Can a Super Coupe (AOD) be driven w/o more damage ... if the cluches are burned out ?

Mavrick

Registered User
Seems my 1990 Ford T-Bird SC has fallen victim to the 'plastic' bushing on the TV rod :mad:. It took out Overdrive and possibly 3rd gear in two miles on the freeway at 70 mph. The SC was purchased new in Sept. 1989 and has just over 29,000 miles. First reaction was a sticking throttle ... instead ... damage to the AOD transmission :(. The concern is ... if the SC is driven in the 'D' position and rpm is kept at 3000 or below (just over 50 mph) ... would the AOD be subject to additional damage? Also, would it be wise to change the fluid (has not been done yet - 29,000 miles) prior to repair of the AOD?
 
If you lost the cable, and drove around for hours then the direct + forward clutches MAY have been smoked. FWIW, 2 cruising miles on the freeway probably didn't hurt it. W/o the cable hooked up, the trans thinks you're off the throttle all the time. It will still shift itself up/down, but the biggest problem is accelerating w/o increased TV pressure which snugs up the clutches.

Best thing to do is check the fluid. If its red and clear and smells like regular mercon, you might not have a problem even if OD isn't engaging. If that checks out, slap it back on, lash it in place and drive on. IF 3rd still pulls and doesn't slip, then you're not really going to make things any worse by using it. So if you need to drive it to get it to the shop or in an emergency, then go ahead.

However, if you want to limit it to 1,2 pull the handle to "L" to start off. When ready for 2nd gear, push the handle back to "D" then promptly back to "L" to hold 2nd gear. That should let you drive 30 or so. Otherwise, the clutch packs will have to be rebuilt which means an overhaul.
 
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THANK YOU for answering !!! :D

I overlooked adding ... that when I got home and looked under the hood ... the TV rod was 'unhooked'. Just happened to have a brass bushing and a locking wire (same as the ford part) in the garage. After fixing that ... there was still
... no overdrive ... just rpms going to waste. In drive (D) ... everything is fine up to about 50 mph. It is most likely that the overdrive and possibly 3rd gear clutch have burnt up and need to be replaced. As that cannot be done until enough $$$ are here (2 months) ... the question about additional damage to 1st and 2nd gears (if driven) becomes a real concern. The hope is that the SC can be driven now and then at 50 mph and less without damage to what is still working well ... 1st and 2nd gear.

Also ... if the clutches are gone ... would not some clutch material have deposited itself in the the transmission fluid? Then ... should the fluid be changed now or left until the AOD is rebuilt? :(
 
Most likely your direct clutch has damage. The O/D band doesn't usually go out, its the direct clutch that spins making it seem like O/D isn't engaging. However, when you put it in 3rd, you have the forward + direct clutch engaged. I'll conjecture that the direct clutch apply pressure increases when its in 3rd which restores 3rd gear. I've had this happen in one of mine. :rolleyes: Its likely that you have some forward clutch burn up too but not as much.

As for the fluid.. you have mostly toasted clutch friction and some metal particles in the fluid, but the filter catches the most of it. What gets past is very small and just sort of circulates around. Given enough mileage, it could increase wear in the valve body.

If it were me, I'd leave it as is until overhaul time since an overhaul is going to rebuild all the clutch packs anyway. If you can stay in 1,2 you're probably better off. That should help preserve the steel plates in the direct clutch pack too so that you may only need new friction plates. Try to drive it as little as needed until then. If you need 1000s of miles, then its probably a good idea to go ahead and change the fluid out to reduce the amount of microscopic particles. Don't forget the converter.. it holds about 1 gallon of fluid itself.
 
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Most likely your direct clutch has damage. The O/D band doesn't usually go out, its the direct clutch that spins making it seem like O/D isn't engaging. However, when you put it in 3rd, you have the forward + direct clutch engaged. I'll conjecture that the direct clutch apply pressure increases when its in 3rd which restores 3rd gear. I've had this happen in one of mine. :rolleyes: Its likely that you have some forward clutch burn up too but not as much.

As for the fluid.. you have mostly toasted clutch friction and some metal particles in the fluid, but the filter catches the most of it. What gets past is very small and just sort of circulates around. Given enough mileage, it could increase wear in the valve body.

If it were me, I'd leave it as is until overhaul time since an overhaul is going to rebuild all the clutch packs anyway. If you can stay in 1,2 you're probably better off. That should help preserve the steel plates in the direct clutch pack too so that you may only need new friction plates. Try to drive it as little as needed until then. If you need 1000s of miles, then its probably a good idea to go ahead and change the fluid out to reduce the amount of microscopic particles. Don't forget the converter.. it holds about 1 gallon of fluid itself.

I agree with your assessment, with one small caveat. If the direct clutch is right on the edge of slipping, and there are little bits of grit in the fluid, wouldn't a change in the fluid run the risk of being too slippery and causing third to disappear as well?
 
I agree with your assessment, with one small caveat. If the direct clutch is right on the edge of slipping, and there are little bits of grit in the fluid, wouldn't a change in the fluid run the risk of being too slippery and causing third to disappear as well?

Haven't we seen horror stories of fluid changes in hi-mile autos leading to damage from the new fluid promoting legacy varnish release, etc.?
 
