[DML] Re: Questions on automatic transmissions

["Harold McElraft" <hmcelraft@xxxxxxx>]

An accurately setup auto shifts nice and smooth hot or cold - in 
really cold weather the shifts are a little smoother - almost 
unnoticeable - warmed up - noticeable but smooth - no banging or 
jerking. I notice the change in engine sound more than anything 
along with more getup, especially at WOT. Never notice down shifting 
at coasting to stops or stopping. Down shifting from throttle 
response is firm but smooth and up shift the same - I try never to 
let the trans have to go through two gear shifts at once - i.e. 
first to third or third to first (I just visualize too much stuff 
going on in there for the by-pass of gears to be good for it).

To get what I consider a really smooth trans took me a few years of 
working with an auto trans that was abused in its early years and 
run for some time with the computer screwed up.

Three critical adjustments: The trans throttle cable, the computer 
working correctly and the vacuum module. And, the engine has to be 
working and idling correctly. In terms of problem areas I'd say 
first computer, then engine running correctly, throttle adjustment, 
vacuum module. Last, trans internals.

The whine - is it in first or at the shift 1-2 only? That sounds 
like a trans filter clogged up or air in the system. Have you 
serviced the trans lately? The harsh down shift is a symptom of a 
faulty computer but an engine with a fast idle or slow to idle 
symptom will cause a similar issue.

Diagnosing a D trans is really an art as much as a science in my 
experience. But, you have to be sure you're dealing with one problem 
not two or more. That requires checking everything one at a time.

Harold McElraft - 3354



--- In dmcnews@xxxxxxxxxxxxxxx, Enid/Jeremiah 
<hispanicangeleyes@xxxx> wrote:
> 
> Hey everyone,
> 
> A couple questions.  I never really paid any attention
> to it, but I was wondering how a ideal working
> automatic transmission shifts.  Obviously,
> 1st->2nd->3rd, but what is its behavior?  Is it
> supposed to shift really hard and firmly, or does it
> shift softly like todays modern cars where one can
> barely feel a shift at all?  Would a change in
> temperature (summer vs winter weather) have a effect
> on the shifting patterns?  Also, when the automatic
> transmission downshifts, should you be able to really
> feel the downshifts or should it be really smooth and
> almost unnoticeable?  My car shifts up very firmly,
> and it downshifts from 2nd to 1st very firmly, but I
> don't really detect any downshifting from 3rd to 2nd.
> 
> One last thing.  Lately with the morning temperature
> in the mid 20's, I've noticed a high-pitched whine
> when going from first to second.  This is if the car
> is driven with no warm-up idle time.  Today, I let it
> warm up to about 160 degrees, and it doesn't make this
> noise driving down the street with warm up time.  Is
> this anything to take note about, or is this just how
> the car behaves when driven from a dead cold start in
> 25 degrees?
> 
> Thank you for your time.
> 
> Jeremiah
> 
> 
> 		
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