1. Fluid level okay while running, warm, level surface.-- yes
1a. Fluid color and smell-- ok
2. Speedometer reading correctly-- yes
3. Shifting normal/hard-- no
4. Shifting into OD okay?-- yes
5. Any service engine light: yes/no--- no
6. If SES light on, what codes do you have?--no
7. Model year:--95
8. Describe symptoms:
9. Does the engine come up to full temperature?-- yes
10. Any service work recently done that may contribute to your issues. -- rebuilt trans 1000 miles ago
11. Does the TCC lock up (or how many "shifts" do you hear?)-- yes all 4
12. Are you experiencing any kind of slipping? yes, badly
13. What type of rear do you have? (Check RPO codes) 4.10/ 3.73/ 3.42 or 3.08--- not sure
14. If you have an accurate tachometer, what is the RPM at 55 or 65?


Well I was driving down the road today and all of a sudden out of nowhere the trans started slipping really bad. It was in Immediate problem, no type of onset or warning or anything just went from perfectly good to hellaciously slipping. Barely was able to get it off the road. The trans was just completely rebuilt 1000 miles ago. Its a 95 6.5l tuyrbo diesel 4 WD. Can anyone help or offer their input as to what may have happened

Definitely a mechanical failure. Not an electronic failure.

I strongly suggest a pressure test be conducted. A pressure test will let you know if you have hydraulic pressure failure in all gears and the reverse gear. I am thinking the fluid going to the transmission pump is restricted or the pump itself.
A Tech II diagnostic test would be your best course of action from a shop that has one.
Furthermore I would make good from the repair facility who rebuilt the transmission.

Sounds like time for a pressure test. Also drop the pan and see if the reverse boost valve dropped out of the pump. Had this happen on a 4L60E before and the snap ring for the reverse boost valve wasn't fully seated and it popped out shortly after rebuild.