A4LD No Reverse

[rdodd1024]

I have a 93 XLT. The tranny has high mileage, has been well maintained, is clean inside, pan was off and fluid\filter changed 250 miles ago. Fluid looks\smells good, no particles. It started not locking torque converter and no 4th sometimes. Then it started slow shifting into reverse. All of the sudden it will start in 2nd most of the time, will not upshift most of the time, even manually from 1st to 2nd, and no reverse. I am new to this tranny, and am looking where to start. I do have some ideas and am still searching these forums. Any guidance is appreciated.

 

[Glacier991]

first off check the hose to the modulator for trans fluid and let's rule out a bad modulator.

 

[TheFox88]

THATS why I always drive manuals. Sorry can't really help you, but there are a lot of resources on this forum, hust get a search going and i'm sure you'll find everything you need. Good luck!

 

[rdodd1024]

The modulator is new, the hose had no oil in it, but I am suspecting the modulator as it was changed the same time the fluid was changed, and it did not seem to shift right since then.

 

[Glacier991]

AH, sounds like the pin fell out and didn;t get replaced. You SURE the pin is in there ?

 

[rdodd1024]

Yes, the pin was in there. I already made that mistake one other time, made sure it was in there, but plan on pulling modulator and pan and looking around.

 

[Glacier991]

might try and remove the TV inside, clean it up, and check for ease of movement too.

 

[mckenzieslayer]

was the filter and fuid changed regularly before the last one?
I have heard of these trannies not liking new fluid after a long time without service.

 

[rdodd1024]

It was changed regularly it's whole life, didn't leak fluid, it was in fine shape the first time I took the pan off. Most everything I have worked on has acted up if you suddenly started changing fluid. I knew one guy that all of the sudden had major leaks in his engine because he "flushed and filled". It has gone about 55,000 miles for me with regular fluid changes, nothing looking abnormal inside. I do need to get inside and look around.

 

[Opera House]

First and reverse are the same gear. I would be looking for a common problem here. When you say that this started when you changed the fluid, I really suspect there is a problem with the filter sucking air. Some forget to install new O rings or have problems when they use the newer style plastic filter and the old bolt which is too long. The filter then drops down. The low/reverse band needs extreme pressure. Anything that reduces pressure will show up in these gears first.

 

[rdodd1024]

Actually the motor had been out for a rebuild. The only problem with it was the freeze plugs, high milage had done it to them. At that time, it had run perfectly, shifted perfectly. It had a leak at the modulator diaphragm, so i decided to change the modulator and fluid, since it was about time. That is when it started acting up, so I am suspecting modulator and filter to check first. I am going to inspect the pan and inside real well, and if any indications, I will pull th VB and check it out. The rebuild diaries you guys have done has helped immensely with my understanding of how this tranny works. I do computer tech work, and I always worked on the premise that if you understood how something worked, you could usually fix it when is doesn't. I appreciate all advice. Even in my industry we sometimes brainstorm, and someone will come up with something everybody else has not considered. I am still reading the diaries, they are quite lengthy.

 

[rdodd1024]

Ok, so the truck is at my buddies shop on the lift, cooling off till morning. He is going to look at the things we discussed. The way it acts in gear, it feels like a low pressure problem of some kind.

 

[Glacier991]

I am glad you are finding the Diaries (mine and Brains and Tn_Explorer's) useful. And yes I agree, exactly about understanding HOW something works. Auto trannies have been made a "mystery" and shark oil salesmen take advantage of the unsuspecting. Knowing HOW and WHY something works is the key. Ever wonder why they have "Theory of operation" sections in tech manuals ? <g>

Please let us know what is found.

 

[rdodd1024]

One thing that I have always been good at is figuring out how something works. I have been able to fix quite a few things - even if I knew relatively little about it. I have fixed microwaves and TV's when I knew next to nothing about them, because I found out how they worked, and paid attention to the dangerous stuff, such as high voltage. I know we will figure this out, we always do. I will keep you posted on progress.

 

[rdodd1024]

The modulator got pulled, pin is there, absolutely no vacuum leak, my buddies shop is so busy today that we haven't been able to get the pan off yet - at least he is making money. Hopefully sometime this afternoon.

 

[rdodd1024]

I have started making a possible parts list if there is trash in the pan, but I have to look for workspace to do the job as I can't do it at my buddies shop. It is my daily driver so I am pretty screwed at this point, and I am currently looking for a new place to rent, am in a damn motel right now. I was in my house for 9 years when they decided to sell it, and FAST. So all help I get is really appreciated. I have one possiblity of a place to use and have not been able to get ahold of him. I am trying to anticipate if there is trash in the pan.

 

[rdodd1024]

Ok, so there is metal in the pan. So, out it comes. I have to find a place to do it, and There is quite a bit of metal in the pan. I will have to get it apart to see what the deal is.

 

[rdodd1024]

I got the vehicle to a place to work on it, put it on stands and started work. I do not have the transmission out yet,(almost) and there were 2 small chunks of metal in the pan. Not even enough to coat the magnet with anything substantial. There is some chalky grey material in the bottom, real fine, that appears to me like friction material off the bands or clutches. There is also no metal on the filter. Something broke, because the two chunks look beat up, but they are not very large. On to the next

 

[Carlos Osornio]

Have you figured out what was wrong with your A4LD yet??
Mine is stock in forward, I place the shift lever in any position (even in Park) and the truck moves forward.
It first started by slipping a bit, when I first started the truck in the mornings I needed to give it some gas si it could engage on D or R
The fluid level is OK and the fluid seems to be clean (changed some 10K miles ago)
It's currently at the shop but they said they had not been able to figure out what was wrong yet

Glacier991, can you please let me know what is the modulator and where is it to be found?

 

[Opera House]

Changing the vacuum modulator is highly unlikely to solve your problem. PARK has almost nothing to do with the transmission operation. A lever sinply is forced into a cogged gear. Either you shifted into park when moving and snapped the lever, or your shift linkage has becme disconnected. I would get under the vehicle and check this linkage first. Safely block the wheels before doing this!