Transmission Fluid Black- Change Or Filter?

[Graham]

Hi guys,

I recently came into a 94 SC400 with 245k miles. Sometime during the past 6 months or so, the transmission fluid turned black, should I change the filter, and leave the old fluid in there hoping it cleans up, or should I also flush the fluid (and watch the seals leak even faster?) or - do nothing?

I found the tutorial on lexls, and I'm fairly accomplished home mechanic, but any tips are welcome...

Thanks!

[lenore]

I would not recommend a flush, but a drain and fill, or a fluid exchange were it is replaced as you add it. Changing the filter is a must.

[JohnH]

Simple question... Would you change an Oil Filter, and leave the dirty oil in the engine? B)

Same answer for the tranny..

[Graham]

Simple question... Would you change an Oil Filter, and leave the dirty oil in the engine? B)

Same answer for the tranny..

Update, in another forum someone suggested that black transmission fluid = slipping clutch plates. So that comes from reduced pressure... which comes from a clogged filter.

Thanks for the advice guys, I'll do the "little bit at a time" from the lexls tutorial and change the filter too. I should have a shot at it this weekend, will let you know how it turns out.

[Graham]

Hi guys, I took the pan off and found someone else was there before me, only 3 of the 4 magnets are there. But at 238k there was little or no metal fragments in the pan or on the magnets.

The filter screen looked clean and I swapped it out with a new one.Then I added 2 quarts. One thing to note is that there is less than 1 quart between the marks. The local autoparts store had the transmission pan gasket.