downshifting delay - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


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Old 03-30-2005, 12:49 AM   #1
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Default downshifting delay

I'm not even really sure if this is a problem but...

I notice that when I am going at a decent speed when the transmission is crusing along in 2nd or 3rd gear, that if I hit the gas it will slowly accelerate. Then it will finally decide to downshift, and I will take off like nothing to it.

Say I'm going 2000RPMS @ 80km/h. Then I hit the gas. It will climb to about 2500RPMS slowly, then downshift, then hit 4000 or 4500 and I will take off. Should it be a little quicker to downshift then that?

Accelerating is perfect under WOT or normal speeds. It shifts super smooth, and on time. I'm just curious about my downshifts.

Thanks.
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Old 03-30-2005, 09:54 AM   #2
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On the older bonnies with the THM440-T4 and in 90-91 the 4T60, these transmissions are hydraulic so it does have a small hang time when downshifting... its not as fast to downshift as the electronic transmissions... Don't worry mine does the same

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Old 03-30-2005, 06:02 PM   #3
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Quote:
Originally Posted by jr's3800
On the older bonnies with the THM440-T4 and in 90-91 the 4T60, these transmissions are hydraulic so it does have a small hang time when downshifting... its not as fast to downshift as the electronic transmissions... Don't worry mine does the same
ditto.
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Old 03-30-2005, 06:47 PM   #4
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The kickdown delay on our '90 SE is less than a second on a significant throttle opening. If the delay is considerable I would make some checks starting with the TV cable adjustment.
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Old 03-30-2005, 07:40 PM   #5
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I was just thinking that. My '89 doesn't have that problem. It does have a delay, but it isn't major. This delay was also with a TV cable that wasn't adjusted correctly. My guess, is that delay was because of the TV Cable being off-of-adjustment. Do you know how to adjust the TV cable? Adjust it, and see what happens.


-justin
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Old 03-30-2005, 08:18 PM   #6
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Yeah its nothing bad on my car either... It just the nature of a fully hydraulic trans... Mine shifts pretty decent for its age and upshifts are clean... The downshifts are a wee bit slower than the upshifts... But nothing that bothers me...

And I do agree a TV adjustment may be in order... This adjustment put my trans in a happier place 4 or 5 years ago...

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Old 03-30-2005, 08:41 PM   #7
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Sounds good. The delay is more then a second, and I just got my FSM yesterday so I will do the adjustment tomorrow morning. It doesn't really bother me all that much, but I will see if the TV cable adjustment fixes it.

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Old 03-31-2005, 05:27 PM   #8
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Thought:

Man, what electronic control and a performance-shift mode would do for our cars... it did quite a bit on the ol' '85 'yota (which had an electronically controlled tranny with "power" mode), I haven't been in an SSEi to check it out, but I can only imagine.

*poke gas pedal*
*instantaneous kickdown*
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Old 04-01-2005, 11:14 AM   #9
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Quote:
Originally Posted by repinS
Thought:

Man, what electronic control and a performance-shift mode would do for our cars... it did quite a bit on the ol' '85 'yota (which had an electronically controlled tranny with "power" mode), I haven't been in an SSEi to check it out, but I can only imagine.

*poke gas pedal*
*instantaneous kickdown*
Even in my 95 Bonnie, 4T60-E the kick down time is actually fast... 30mph mash pedal to floor and wham first gear through 45-47... There is not waiting for the shift it just shifts.... Unless you are over 35 or 36 then you kinda get to bog in second gear...

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Old 04-01-2005, 10:19 PM   #10
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I've got the '87, and mine downshifts lightning, like a fraction of a second. Course i just rebuilt it maybe that changes it.
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