I just bought an 88 Bronco about 6 months ago from my neighbor. The thing that I wanted to ask was when it is in overdrive and goes to disengage at around 45 mph something underneath hits pretty hard. This can be somewhat controlled by how you let off the gas around 45 but kinda has me wondering what it could be. It only does it in Overdrive , Regular drive does fine. My neighbor said it had been doing it since he had it but that was only about 2 years. It sat there in his yard for a while and I couldn't stand seeing it just sit so I talked him into selling it to me at a pretty good deal. I am trying to do a little at a time and fix it up but really the Overdrive thing is the only thing that seems like it could turn into something real bad. New user here, glad I found this site. Thanx in advance for any suggestions or input.

 

I use to have a 88' Bronco with a 302/AOD that did the same thing. It felt like loose u-joints. I felt like it would shift in to OD to early and wait to long befor downshifting. In any case I got in the habit of shifting directly in to 3rd gear. (not OD) The only time I would shift in to OD was on a long trip on the highway. I would shift back to 3rd when slowing down.

 

My 89 with 302/aod does the same thing and I have been doing the same thing as the previous reader as well as being gentle with the gas peddle when I know it is going to downshift.I also use the shifter at times to manually shift in and out of OD. I am pretty sure this is a common problem of these tranny's, my buddies 88 also does the same thing. Hopefully somebody in the know sheds some light on the subject.

 

Thanx guys. I wasn't sure if it was something that I could just deal with for a while till i have time to get into it or if it was a timebomb that was waiting to explode. Sounds like at least others have the same issue so that makes me feel somewhat better. Think I am going to work on some of the smaller issues for now and hope this doesn't come back to bite me before it can be figured out.

 

I recently took mine to a trans shop for another issue and I asked about the hard upshift from 3rd to OD (kind of a clunk). He drove it with me in it and insisted that it was not a problem. Mine only does the clunk when I let off the gas while I'm in third and my speed is under 40 mph. I have had mine since 1995 and it has always done the clunk.

If you look in the owners manual it tells you it won't shift into OD unless you let off the gas a little. Mine had always done that but I did not know it was normal until I bought an owners manual off of ebay.

I use 3rd gear unless I go on the interstate.

 

Here is a couple of pages from the owners manual.

 

rule of thumb with the AOD, stay out of OD gear unless your driving faster then 50-55 otherwise you can do damage to the overdrive band. also i would get the tranny serviced just for a new start since your ownership of the rig. also check the pinnion nut on the rear end and make sure its tight. the TV cable might need adjusting but have a professional do this. if its adjusted wrong the tranny will be toast in a matter of miles and this way it would be on them and not you.

manualy shifting will work fine as well

 

1988 302 AUTO/OD Mine does it too, has for as long as I can remember. I have 200K on motor and trans. I have replaced the knuckles and u-joints as part of regular maintenance. Learned to do as others have mentioned, use my OD only on the freeway.

 

Could you enlighten me on the TV cable. I have tried searching but it won't show up in the search.I'd like to know what it does and does it create a problem for swapping transmissions in your own garage.Problem being that you need a professional to adjust it.When the time comes I would like to be able to drop and have trans rebuilt then install myself to save on labour.
Good tip on the pinnion nut as mine is loose for the second time on my offroad truck, but it is getting replaced with a 9" very soon.
Thanks for your help.

 

go to google and search for AOD TV cable Adjustment. ive never done it but a few on here have Helrich might know being he has experience with that tranny. just understand that if you dont adjust it properly the tranny will fry very very fast. like in a mile down the road fast. I suggest also taking to a very reputible tranny shop and see if they will show you.

 

I have adjusted mine on my old Bronco. It is basicly a kick down rod. Except its a cable. The adjustment deturmins when your trans will upshift and down shift. I think it compares throttle position and vacume. All I did was to adjust it so it would not shift until a little higher RPM. (I think I had it shift at 4000 full throttle) Its been awhile now and I cant remember how I did it. I know the adjustment was at the throttle body end. Also it was easy. Now, I had not heard about frying the trans. I'm not sure why it would. Maybe if you adjust it to shift at a lower rpm, it could cook the 2nd and 3rd clutches.

 

I did a google search and found an actual video of the adjustment being made on a 5.0L Mustang and a truck intake. It is on Youtube if ya want to check it out.Kinda of cool that you can see someone actual make the adjustment. And it does look quite simple.There is also info stating that if you drive around with it way outa whack you will damage your transmission.
Thanks guys, I'll have to remember to use google more often.

 

Almost any of the mustang forums or the supercoupe forums (SCCOA, TCCOA) have excellent articles on the AOD's including modifications. TV cables and shifting articles are aplenty--in fact, more than you really want to know They all have very good people (knowledgeable) on those boards.

 

Sorry for the double--. Forgot to mention that the 3-4 and 4-3 shift jerk is an indication of some deficiency, maybe just VB cleaning, filter whatever. It can be cured or diminished in severity!

 

AOD: First offered in 1980 on LTD's, T-Birds, Merc Grand Marquis, Lincolns.

AOD = the worst, most troublesome A/T Ford ever offered.

Even worse than the POS A4LD, and that's saying something.

The warranty repairs by 1985, had cost Ford more $$$ than all the previous auto trans warranty repairs combined dating back to 1951.

AOD = STAY OUT of overdrive in heavy stop and go traffic.

The constant searching up/down between drive and overdrive fries the transmission. It doesn't take too long for this to happen, either.

I'm sorry to have to tell you...that....CLUNK...means the trans is fried.

Y'all can adjust the bands, change the modulator valve, diddle with the cable, wave a magic wand..but once it starts clunking, the only cure is an expensive overhaul.

Preserve your AOD:

Add the largest external trans cooler you can find...and STAY OUT of O/D in heavy stop 'n go traffic!