Hi Guys,
I've finally got my truck back from the transmission shop & it's not shifting right. It's a 1950 F1 with a 351W, Mild cam, Edelbrock top end kit & Carb, & an AOD transmission. I've had it back to the shop multiple times & they say it's fixed & it still has the problem...

The symptoms - The truck starts up fine & runs but it shifts into second way too early - bogs down & shudders & will slowly come out of it as you continue to accelerate. It's like a manual transmission when you skip a gear & go from first to third - maybe it's not hitting second at all.

I'm not sure how familiar this shop is with AOD's - it would help if I could
tell them what to adjust or look for. Any help would be great.
The Speedo also registers at best half the speed I'm actually going - Is there a way to determine the right speedo "color" gear for my truck?


Ben in Austin

(I think this shop is hesitant to open the trans back up for adjustments - Can they do what they need to externally? I'm failry useless with transmissions unfortunately).

 

Is this AOD stock? What did it come out of? What rpm does it shift into 2nd when you lightly accelerate in first/normal driving? 1/2 throttle? full throttle?

Also for what color speedo gear, what is your rear-end gear ratio?

 

Did they install and adjust a TV cable set up? (TV = Throttle Valve). Transmission failure is a kiss away without this set up correctly.

 

Hi GTStang,
Thanks for coming back on this one. Let me see if I can answer your questions:
"Is this AOD stock? What did it come out of? What rpm does it shift into 2nd when you lightly accelerate in first/normal driving? 1/2 throttle? full throttle? Also for what color speedo gear, what is your rear-end gear ratio? "

o The AOD is not exactly stock - The Overdrive belt has been upgraded to Kevlar & the clutch packs are aftermarket - I believe they are raybestos blue if that makes sense. (My AOD has the "B" size servo).

o It shifts into second under a 1000 RPM.

o I haven't tried full all out throttle - just normal driving coming off a red light - first gear is fine then a quick shift to second & it bogs down till you get up past say 35mph. (I'm guessing a bit here as the speedo doesn't work).

o The rear end is out of a 2001 Explorer - 8.8 inch - My best guess is 3.73 - I'll have to confirm as well.

I'm not sure what the AOD came out of - it was a core exchange at the transmission shop.

Ben in Austin

 

Hi 85,
Yes it has the TV cable set up & it's been adjusted to get the right pressure. We had it another shop i& they had 2 transmissions fail
on it so I moved the truck back up here to Austin - hoping to have a better shot at the 3rd AOD install. It seems to be in & working but it definitely doesn't shift right from 1st to 2nd.

I had it back in there Tues of this week - got it back today - no improvement.. The truck itself is still idling rough & doesn't appear to be happy - have more work to do there on the carb/timing.

Any thoughts on the transmission from afar?

Ben in Austin

 

Have you checked the line pressure? Is the vacuum modulator hooked up and receiving vacuum? Some of it may come from the engine running like ***.

 

There are calculators tp help figure out what transmission speedo driven gear to use. I had to get a special one cause of my 3.55 gearing and 20 in wheels. Google is your friend here.

I also think the vacuum modulator is not connect properly.

What's the issue with idle?

Did they put a shift kit in the tranny?

Sam

 

Hey Sam,
I tried to encourage the trans guys to get the Baumann shift kit
but I don't think they did - They resisted & wanted to use their own suppliers. They talked about Raybestos but I have no idea what they used in the end they rebuilt the trans & said not to worry about it I had a 2 year warranty. I also wanted the 2 inch wide "A" overdrive servo but they went with a 1.5 inch kevlar one.

The Engine - Hmmm I think it's partly I don't know what to expect - It's been a while since I've driven a carburated engine especially one with a mild cam. There isn't anything smooth or quiet about it - It hisses & chugs & rocks. Is this how it's supposed to run or do I just need to give it time to break in? (I have had an old school car guy re-set the timing, choke, & carb - but it doesn't feel or sound right to me).

He said he set the carb rich till we get past the 500 mile break in mark....
At a minimum I'm going to put different mufflers on it so all my neighbors don't move out of the county. Are you up for a 5 minute listen to the new truck this weekend some time? It runs - it just doesn't have any manners & it shifts early.

Ben in NW Austin

 

Sure, we can figure something out.

Run a calculator, I might have a speedo gear I can bring.

Sam

 

Is your engine a carbed engine? I have read that on the instructions it says that the TV needs to be adjusted to where the vacuum gauge reading says "0" at idle and with the TV cable "tool" in place it should read 35 psi. BUT with a carbed engine the TV cable sometimes needs to be adjusted where the idle reading "without the TV tool from lokar" is around 3 psi or so. ALSO did they put a stronger return spring in place of the week lokar return spring? This one is mounted down on the trans. Check this video out. I would try to adjust it this way and check to see if the return spring has been replaced with a stronger one.

AOD Setting - YouTube

If you do the exact thing this guy does and it still acts up, I would try what I said about uping the PSI reading from "0" to "3" at idle without the tool in place. I read an article online how a guy had some terrible trouble with his brand new TCI trans and found he just needed to adjust the idle psi from "0" to around "3" and it fixed his problem.

 

Hey Sam,
I took a run at the Speedo calulator - hmmm... - Had to actually put my thinking cap on for that one. There are a few calculations in this one.

- # of teeth on the speedo gear? My guess - If this particular AOD is
from '88-'93 it should be an 8 tooth gear.

- Tire size - 255-45-18 (Not a guess).

- Tire Height - According to the on-line tire size calculator - 27.04 in.

If all that is right it would need a 22.3 speedo gear - Chinese anyone?
I haven't thought about diameters & Pi in a few years - I'm feeling inadequte at this point we have stretched my rudimentary higher math skills beyond comfortable.

Ben in Austin

 

Hey Reed,
I hear you - I'm reluctant to touch that cable - It's a $2500 mistake if
I screw it up. I've been relying on these guys to be the AOD tuning experts - I'm sure my warranty is out the window if I adjust that.
I will send them that video post prior to the next round of adjusting...
(If this wasn't my third try I'd be more adventuresome). Keep sending thoughts - I put that one in my memory banks for use later when/if I get desperate.

It's tough as I'm in the break in period on the engine/carb/exhaust as well - trying to adjust the right things to move toward a smooth running ride.
(The brakes were locking up every mile last week but after a few hours of fun with some help they now work - keep moving forward). I couldn't really sense check much on the trans or engine till that brake issue was solved.

Ben in Austin

 

No I ment for you to have the shop to do it lol I should have said that in my other post. I would be hesatant to do it myself too lol. I'd give Lokar a call and ask them as well. I have read numerous times about people having trouble with their AOD and it turned out to be that return spring being too weak.

 

Hey Reed,
Thanks for the help - I'm just in shake down mode trying to figure out
what needs to be adjusted. You'd like to just be in the end zone & you fire it up & it works like a champ & off you go. I think reality is more of
spending a few months working through things & sense checking everything. (I can tell the transmission isn't shifting right - now what do I need to adjust to get it nailed - hmmmm pull the right lever...).

Ben in Austin

 

8 is probably right for the drive gear.

the top gearing is the purple gear at 21 teeth.. (D0OZ-B)

what I have in my green truck.. Only place in town is Leif Johnson Ford on Koenig Lane & Burnet rd. You can change this yourself in less than 5 minutes..

the rest of the difference (21 vs 22.3) has to be made up with speedo head unit adjustability.. (mine has switches across the back to apply those changes)..

sam