Overdrive issue

ANYTHING RELATED TO MANUAL OR AUTO TRANSMISSIONS GOES HERE.
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Mrbarky
I am merely driving my van
I am merely driving my van
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Overdrive issue

Post by Mrbarky »

Ok so when I'm driving at about 60mph this thing will just down shift for no reason and then shift back into OD does anyone have any clue as how to fix this? Its a 92 Astro also thanks.
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kings-x59
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Re: Overdrive issue

Post by kings-x59 »

the clutches in the torque converter might be giving up the ghost, or the torque converter lockup solenoid might be going bad.
First thing is check the wiring to the tranny and the connector to make sure all that is good. bouncing along with a bad connection could cause the tcc solenoid to kick in and out, but then you'd probably notice your speedometer jumping around as well.
How many miles on the transmission?
'89 Astro, 4.3L, TBI. Minor intake and exhaust mods. Rebuilt 700R4 trans (by me). Corvette servo, 0.5" boost valve, police grade 1-2 accumulator spring (shifts fast and solid). B&M stacked plate trans cooler. Bilstein shocks. Belltech sway bars front and back. New head unit, speakers and subwoofer. Needs paint and a new headliner.

name's Steve
I can't remember all I've forgotten about that....

Topic author
Mrbarky
I am merely driving my van
I am merely driving my van
Posts: 19
Joined: Mon Jul 19, 2010 4:49 pm

Re: Overdrive issue

Post by Mrbarky »

Not a clue on miles #-o It has a custom sheet metal dash with aftermarket gauges and what not.
Where is this solenoid and how hard is it to replace and is there anyway to test it? Also the speedometer doesn't jump at all.
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kings-x59
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Re: Overdrive issue

Post by kings-x59 »

You can get to the solenoid by dropping the pan on the transmission. If you go to rockauto.com they have an image of the part so you know what you are looking for. they have it listed as a "control solenoid" under the transmission parts section.
As for testing it, I don't know the answer to that.
Likely someone on the site does though...post up brethren, need some hep here.
'89 Astro, 4.3L, TBI. Minor intake and exhaust mods. Rebuilt 700R4 trans (by me). Corvette servo, 0.5" boost valve, police grade 1-2 accumulator spring (shifts fast and solid). B&M stacked plate trans cooler. Bilstein shocks. Belltech sway bars front and back. New head unit, speakers and subwoofer. Needs paint and a new headliner.

name's Steve
I can't remember all I've forgotten about that....

rlsllc
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Re: Overdrive issue

Post by rlsllc »

Check the TCC switch that is on the brake pedal. If it is adjusted to loose it will be touchy, and unlock the converter with the slightest touch or bump/dip in the road. This can also cause the cruise to disengage if the switch for that is too touchy. Also be sure that the pedal is returning and stays 'up'.

Topic author
Mrbarky
I am merely driving my van
I am merely driving my van
Posts: 19
Joined: Mon Jul 19, 2010 4:49 pm

Re: Overdrive issue

Post by Mrbarky »

Ok I will check that out because the cruise control doesnt work either.

Topic author
Mrbarky
I am merely driving my van
I am merely driving my van
Posts: 19
Joined: Mon Jul 19, 2010 4:49 pm

Re: Overdrive issue

Post by Mrbarky »

rlsllc wrote:Check the TCC switch that is on the brake pedal. If it is adjusted to loose it will be touchy, and unlock the converter with the slightest touch or bump/dip in the road. This can also cause the cruise to disengage if the switch for that is too touchy. Also be sure that the pedal is returning and stays 'up'.
Just a liitle update after little adjustment problem is gone Thank You for the advice. :bounce:

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Re: Overdrive issue

Post by Cobra »

good to hear the fix was so easy
1998 GMC Safari AWD, BFGoodrich AllTerrain T/A
Jet performance tuner 91 octane preset, Jet under-drive pulleys
Rancho 999000 series shock, on-board controller to be installed later
DHC rock rails and skid plate Add-A-Leaf
G3500 front calipers
Zexel Torsen Diff
11" drums
180 amp Alternator
Long tru-cool 4590 trans cooler

1997 gone
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