Any way to cure the infamous auto clunk into OD?

SuperCoupeDave

Registered User
Hey guys, I've had 2 auto SC's and both have the clunk into OD. My 89 I have now only has 47k miles on it. My dad said its just the way they were. Is this true? Or is their a fix?

I plan on having the trans flushed soon. Dont know if that'll help.

Thanks!
 
I have never had a clunk 3 autos in my 89 till I got one with larger od band and bigger gears with shift kit 1to2 servo bands removed.
 
After a while you learn how it shifts and you'll find yourself lifting the gas pedal slightly w/o even thinking about it and it'll be smooth as glass. Its not really a problem until you notice it in traffic and then it gets to be annoying... My advice... shift into "D" and drive until you're on open road again. :cool: Its caused by the timing/rate of the OD band apply. There is a shift kit fix for it. The kits try to shorten the rate.
 
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I've always found that fresh fluid takes care of the problem. Though Ford says atf in an auto is a life time fluid it really needs to be changed regularly. Once you get fresh fluid in you should notice a difference.
 
I think it was always a bit of a problem. In fact, there is a part in the AOD called the "anti-clunk spring".

It may be exacerbated by worn transmission mounts or slop in the rear end gears.
 
The best way to fix the "OD Clunk" is replace the direct drive AOD converter with an open/non-lock converter. Every AOD I have ever owned experienced this OD issue. Now both of my AODs have non-lock style converters and no more clunk into OD. With the non-lock style converter you will sacrifice about 1MPG on the highway but no more clunk is worth it IMHO. Plus by installing a non-lock converter you gain torque multiplication in 3rd gear. The 3 best improvements to an AOD IMHO are... non-lock converter, Lentech electronic OD delete valve body, 2" OD band + associated AODE upgrades.

Bryan
 
Even when my original trans was singing its swan song, I never had this issue. My new one is firm but no clunk. It is a 5.0 mustang trans with a few parts swapped out of my SC trans. but it shifts like a champ minus the 2nd to 3rd but im getting used to that.
 
Thanks guys for the info! This car is gonna get very limited drive time. Maybe 500-1000 miles a year if that. Or atleast until I get the $$$ to get the upgraded head gaskets. The other 2 SC's I had blew head gaskets right at 150k. This one only has 47k so I have about 100k to go, but I will replace the head gaskets before it has a chance to blow.
 
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