A4LD Slow shift into forward gears

[Zed]

Have a rebuilt transmisison with about 60,000 miles (Engine has 202,000) that has slowly over the last few months began to shift into drive more slowly. Initially just a few seconds, and more recently 4 minutes. I have replaced the fluid which was a little dark, but nothing too bad. There was some sludge in the pan, but nothing any worse than I have ever seen changing tranny fluid. The fluid change did no good. It has steadly gotten worse over time and now that it has gotten cold, it takes as long as 10 minutes for it to engage ( longer than most would even wait). Once the transmission engages it shifts just as good as it ever has and when I do park the thing it goes back into drive in less than 10 seconds. I am a mechanical person, but have never worked on a transmisison. I did replace the vacuum diaphram on the outside of the transmission during my fluid change (I did replace the pin).

I would like any suggestions for a path to follow toward a fix.

[fixxxer]

Hi and welcome.
There are a few tranny guru's on this site, at least one may see this post, but it really should be posted in the correct forum.

[fixxxer]

My bad, it IS posted in the right forum
(note to self, need more coffee)

[fixxxer]

o Slow initial engagement.

Possible Source(s):
§ Improper fluid level.

Action(s) to Take:
§ Perform «Fluid Level Check» .

Possible Source(s):
§ Damaged or improperly adjusted manual linkage.

Action(s) to Take:
§ Service or adjust manual linkage.

Possible Source(s):
§ Contaminated fluid.

Action(s) to Take:
§ Perform «Fluid Condition Check» .

Possible Source(s):
§ Improper clutch and band application, or low main control pressure.

Action(s) to Take:
§ Perform «Control Pressure Test» .

o No/delayed forward engagement (reverse OK).

Possible Source(s):
§ Improper fluid level.

Action(s) to Take:
§ Perform «Fluid Level Check» .

Possible Source(s):
§ Manual shift cable misadjusted/damaged.

Action(s) to Take:
§ Check and adjust or service as required.

Possible Source(s):
§ Low main control pressure (leakage). Forward clutch center support seal rings leaking.

Action(s) to Take:
§ «Control Pressure Test» , note results.

Possible Source(s):
§ Forward clutch assembly burnt/damaged/leaking. Check ball in cylinder/leaking piston seal rings.

Action(s) to Take:
§ Perform «Air Pressure Test» .

Possible Source(s):
§ Valve body bolts -- loose/too tight.

Action(s) to Take:
§ Tighten to specification.

Possible Source(s):
§ Valve body dirty/sticking valves.

Action(s) to Take:
§ Determine source of contamination. Service as required.

Possible Source(s):
§ Transmission filter plugged.

Action(s) to Take:
§ Replace filter.

Possible Source(s):
§ Pump damaged, leaking.

Action(s) to Take:
§ Visually inspect pump gear. Replace pump if necessary.

[BrooklynBay]

Welcome to this forum! You could start with a pressure check. Connect a 0-300 PSI gauge onto the rear test port, and see what kind of pressure you get in all gear ranges. It's possible that the valve body might be clogged or you have blown valve body gaskets. # 10 in my list of useful threads has information on performing a pressure check. Did you replace the filter on the last fluid change?

[Zed]

I have seen this suggestion on other threads and will attempt the procedure. I did replace the filter with the fluid. It was curious that immmediatlly after the fluid change the time seemed to increase from about 1 min to 4 min. I have made sure that all fluid levels are correct.

[BrooklynBay]

Did you put 2 new O rings on the filter when you replaced it?

[Zed]

Thanks for the reply. I was careful to make sure that the o-rings were in place. Because time is a factor, I went back to the person that rebuilt the tranny for me in 2000. He said that there was probably something wrong with the forward shifting bands and he would have to pull the transmission and probably do a complete rebuild. Being that I have no clue on how these things work, I can only assume that he is correct, but I don't understand why once the thing gets into forward gear ( it has been setting for a week and it took 30 mins for it to engage) the thing runs just fine. Seems to me in my total ignorance that if the bands were worn too much that once it got into forward gear it would not seem to work as well as the day it was rebuilt. I have a hard time swallowing around $1000 on a new rebuild with 200,000 on the thing, but before I wave the white flag I am thinking about attempting the rebuild myself or getting one from a junk yard and taking my chances. I can afford for the Explorer to be out of commission for awhile. How hard is this? I am not afraid to take the plunge as I have rebuilt a few engines, but never have done anyting more than a fluid/filter change on a transmission. Also how much can I expect to spend on parts if I do this myself? Thanks

[BrooklynBay]

There are 2 sticky threads in the transmission section called the A4LD rebuild diary, and the A4LD valve body rebuild diary. Start with the valve body before you rebuild everything.

