Hello everybody I have a 1994 Ford ranger 4.06 cylinder. I am having transmission problems that start it off with delayed shifting from 1st to 2nd and third. I found the vacuum diaphragm was bad, it had fluid in the vacuum line when I disconnected it. I changed it and dropped off he pan and replaced the filter. Now the truck will not shift from 1st to second unless I manually go from drive to 2nd. It will not shift any higher than second no matter what I do. I would appreciate any feed back I could get.

 

Welcome to FTE.

Lots of unknowns on your one year old inherited father in laws 94 4.0L 4X4 250K mile Ranger. Post up any scheduled maintenance or repair history, as it might help the forum being able to get our minds wrapped around your current woes.

Good trouble shooting finding tranny fluid in the modulator vacuum line, indicating a failed modulator diaphragm, its a common problem part on vintage Rangers. Also good idea to have dropped the pan, change the filter & to inspect it & the pan for deposit load & type.

In the year you've had it, how low did the tranny fluid get & what kind of shape was the fluid & old tranny filter in & what did you find in the old tranny filter & pan in the way of deposits or debris when cleaning the pan & magnet? Did you find any varnish on the valve body when changing the filter?

Did you also replace the modulator vacuum line???

Did you opt for OEM Motorcraft / Filtran replacement tranny filter & Motorcraft modulator, or the lowest price aftermarket parts???

Have you checked to make sure the new modulator & vacuum line are holding a vacuum??? Murphy's Law might be messing with you. I've seen bad new parts right out of the box!!!!.

EDIT: Have you checked for proper fluid level after a full fluid warm up, say a 10 mile out & back drive, vehicle on level ground, at warm idle in N or P after having been shifted into All gears including R ???
Have you checked the tranny shift cable & linkage for proper adjustment or wear & to make sure all fasteners are tight ???

Seeing as how you were having some delayed shifting before the pan drop & filter change, the valve body may have line pressure problems, so have you performed a line pressure check??? Or maybe deposits have been loosened by the new tranny fluid detergents, or any additives you may have added & are mucking things up in the valve body???.

If you've scanned for trouble code clues, post All code Numbers, as they can often help focus a trouble shoot.

A bunch of beginning thoughts that have come to mind for consideration, let us know what you find.

 

Thank you for responding I really appreciate the help.
i will start from the beginning, I found maintenance records that my father in law had kept on the truck. I found none on any transmission work or maintenance. Since i’ve Had the truck i’ve Never had to add more than a quart at a time.
the first issue I had was the speedometer bouncing and going to zero intermittently, I changed the VSS with no change. Speedometer actually got worse, would only work until it shifted out of first would then go to zero. I ordered a cable but have not installed it yet. I then changed the vacuum modulator. The truck now does what my original post says which is from stop it will not shift out of 1st but if I manually shift to second it goes to 2nd. If I shift to drive after that it stays in 2nd or goes out of gear like it’s in neutral.
when I changed the vac mod I also changed the filter and cleaned the pan. There was a substance in the pan around the magnet that I would describe as liquid metal gray silver color.
I did not change the vacuum line or check the linkage yet. I drove the vehicle for approximately 30 minutes but due to the nonshifting I doubt I went 10 miles but the fluid did check ok.
Now I am going to start on the list you gave me of the things I can do. I bought a obd1 and vacuum test kit and I will check each item and get back to you with the results.
thanks again for all your help.

 

Ok, it took me awhile but I finally finished the list that Pawpaw sent me. I re replaced the modulator valve and checked the engine vacuum at the valve it was good. I put in another new VSS and speedometer cable. I removed the pan again and made sure that I didn’t screw anything up with the filter or wires on the solenoids. I performed the linkage adjustments on the shift linkage and the kick down cable. I scanned the for codes and found only cm codes for the o2 sensors. KOEO PASSED KOERNER PASSED.
after doing all this the results are that when I start out in OD the truck does not shift from first to second until 5000 to 5500 rpm. It will then shift from second to third at around 4500 to 5000 rpm. It appears to be downshifting because when I come to a stop it starts out in first again. I put a pint of sea foam in when I filled it up after dropping the pan again.
if anyone has anymore advice or things for me to check I would appreciate it. I’m at the point of just replacing the transmission or having a shop check it out. Thanks for all your help.

 

Ok good feedback on the trouble shoot doings thus far. SO, lets think about this some more. Seeing as how you've not found any tranny trouble codes & it's now up-shifting But at such a high rpm value, post up your tranny line pressure Number.

