My first transmission rebuild :)

[crom9111]

Hi all, after all the other problems I have had with my possessed 95 windstar the tranny decided to go all psycho on me..Finally got the cooling system bled and it started slipping really bad.I unhooked the "neutral safety switch and it shifted fine so replaced that. Took it for a 20 mile test drive with no issues, parked it for the night. Next morning went to get parts for a Jeep I am working on and made it a mile before it started shuttering really really bad and would not go above 10mph. Tried to back home and had no reverse. The only gear it will drive in is neutral and park lol.. So I think it is time to learn how to rebuild one of these beasts. We have bought a new to us van and do not "need" the windstar anymore but I would love to have it for dump runs or lumber runs. So I will keep you updated on my progress ( if there is any )

[Plata]

Dear Frien i know your enthusiasm, i have the same when my van started to fail, and well i do it, i bring the transmission of the van, i opened it, i rebulid it (i use the rebuild manuals from the ATSG) and well the tranny was just rebuild,i have just spent on it 600 USD and i have changed planetary gearset, all metal and friction discs, both bands, and well the transtec kit. also replace the washers and nedle bearings

You will supose that i own a windstar with a well rebuild tranny, well, let me disappoint you, my fisrt rebuild was a complete dissaster, the transmission started working properly, i was so happy, but after 5 minutes of driving CLAMP i hear that sound from the engine bay, and when i floored de accelerator pedal, bad news, i have no first gear, when i tryied to go reverse, more bad news i have no reverse gear.

All the other was right so i use the van for a while until i have enouhgt time for rebuild it right again, well, one day it becomes overheat and stopped working all the gears, i have to bring home but i has to wait for two hours until it cool down.

Second rebuild, i view some mistakes on the fisrt rebuild, the principal was that i havent checked clearance, and the drums were more "out" of the normal, that causes the 1st-reverse clutch (low clutch) stays locked and well it was completely destroyed.

This second time i checked all clearance and it was all well, checked free spin and it was well, and you have guessed, all was right until i drive it by a large period of time, this time all gears were aproached (well no, in city i only use first and second because of traffic), but when i was taking the highway SURPRISE, no third gear, RPM go very up and transmission goes to neutral, i left the accelerator and transmission goes into overdrive or 4TH properly, so, again, more failures, but this time i know that transmission from feet to toe, i know very well its functionality, and this time, the failure was "direct clutch" but when i rebuld i put the direct clutch into clearance, well, this time i was desesperated, totally i have spent in both rebuild and the oil 1200 USD almost 1300 if i consider the gas i used for loooking for the pieces in my other vehicle.

I tooked the van to an expert, frien of a friend of mine, and well i talked to him how i rebuld the tranny, first of all he tells me that rebuilding a tranny is not so easy (i already know that, i do it twice) and it invloves many problems that you learn from practice (obviusly the especialist wont tell you his experiences) but well, he tell me some experiences, and obviusly instead of tell me that i just need to replace the tranny again, he also explain me what was the failure, in my case, the second rebuild was OK, but just a little detail, for changing the pistons you need a special tool, almost similar like the tool you use for changing engine piston rings, if you dont use it, you surely damage the piston seals, well that happened to me, also that tool is expensive and not so easy to find, he tell me that the procedure i follow was OK, but he was sure that i have damaged the seal of the piston of 3 gear because of not using the tool.

My recomendation, and remember its just my recomendation, its to buy a rebuild tranny with warranty for at least one year, here were i live this coast aprox 900-1200 USD just the money i have spent.

And let me tell you something at this moment i am selling the van because i have no money for repair it, also i am selling it as "failing transmission" and discounting the 1200 USD that coast a new tranny from the normal price of the windstar.


That's my storie my friend, and believe i dont want that anyone live it again, it literally is money spent to the garbage.

If you want to know how is the transmission, go, open it, know the elements, its ok, it doesnt matter, because you could buy a new one, also if you need to give the old one tranny on "change" because you buy a rebuild one, well you could rebuild it without checking clearance and anything, because you will not use that transmission anymore, you just will give it to the repair shop.

Greetings from Mexico, sorry for the bad english.

[Ed_Strong]

Did you re-checked the TRS ("neutral safety switch") again? Maybe the switch got shifted/misalligned or knocked out of place!

[tomj76]

I have only rebuilt one transmission, a GM 4T60, which is a four speed, transverse mount. I needed to rebuild it because there were no forward gears, the result of a failed servo band (broken). I would encourage you to make sure to pay attention to all the details, particularly cleanlyness. When cleaning parts, do not use any paper towls since the fibers can interfere with the valve body operation. It helps tremendously to have good documentation (I had the factory service manual).

The biggest problem I had in doing mine was finding a rebuild kit that included all the parts as advertised.

It's best to consider this a long project, to avoid the time pressures that would lead to overlooked details. I think it took me about 3-4 weeks to rebuild and reassemble the 4T60, a lot of which was cleaning.

Keep us posted with your results. I'm considering rebuilding my Windstar transmsission, since it will not shift into 3rd or 4th gear.

