dying transmission (OD band?)

[johnunit]

I hate to admit it to myself, but I think my transmission is dying.

It occasionally bucks at about the rhythm of a rough idle (rather quickly) at 30-42mph with low throttle in 3rd gear, and I THINK I've felt it do it at higher speeds (50-60mph) in OD. I also think I smell a hint of burnt on the dipstick, but I'm not 100% sure.

If the tranny goes, it goes. I park the car for a few months while I save up the money for a rebuild kit (and maybe some other goodies), and teach myself how to rebuild a tranny in the meantime.


There are two main things that I think could have contributed to the demise of this tranny (assuming it is dying):
1. I think the TV rod has been at both too low and too high a pressure at various points. Chock this up to me not being very experienced and having trouble re-adjusting it properly after changing the idle speed, which influences TV pressure on a VV setup.

I had felt it slip a bit before, and very slightly adjusted the rod to a higher pressure (thinking a lack of pressure was causing my OD band slippage). It doesn't seem to have really stopped it though, and I'm worried that my slightly harsh shifts are just making it worse.



2. There was way too much fluid in the tranny when I checked today. I remember it maybe being slightly over the proper level when I checked before, but today it was over an inch too high on the dipstick. The guy I bought it from did add some tranny fluid the day I bought it, I guess he added too much. "

This probably is causing some frothing issues.



So I guess my questions are these:

1.Other than getting the TV cable properly adjusted, what can I do to slow down the demise of my tranny? driving techniques, speeds to avoid, maybe some snake oil additive? Anything like that.

2. What are some good resources for learning to rebuild and AOD? What parts/rebuild kits would you recommend? I'm thinking of putting in this rebuild kit:

http://www.summitracing.com/parts/TCI-438900/

3. anyone have experience with this? A TCI tech rep told me that I'd see shifts just south of 5000RPM at full throttle and that it'd be like an HO valve body with a shift kit. It also has the obvious advantage of constant pressure, as in I can't fuck the tranny up by messing with the TV rod anymore. http://www.summitracing.com/parts/TCI-436020/

4. Is there any chance that I just need to redo the OD band? Is there any point in yanking the tranny and getting in that deep without doing a full rebuild, considering my budget constraints?

[mrltd]

if it's gotta be pulled out and have the OD band repaired, it'd be stupid not to rebuild the whole trans.

[johnunit]

ok, that's what I thought. Just making sure with someone who knew better than me.

[gadget73]

If its the OD band, you would not feel it in third. Its only applied in overdrive. Usually what you see with a cooked OD band is the engine speed increasing on a slight incline, and the car doesn't or it slows down. Sounds to me more like you've got some random engine misfire. There is no torque converter action in 3 and 4, so any running problems with the engine become more obvious.

[cld783]

mine did the same stuff and it's still going strong. I've never changed the fluid or filter and it has over 200,000 abused miles on it. the bucking is usually a result of the transmission hunting between OD and 3rd, i've been downshifting mine to prevent that for a few years..

keep it out of OD as much as possible and hope for the best..

[johnunit]

Allright, that's somewhat of a relief. Thanks guys.

I guess I'll replace the cap and rotor (they're sort of borderline), keep it in D instead of OD around town and see if it gets any better.

It does idle roughly, so I guess it would make sense if the same roughness I felt at idle was occasionally felt during lockup at low RPM.

[FordMan77]

Yes, that would make sense, because if you are getting a rough idle due to a miss or something it would only get worse under a load, and that is what you are probably getting when it hunts for OD under a low speed condition. The motor gets lugged down by the shift into OD at such a low speed.

My 84 used to do this when it needed a tune-up and I forgot to keep it in D until I was over 45mph.

Jay

[Brooklyn]

The transmission on my 1987 has the same problem. It will occasionally act like it is going to shift gears when I am cruising but then just stay in the same gear. I am going to keep driving it as is and hopefully it won't get worse.

[ald872000]

Yo fellas I have a tranny question.

when the tranny shift from 3rd to 4th is the car suppose to slow down a bit then catch speed? I ask because I get this while im on the freeway

Another question is:
if there is too much tranny fluid in the tranny can that cause the tranny to shift early?
I ask because i've been getting early shifts when I found out there is a bit to much fluid in the tranny.

[gadget73]

if there is quite a bit too much, you might be experiencing foaming, which could screw things up. Air is not a good hydraulic fluid.

Mine doesn't slow down, unless its on an up grade. On flatish highway it does drop off the acceleration quite a bit but it shouldn't actually drop any speed.

[Leo]

On flatish highway it does drop off the acceleration quite a bit but it shouldn't actually drop any speed.

gadget73 mang,
what if it does drop in speed?! for example my 85 tbi cv drops in speed on flatish freeways.

there are no head winds, all tires are properly inflated, recently had a trannsmission fluid and oil changed.
could there be anything else that could slow the car down or make it feel sluggish?!
obviously the car is a brick but its strange that it drops speed rather quickly. sort of like engine braking or the brakes are claming up a bit.
i know my differential is leaking a bit. im going to change the gasket & fluid tommaro. i dont know if that has anything to do with it. hmm..

thanks

[gadget73]

dont know, unless its shifting so early the engine is way out of its power band, or you have such a tiny amount of foot in the throttle that it just can't keep itself moving at speed.

[Spaceboy]

I have a similar problem (I'm at about 80000 miles). When going easy on the gas, it sometimes seems to buck and if I give it a little gas sometimes it feels like it grinds between gears.

Still goes OK, but I think the tranny is flaking out. Only seems to do this around the OD gear. At first I thought it was the engine misfiring, but definitely seems tranny related.

Any way to cure this before it gets really bad? I don't have the money (or skills) to rebuild a tranny.

[Brooklyn]

UPDATE on my bucking on the highway problem. Turns out it was bad plugs. I went to change my plugs today and found most of them loose and the plugs at the 2 rear most cylinders to be fouled with ash/carbon. Put in some fresh Motorcraft plugs and the problem is gone! Took it on a 40 min highway drive back home today and never bucked. So it was a misfiring problem-everyone be sure your plugs are good!

[pantera77]

gadget73 mang,
what if it does drop in speed?! for example my 85 tbi cv drops in speed on flatish freeways.

there are no head winds, all tires are properly inflated, recently had a trannsmission fluid and oil changed.
could there be anything else that could slow the car down or make it feel sluggish?!
obviously the car is a brick but its strange that it drops speed rather quickly. sort of like engine braking or the brakes are claming up a bit.
i know my differential is leaking a bit. im going to change the gasket & fluid tommaro. i dont know if that has anything to do with it. hmm..

thanks

I'm pretty sure that my car does the same thing. Almost feels as if a brake is sticking or something? I just learned to live with it.