a4ld tranny won't 1-2 shift. | Ford Explorer Forums - Serious Explorations

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a4ld tranny won't 1-2 shift.

Brett

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City, State
Littleton, CO
Year, Model & Trim Level
94 Explorer Sport
Hey all -

any ideas for a 1-2 shifting delay? It runs out around 45mph before it will shift from 1-2 while in D. If manually selected in 2 it will start out and maintain 2. However, shift to D and it drops right down to 1. 3-4 shifts and 4-3 shifts are okay.

Thanks,
Brett
 



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Do you also have a delay going into reverse, or drive from park? When was the last time the fluid, and filter were replaced? Was anything hard floating around in the fluid, like metal shavings? Did you ever replace the modulator, or servo pistons? How many miles do you have on the transmission? What kind of fluid do you normally use? How is the fluid level? These transmissions are very fussy when it comes to the proper level. If it's only a little low, it doesn't shift properly. Sometimes the governor could be sticking too. First check the simple things before replacing any parts.
 












BrooklynBay said:
Do you also have a delay going into reverse, or drive from park? When was the last time the fluid, and filter were replaced? Was anything hard floating around in the fluid, like metal shavings? Did you ever replace the modulator, or servo pistons? How many miles do you have on the transmission? What kind of fluid do you normally use? How is the fluid level? These transmissions are very fussy when it comes to the proper level. If it's only a little low, it doesn't shift properly. Sometimes the governor could be sticking too. First check the simple things before replacing any parts.

Thanks for the reply. Here's the info to your questions.
No delay in reverse
Fluid and filter are brand new. Tranny was just rebuilt. Also dropped the valve body and found a stuck valve (Transgo shift kit diagram was incorrect)
New adjustable modulator (I am beginning to suspect this piece)
Servo's are new
50 miles on the rebuild
Mercon/decron III
fluid level - right on the line while warmed up and running.
I used the governor update spring and made sure it was operating correctly. (it could still be the source of the issue so I won't rule it out)

Thanks for any info! Brett
 






There is also a linkage cable that might need an adjustment. It has one part going to the throttle pedal, and the other side is near the area where the shift adjustment rod moves the bore on the valve body on the side of the transmission. There is an adjustment that is under the hood, connected to this cable. It is at the point where the firewall is met with the cable. You just squeeze the piece on the side of it, then you have to make it as tight as possible. When you step on the accellerator/throttle pedal, it will "automatically" adjust. You will hear it move, and feel the teeth rub on it. By the way, did you have this same problem before the rebuild? Maybe it's a valve body problem, since the valve body is not always thoroughly cleaned out.
 






Great Thread

Tag for information and reference
 






Brett... to start out, remember that the 1-2 shift in the A4LD is an old fashioned one - no computer inputs used. What is used are the TV (modulator), the governor, and the 1-2 shift valve (bore 204) and the 2-3 backout valve (bore 211). Of course the intermediate band and servo are used in this shift as well, but they are so low on my list of probables as to be of little obvious concern.

In your situation, as was noted by BrooklynBay, I would direct my attention to the things easiest to get to. You DO have a modulator pin installed, right ? (please do not take offense, just needs to be checked) Got the correct version of the modulator? (I can ship you one to try out as a test if need be). The VB may yet be a litle sticky in those bores, next step would be to pull it and recheck those. While it is out, Sonnax has come to market with some bore end retainer plugs with O rings that I am thinking might be a worthy addition. I'll be posting something on those soon. Lastly of course, we have the governor. I think I will go back and post the info and recommend replacing the body as a matter of course. It is not that expensive. Also the 35mm weight that I had trouble finding is now more available.

I know this isn't much help, but that's where I'd start. I'd put the modulator (and valve and pin) high on my suspects list.
 






Another thing to check is if they remembered to put back that small pin behind the modulator. The modulator won't do any good without it. Some guys do a very sloppy rebuild. I once bought a rebuilt "Ford" A4LD hoping that it would be like a factory transmission, and I was sorry that I blew my money on it! It wasn't any better than going to a local garage.
 






One thing I was thinking about is that if you just had it rebuilt, maybe it might void the rebuilder's warranty to touch anything on it. I would try to go back to him first. If they don't do anything for you, maybe then you should start to work on it.
 






Thanks for the replies guys.

I have adjusted the kickdown cable. The tranny does kick down to from 4 to 3 while on the highway (65 + mph).

I'm suspect of the modulator. It is an adjustable replacement piece (the one with the big dial on it). I have the original I can put back in. I did put the pin back in. I recall that very vividly.

