Boxcar wrote:Thanks all for reccomendations.
Shift points are manageable. I never drove a flat four auto before. Stated differently shifts are quick, and there is no sense of any slipping which is desireable.
I have driven many many automatic buses, and they can be remarkably smooth and unobtrusive.
At light throttle they hit 2nd at 10 mph and glide into 3rd at barely 30. They will immediately downshift into 2nd if you apply the accelerator at 30 and they will stay in 3rd once you are closer to 40 and up.
The "kickdown point" is not a "point". Your floored accelerator executes the kickdown.
Boxcar wrote:
My one undesireable area which I would not turn anyone else loose with this Bus on is the kickdown point being too fast in3rd, and way too fast in second.
What do you mean?
A "point" is not a "fast" or "slow" thing, it is a moment.
Is the vehicle shifting too late into 3rd on the upshift?
Is the vehicle shifting too soon into 2nd on the downshift?
Is the shift too firm? Spell it out. I think our discussion upo to this point actually has spelled out as clearly as you are likely to get, what is going on.
A "kickdown" is a decision. Does the transmission actually knock it down into 2nd at your floored accelerator command at 40 mph? THAT is a kickdown. And if you left your foot into it, it should stay in 2nd until 50 mph. BUT! If it violently shifts down at too high of a speed for your light accelerator position, I think we discussed that your vacuum signal is inadequate. I will blame your camshaft, but make sure your vacuum signal is optimal, nooooo leaks.
Boxcar wrote:
Of course I can drive around the severe downshift by gauging hills etc.
You mean, by loading up the engine so the shift is absorbed by increased work?
Boxcar wrote:
How does the vacuum accumulator adjust + or - or if at all to lower 3>2 kickdown
Or to make it LESS likely to shift down is more better.
"less likely is more better" I shouldn't give you any indication that I understood a damn thing here, but
what you are asking is:
"how can I fool the modulator into thinking there is more vacuum than is actually available?"
Well, try to optimize whatever vacuum the engine is generating:
*increase idle timing
*ensure NO vacuum leaks, even the dipstick
*clean out vacuum modulator nipples on both ends use a larger vacuum hose (if 4mm use 5mm and use a sleeve on the nipples for a tight fit
Please understand that the vacuum modulator may very well be plumbed into the brake booster circuit, and you HAVE to check the integrity of the entire circuit. A leaking brake booster can cause violent shifts, or any leak along the entire run, including the wye in the engine compartment. As I remember, the vacuum modulator is teed off the brake booster downstream of the one-way valve under the car over the driveshaft. But you already know your modulator right? So where does it get its vacuum.
If it does tee off the brake system, can your brake booster give you an assisted pedal after five minutes or does it lose it after only 20 or 30 seconds?
If everything is definitely excellent, then call your VOLKSWAGEN 003 EXPERT and make damn sure you are communicating with clarity exactly what your issue is.
"My engine has a modified cam that has reduced my vacuum signal, now the vacuum modulator is banging out shifts as though I were flooring it all the time. Can I adjust it?"
Boxcar wrote:
Is that a kickdown switch function, or vacuum accumulator function?
Vacuum damn accumulator? This ain't no Lincoln, this ain't no Benz!
But is the function of the vacuum modulator to stage the shift point speeds . . . .
Colin