I need some help diagnosing my transmission problem. It all started whilst I was driving home one night going around 80kms and then I can hear my engine rev but it continues to slow down until I reach about 30kms and then it grabs again. I have to continue at a low speed or the transmission will slip again and I had to crawl home at one point it wouldn't even move for me so I waited and eventually it would again. The next day I tried putting it in gear and it was able to move again I drove about 150 yards and then it completely stopped working again I waited a few hours and I was able to drive it back into my driveway, but no further. I have not attempted to move it again. The fluid is red and at the right level. I am wondering if I need a rebuild or if there is some other small problem that can be easily fixed? Your time and help is much appreciated!

 

Hard to tell. If you know anyone with transmission experience locally, I'd give them a call.
It will make it through 1st and 2nd gears, but then slip after? That's the 3-4 clutches gone(common).
However if the fluid is still red... at least on the dipstick. It may be a leak in a seal. A leak in the forward apply circuit would cause issues.

I would start out by checking the A+B shift solenoids (search). While you're at it, go through the electrical system and check for low voltage. i.e. Battery, alternator, transmission harness, ECM connections.

You also may want to locate a scan tool that will give you a readout of sensor status. I put up a post that listed at least 6 sensors that affect transmission shift points and fluid pressure control. Any of those could be suspect as well. It's better to do some research before throwing away $500-$2000 on a transmission when you end up paying for something different later.