Bronco Forum - Full Size Ford Bronco Forum banner

AOD Torque Converter Woes

9204 Views 17 Replies 7 Participants Last post by  Crash138
Ive been wrenching for 30years, but Im no expert at anything, done just about everything once or more in some cases except rebuild a transmission, therefore I know very little about their internals, however I have replaced(swapped out) several...

cutting to the chase, this is my first AOD to handle and I am having one hell of a time trying to get the torque converter(TRQC) seated properly... is there a trick to this? Ive been trying for a week meow, to get this thing seated, trying to find info on the internet, and Im at a loss. Im figured that I need 1" from the face of the bellhousing to the seat around the studs on the torque converter for the flywheel to mount to, Im off about 3/8" to 1/2".

here are the facts: 1: 1990 bronco, originally a 302/AOD, bought without engine, everything else intact...
2: bought 1991 302 out of an f150, replaced flywheel to AOD from e4od... 164 teeth, 50oz external weight
3:I thought maybe the TRQC that came with truck was wrong, bought a new one, exactly the same problem...
4:Measurements- the depth of the TRQC is 6-3/4" from front (goes into flywheel) to end that sinks into pump...
5: end of input shaft to pump is 6-1/2" so a little shorter that the converter depth
6:flywheel face to inspection plate on block is <1" by a couple of butthairs...
7: end of input shaft to face of bellhousing .437" (handy digital micrometer)
8: tip of TRQC(goes into flywheel) to flywheel seat around stud is .866"
9:Inner shaft once pulled out measures 15-7/8" in length, and after I stick it in the TRQC its depth reaches 6-5/8" meaning the front thickness (toward the flywheel) of TRQC is 1/8" which is reasonable to me...

Calculations: 6.5"+.437"= 6.937" for total depth from face of bellhousing to pump face
6.937"-6.75"(depth of TRQC)=.187" is bellhousing face to front of TRQC when installed properly?
.187"+.866"(#8 above)= 1.053" which should be just enough room for the flywheel and allow tranny to seat against block, provided i could get the TRQC all the way seated.

Observations: Ive heard of mushrooming the inner input shaft but mine appears do be fine, no apparent damage to splines on either side... on the input shafts, the middle or inner hollow shaft has a tiny bit of wobble to it... the TRQC has stamped on the side "20g" which i assume is a weight for balance, "58A" stamped near a stud with several what appears to be intentional marks through it "55A" stamped near another stud not crossed out, also "55A" in paint stick on back of TRQC.

anything to help or point me in the right direction? something is wrong here and Im at a loss ... :banghead
See less See more
1 - 18 of 18 Posts
I did an AOD a while back and it slid right on easily, just like any other trans.

sorry no ideas
An AOD transmission has a 14 bolt pattern on the pan, E4OD has a 17 bolt pattern....?

Usually when you bolt a tranny to the engine with the TRQC set in, you just tighten up the TRQC bolts and that should seat it properly at that point so are you sure you have the correct one or a TRQC "stud" length issue, is the seal correct inside.

If you dropped the pan is it possible to see inside that way when trying to seat the sounds like some sort of "blockage" preventing it from going in all the way...IDK

Let us know when you find out what the issue is...OK

Good Luck ~ :thumbup
the AOD has the 14 bolt bolt pattern... before you bolt the trqc to anything, it has to be slid onto the trans input shaft, then the trans mated to the engine block then you put the nuts on the studs that come thru the flywheel... you cannot see anything thru the pan, as the trqc mates to the pump on the outside of the trans... I did buy another trqc and it was exactly the same as the one I had... Ive checked splines to make sure they are not damaged in anyway... Im outta ideas to check.. supposedly the trans was rebuilt with less than 5,000 on it before the previous owners motor blew, but I have no proof... it is very clean unlike the rest of the undercarriage... I can see the flat spots on the pump that the trqc should slide into, everything I have read has said they are at 12 and 6, and they were when I first started this but now they are at 8 and 2 now. Im so perplexed... I know it shouldnt be this hard, but I figured the problem would be obvious, but it isnt to me... im afraid at thsi point my frustration level is so high that Im "blind" to any further troubleshooting ideas... so any help/ideas is appreciated. I know of a guy in Austin that had this same problem, he had his flywheel machined to to make everything fit, but this is not the way I want to go...
See less See more
Am I understanding this correctly? You are trying to get the torque converter on to the flywheel and you are off almost 1/2"?
No, Im trying to seat the torque converter on the input shaft of the transmission, but it wont go on all the way for some reason totally oblivious to me...
I'm just guessing but the aod uses that dual shaft input where the internal shaft drives the lockup function. Maybe the internal splines are not lining up?

