Should I change the fluid in my 1990 AOD?

Trentman2004

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Aug 6, 2018
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I have a 1990 5.0 with an AOD and it has 180K miles and the AOD has never had the fluid and filter changed. The transmission seems to shift and drive okay. I want to just drop the pan, change the filter, and refill with new fluid. My worry is that the transmission will slip because all of the clutch material will be gone in the fluid that keeps it from slipping. (at least that's what i've heard and read)

Any pointers?
 
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Wayne Waldrep

Before I post a pic, do you have one of yours?
15 Year Member
Apr 14, 2003
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"Shifts and drives ok".....I don't touch automatics as long as they are working.
 

1990 5.0 LX

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Apr 11, 2019
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Sure, get the tranny serviced and it'll be fine. They'll drop the pan, change the filter, check bands for adjustment, and put it back together with new fluid, and off you'll go.

For what its worth, I have a '90 with an AOD and have had the tranny serviced three times since I got the car with 200K miles on it. It now has 320K miles and the tranny works great.
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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It can be a roll of the dice, after the service some will back up but not go forward but I suspect they had burned up bands or something else wrong.
 

1990 5.0 LX

Member
Apr 11, 2019
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If by "roll of the dice" you mean that the shop may be incompetent, then find a good shop. The servicing if done correctly will not create a problem that didn't already exist, to believe that it might is magical thinking:)
 

Mustang5L5

i'm familiar with penetration
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Feb 18, 2001
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I'd do a drain/fill. I wouldn't do a flush.

Drop pan, change filter, reinstall pan and refill with same amount of fluid that came out. The flushes tend to be what ultimately causes issues.

I only serviced my AOD once...twice if you count when I drained the fluid to remove the trans and stuff it in a corner when I put the t5 in.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
17,438
5,618
193
polk county florida
If by "roll of the dice" you mean that the shop may be incompetent, then find a good shop. The servicing if done correctly will not create a problem that didn't already exist, to believe that it might is magical thinking:)
the 'roll of the dice' comment was not pointed at the shop. It's more to do with the condition of the trans.
 
Feb 11, 2018
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I have a 1990 5.0 with an AOD and it has 180K miles and the AOD has never had the fluid and filter changed. The transmission seems to shift and drive okay. I want to just drop the pan, change the filter, and refill with new fluid. My worry is that the transmission will slip because all of the clutch material will be gone in the fluid that keeps it from slipping. (at least that's what i've heard and read)

Any pointers?
I was told on my 99 that since I DONT have a trans filter, but a magnet - to not change the fluid at 150,000 plus IF it had never been done - I think mine has been changed 3 times, and I now have 188,000 miles on the original 3.8 engine and auto trans - with no problems with the main engine or trans - I find myself thinking that IF You have a filter (as I would prefer) then maybe it is okay to go ahead and service the trans - at a very good trans shop - but I would also ask their advice -