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Converter R&R Advice

2K views 25 replies 7 participants last post by  Rebel Racing 
#1 · (Edited)
Hi Guys,

After coming to the realization that our custom converter in our 347/AOD (custom valve body), 3.80 rear end combo is not exactly right for our set up, I feel we need to send it back for a re-stall. I feel it is too tight. It's better than our original stock set up but still, under light throttle, it's shifting into second before you get through the intersection and into third real soon after that.

Now, my next question will likely elicit a WTF (since I built a complete motor from a bare block 2 yr ago), but, I have never pulled a trans or converter. So, what I am asking is......what is involved in taking out a converter from an AOD? I have a service manual from our '93 car (AODE) and I do have a manual from the '68 which, of course covers the C4. Between the 2 books, is that all the info I need?

I have a hoist and a good assortment of tools including air. I'm sure I can do it but having never done it, I am a bit apprehensiveness. Thoughts??

Thanks!!
 
#3 ·
The TV cable (when tightened, within spec, can firm up the shifts) but the converter just seems too tight. I feel that a looser converter will let the motor rev a bit higher between shifts. It also has a high rev govenor--that helped a bit but still not enough.
 
#4 ·
Not at all sure if another converter will do what you want but not really my area.
How I'd do it.
Disconnect the battery.
Take the radiator shroud loose. (Don't have to remove.)
Disconnect the TV cable completely.
Raise the car.
Remove driveshaft. Have a catch pan or a tailshaft plug ready for the small amount of fluid that will leak. The yoke may also dribble a bit out as you set the driveshaft down.
Disconnect shift linkage.
Take the starter off.
Remove the crossmember. This will let the tail of the transmission DROP some. So you'd want to ease it down instead. Pro shops have tall purpose-made transmission jacks. A "pole jack" works great if you have one. A guy I know used a shop cart with a sort of metal milk crate upside down on top of it. Sounds silly but I used his setup more than a few times and it actually worked great. You have to crouch down a bit to ease the lift down and then duck walk under to get the bolts out. Then raise the lift back up. (More ATF leaking out the tail!) It doesn't hurt anything to let the transmission hang like except on some cars the fan might hit the top of the shroud (not if you loosened it) and rod type throttle linkages sometimes touch the firewall. Hanging like that makes the bellhousing bolts a LOT more accessible and that's how the pro's do it. (Except for Jeep Cherokee 4.0's)
Now that you have some more room, crack the transmission lines but don't take them off yet. They'll dribble.
Remove dust cover/access plate is you have it and the converter nuts. Converter nuts are "shallow" so I like to use my best quality and least worn socket on them. On some setups (not likely) you have to use the starter hole to access the nuts. When the last nut is off I like to push the converter rearward a smidge to pop it loose from the crankshaft pilot hole. Sometimes they stick, paint on the converter nub is a prime cause.
Pull the NSS/backup light connector loose.
Remove bellhousing bolts. I like to pull all but one on each side and then prepare whatever is going to be holding the transmission. Jack, cart rig, weightlifter helper, etc. If you have floor jack style transmission jack then lower down to it and get your creeper
THEN, when the transmission is supported, crack and remove the two remaining bolts. Don't break them loose until you are ready to fully remove them. Though I have been known to crack them loose and then retighten them almost as tight as they were. Hanging the transmission off two bolts is only OK if those two bolts are tight.
Remove the cooling lines and plug them or let them dribble.
You should be able to yank the tailhousing from side to side to pop the transmission off the engine. Sometimes they stick (paint and/or corrosion) and you have to pry a bit. Don't pry against the flexplate, you can bend it.
With a tall pro-type transmission jack you can tilt the transmission towards the driver's side. If your setup doesn't allow such tilting, try really hard to keep the dipstick from popping out as fluid will GUSH from the hole. There are plugs for that but you can't really swap one in fast enough.
And it should be out. Anytime you swap/remove a converter it's an excellent idea to swap in a new pump seal too.
How I don't do it.
Obviate a lot of the mess making by pulling the pan and draining the fluid first. This will not drain the converter or do anything for the cooling line dribble but does for most of the tailshaft leaks and the dipstick tube is no longer an issue.
Don't ask why I don't drain them first, I don't have a good answer. I feel like I should have just lied earlier and said I did. :)
Lastly.
You may or may not have to remove some or a lot of exhaust. I have no idea what you have. On some I have seen you can take the exhaust loose just at the muffler so the drivetrain will droop correctly. Others with all welded joints and an x-pipe have to be pulled from the headers back. It's not unusual that dealing with the exhaust is one of the most difficult parts of the job.
Off the top of my head. I may have forgotten something.
 
