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1988 GT won't down shift?

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Old 07-05-2015, 09:12 AM
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6605stang
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Default 1988 GT won't down shift?

Bought a 1988 ASC McLaren Mustang yesterday with 25k miles on it. Great shape for the most part and just a couple issues....

First when you get on the gas hard it really has a hard time downshifting, if at all. The engine seems really strong and it revs like it it's going to downshift, but then just hangs and goes back to the original high gear. Previous owner said a recent tuneup trip yielded a recommendation to flush the tranny... Could old fluid be the culprit here or am I looking at something more significant?

Oh and the AC is toast... Blows hot air. New compressor? Or just recharge if it has 25 year old freon?

Thanks in advance folks. Looking forward to putting this unique Mustang back in action!
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Old 07-05-2015, 11:07 AM
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eb2gt
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fluid and filter change would help possibly repair. it's not the expensive to do, why not?
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Old 07-05-2015, 11:13 AM
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dawson1112
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Check your TV cable at the throttle body and the transmission. Make sure the cable connections are not broken, and check to make sure its adjusted properly.
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Old 07-06-2015, 08:08 AM
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88 orangepeel notch
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+1 ^^^

Does it shift OK during normal everyday driving ? Of does it seem to run thru the gears pretty quick and your in 3rd before 20 mph.

Just asking as when I bought my car, my TV cable wasn't connected and those were the symptoms along with pretty hard shifts. Don't drive the car without the TV cable attached and adjusted. It'll burn up the tranny rather quickly.
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Old 07-06-2015, 10:47 PM
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6605stang
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Originally Posted by dawson1112
Check your TV cable at the throttle body and the transmission. Make sure the cable connections are not broken, and check to make sure its adjusted properly.
Pardon my ignorance but what the TV cable? Not savvy to these older steeds!

As for how it's acting... it seeeeeeeeems to go through the gears find under regular light throttle. And does get to third fairly quickly. The main thing I notice is that when I put the throttle down hard, it hesitates for a good period of time and then revs up like its going to down shift and then just slowly goes back into third or 4th gear again... doesn't want to shift down.
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Old 07-07-2015, 12:03 AM
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dawson1112
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Its called a throttle valve cable, and it controls the line pressure and kick down at various throttle positions.

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Old 07-07-2015, 07:23 AM
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88 orangepeel notch
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They are held on to throttle plate by a ball / socket connection. A plastic clip locks it on, this plastic clip gets old and brittle, and when it finally breaks, the cable can come off, causing your problems.

EDIT: I might have my throttle / TV cable connections mixed up, it's been awhile lol. If you see a loose cable laying under throttle, that's your problem. But as Dawson said, check the connection on the tranny also if throttle is good.
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Old 07-07-2015, 03:39 PM
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6605stang
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Thank you so much for this info! It's fun getting to know all the nuances of a new (to me) era of Mustang. I know S197s like the back of my hand but these Foxes are all new to me! I'll check the cables when I get home tonight.
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Old 07-09-2015, 08:27 PM
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Like so?.... So how do I find the plastic clip that's supposed to be on the top (but gone)?
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Old 07-09-2015, 09:26 PM
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dawson1112
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That's definatly your problem. Do your self a favor and park it till you get that fixed, it can burn up the transmission pretty quick. It causes them to slip really bad between gears.

http://www.latemodelrestoration.com/...-AOD-TV-Cables

Last edited by dawson1112; 07-09-2015 at 09:29 PM.
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