Originally Posted by Tuzmaster
I used a failsafe thermostat and bought it in Colorado Springs. I think there is only one thermostat. Have never heard of 2. coolant seems to flow fine although at one point i drained it and flushed it with water and the flow was okay out of the engine. I have installed that brand of thermostat on my last jeep and it worked fine. I don't know what else to check.
On the T-case i was told to hammer slightly in the linkage that goes into it. Should i try that?
There are multiple thermostat models. I'd quote from the Factory Service Manual, but sold it to the guy who bought my 95 Limited ZJ 4.0
The thermostat only controls when it opens to run coolant thru your radiator. Once it opens all the way, from then on the engine temperature is a function of how well that radiator can keep dumping heat. The 4.0 radiators tend to be rather effective at this even in places like Death Valley. If you have an aftermarket it may be even better than a factory one.
If you don't have the California emissions stickers anywhere, you would not NEED that thermostat.
I wouldn't hammer on the linkage, but firm tugs, etc. would be appropriate.
The transfer case isn't that big a deal to pull if you have good ramps or safety stands and a few buddies. Mine never had issues at mileage similar to yours, so never had to do this myself.
FSMs should be available on EBay if they aren't still available at Tech Authority. Best investment you'll ever make.