Which SeaFoam product did you add to the tranny fluid, "Trans-Tune", or the engine additive??? Seeing as how you added the entire can to a tranny with 150K miles on it & no evidence of ever having a prior fluid or filter change, lets hope the additive, along with the new fluids new detergent ad pack doesn't cut loose too many deposits too quick & muck up something important in the tranny valve body!!!

Again, when you First changed the tranny filter, how did the old filter Media deposit loading look & did you notice any varnish, gum, or sludge deposits around, in, or on the valve body where the filter connects then, or around, or on shift solenoids on the second pan drop & internal wiring inspection. Also how the new tranny fluid color & pan & magnet deposits look on the Second pan drop???? From your description of the pan & magnet metallic "paste" deposits on the 1st pan drop, they sounded normal.

You say it upshifts at high rpm in "OD", so how does it up shift just in "D", or when you upshift to "2nd" manually? Do the shifts feel normal when done manually??? How do the high rpm upshifts feel??? Is it just the 1st -2nd shift that's hanging up, or all of the up-shifting delayed????

EDIT: Forgot to ask, have you used a vacuum pump tester, connected to the tranny modulator under hood, engine end of the modulator vacuum line, to see if the line run to & the modulator are Holding applied vacuum???? Just because the modulator is new doesn't automatically make it good, I've seen bad new parts right out of the box, so "Murphy's Law" may be messing with you. Were the parts & fluid Motorcraft, or after market???? Seeing as how Mercon is no longer licensed or sold, which fluid did you install, hopefully not one of the low viscosity recipes.

EDIT #2: Was the modulator cat converter heat shield still in place & Did you reinstall the heat shield, so the new modulator & vacuum line aren't being cooked by the cat converter heat???

 

Good morning,
yes the heat shield was in place and I did put it back. The old filter had a lot of deposits on it. I did see some varnish and sludge on the valve body but did appear to be a lot. No build up around where the filter connects. The fluid did not look bad and on the second drop there was not any sludge or foreign matter in the fluid or pan.
it doesn’t matter whether it’s in OD or D it does the same thing. When it shifts from first to second it feels a little harder than it should be. The shift from second to third seems to be a little closer to normal. All the up shifting is delayed.
I have not checked vacuum under the hood but will do that today. I bought a vacuum tester kit.
I have not done a line pressure test as of yet, I’m having trouble finding directions on how to do this. I used parts from a local parts house here instead of autozone or oriellys. The parts were not motorcraft. I used castorl mercon v fluid.
Do you think it would be beneficial to flush all the fluid and can I do it myself or should I take it to a shop. Thanks again for taking your time to help me with this.
mis spoke above I meant to say it did not appear to be a lot.

 

Ok more good feedback. On the vacuum holding ability of the modulator & its vacuum line, do it with a hand pumped mighty vac, or the like vacuum pump, or if you don't have one, rig a test apparatus by inserting the disconnected under hood modulator vacuum line to a "T" connector, then attach your vacuum gauge to monitor a vacuum & a syringe to Create a Test vacuum reading on the gauge. Then watch to see if the modulator & its vacuum tubing & its connections will Hold a vacuum. If they wont, find which one is leaking & replace that part & see how the shifting goes. The vacuum tubing needs to be in good shape along it long run, & fit Tight on Both ends. No dry rot splits, cracks, nor soft mushy, or hard loose baked out fit on its vacuum nipples.

If all that is ok but still no shift improvement, check the tranny fluid line pressure & if it's low, maybe with the miles on it suspect a weak/ worn tranny pump.

If all that checks out & the tranny fluid had 150K on it without fluid changes every 30K miles, the valve body very well could have sludge, gum, or varnish mucking things up a little inside. SO, if you come to believe that might be the case, If you just performed a pan drop, filter change & pan refill, you only removed about 40-50% of the old fluid, as most old fluid remained in the torque converter, valve body, lines & radiator heat exchanger.

If that's so, lets think about this some more, the Castrol Mercon V fluid should be fine, as Ford changed the recipe so it was back compatible with older Mercon specified tranny's. So since you added a full can of ??? Seafoam product & have maybe 30'50% new fluid in there, try shifting through all the gears multiple times while running the engine or driving long enough to get the tranny fluid Fully warmed up & circulated & see if the new fluids detergents & Seafoam product can tidy up the valve body enough to improve shifting, if deposits are the problem.

Keep a close watch on the fluid condition & color. If shifting improves some then slows or stops, I'd probably drop the pan, refill it, disconnect the tranny fluid return line close to the radiator & perform a Full fluid pump-out, to get as much new fluid into the system as possible & drive it some to get things warmed up fully, to see if that helps the new fluid detergents finish, or at least clean up deposits some more.

