2nd to 3rd shift flare

[Corvo Gold]

Hey there,

My 1988 300CE was flaring by about 1000 RPM when shifting from 2nd to 3rd. I replaced the K1 spring inside the trans, which helped reduce the flare by about 500 RPM, but it's still not perfect. I also replaced the vacuum line that runs from the manifold down to the shift modulator, but that did nothing.

If I accelerate gently I can reduce or even eliminate the flare. However, that's not convenient during day-to-day driving.

Any thoughts as to what I should be looking at next?

Many thanks,

Corvo Gold
1988 300CE
1987 300TD

[daantjie]

Triple check fluid levels. New filter can't hurt either.

[Diseasel300]

Make sure you're checking the fluid level properly, car driven 15+ miles to get the trans hot, parked on level ground, engine running in park, level between marks on dipstick and preferably towards the high mark. Sounds dumb to suggest this, but it's an easy thing to do wrong and too much or too little fluid won't reward you with great shift quality.

Is this a recent development or has it always done it since you've had the car? If it's always done it, the modulator may be turned in too far, try backing it off a bit and see if it helps.

[Corvo Gold]

Fluid is just at the bottom line when cold, right beneath the top line when warm.

The flaring started without warning. First, there were times when it wouldn't shift from second to third -- it would just get hung up and accelerate. I refreshed the filter and fluid which seemed to help with that problem, but then the flaring began. Like I said, I replaced the K1 spring which reduced the flaring without eliminating it completely.

Thoughts?

Corvo Gold
1988 300CE
1987 300TD

[bigpanda16]

Adjust the modulator a little to see if that can help