Transfer case fluid levels

Back story: Last year I started having shifting problems in my 95 S-10 4x4 W-vin (167K). Took it to my local mechanic and he said I was low on Transfer case fluid, which he took care of. Up until recently, the shifting has been fine.

A few weeks back my 4x4 wouldn't engage (not related) and I had the local Jiffy Lube check my transfer case fluids while I was watching. When they removed the fill plug easily a quart of fluid spilled out. I'm very confused as the manual says to fill from here and I honestly don't know how anyone could fill above that fill plug.

So now, I'm starting to get a hint of shifting issues again. Specifically with overdrive. I'm naturally suspecting the transfer case fluid. All my other fluids look good.

Is there another fill point for the transfer case? How would it have got this full?

Thanks ahead of time for your advice.

they probably used a pump to fill it. it can be filled high and the plug can easily be screwed in quickly. also the transfer case needs to be filled on level ground. if you fill it on an incline or a decline you you will overfill or underfill the transfer case.

No the fluid from your transmission is getting into the transfer case . Check the trans fluid level i bet its low . Then you will need a new transfer case seal

we checked the fluid levels in my transmission immediately following opening the fill plug on the transfer case. It was fine.

I will say that it periodically gets a bit a low, but for a transmission that has 167K on it without any work, I'd say its normal consumption.

I'm not sure how it could have gotten that full.

I asked because in the last week, I've noticed my shifting into Overdrive has been slow, sometimes taking it a mile or so at 70mph to get it to shift.

I know how it got there I have seen it and fixed hundreds of them

Just thought I'd let you know that a jiffy-lube kind of place overfilled my transfer case using the pump method. I originally thought that they put the wrong oil in because it was binding and shifting so poorly, but after I took out the fill plug and quite a bit ran out I saw that it was the correct fluid. Just unscrewing the filler plug removed the excess fluid and it shifts just fine now.

glad that was the problem. cant beat a free fix!