Transfer Case drain and fill Fears coming true?

[devildog0]

Originally Posted by Tim_MN

A rattle at the 4x4 shifter is typically worn out bushings in the shift mechanism.











You seem to have the Cherokee manual transmission confused with the transfer case. Both the NP231 and the NP242 use ATF, not gear oil or 10W-30. Some people claim that New Process 231 and 242 transfer cases can safely use synthetic 5w30 engine oil, but there is no reason to use other than what is recommended, ATF. My 98 has +284,000 miles and the ATF filled transfer case shifts smoothly and makes no noises.

Novak claims on their site that many folks are running 30 weight oils in the 231 and 242 woth no ill effect. Who knows. ATF is cheap and works fine.



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[Wayne Sihler]

Thought there were clutches? May be that's the 249 I'm thinking about.

[lawsoncl]

Originally Posted by devildog0

Novak claims on their site that many folks are running 30 weight oils in the 231 and 242 woth no ill effect. Who knows. ATF is cheap and works fine.



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I'd be hesitate to run 10W-30, since the viscosity is twice as thick as Dex-III at 100*F.

[Wayne Sihler]

Originally Posted by lawsoncl

I'd be hesitate to run 10W-30, since the viscosity is twice as thick as Dex-III at 100*F.

10-30 was only suggested to be run in HIGH heat,HIGH load situations, where ATF was foaming and misting out the vent.

It was not to be used in NORMAL situations.

[cmahaff]

Hello 👋
I've been out of service for a few weeks

I am confident in the fluid that I used and don't think that is causing the sound.

I wonder if my Google drive link worked and anyone can hear the sound. It's most prominent starting at about nine seconds.

[blu3fan]

having just rebuild my xfer case due to a rear pinion leak. I can say. you can change the chain without pulling the case.
in fact I recommend you do it this way.
if you want to do the bearings too. pull it.
its a days work.
You need a slide hammer and the special pliers.

[cmahaff]

I guess if the chain was loose enough it could be making a metal on metal sound due to engine vibration. I'm hesitant to blame the chain now, because it hear it when the vehicle is not moving.
The chain shouldn't be moving in that instance right?

[Tim_MN]

A rattle under the floor console is typically worn out bushings in the 4x4 shift mechanism. The chain would only make noise if it was moving.

Applying some light downward pressure on the shift handle, or pulling up very slightly usually stops the rattle, and confirms that the shifter mechanism is the root cause. Naturally you need to also check that the exhaust is not making contact with the crossmember, or the unibody.

[cmahaff]

Originally Posted by Tim_MN

A rattle under the floor console is typically worn out bushings in the 4x4 shift mechanism. The chain would only make noise if it was moving.

Applying some light downward pressure on the shift handle, or pulling up very slightly usually stops the rattle, and confirms that the shifter mechanism is the root cause. Naturally you need to also check that the exhaust is not making contact with the crossmember of the unibody.

To me, the noise represents more of a light grinding than a rattle. I will check the shift handle and see if any change in its position alters the sound

I also want to put it in 4wheel drive and listen for the sound

I intend on fixing the exhaust resting on the cross member soon. I know that is making a noise. But I think it's different. In the mean time I want to put a wood door stop between the two, just to rule it out

[md21722]

Nothing inside the transfer case moves when the vehicle is stationary.

In 2wd drive mode, the chain turns with the front output yoke turns, so typically anytime the vehicle is moving & the front driveshaft installed. In this case its 'freewheeling' and not under load.

In 4wd move, the chain is under load as it's being 'driven' by the main shaft. The transfer case forces the front output yoke to turn.

All 'selection' and 'operation mode' is done by way of forks on the main output shaft which selectively engage or disengage the chain/front output.

The way the transfer case is built, the front output is 'direct drive' via the chain to 'main shaft'. So by way of mode selection, the front output/chain are either freewheeling or driven and this occurs by way of the forks on the main shaft side of the case.

This may make more sense if you ever split the case open.