[Zed]

I have ordered my pressure gage as I was unable to find anything locally. Too bad especially here in the "big city". In the meantime I have been reading the procedures for the tranny overhall and the vb overhall. These are just awesome. I feel after reading these that I can actually pull this off and don't feel intimidated.

Having said all of this, during this reading I came across the low/rear servo portion in the rebuild diary of Glacier991. It states that for slow shifts into reverse and first are usually traced to this. I only have a slow shift into forward, so can I assume that this isn't the problem and just go forward to a complete vb rebuild or should I just try and replace this gasket and hope to get lucky?

[BrooklynBay]

Replace those seals anyway. I would recommend the TransTec Viton D ring kit. It is only a couple of dollars from WWW.TransmissionPartsUSA.Com.

[Zed]

Okay, Here is my shopping list so far. Is there anything else you think I will need? I will purchase a new filter and pan gasket locally. I added the boost valve and manual sleeve as a result of the reading of the rebuild threads.

23933 A4LD Shift kit®, Transgo shift kit 1985-on $20.71
23128 C3 A4LD 4R44E 5R55E transmission reverse servo cover gasket
$0.79
23256K A4LD 4R44E 4R55E 5R55E reverse servo piston D-ring kit
$2.29
23135K A4LD transmission valve body gasket set 1986-94
$3.41
56947-02K A4LD transmission large boost valve kit
$24.39
56947-01 A4LD Manual valve index sleeve.
$17.69

[BrooklynBay]

Get the Sonnax end plugs with the O rings.

[Zed]

Okay, I received my parts and have hooked up the pressure gauge. At startup the gauge spikes to 160 psi and then back to 65 psi. Where it stays in park. Reverse 90 psi. Neutral and all forward gears all have the same pressure as park around 65 psi. I do notice that there is a slight increase in rpm when I shift from neutral to OD.

If I give the gas a quick jolt the engine in any gear or park/neutral the gauge peaks around 250. The fast idle pressure in reverse is 150 psi at 1500 rpm and 120 at 1200 rpm. In neutral/park or forward gear there is no change in pressure unless I really goose the gas. I didn't wait for the 40 minutes it takes for the forward gears to enagage to test the pressure when I know the transmission is engaged in forward. I didn't attempt a WOT test.

I hopes this info will help with troubleshooting the problem. I think I will go forward with the valve body rebuild this weekend.

[BrooklynBay]

There is low pressure until a certain point, then it doesn't maintain the correct amount of pressure. I think the new boost valve, end plugs, and gaskets might help.

[Zed]

Okay I decided to start early. I have a couple questions. First, I don't see the small filter that is supposed to be in the seperator plate on my vb. Does anybody know if I could have lost it when I removed the vb from the explorer or if it is held in place by the seperator plate screws. Where can I get another one of these, and what is the part number? Second there appears to be a spring on the upper portion of the transmission that the vb bolts to. It is located near where the solenoids are. I have a picture, but don't know how to make that appear here. I assume it belongs there and should stay.

[BrooklynBay]

WWW.TransmissionPartsUSA.Com has those small sock style TCC snap in filters. Here's a link: http://www.transmissionpartsusa.com/...-00023330a.htm

[Zed]

I made a tour of some local tranny shops looking for a check ball to install with my shift kit. I had a lengthy discussion with the rebuilder at one and he was convinced my problem was hard seals and that I was wasting my time. A little discouraging, but maybe true. He basically said that I needed to increase my pressure to overcome this. I have no idea, but it got me thinking, what is the purpose of drilling the hole in the vb as part of the rebuild? It is near the boost valve assembly. Will this increase pressure? In all of the reading I have done, nobody has explained why to drill the hole, just to drill it.

[Zed]

Update. I rebuilt the valve body and installed everything. Same problem seems to exist, but now when I wait the transmission won't shift past 1st gear. I do notice an increase in pressure and there seems to be a firmer shift into reverse. Any suggestions? I must have done something incorrectly during the rebuild process.

[BrooklynBay]

Did you use a 1/4" drive In/Lb torque wrench on the valve body bolts?