Bought this clean 2.9 Bronco II 6 months ago with 140,000 miles and was told tranny rebuilt 20,000 miles ago. It drove perfectly for about a week and then one morning upon slowing for a stoplight it felt like it stayed in D and not downshifting so tranny/drivetrain clunked. The next stop I shifted to N upon slowing,stopped and shifted to D. No clunking and everything was fine. I did this regularly for a month and then one day it cleared up and started downshifting correctly upon slowing. All upshifts including OD were perfect but last month upshifts started acting up. Take off in D and wouldn't shift until RPM's were 3500-4000 and this slowly started to get worse.

no shifting until tranny warm
will only shift if I manually start in 1 and shift thru gears
want ingage in D or R unless you throttle engine up
will manually go thru gears 1-D if you give engine hell
tranny will not shift on its own now

I have changed filter/fluid (red and no trash in pan), replaced vac modulator (not leaking) and hose up to tee, replaced VSS at tailshaft.

Advise on some tests I can try or possible fixes; I don't feel like tranny has gone south - something is making shifts erractic.

 

It sounds like the governor is sticking.

You have a two options, one is remover the governor and clean it or better yet replace it with a new one.

One trick that I have done that sounds a little crazy is to drive the vehicle between 20-30 mph and put the shifter into park for about a second a few times. Its going too fast to catch and the vibration from the parking paw skipping across the top of the park gear can rattle the valve in the governor free.

The governor is bolted to the park gear so you will have to remove the drive shaft and transfer case to reach it.

I also have used a product called Lubeguard to help keep valves from sticking.

International Lubricants, Inc. > Transmission Products

Hope this helps

 

As the shifts are vacuum controlled on this transmission, I might check for a leaking/broken/plugged vacuum hose between the engine and transmission.

 

I replaced the hose from the modulator to the vacuum port at rear of engine when I installed the new modulator; would adjusting on the modulator give me any different results than what I already have?

Tackling the governor issue did come to mind - would the governor play a role in how the tranny is acting; from not downshifting correctly when slowing then that problem goes away but then not upshifting at all unless I manually force it to (heavy foot & high rpms).

Correct me if I'm wrong but no trash or fine particles in the pan when I changed the fluid/filter and that I can get the tranny to manually shift leads me to believe that this A4LD isn't dead.

Other possibilities that I thought of exploring are:
-throttle position sensor
-valve body malfunction (dirty/sticking valves)
-map sensor
-electronic shift solenoid
-kickdown linkage malfunction

 

TPS, MAP, or shift solenoid would not be the problem. Your A4LD's only electronic control is for the torque converter lockup clutch, which has nothing to do with 1-2, 2-3, and 3-4 shifts. Of the additional possibilities you've listed, a malfunction in the valve body is certainly a possibility, and maybe the kickdown cable is doing something to screw up the shifts.

 

I have a ATSG technical service manual for the A4LD that is world of knowledge so I do have several possibilities that could cause my problems. Reading through the manual I do recall some work I performed when I aquired the Bronco II. The speedo cable was noisy and making the needle jump up and down while driving and I want to say this was going on at the same time I was having my downshift problem and the tranny was shuddering/chattering when I slowed. I replaced the cable with a NOS Ford original cable and a new vehicle speed sensor at the tailshaft ( the plug up was cracked on the old one) and my downshift problem was corrected. From that point the tranny performed perfectly for awhile (months) until the upshifting problem began. It began slowly; letting the Bronco II warm up in the morning before leaving for work,pulling out of the driveway in D and the rpm's would hold to 3500-4000 and when I would pat on the pedal a few times tranny would shift from 1 to 2 and shift correctly from then on to work. I would have the same issue leaving work in the afternoon heading home. This situation grew worse each day to very erractic shifts but sometimes perfect shifts.



1969 prostreet F100 (393 stroker)
1995 7.3 Powerstroke
2007 Explorer Eddie Bauer
1976 F250 Camper Special
1974 F150 long bed
1989 Mustang hatchback (work in progress-prostreet)
1986 Bronco II
1973 F100 (fixing to purchase/one owner garage find/mint)

NO CHEVYS IN MY STABLE - FORDS RULE

 

Need some help guys; Bronco has been sitting for about 3 weeks since my last post. I changed filter/fluid at that time and problem was still present but today I fired it up and after letting it warm for 5 minutes it shifted perfectly in D and R engaging quickly. I drove around the block and did the D to P to D test 3 times at 15-20 mph as one post suggested and then drove 30 minutes at city and highway speeds. Everything felt good upshifting and downshifting to a stop. As I almost got home I pulled off from a stoplight and rpm's and acceleration was sluggish (slow to fully engage) but I shifted to 2 and it pick up and I shifted to D and it felt OK. Now shifting into D and R sitting in the driveway doesnt engage quickly and I have to throttle it alittle for it to grab but on the road it upshifts and downshifts correctly. Any suggestions were I go next to correct this A4LD?