#5 ·
Not at all sure if another converter will do what you want but not really my area.
How I'd do it.
Thanks for the detailed write up!! I need to find out for sure if a looser converter would help or not--I'd hate to go to all the work and not be any further ahead than I am now.

My biggest complaint is shifting into second before you are even through an intersection and then into third real soon after that (under light throttle). It shifts fast and pretty hard/firm under WOT which is what I wanted and, if I put the shifter in first it will hold first gear indefinitely.

I was hoping that the custom valve body would solve all our issues and toa certain degree it has but it isn't ideal. Some have told me that since there is a 3.80 gear in the back, it won't get any better........I'm sure there are a lot of AOD's out there with that gear that don't have our issue--maybe I'm wrong though and I just need to live with it. Thoughts???
 
#6 ·
After coming to the realization that our custom converter in our 347/AOD (custom valve body), 3.80 rear end combo is not exactly right for our set up, I feel we need to send it back for a re-stall. I feel it is too tight. It's better than our original stock set up but still, under light throttle, it's shifting into second before you get through the intersection and into third real soon after that.
Sounds to me like ultra-normal behavior for "light throttle" acceleration. However, it seems to me that the vacuum modulator, not the painful and expensive converter, should be where you start. What is you operating engine vacuum?
 
#7 ·
To be honest, I don't recall right now since it has been over a year since we tuned the carb with the vac. gauge and wide band O2. I know it was not super low though. I can hook it back up this week and report back. What is involved with adjusting(??) or replacing/upgrading the modulator?
 
#13 ·
I'm thinking since it's an AOD it does not have a vacuum modulator and due to different gear ratios that chart above doesn't really apply. The tweaking is in the TV cable, the governor, and various internal valve body bits. I seem to recall hearing that this is a common issue when you jack an AOD up with all sorts of custom modifications but haven't delved into it myself as I keep mine pretty close to stock and haven't experienced this.
 
#14 ·
I'm not sure how the chart would apply to our application....347 ci and a 3.80 gear.

I'm going to call up Chris at Lentech and see if a different vb might be the answer. I know he makes ones that eliminate the TV cable all together but not sure if that is for an AOD or the AODE. Hopefully there is a simple solution to this.
 
#15 ·
You could do a lot worse than talk to Silverfox- here: Home
Or just post your issues at this very AOD-oriented forum - Click Click Racing (If you haven't been there already.)
But if you already have a Lentech valvebody it's likely best to stick with them.
 
#18 ·
Convertor is not the problem - you are on the right track in contacting the fox - he will set you straight.


I have a 3200 stall convertor and still have that problem with my 3.89 gears. No mon.0ey to throw at th car so it will be ok for a while.
As I recall, Lenny spec'd out our converter to around 3200 but it sure doesn't feel like it. Maybe I will have to live with it since I don't want to go to a higher gear--I like the acceleration and with the OD, it is good on the highway. Besides the VB,TV line pressure and the converter, what else is there to change?? Now the Wife says she wished we put a 5 spd in it........I'm all for it but would like to know for sure if this can be made better with just a couple small changes.
 
#20 ·
I put the baumann recal pro shift kit in my son's fox over the winter. It includes various shims to adjust the shift points. If you already have a custom valve body, it would not be the thing to use though.

On my '65 I went with a 4R70W and a programmable TCS. So, on my car, all I have to do is hook up a laptop and it's a 1 minute deal to change shift points to whatever I feel like. Also, not much help for your situation.

Phil
 
#21 ·
On my '65 I went with a 4R70W and a programmable TCS. So, on my car, all I have to do is hook up a laptop and it's a 1 minute deal to change shift points to whatever I feel like. Also, not much help for your situation.

Phil
That would be cool. I remember in the mid to late 90's, our tuner (for the race car) was doing something similar with the AODE's and something from Bauman, I think he called it the Baumanator and it would change shift points also via a laptop. However, if the trans needs to come out of our car a Tremec will be going into it. I always wanted a 5 spd in it but the PO had installed the AOD in place of the C4 so I really want to give it one last "chance".
 
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