A4ld symptoms after re-build

[Rfoley22]

I recently re-built my '92 explorer's A4ld Transmission, all went well, replaced all soft parts, and some hard ones. endplay is in specs. replaced the torque converter as well.

Post re-build it shifts perfectly. strong shifts that are firm but not harsh. no jolts and whatnot. Also no slipping!

Problem is that it now shifts at the wrong speeds. 1-2 is over 35mph and only then with foot off gas. (this was a problem before but not as much)

very difficult to go over 55 in overdrive. (lack of overdrive?)3000-4000rpm
very difficult to go over 45 in drive. (lack of 3?)3000-4000rpm

2-3 shift is on time, usually.

problems found during overhaul were stuck valves, broken valve spring, and lots of sludge. friction material was also very worn.

I did not replace the servos, Solenoids, or the modulator.

could this be the modulator, servos, or solenoids? if not then what are other ideas?
could it be a bad torque converter?

gears inside are good, friction material is good, fluid is less than 2 days old 100% replaced. what are likely problems?

 

[4x4xbrian.com]

Always replace the torque converter! It holds soooo much junk. That crud has gotten back into you valves......

 

[Rfoley22]

Always replace the torque converter! It holds soooo much junk. That crud has gotten back into you valves......

replaced the torque converter as well.

I replaced all clutch packs, bands, and the torque converter (and all of it's junk. there is no crud in the system)... the major parts not replaced were shift solenoids and vacuum modulator.

all valves moved freely upon valve body re-build. All hard parts were fine, or replaced. pump was aligned with tool. endplay was checked and adjusted with selective thrust washers.

more details on shifts...

at 2500 rpm

overdrive
1-2, 29mph.
2-3, 38mph.
3-4 (overdrive) 63mph.

Drive
1-2, 29mph.
2-3? 55mph.

at less than 2500 rpm I cannot get past the 1-2 shift.

Failure was due to friction material wear, and sludge causing clogged valves and slipping. Failure was not due to hard part wear or failure.


shifts are way too high, any ideas or recommendations? thanks!

 

[Rfoley22]

3 months ago the tranny worked fine, shifted at correct times,
as of two weeks ago it was slipping and the shifts were harsh and not firm, but on time for the most part.

now shifts are good, tranny is clean, but shifts are at wrong times, high rpms before shifting.

 

[4x4xbrian.com]

I missed your mention of the T.C. earlier, sorry.

Was the govenor loaded up when you rebuilt?
if the shift quality is ok but timing is delayed, I would try swapping out or replacing the governor, it can be done through the extension housing.

 

[wood1]

What kind of shape was your governor in? Did you inspect it when you had the trans apart? You didn't replace the modulator either, I would check it. Did you have it off and if so was it put back with that little rod?

I rebuilt my VB and the governor immediately started acting up. I would have issues while the trans was cold, then later on I would have to manually shift into 2nd, 3rd. My issues were solved with the new governor.

Is your TCC working? Lightly touch the brake pedal with your left foot while driving at highway speed (keep your right on the gas, maintaining speed) If it is working the rpm will flare slightly as the TCC unlocks.

EDIT:
I should mention that I tried to remove and polish the old governor stalk but ended up replacing it and the weight afterwards. For a couple dollars, replace the stalk and weight and you will only have to remove that transfer case once, not twice like I did...

 

[Willard]

Yea replace/clean that governor and see what happens. That sounds like a good bet.

 

[Rfoley22]

re-inspection of modulator= the body of it is slightly bent.

governor looked fine, and was cleaned/polished so that it moved freely with it's own weight, but will check that too.
it is my daily driver, so I need it, and will have to bear through bad mileage that comes with bad shifts... Hopefully at the beginning of next week I will have time to tear it apart again.

Will order new modulator and also governor and post results. they should get here Monday.

thanks for the replies and ideas.

 

[Rfoley22]

this is not mine, from re-build diary.

mine has a bent/ not symmetrical bulge along the ridge at #1.
slightly bent at #2, not straight.
Bulge/dip/bent slightly along line at #3.

are all modulators straight/smooth/symmetrical at these places? would these cause problems with modulator function?
as far as I know this damage was done pre-rebuild, when the shift timing was still ok.
thanks

 

[BrooklynBay]

A bent modulator would bind. Replace the 2 servos when you replace the modulator. Did you flush the front cooler, and the lines before you reinstalled the transmission? Adjust the bands, and the kickdown cable.

 

[wood1]

re-inspection of modulator= the body of it is slightly bent.

governor looked fine, and was cleaned/polished so that it moved freely with it's own weight, but will check that too.
it is my daily driver, so I need it, and will have to bear through bad mileage that comes with bad shifts... Hopefully at the beginning of next week I will have time to tear it apart again.

Will order new modulator and also governor and post results. they should get here Monday.

thanks for the replies and ideas.

Yeah, I replaced the weight and polished the stalk of the governor when I first did the VB, figured it had to work right. A few weeks later after replacing the stalk, all was well...

FYI.
Wood.

 

[ryoungo2]

Exact symptom of bad modulator

 

[Rfoley22]

sorry for the late reply.

switched jobs, and moved in the meantime but thought I would post the solution in hopes that it can help someone else.

it was the modulator. but it was also the modulator rod (dowel/pin). the old pin was slightly different length and shape than a new one from ford. Both are genuine ford parts. ???

The modulator I bought at auto zone for $9.85 with a discount coupon, they are usually $12 or something there. it is not adjustable but was cheap and works.

The new modulator worked worse than the old one.

When I asked a guy at napa that had done several A4LD transmissions he said to get a new rod for between the VM and the valve.

New VM and new rod work great. Transmission re-build was a success.


thanks everyone for the replies!

The hardest part of re-build was getting parts and getting the thing out of the car. That took 2 weeks, the re-build itself took about 10 hours mainly because I had never done it before.
I found a 1$ ford part: vacuum modulator rod kit!

 

[BrooklynBay]

Thanks for the update! What's the Ford part number of that rod kit?

 

[Rfoley22]

The Ford part number is F E5TZ-7A380-B
It is a 1 3/8" pin or rod. (one and three eighths inch)

It was also recommended by a local shop that you could make one with a coat hanger or nail, just make sure to smooth the edges very well. the diameter does not have to be exact just the length.


when calling ford store one did not have it, but said that another did. Store two said that they did not have it and it was discontinued in 1993.
store one again confirmed that store two had it. Store two continued to deny having it.

Store one called store two. Store two found a part but, "I don't see it registered to your vehicle. It doesn't show that it goes to your vehicle."

what vehicle does it go to then?
"we don't show it registered to your vehicle. my system does not show me anything, but it must go to some type of vehicle. It is not for your vehicle and I don't think that it will work, but we have two in stock."

Lesson, call around, find a good store.