Been reading up some more on this.

I've seen people say that a flush is bad on high mileage trucks that have not been serviced before....and to only do the filter and fluid in the pan.

Is this true?

 

As the clutch plates and gears in your trans wear down, they release small particles of metal into the trans fluid. Those particles help the clutches grip as they get older. When you change the fluid your taking out all of those particles and putting in new fluid which is rather slippery. When the new fluid hits the clutches they may start to slip if they have enough miles on them.

I have flushed fluid on a high mileage trans and had it start slipping on me. My personal rule of thumb is either change it regularly from the start, or leave it alone and continue to top off the trans fluid as necessary.

 

So would it even be wise to drop the pan and change the filter..or just leave it be? If it ain't broke don't fix it type of thing.

 

I had a transmission (older car) that wouldn't even move forward in "D" so I flushed with sea foam trans tune and then added lucas transmission fix after I changed the fluid and filter. Transmission shifted super smooth after that and lasted another 30,000 miles before acting up again. I plan on using AMSOIL universal ATF when I do service mine.

 

Mercon V

or...

 

I'm at 180,000 miles on mine. I've put on the last 60,000, and I have never had the tranny serviced, and not sure if the previous owned did. Trans shifts fine. Been told that it has a little "burned" smell in the fluid as well. I've read so much about NOT messing with an older tranny. Not sure if I should change the fluid or not.

 

Is there a how to for this?

 

Remove the bolts from the trans pan.
Get the hell out of the way when the fluid starts coming out.
Catch it with a drain pan.
Remove the filter.
Install the new o-rings on the filter and install the filter.
Clean the sealing surface.
Install the pan with new pan gasket.
Fill up the tranny with Mercon V.
^That's basically how to...

If it hasn't been done, I wouldn't do it depening on mileage. My ranger has 114k miles and I recently rebuilt the engine in it. I changed the tranny fluid and filter and not long after it started slipping. I now have a $1,700 tranny from AZ sitting in my garage waiting to go in...

 

I'm at 45k though.

 

Alright, so flushing the tranny for the first time at 152k would be a bad idea then? As far as i know it was never flushed, I've had it for 10k miles

 

i just did a full flush at 104k and now when its cold it wont go in gear till the truck warms up a little it will rev then slam into gear..

 

Exact same thing happened to me.

 

Flushing can make hidden problems become apparent if the trans has never been flushed before and has high miles, but in most cases it is beneficial. Burnt fluid is always bad and it means the transmission has gotten hotter than it should.

I flushed the original trans in my Explorer at around 150K miles. The previous owner said the trans was original and had never needed any repairs. I don't know what he did for maintenance, but the trans shifted great before and after the flush. There was no change...and ideally it should be that way. If you notice a significant change in the way your transmission shifts, you probably waited too long to change the fluid.

 

.... That ***** gonna go out B "black voice"

#WhyMyTrucksParkedNow

 

Having owned and operated a transmission shop for many years the best advise I could give is leave it alone! Soft parts (seals) in transmissions harden over time which causes slow engagement (mostly when cold) and possibly slipping. Most folks think a trans service will help but, trust me it never does. Transmission fluid has a ton of detergents in them and will wipe out any failing seals making problems or symptoms worse.

If your fluid is red: top it off as needed

If fluid is brown (burnt) you have problems and no service is going to help. Always keep in mind trans fluid never gets dirty. Transmissions are a sealed unit the only way fluid gets brown is from heat breaking the fluid down.

A soft parts rebuild is a lot cheaper than a trans that is fried and requires new hard parts to rebuild. Period.