If you change your fluid at the regular set intervals then of coarse its not gonna hurt anything. But when its never been changed and then flushing it at 150k will hurt it. Metal shavings will have built up in the converter and then when its flushed some of them will release and not make it out with the fluid thats being flushed. I dont know how anyone can argue with that. Cut a high mileage converter apart and your gonna see an assload of metal shavings caked around the perimeter. Hell any reputable oil change station wont flush your tranny if its got a ton of miles because they have seen it happen too many times.

 

The change of fluid on a high mileage Trans failing has to do with the friction plates and the new fluid comes the new different fluid properties which could have a negative effect on the friction plate material.

The reason IMO of the high failure rates after a fluid and filter change are do to:

1.The trans starts to act up, slipping or shifting hard into gears, now the owner’s desperate act is to service the trans with a fluid and filter change, which by now is too late..

2.High mileage without service will result in a semi-clogged Tran’s filter which will cause lower line pressure. Lower line pressure result in softer shifts, which results in more friction plate wear. More friction wear results in thinner plate material. A fresh oil and filter change will boost the line pressure and the added sudden force may violently rip apart the thin friction plates. (Before you change the fluids and filter, put your car into Drive and then reverse and back to Neutral, feel how soft the shifts are, change the filter and fluids you should be able to feel the shifts.)
[ol][/ol]

 

If you are debating if you should or should not replace your Trans fluid and filter.

I believe you have only one choice and that is to replace the trans filter and fluids and hope for the best.

 

one last time.

it does NOT hurt anything. Stop listening to ancient myths preached by someones grandfather about his 55 oldsmobile.

 

Christ people. Anyone that thinks changing the trans fluid at 100k is harmful needs to be kicked in the *****.

Listen to Manybrews.

 

One last time hear too. It will hurt your trans. Go flush it and report back.

 

Wow, glad to see this is still going strong but sad to see there is such dispute. I'm still a bit torn on this and am leaning to just having a "drain and fill" done. The filter cannot be replaced in this gen correct?

 

being as Ive done it about 4 hundred times, Id say you have no idea what you're talking about.

 

correct.
The internal filter is not servicable. Up to about 2000 they had external screw on filters that were deleted after that.

 

After high mileage the Trans fluid properties change.

The friction plates are use to the evolving old fluid, a complete flush could have an effect on the friction plates.

I do not think anyone would argue that you should not use the wrong type of Tran’s fluid.

Why is that? Different types have different properties.

Why not play it safe[/b] and do a partial fluid change with filter and after 15,000 do another partial change. Do not flush out the torque converter with a system flush.