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I bought this 1993 Jeep Grand Cherokee, 5.2 V-8, Fulltime 4wd
It runs great, drives nice until it reaches operating temp.
Then I intermitently lose O/D. In the mornings, It starts the first time your release the excellerator it shifts hard out of O/D from 60mph,
It works fine again for about another 15 minutes, then it will only shift to O/D after 65mph, and it takes another 5 minutes then I have to hold 70mph to shift to O/D. Shifts back to 3rd and won't have O/D until it cools back off.
5pm I only have O/D for about 10 minutes at 65mph and then its gone.Shifts great through all of the gears up to 3rd.
Then no O/D until morning. I'm Thinking now that the O/D band in the trans may be out of adjustment?

After all that Happens I start noticing an intermitent misfire. It sometime comes and goes quickly, 2 to 3 second interverals. sometimes more random. It kicks off the cruise control. Which I understand.
Wires, plugs, cap, rotor all new. Coil tested good. Could it be the Cam or Crank sensor?
The miss sometimes feels like a lack of fuel but other times it feels like a spark issue.

Any Ideas? I hate just randomly spending money on different sensors. It does have a new TPS.
 

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Welcome to Allpar.
Any fault codes?
Is this the 46RH or 46RE transmission?
No band for OD, it is a series of clutch plates that may be fine. It sounds like a hydraulic pressure 'leakage' issue? ATF thins as it warms.
Test ports are available on the side of the case for a pressure gauge hook-up while driving to monitor pressures for diagnosis if there are no fault codes.
 

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These transmissions are designed not to shift into overdrive until the fluid gets to a certain temperature. They are also designed not to shift into overdrive if the fluid overheats. The temperature sensor in 1994, I believe, is on one of the cooling lines to the radiator.

Since the failure is after it warms up, I suspect that your fluid is overheating for some reason, or the sensor thinks that it is. Check the condition of your radiator, and also if you have an auxiliary cooler. There may be blockage somewhere. Does the coolant temperature gauge show normal?
 
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