Auto Transmission Failure
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Joined: Dec 2004
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Auto Transmission Failure
Drove the 1984 F250 2WD 5.0L the other day and it would shift out of first but never engage second gear. It was about a mile to return home which I did (slowly). The transmission shop said that there is valve in the carb that sends a vacuum signal to the transmission to shift. They often degrade. Easy fix but they told me that driving in this condition could reck the tranny. They replaced the part and indeed they said that 4th gear is "burn" and the tranmission has to be rebuild. Should cost less than $2,000 OUCH.
I would like to know if this is a common problem and if the cost to repair seems resonable. I love that truck and will pay the expense just want to make sure I'm not being taken for a ride. Thanks friends.
I would like to know if this is a common problem and if the cost to repair seems resonable. I love that truck and will pay the expense just want to make sure I'm not being taken for a ride. Thanks friends.
Post Fiend
Joined: Dec 2007
Posts: 8,521
Likes: 16
From: Lost
Well, first off, the 4 speed auto doesn't have the modulator valve.
There were 2 auto trans available in 84. A 3 speed (C6) and a 4 speed (AOD). Neither should cost anywhere near $2000 to rebuild.
I'd say get a second opinion.
There were 2 auto trans available in 84. A 3 speed (C6) and a 4 speed (AOD). Neither should cost anywhere near $2000 to rebuild.
I'd say get a second opinion.
Cargo Master
Joined: Dec 2004
Posts: 3,362
Likes: 22
From: Florence, SC
Originally Posted by Robobike
Thanks Rogue, It is an AOD. If there is no "modulator" where does in shift signal come from?
On carbureted models, there is a rubber bushing that fits the TV rod to the carburetor throttle lever. If this bushing deteriorated and the TV rod came loose or came off, it could have very well burned up the clutches in the transmission if driven that way for very long.
I had my AOD rebuilt two years ago for about $1000.
Senior User
Joined: May 2009
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The AOD does NOT use a vacuum signal to shift the transmission. The transmission line pressure that shifts the gears is controlled by a throttle valve "TV" rod (some models used a cable) that runs directly from the transmission to the carburetor throttle lever. This is a *very* critical adjustment. If this rod or cable is not adjusted correctly, or comes off, the AOD transmission will burn up - FAST.
On carbureted models, there is a rubber bushing that fits the TV rod to the carburetor throttle lever. If this bushing deteriorated and the TV rod came loose or came off, it could have very well burned up the clutches in the transmission if driven that way for very long.
I had my AOD rebuilt two years ago for about $1000.
On carbureted models, there is a rubber bushing that fits the TV rod to the carburetor throttle lever. If this bushing deteriorated and the TV rod came loose or came off, it could have very well burned up the clutches in the transmission if driven that way for very long.
I had my AOD rebuilt two years ago for about $1000.
Sorry to steal your thread.
The aod is a simple transmission from what I have been told, around 1200 parts and labor.
Post Fiend
Joined: Dec 2007
Posts: 8,521
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From: Lost
As an example of how cheaply a trans can be rebuilt, I had my C6 rebuilt a couple years back. $200 for parts, and $250 labor for R&R + rebuild, with 5yr/75K warrenty.
An AOD would be a bit higher than a C6, but $2000 is excessive. I'd bet that kind of money would get you a new trans from ford......
An AOD would be a bit higher than a C6, but $2000 is excessive. I'd bet that kind of money would get you a new trans from ford......
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Freshman User
Joined: Jul 2009
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not to sure about AOD trannys. But i got quotes on a c6 of course in washington state. and that was only 600 to 800 to rebuild and that with a new casing. i would aggree with the above people that 2000 is a little high. I would goto yellowpages.com and search transmissions and call a few places
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Logistics Pro
Joined: Jun 2008
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From: Florida
My dad had his C6 rebuilt for $600.$2000 is way too high IMO.I wonder if the owner is familiar with the AOD and charging that to try and keep from working on it?
Post #11 reminded me,my dad's truck was originally an AOD truck,but a previous owner swapped it out to the C6.The truck only had 80,000 on it when my dad got it,and my dad said the truck was well cared for by an older man,so the AOD musta been one of those that was destined to fail early.I can't trash talk the AOD because i've seen some last pat 100,000,but you still have to know how to service them to achieve that in most cases.
Post #11 reminded me,my dad's truck was originally an AOD truck,but a previous owner swapped it out to the C6.The truck only had 80,000 on it when my dad got it,and my dad said the truck was well cared for by an older man,so the AOD musta been one of those that was destined to fail early.I can't trash talk the AOD because i've seen some last pat 100,000,but you still have to know how to service them to achieve that in most cases.
Cargo Master
Joined: Aug 2007
Posts: 2,561
Likes: 70
From: New Zealand
The AOD is more expensive to rebuild than the C6.
I have an AOD in my F250 & got prices a couple of years ago to rebuild it & also on rebuilding a C6, as a replacement option.
At the time it would have cost me (in New Zealand $) $2000 to get a C6 core, & have it rebuilt & installed.
To remove, rebuild & reinstall my own AOD trans would have been $2500, by the same company.
The AOD isn't very durable without upgrades, & the price you were given probably was taking this into account.
I decided to go to a manual trans, just because I don't particularly like automatics.
But as Rogue Wulff said, the AOD doesn't have a modulator valve, the C6 does.
I have an AOD in my F250 & got prices a couple of years ago to rebuild it & also on rebuilding a C6, as a replacement option.
At the time it would have cost me (in New Zealand $) $2000 to get a C6 core, & have it rebuilt & installed.
To remove, rebuild & reinstall my own AOD trans would have been $2500, by the same company.
The AOD isn't very durable without upgrades, & the price you were given probably was taking this into account.
I decided to go to a manual trans, just because I don't particularly like automatics.
But as Rogue Wulff said, the AOD doesn't have a modulator valve, the C6 does.
Freshman User
Joined: Mar 2010
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sorry to sound like a noob here but what is a 4r70w? i have a c6 in my f350 and man does she like gas overdrive sounds great, and everything iv heard tells me not to waste my time with an aod.
ok just read up on it so next question is would it bolt up to a 460?
ok just read up on it so next question is would it bolt up to a 460?