I've used 1/2 a can of SeaFoam Trans Tune to tidy up hanging up shifts in my 94 Taurus AXODE tranny about 15 years ago & remember one FTE member adding a Whole can of Seafoam Trans Tune all at once, & got positive results on his hanging up shifts, although it was suggested he not add more than Half a can at a time, to see if he would get positive results.
Our tranny deposits come about slowly over time, so we should try to clean them up the same way, not with a shock treatment on a unknown deposit condition, that could loosen up large pieces that could clog up something important. We want the deposits to be dissolved Slowly over time, like they were formed, so they don't cause any more mischief on their way to the oil sump, or tranny filter.

Detergents aren't going to solve electrical, worn, or a broken parts problem, but may be able to tidy up a deposit problem caused by lack of proper maintenance, or lubricant failure deposits from severe service operation, like mine were on the Taurus.

Again, which Seafoam product did you use in the tranny fluid???

 

I used the trans-lube seaFoam. Do you know where I can directions to do a lube pressure test?

 

Ok good feedback on using the SeaFoam Trans Tune product in your tranny fluid. I only added 1/2 can to the 94 Taurus AXODE tranny & it took 3-4 days for it to stop acting out, Then without delay I performed a pan drop, filter change & Full fluid 13qt pump-out, to remove all of the old tranny fluid & SeaFoam Trans Tune, Here is a link to how I did the same full fluid pump-out procedure on my 99 Ranger 5R55E tranny https://www.ford-trucks.com/forums/6...-pump-out.html, if you come to wanting to do that on your 94.

Would be helpful to know which tranny it now has, (it's usually embossed into the bottom of the tranny pan, in case it's been changed out in the past), so maybe some member that has the same tranny & line pressure specifications for it & knows where the line pressure access port is located on that model tranny case, will answer up & enlighten us.

 

Thank you, the transmission is an A4LD. I found a manual for it that shows the port what I’m confused about is what the figures should be when I check it. The manual shows where and how to hook up for the test but then references a special bulletin for what the pressures should be in the different gears. Those are not in the manual I found online.
i will do all the checks tomorrow and let you know what I find.

 

Good afternoon,
well my journey continues, I was finally able to do all the vacuum and line pressure tests.
the vacuum test were all good. The line pressure test was not.
The idle test showed that pressure was high in all shift categories
OD-140 should be 57-78
D- 140 should be 57-78
2- 95 Should be 57-78
1- 140 should be 57-78
n/p- 180 should be 57-78
R- 150 should be 67-105

Wide open throttle test showed,
OD- 210 should be 205-235
D- 210 should be 205-235
2- 180 should be 205-235
1- 210 should be 205-235
R- 200 should be 282-316

specs show that if all pressures are high at idle the the problem my be modulator, vacuum line, modulator rod sticking or sticking regulator boost valves.
the WOT test only shows results for low pressure results. 2 and reverse were low on the test. Specs show that low pressure may be caused by forward clutch/overdrive clutch and intermediate servo.
Reverse shows that the low pressure could be caused by reverse-high clutch/overdrive clutch and low and reverse servo.
So with all that I’m thinking that the calve body and components are most likely the problem. I flushed the system but symptoms the same.
i can buy a completely remanufactured valve body from Sonnax for around 400.00 it comes with all new solenoids and valves. Remanufactered transmission runs 1500-2000.

Ok now if you have anymore thoughts I would greatly appreciate them. Again I want to thank you for all your help. I have to say I’ve learned a lot.

 

Dang my reply yesterday didn't take, so I'll try again. Since you haven't found receipts that it had ever had a tranny fluid & filter change in 250K miles & the old tranny filter had loaded with gunk, its a good chance the valve body is mucked up inside & the new fluid & SeaFoam Trans Tune haven't been able in this short time, to tidy up things enough to begin making the problem better, or to clear the problem.

Since your considering replacing the valve body, maybe drop the old one & open it up to inspect & if not too bad, try spray cleaning it in side with a plastic safe spray cleaner & see how it goes, if your just going to get it running good enough to sell..

If you intend to keep it, with 250K of unknown service history on this tranny, I'd probably consider a replacement / reman, as the clutch packs & pump are likely at the end of their life on a 250K mile tranny, so its likely to need more repairs sooner than later, which can become a drain on your gold & nerve reserves!!!! Let us know what you do & how it goes

 

There is a small pin that sits in the modulator, if this pin does not get installed with the new modulator it wont shift right if at all.

If I missed this info above sorry, just trying to help.

 

^+1, Good & Important Detailed point that wasn't discussed, just inferred & since Murphy's Law is still in effect, we shouldn't take anything for granted, so thanks for the heads up & Detailed illustration jk080.