This is into a lot of speculation at this point. His trans is rather low mileage so I sorta doubt fluid is holding anything together. None the less, IMO there's not much to be gained by changing it out. Thats probably why I'd just leave it as is if.. twere me. :D And try to just use 1 and 2 and avoid any cross country trips. :cool:
 
Under his circumstances though its better than allowing direct clutch engagement. Whats wrong with LDL?

OK.. found the answer from some guy called "SilverFox" of all people.

manual 2nd applies the OD band and the biggest issue is the 2-3 manual shift will engage the direct clutch faster than the band can disengage - causeing a slight bind that burns it....over time = no band.

Under the circumstances, he shouldn't be shifting to 3rd so I think he'll be OK. If he does... well he gets what he gets. :rolleyes:
 
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Sounds like he can put it into D and it will upshift and downshift okay...and just isn't shifting into OD like it normally would at around 45-50 mph. If that's the case I'd just keep driving it until it quits. A rebuild is going to cost about the same no matter what condition the transmission is in.

doing the 1-D-1 shuffle is not very advisable

Yeah I don't think it's going to help in this situation, because as I recall you had to keep the throttle planted to hold 2nd gear and if you let off it downshifts to 1st.

David
 
Tv pressure kills these AODs also if u dont hsve a transmission oil cooler you get a good one the wimpy OD band may be giving up on you but you can drive the trans out of OD
Usually I dont use OD in the city I keep the lever in D most times only on the freeway ti shift to 3rd I move it to the OD position

But this is after I had the AOD go out twice on me I learned the lesson

Like david said drive until it goes out
That way when u do a rebuild it will be all fresh for beating
 
as I recall you had to keep the throttle planted to hold 2nd gear and if you let off it downshifts to 1st.
David
It holds 2 for me with part throttle. I do it for kicks.. well and in traffic sometimes when 3rd is too high of a gear.

I never really have a need to LDL because I really never drag race it anyways. On those rare occasions when I do, I usually just let it do its regular shifting from OD. By the time I'm at the end of the track, unlike some of you, I've still got plenty of RPM and gear left. :rolleyes: :D
 
It holds 2 for me with part throttle. I do it for kicks.. well and in traffic sometimes when 3rd is too high of a gear.

I never really have a need to LDL because I really never drag race it anyways. On those rare occasions when I do, I usually just let it do its regular shifting from OD. By the time I'm at the end of the track, unlike some of you, I've still got plenty of RPM and gear left. :rolleyes: :D



I never do the 1D1 shuffle either :p maybe at the track I can the transgo manual valve will hold 1st 2md and 3rd to any rpm but just letting it auto shift with the high rev governor valve it shifts 1st at 5500 at WOT 2nd 5200 3rd 4900 thats plenty good for too letting it do its own thing :D

I gotta dyno and see where the power band falls flat I may be letting it over rev a bit on 5500 1st to 2nd :(
 
This is wonderful !!! :D So many of you responding.

Thanks to all for your help :p

It seems that my Bright Red / Black Leather 1990 Super Coupe with only 29,000 miles ... can be driven from time to time without fear. More Importantly ... without having a higher repair cost than it is now.

Just will keep the rpms at 3000 or under and use only the 'D' when driven. That works so well (as long as you do not go beyond that) ... you would never know there is a problem with the AOD. :cool:

Does anyone know if you can modify this 1990 AOD to use the electronic control from the 1994 and newer? As well ... is it worth doing ... considering cost and labor?


THANK ALL OF YOU AGAIN !!!
 
This is wonderful !!! :D So many of you responding.

Thanks to all for your help :p

It seems that my Bright Red / Black Leather 1990 Super Coupe with only 29,000 miles ... can be driven from time to time without fear. More Importantly ... without having a higher repair cost than it is now.

Just will keep the rpms at 3000 or under and use only the 'D' when driven. That works so well (as long as you do not go beyond that) ... you would never know there is a problem with the AOD. :cool:

Does anyone know if you can modify this 1990 AOD to use the electronic control from the 1994 and newer? As well ... is it worth doing ... considering cost and labor?


THANK ALL OF YOU AGAIN !!!

Yes ive seen a couple do the 4r70w or Aode swaps here and there dont know how hard or worth it tho

Those also have the internal parts u would want on a built AOD
Stamped steel drums and wider OD band plus the OD is on a switch so it can be turned off when ever u want unlike the aod that u must get a valve body with OD on a switch for it
 
Yes you can but you will be looking at $2k-3k for a installed built unit. Can get it down to ~$1k if you do the build yourself and stay AOD.
 
Yes you can but you will be looking at $2k-3k for a installed built unit. Can get it down to ~$1k if you do the build yourself and stay AOD.

Yep ^^^ what he said

I spent 1350 buying a mild converter and shift kit good clutches ..... then I spent another 700... cuz I snapped the input shaft with bolt ons .... and I had to re do it
MAKE sure once u do it get an AODE u want the late model stamped reverse drum the stamped direct drum ur aod should have a stamped fwd drum to re use , ull want the 4 clutch intermediate set up from the aode too u will also need the sun shell that way you can use the 2" wide overdrive band
 
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