Yesterday my transmission went bad after my father drove it for two hours with no problems. Its slipping real bad pulling out, I can only move it in first gear not drive or overdrive. I have not looked deeper into it yet. But any ideas here?
possible switch to the 4t60ehd or 4t65hd?
thanks

If you get no forward engagement in D or 3, but putting it in 2 or 1 give you a slipping engagement, that typically means your foward band broke. Only way to replace it is to disassembly most of the trans. Which suggests a rebuild or different transmission.

So mainly you dont think it could be electrical or mechical solenoid problem? Also, the weird thing is that the VATS is.throwing a security light when trying to start the car, took about three tries.

And will the 4t60 hd bolt right up with no mods on the computer?

Thanks

And that is correct, but there is no engagement in od and d 2 and 1 the car engages with slippage, in d and od the engine revs to switch gears but no feeling of engagement

The 4t60-hd doesn't have anything that'* drastically stronger. The diff is the same size and all the hard parts are the same. The differences, other than FDR, are in the valve body and accumulators.

The problem is purely internal.

Correct.

There are two different types of PCM programmings: those that can control a 4T60E-family transmission, and those that can control a 4T65-family transmission. Therefore, being a 1995, your car should accept any 4T60-E or 4T60E-HD that fits and plugs in.

Bear in mind if you get one with a different gear ratio, you will need to re-tune, otherwise your shift points will be off by a couple hundred RPM.