So I've got an '01 S40 with 190K, and I've never done anything with the transmission. It's always worked great.

Now I've started to notice a slight "thunk" when downshifting into 2d and 1st when decelerating. It's not a big deal; but it is a thunk that is far more noticeable now.

Is there anything I should be doing to caress and show my love to my transmission? In the manual, there is no notice about where to even check fluid levels. Does it use transmission fluid?

Arro Smith
Austin, Texas

Are you driving an automatic or manual? All automatics use ATF and have a dipstic to check the level. Manual trannies use gear/motor oil and do not have a dipstick.

In either case, check the motor mounts first. If an automatic, check the fluid level after the car has been driven for at least 30 minutes with the engine running and start thinking about flushing it.

Klaus
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The more I learn, the more I forget. So why learn?

If the car has never been flushed, it may cause more harm then good if you flush it now because it could cause the clutches in the trans to start slipping. Just keep that in mind.
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FCP Groton

Sorry, FCP, but that is an old wive's tale. People who have their tranny flushed by machine or by persons that know nothing about trannies, can and do have problems after dislodging dirt/sludge and having it move to a pump. Or by releasing 3 quarts of fluid at the drain plug and not refilling it properly.

Besides, the car in question has not been sitting around for the last 8 years or only been driven by a little old lady to the grocery store.

Flushing a modern auto tranny, or manual, is a good thing regardless of mileage. Smoother shifts equal less strain on the other drivetrain components.

Klaus
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The more I learn, the more I forget. So why learn?

I will second Klaus's last thought. You've got nearly 200k miles on the original trans fluid. I'd be willing to wager when you check your fluid it's going to be brown-ish looking, and not smellin' very good.

Get yourself a flush pronto.

With that many miles on the original fluid I would say start with regular fluid, and do a complete flush, and then next year do a complete flush again with expensive fully synthetic fluid. (unless your trans takes the 3309 fluid, in which case use that both times;) )

DON'T have one of the 'power' flushes done. The only pump hooked up to your tranny should be the pump that's already inside the thing. If you don't/can't/won't do the flush yourself, make sure your mech does it the old fashioned way and let the trans pump push the fluid out for you.

The are lot of articles on this forum and others about how to accomplish this on the 850/70 series cars.

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1998 V70 AWD Turbo 195k+