I am taking out my np203 that is having problems and installing a good one. I will be unbolting the old one from the adapter. is there a gasket that I need or can I just use rtv sealent ?
thanks
are you driving with Hi loc on the street?well I used ultra black rtv when I did my 208 case a couple times on my s10. I wasnt sure if I could do the same with the 203. I will call around for a gasket. If I cannot find one , ultra black it is.
The 203 is making a load clicking sound in 4high loc as I take off from a stop and it gets faster as I speed up , but not as loud. then it kinda disappears when I am coasting then comes back louder as I slow down. I dont know what it is. Since I have another np203 I might as well just change it out, hopefully theres nothing wrong with the spare.
are you driving with Hi loc on the street?
That is like driving in 4wd on the street, not good for anything in your truck
Only if you have snow on the ground to let the tires slip when it's bound up.
well I used ultra black rtv when I did my 208 case a couple times on my s10. I wasnt sure if I could do the same with the 203. I will call around for a gasket. If I cannot find one , ultra black it is.
The 203 is making a load clicking sound in 4high loc as I take off from a stop and it gets faster as I speed up , but not as loud. then it kinda disappears when I am coasting then comes back louder as I slow down. I dont know what it is. Since I have another np203 I might as well just change it out, hopefully theres nothing wrong with the spare.

Sounds very similar to the symptoms mine has. There is a shift fork that the differential linkage pushes towards the tail of the case. This engages a crown gear to lock the differential in the case (locks in 4x4). Since my shifter plates are really worn out, vibration causes the shift lever to fall forward towards the dash when I'm in 4hi-loc. When braking or coasting, that crown gear catches but does not fully engage, making a really irritating clicking/grinding noise.
Mine has hubs and is a trail rig, so I've just gotten in the habit of holding it in place when I'm in hi (which is almost never). I'm replacing it as soon as I have time to rebuild my 205 and buy a doubler plate, so I haven't put much effort into the shifter. It might be worth it to you to swap out the shifter or even just try adjusting it. The shifters are junk and prone to being out of adjustment, but they take all of 5 minutes to replace if you pull the tranny tunnel off.
Might save yourself all that heavy lifting. Unless a seal is leaking or the chain is twisting off the gears, there really isn't anything else to wear out in these. Mine still had the tag from 1976 and all the bearings were even still in pretty good shape.
This is the collar.:
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If you pull the tail cone off you'll see it right there with the shift fork wrapped around it...not that you'll need to do this if it's just your shifter. Maybe it will help you visualize![]()