Now that gave me a good laugh!...

 

If the trans isn't damaged new fluid can only help it. If it has terminal damage it's going to fail whether or not you change the fluid. It doesn't sound like your trans is damaged.

A pro that knows what he is doing never reuses old fluid. A mechanic that should have a different job would reuse old fluid.

A heated flush machine isn't needed for this transmission. A non-heated flush machine will work just fine on this transmission.

I do recommend MERCON V fluid.

That's because there is an internet myth that flushing a transmission damages it. That isn't true. But you're welcome to believe whatever you like.

I disagree with your disagreement. MERCON V is a superior fluid. It was originally developed to eliminate shudder. It seems like a good choice for a trans that has developed shudder.

A flush machine that is used properly cannot damage a transmission. If it is done wrong, just like if a fluid change is done wrong there can be damage.

The filter doesn't need to be changed. It doesn't need to be changed until the trans is rebuilt. The flush machine doesn't churn up gunk any more than driving the truck churns up the gunk.

Is there a point to that comment?

No, it's because MERCON V is a superior fluid. It was reformulated in 2006 to be compatible with the older transmissions. I wish Ford would have given the reformulated fluid a new name. It would have made all of this simpler.

It probably does have one.

Here is a DIY way to change all of the trans fluid: https://www.ford-trucks.com/articles...-transmission/

 

Mark, thanks a ton for the info and for debunking the myths. I will be getting my transmission flushed with a new filter and fluid as soon as possible.

 

It's not an internet myth that transmission flushes damage transmissions. Transmission flushes are unnecessary. Draining and changing the fluid at regular intervals is the best way to maintain a transmission.

There are plenty of mechanics who reuse old transmission fluid on an old transmissions on it's way out.

I've had three subarus all go above 200k before I sold them on the original transmission. They shifted great. Never flushed the transmission fluid. Only drained and changed at regular intervals.

I'm sorry this guy has been convinced he needs to spend extra money on a pointless maintenance technique.

 

Thank you for responding Mark. Appreciate it.

 

I was tech for 10 years and no one ever reused the old fluid. How would you even collect and filter it? That’s some shady stuff there. I wouldn’t let them work on anything of mine.
No. it is also a word of mouth myth. I rebuilt transmissions while at the Mopar dealership. Old hard seals and/ or burnt clutches are not going to helped or hurt by replacing the fluid. If the trans is dying it isn’t going to matter.

When Chrysler was still using ATF +3 the recommended service interval (drop the pan and replace the filter) was every 15K miles. If you serviced the trans according to Subaru’s interval then I agree there is no reason for a complete fluid change however that is not what was asked. The OP has no idea when it was changed and would like to replace all the fluid at one time. You can change the majority of the fluid in your driveway without paying a shop for a machine flush.

Mark was a Ford transmission engineer. Interesting that you don’t believe him.

 

Yeah so I'm new to the website and I don't know who is who. I'm not a professional mechanic but I am an HVAC and refrigeration service tech so I have mechanical understanding.

I'm not saying I have to be right about the flush I'm just going based of my personal experience and what I've heard from trusted mechanics. I don't know of any shops that would ever save and reuse fluid either. I've got a family member who has been a private mechanic for 30 years that knows their stuff. I go by them and my own personal experience. Even people like scotty kilmer says trans flushes are unnecessary. I'm not saying that guy is right about everything, but he seems to be genuinely trying to provide people honest information.

Anyways, not trying to make any kind of an argument. This has just been my experience. Could be wrong.

 

Scott Kilmer is a joke, I would rather take vehicle advice from my mail man......


The only thing he did that I didn't is make 10million off YouTube in 5 years. I will give him props for that!!!

 

I figured I would update this thread for anyone who might discover it in the future. I had the transmission flushed and filter changed in the beginning of November and all shuddering has stopped completely. It shifts smoothly into and out of 4th. If you are experiencing similar symptoms I would recommend changing the transmission fluid.

 

Good deal. Sounds like the additives in the new fluid helped.