I changed my transmission fluid and filter and adjusted my rear band. my truck didnt have reverse before but has it now, now the forward gears are slipping and they were fine before i did the adjustment. what could i of messed up to cause this, its a 46re tranny

 

A couple quick questions, dont take offense just have to ask:

Did you use the correct fluid? Those trans are PICKY about the fluid

Fluid level OK?

Any idea how many miles were on the fluid that got flushed out? Have seen cases where a truck with, say about 100,000 miles on the original trans fluid gets flushed then the new fluid cleans up the crud that got built up with the old fluid and it can create issues with the valve body. Even seen it lead to complete transmission failure.

 

It shouldn't have contributed to this but, you didn't mention that you adjusted the front bands.

Get in there and do it again. And make sure to clean out any junk that you see, really well.

 

atf+4 full synthetic fluid from oriellys, not sure on the miles of the last fluid i had just bought the truck for 1000 so some fixing was expected just not sure if i messed something up. i turned the truck on let it get up to operating temp checked the fluid level it read ok. one thing i noticed that made me worry was as i was tightening the adjustment screw to the 72ft-lbs it made a pop and the cylinder where the rear band adjuster is went up more fluid dumped out and i couldn't get the adjustment properly torqued after that, i unscrewed the adjustment screw enough to torque the lock nut in place. still moves just slips in forward gears reverse works good now and i was pulling to a stop in the driveway and it stalled the engine

 

i did not adjust the front bands

 

Do the fronts too.
And you did make sure you run it through all the gears and check the fluid in neutral, right?

 

didnt run it through all the gears i got nervous after i felt 1st slip and i checked the fluid in park this was my first transmission fluid change i've done

 

You must check it in neutral since the pump on these transmissions only run in N or any drive gear. There is a possibility you have a low fluid level.

I know mine would slip when the level was low.

 

i put in 4 quarts. ill go check again, should i go run it through all the gears then check it or just start it, let it warm up then check it in neutral

 

Well, have you driven it? If yes, then running it through the gears would be unnecessary, me thinks.

Just let it warm up and check it in neutral. 4 qts seems a bit light, but I don't know how many light. lol