Hello everyone, just joined the forum. Question is just bought 2000 ram 1500 truck with 159,000 miles. Want to change the transmission oil because don't know if it ever changed. Heard numerous horror stories on changing oil and transmission dies later. If I change it should I put some of the old oil in with the new or just go all new oil.
Thanks for help

 

if you do a pan drop and replace the filter; half of the systems fluid will remain anyways. the only way to get it all out is with a exchange machine. do a pan drop and see how it goes.

I have access to a exchange machine so I have changed the entire volume for the old cars I bought...the 4 I have done have been fine.

 

That is a new one on me. Older vehicles would have a drain plug on the torque converter and removing it completed the fluid drain process. When you drain the pan, check the smell of the fluid. If you get a burnt smell, you are pretty much overdue for a fluid change. In this case that exchange machine sounds like a good plan. As I recall there is a magnet inside the pan, so clean it and replace the filter of course.

 

I rebuilt a 2003 Regal for my Step-Son. The transmission fluid was black with 150,000 miles on it. I bought the car from my sister so I know how it was run. She drives like a little old lady so I knew the transmission was still in good shape. I dropped the pan and changed the filter. I top off the fluid, then I put the car up on jack stands, unhooked the Transmission line going to the radiator at the trasnmission, I attached a rubber hose to it that was clear and hooked it to a bucket. I started the car up, put it in neutral and as the old black fluid ran out I was pouring in new fluid. When the fluid coming out of the hose turned red, I put the car in park, shut the engine off and hooked everything back up. I topped off the transmission fluid and it's been fine every since. I spoke to a mechanic that I am good friends with before doing this and he said transmissions should be serviced every 30,000 miles.

 

I have exchanged fluid that way and have had no problems. the concern is lube circuit; it's after the cooler line so it will be starved unless you fill from the cooler return line.

 

I always had the same question. I have done a lot of reading into this issue, its always been the reason I have stayed away from anything to do with a transmission. I have mixed feelings about it but.. after thinking about it, it kinda makes sense.

So where that originates from, is people who have not services their transmission like they should have ( or are very hard on them) and essentially after awhile this damages/breaks down the clutch packs and other components within the transmission. The FLUID if not changed in awhile has little metallic shavings or debris in it that helps the worn clutch packs turn, allowing the truck to shift gears. When flushing the transmission fluid you have taken away that debris which helped it shift. This makes sense to me, its why I never drained or flushed my transmission fluid on an older car that was not mine from the beginning.

However I read, that if you have metal shavings or debris in the transmission fluid than the truth of the matter is your transmission was on its way out the door anyway. Either way, down the line it would have failed. I suppose its better to know ahead of time than one day when you're driving and it leaves you stranded.

I have also read that if you drain the liquid into a clean jug (or whatever) and there is obvious shavings and debris, you can put the fluid back in and not flush it, which may buy you some time to save up enough to get the transmission rebuilt.

In my opinion its best to change it and at least see if you have a problem.