, but engaging the actuator will slow me down, since am still hunting for a 3 pin OEM pig tail. Atleast I will be able to drive in 2wd for the time being.


Any input would be appreciated,

 

[swathdiver]

Little update, Took my Tcase out, found a lot of ATF in the adapter, I believe 4l60's in 4wd config dont have a seal at the back of out output shaft. I would say I easily had below half a quart of oil inside the adapter, no idea if that is normal although, I did overfill my tranny last time, if any of you would chime in. Tcase fluid looked brand new blue, so no cross contamination, seal is good in tcase.

Now as far as the Tcase I took it down and turned the input that connects to the tranny, turned it by hand and it also engaged the front ds output, so I'm now wondering if the reason my tcase was clunking was because it has been permanently stuck in 4wd, without me realizing it, and the only thing saving it from potentially blowing up has been the front actuator not being engaged at the front.

I know early 246's were supposed to be engaged, or atleast spin the front ds, with the clutches barely engaged, but I thought it was discontinued in later years, mine is an 04.
and I know the 246's are different for 02 and later.

At this point I debating whether or not to do the 241c manual swap, I pretty much have everything including the new front D/S but I still need to do the 4lo mod, to be able to get 4lo working, the vss should be straight forward, but engaging the actuator will slow me down, since am still hunting for a 3 pin OEM pig tail. Atleast I will be able to drive in 2wd for the time being.


Any input would be appreciated,

Eric, go to the Heritage Center at GM and download the Restoration Kit for your truck. In it you'll find descriptions on how the various transfer case and driveline systems work which will either confirm or correct what you know about them.