My original 208 transfer case failed. So I replaced it with a NP 261. Bolts right up no problem. So what fluid should I use in it. I have done some research and some say use Dex6. Some say use 5w30 synthetic. Any thoughts?
CK5
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NP 261 Fluid
- Thread starter Tiger5
- Start date
Np 241 or do you have a drivers side front axle to use NP261. If NP241 then it is ATF Dex 6
I believe it is. It physically fit in place of the 208. The 261 is also leaking out the tail shaft. It appears any way. I installed a new seal. Lubed the slip yoke ss well. What else could it be? The vent appears clear too.
I am considering pulling it back out and having it overhauled. Everything thing else is redone.
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Still trying to understand how you are using a NP261 in a square. The 261 is set up for the front diff to be on opposite sides than a NP208. Are you sure you don’t have a NP241?
Here is what I know, I had been taking parts off of a K5 at a local salvage yard and I needed a transfer case. So I called over there and said that I wanted it. I went to the office and it was sitting out front. I loaded it up and to it to my friends shop. They installed it. I thought it was a 208 until yesterday. I looked at the tag. It said 261. I will verify in a day or so. You have me second guessing.
The np208 was replaced by the NP241 in 1989(passenger side drop) driveshafts and linkage will bolt up. The NP241 from the 1988 and up pickup trucks are driver side drop. NP261 is driver side front drive shaft and does not fit your K5.
If it is leaking from the case, check for pump rub issues from the oil pump towards the top rear of the case near where the slip yoke output housing is bolted to the case half.
wasted wages
1 ton status
Or they are looking at it and saying...
" I wonder how the front driveshaft is going to fit now "???
" I wonder how the front driveshaft is going to fit now "???
261 on the tag might be referring to the ratio. NP208s have a 2.61 low ratio which is stamped into the tag.
Great comment 305. Here is a pic. I took it today.
So what do I have?
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False alarm. Lol. 
Top line says np 208 c that is the model number.
Bottom says 2.61 that's the low gear ratio
And since it is a 208 atf dex3 or hydraulic fluid also works
Crisis averted. Whew! I owe you guys a beer.
The leak was the drive shaft yoke. So I cleaned it up and put an epoxy on it. Let it sit for 30 hours and it stopped it.
Had that on my van driveshaft.
Pain in the ass to find but easy fix