I did the rebuild on this tranny. So the warranty is on my own shoulders :-)

I know what you mean by sloppy rebuilds. I've seen many of them. I have a couple of "rebuilt" a4ld's that I use for spare parts and when I tore them down they were complete junk inside (with the exception of new frictions...)

Here's my plan of attack: Please chime in w/ suggestions
1. Adjust kickdown cable
2. Swap modulator, ensure pin is correct.
3. Suspect governor. Pull tcase/ tranny extenion housing/replace governor.
4. Valve body sticking. Drop valve body (again). Replace
5. The FORD shop manual also lists some additional steps to test the vaccum pressure.
 






One last thing I should have mentioned is to check the vacuum line going to the modulator for vacuum. I once had the other side of the hose going to the octopus on the intake manifold crack off. Sometimes these hoses get dry, and brittle. If there is no vacuum on the modulator, then you might have a problem like this too.
 






Brett, your plan of attack is a sound one and intelligently thought out in terms of effort and possible success. Go for it and keep us posted.
 






Brett I have a 93 xlt4x4 w/ the same exact problem except when yours is dead cold does it not want to stay in 1st until it is driven a few blocks a/o about a mile? I've replaced my modulator(nightmare) and it still is acting the same. if you find the problem I'm dying to know. my e-mail is nasbast@yahoo.com the only sreious mech problem this truck has is the tranny. P.S. where can I find a comprehensive repair manual for the a4ld? the haynes manual is useless for transmission probs.
 






haynes manual is useless

I find that to be true anyway, all the pictures of the engine compartment that are supposed to be my year (the ones showing emission connections) have the battery on the wrong side...what a joke.

Dwight P
 












A no 1-2 shift when cold fairly screams for a governor cleaning and reinstall. Do a search on A4LD governor. That is a pretty good bet as to what your problem is cdutt.
 






Glacier, on the newer 5R55E, would the symptoms be the same on the electronic valve body without the manual Governor? I know that the shift points are completely computer controlled on that, and determined by RPM, speed output of the VSS, TPS position, and maybe other things I'm not aware of. I assume that those still use a modulator, but I don't have first hand experience with them, only the A4LD at this time. Does it still use the kickdown cable? I would also assume that they kept this too.
 






No 1-2 shift

Don't know if this is the right place to go, but I have the same problem. Got vehicle at 120K and have put 40K on it with no problems. Kid drives it one night and now the 1-2 shift is completely crazy. It will shift if the rpm is high, speed is over 25, and ya let up on the gas. All other shifts are normal. Checked modulator vacuum; checks OK. Checked kickdown linkage; seems OK. Fluid is OK, clean & red. Is there any info to be had with a pressure gauge? I don't relish the thoughts of tearing into it right now due to time, weather, lack of space & money, etc. etc. Any info would be appreciated.
 






Maybe it might be instructive to describe what happens when you get a 1-2 shift in the Explorer from an internal hydraulic standpoint. From the FORD Manual (I am not making this up and this is their wording, not mine):

1. Line pressure is being supplied to the hydraulic system by the pump.

2. The manual valve (206) [Glacier note - this is the valve the shifter is hoooked up to, and when you shift gears it moves this to a different position to direct fluid to different circuits in the transmission] directs the fluid to the governor, 2-3 backout valve (211) and the low/reverse band release side.

3. Governor pressure continues to increase with higher output shaft speeds.

4. Governor pressure is now moving the 1-2 shift valve (204) to allow secondary (line) pressure to move through the D-2 shift valve (204) and the 2-3 backout valve (211) to apply the intermediate band.

5. During the shift, intermediate servo release accumulator valve (216) regulates back pressure on the release side of the intermediate servo [Glacier note - this servo applies the intermediate band which effectuates the 2nd gear engagement]. This helps cushion the 1-2 shift. The fluid then exhausts through the manual valve (206).



Glacier again: You can see what parts need to move to cause this shift. It could be a governor issue, sticking valves in the VB, or even a leaking servo.
 



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Thanks for the info. It helps to understand just how things are done. I finally found my ATSG manuals (They were hiding under the bed). They're great at telling ya how to tear it apart, but not good at telling ya how things are done. I'll probably drop the valve assembly first cause it's easier. But for now, I'll just baby it till the weather is better and I have more time. All the shifts seem firm, and there is no sign of slippage or clunking, so I'm guessing I'll be OK for a while. Thanks again.
 






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