PM FSB member "miesk5" with your dilema and see if he can point you in the right

I'm stumpped too......:doh0715:

Good Luck ~ :thumbup
ive taken the internal shaft out, and stuck into the torque converter....

"9:Inner shaft once pulled out measures 15-7/8" in length, and after I stick it in the TRQC its depth reaches 6-5/8" meaning the front thickness (toward the flywheel) of TRQC is 1/8" which is reasonable to me..."

ive cleaned and examined all the splines on all the shafts, ive found no irregularities that would prevent the TRQC from going on all the way, which I am assuming that as far as it does go that it is at least starting to go onto all three shafts as it should, just something preventing it from seating all the way...Ive drained the TRQ and filled it three times now looking for foreign objects inside it...

BTW, if I seem to be a little short with anyone I'm very sorry...Definitely not intended, Ive just reached a new level of frustration that I haven't seen since my ex wife... hehehe... I certainly do appreciate any attempts at diagnosis... Thank you JKossarides I will do that...
See less See more
yo Crash,
Again, I'm having huge Comcast connection issues; this is what I have from my MS WORD Notes;
So far, I have:
The back spacing between aod/c4/fmx/aode/4r70w and the backspacing between c6/e4od/4r100 flexplates are different. You must use the correct one for your transmission.
by Alan at
go to his site and e mail him for the dimensions;

I have these dimensions for the AOD TC;
Hub to Stator distance, cm (in) 8.255 (3.250)
Hub to Turbine Spline, cm (in) 11.557 (4.550)

Next up;
"...The Fitting Room
A common complaint about aftermarket torque converters is fitment. Often, a new converter will not fit the transmission's input shaft because it is built to closer tolerances than OEM converters, so the hub-to-input shaft fit is tighter. Just because the new converter will not slip onto the input shaft doesn't mean the converter is defective-just use a little extra effort.

A good way to check if a new converter will fit properly is to compare it to the stock converter you are taking out. The three critical dimensions: overall length (from engine mounting face to end of hub), hub slot depth, and hub slot inside diameter. Before you remove the old converter, check the dimension from the bellhousing to the front. This will help you position the new converter properly...." source is
See less See more
Sorry, my CC conn is so bad that I over-write some info.
I don't have much AOD hands-on experience; been so long that I have to rely on shop manuals to do anythAng.

What is the TC Brand name and part #? Doubt that even w/that info I can do much from here though.

Hopefully someone else here will post-up w/better help for you

and Alan will help out; he has been active in other Ford Forums in the past.
Had the same problem, spent two days trying to get it to seat.

Slowly turn the torque converter wile moderately tapping it on the center with a rubber mallet. Don't beat the crap out of it, but give it a good firm tap.

After 30 seconds of doing this it suddenly poped back to where it was supposed to be.

I have to thank you Miesk5! that bit about aftermarket TRQC's being snug fit was very correct, perhaps with the tranny being rebuilt new pump gears compounded this problem... HOWEVER, love taps with a rubber mallet were not enough to make it work, but a little, and I do mean a little love from a bastard file on the TRQC's flat spots and WALLA! cant thank you guys enough for the help! now maybe my hair will stop falling out... hehehe... now, on to the next crisis! which my guess will be some ignition doodad, whose electrical tape got the better of my curiosity and I couldnt help but to pull it off to discover burnt crispyness and a total lack of intactibility without said electrical tape... well it started before I pulled it out of the donor vehicle... but meow I have my doubts....
See less See more
that's good!

take a pic of that toasted stuff.. and post it up
fed ex just delivered new flywheel... time to get dirty... flywheel, check, 30 stones, check... case of wanto, shit, I knew I was missin somethin....
1 - 18 of 18 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.