Can't Start out in OD with 91' A4LD

[morganismo]

Hey all you trannie guru's out there...here is a question that I haven't seen addressed in any posts, but I havn't read all 600,000 of them yet.

I have a 1991 Bronco II with a 4.0 and an A4LD trannie to match. It is 2 wheel Drive and recently (about 1 week ago) I was driving back to Tulsa from a Junior High Church Camp (I'm a Youth Pastor) and I stopped at a stop light after traveling about 60 miles on the turnpike in OD. When I got ready to go when the light turned green, it was like the trannie never downshifted into first. The motor reved and I sqweeked forward very slowly. I am sure it was stuck in 4th gear. I manually shifted it to D and after a few seconds the engine RPM kicked down to around 1000 or so and popped into 1st. There was no grinding or loud noises, and it shifted fine in D all the way through 3rd. I can kick it into OD on the highway from D and it shifts into OD fine and even the detent will kick it back down into 3rd to pass. If I really slam on the gas to get around someone it should kick into 2nd, but it never does. It tries to, but its like there's no 2nd gear to shift to. After I take my foot off the gas it will go back into 3rd fine and then back into 4th too. The issue is that it just will not downshift out of OD when I get lower than about 45MPH. I have to manually put it in D everytime I slow below 45MPH.

The fluid level is fine and it's not black or burnt smelling, but it is off colored. I will change it and the filter this weekend and run some trannie flush through it to clean it out a bit. I was just wondering if anyone out there has experienced anything like this before and can give me tips on how major of a process I'm looking at if I try to conquer it myself. I am recently married and as I mentioned before I'm a Youth Pastor (so I have no money!!!). I have all kinds of engine experience with my other restos: 52' Chevy 1/2 ton, 641/2' Mustang 6cyl, 65' Mustang V8, 69' Opel GT, 91' Toyota MR2...but I have never dealt with an automatic trannie before. I see Glacier's posts about his rebuild of an A4LD, but I'm a bit afraid to tackle it myslef! Can anyone help me diagnose the problem? Can anyone help me fix my baby?

Thanks in advance!
-Matt Morgan
morganismo@hotmail.com

 

[BrooklynBay]

Welcome to this forum! Start with the simple things first like band adjustments, and adjusting the kick down cable. Your A4LD also has a modulator which sometimes leaks. Check the vacuum line going to it. The valve body has a filter which might be partially blocked. GLFredrick is also a Pastor, and a member of this site.

 

[morganismo]

Is there some sort of Book that might help me to better understand my trannie??? I really have no idea what a band adjustment is...when it comes to transmissions I feel a bit stupid. Can you tell me more about a band adjustment? Also the locations and descriptions of the Modulator and Vacuum lines? It sure would help out a newbie like me a ton!

Thanks!
-Matt

 

[Glacier991]

The A4LD Diary above in the stickies and the A4LD valve body diary should be helpful to you. Brooklyn has suggested easy things to try first, the next step after those would be to rebuild your valve body or replace it and/or investigate the OD band servo.

 

[BrooklynBay]

The vacuum modulator is on the passenger's side of the vehicle. There are 2 servo covers in front of it. The modulator is underneath a heat shield (or should be unless somebody removed it). Check the sticky above called the transmission band adjustment chart for some pictures of band adjustments. I have other information in my list of useful threads on other things you might of interest.

 

[morganismo]

Glacier and Brooklyn,

I keep trying to adjust the bands, and everytime I do, either R and D shift hard or not at all and OD works perfectly or OD won't work at all, and R and D are fine. Does this give you any insight on a different problem? Its as if the slightest adjustment makes the whole thing not work. I haven't tried looking at the modulator yet because it is behind the Catylitic converter and I have to drop the upper part of my exhaust to get at it. By the way there is no heat shield and sometimes when it is pushed really hard (like when I tow my boat with it) it starts to leak trannie fluid. There is already a cooler for it, but I don't think there is ay room for a heat shield...is there anything else I can do to keep it cool?

Thanks in advance.
-Matt

 

[BrooklynBay]

Are you using a torque wrench to adjust the bands? Did you follow the instructions in the band adjustment thread? The dealer sells heat shields. It is recommended to get one. The leak you are describing is the front seal blowing out. Don't tow in overdrive, make sure that your coolant level is full, and check your fan clutch.

 

[morganismo]

Brooklyn or Glacier,

I followed the instructions to a TEE, but still no luck. I am using a torque wrench set at 10ftlbs. The tranny is out of a 91 ranger so I even tried the 31/2 turns back and still no luck. Like I said in the last post, If I play around with the bands I can get it to start out in OD, but the D doesn't work right. I'm pretty sure that it has to do with the bands...but I don't know what else to do to adjust it. I don't see a vacuum hose going to the tranny, just the lines that goes to the radiator and tranny cooler, so I can't check for leaks. I ordered an A4ld book on ebay and I should get it soon, so I hope it will have more info about this particular problem. I hate to keep asking for help, but do you have any more ideas or suggestions? Thanks a ton for your help so far!

-Matt

 

[BrooklynBay]

It's possible that one or both of the servos are leaking like Glacier suggested in post # 4.

 

[morganismo]

Do you mean internal leaks, because I don't see any leaking fluid from the outside...just a small dribble when the tranny gets super hot? Nothing majorly leaking though.

 

[BrooklynBay]

Internal leakage from dried up servos not holding pressure.