[tomj76]

I removed the transmission and disassembled it. So far I found that the rear planetary gear has many broken & chipped teeth on the ring, planetary and sun gears. Also the steel backing plate on the forward clutch is broken. However, both one-way clutches (sprags) are OK. So, I don't know why 3rd/4th gears were missing. Next check is the Direct and Intermediate clutches, focusing on the Direct clutch since that applies when going from 2nd to 3rd.

[tomj76]

I've disassembled all the clutches, inspected everything that I can, but I don't see a clear and definitive reason it doesn't work.

I'm fairly sure at this point that the direct clutch does not engage. The shift from 2nd to 3rd requires that the direct clutch engage. The direct clutch locks the direct one-way clutch to the input shaft which prevents free counter rotation of the clutch drum. When the forward clutch (which engages a one-way clutch that operates in the opposite direction) and direct clutch are both engaged, the sun gear must turn in both directions with the input shaft. When the intermediate clutch is also engaged the sun gear and planet gears of the first planetary assembly are forced to turn together. The low-forward band must release to allow the differential to turn.

The gears work as follows:
First gear: low-foward band holds the 2nd planetary assembly, forward clutch connects input shaft to the sun gear of the 1st planetary. When the input shaft turns slower than the sun gear, the one-way clutch overruns (coasting).

Second gear: low-forward band continues to hold, forward clutch releases?, intermediate clutch engages to turn the planet gear of the first planetary. The sun gear will overrun the speed of the input shaft. (like coasting).

Third gear: low-forward band releases, forward clutch and intermediate clutch engage to turn both the sun and planet gear of the first planet at the same speed. No coasting is possible with both forward & int. clutches engaged.

Fourth gear: over drive band engages, forward clutch release, intermediate clutch remains engaged. The input sun gear is held stationary and the planet gears of the first planetary are driven.

I can confirm that everything but the direct clutch works:
-low-forward band engages, because first & second gear work.
-low-forward band releases, because reverse works.
-forward clutch engages, because first gear works.
-indirect clutch engages, because second gear works.

If the direct clutch doesn't engage, then forward one-way clutch will overrun. I don't see why it would behave like first gear.

I suspect that rings and/or seals are not tight and the failure is caused by the lack of adequate pressure, that there was contamination somewhere in the valve body that kept a valve from moving, or a check ball was leaking. There is a way to check the direct clutch pressure before removal of the unit, but my ignorance got the best of me.

My plan at this point it to replace all rubber gaskets plus anything that is broken or worn out (I'm going to check bushing clearances next). I'll rebuild the unit while checking very carefully for any contamination (metal, dirt, or otherwise) that could cause sticking valves or leaking seals.

[tomj76]

I went through the transmission very carefully. I never found anything that was a sure indication of the symptom that I saw. However, there were several things that required attention:
1) Forward clutch wave plate was broken (replaced)
2) Scoring of the valve body sleeve (pump shaft passes through this)
3) Several worn bushings
4) Broken teeth in the final drive planet assembly gears
5) Purchased an overhaul kit for all seals and gaskets
6) Replaced all bonded pistons with new. (potential cause)
7) Replaced all three shift control solenoids (potential cause)
8) Replaced the turbine speed sensor (original was cracked)
9) Found one of the clutch return springs was warped, so I straightened it.
10) Found a retaining ring was swapped between a clutch assembly and the final drive assemble in the housing by the prior rebuilder.
11) Wiring harness intermittently measured high resistance (replaced)
12) Worn turbine shaft (replaced)
13) Replaced the pump shaft as a precaution.

This transmission is very interesting, in that you need to know exactly which version you're working on, because Ford created many different variations over the years. One of the most noticeable ways this is seen is when choosing the correct valve body gaskets... some come bonded to the plate, some are paper only, they are different depending on if the transmission is from a Taurus, Windstar, and year. I even found one of the clutch pistons was like the AX4N rather than the illustrations shown in my manual for the AX4S.

I now have the transmission installed in the vehicle, and now I'm about to put the engine back in.

[12Ounce]

Good luck to you ... you are obviously not afraid of a bit of work. Good for you.

[tomj76]

Well, I was inspired by and considered the approach you used... installing a rebuilt transmission, and it especially seemed attractive since this one is not the original, OEM unit, but rather of unknown origin and pedigree. However, I tried to get "good as new" at 1/10th the cost by taking this rebuild on myself. Now, if you count the hours I've spent going over it, and paid me minimum wage for that time, I could have bought a factory rebuilt transmission at least one or two times over. Of course with a rebuilt unit I'd miss out on all this fun.

I'm cleaning the lifters and fuel injectors as I make the final preparations to drop in the block.

[12Ounce]

And you did it without lowering the sub-frame? That's a significant difference in approach ... it may be better than what I did.

[tomj76]

Yes, I did. The engine has to come out (and go back) in pieces to do that, but since I am overhauling the engine at the same time, it made sense for me.

I did it by removing the heads, water pump, oil pump & harmonic balancer (not to mention everything else that has to be removed to get to those major items). It might be possible to do it with the heads & lower intake still in place but I think the exhaust manifold might need to be removed first no matter what.

[tomj76]

I've now inserted the block with front cover, heads, and lower intake manifold.

If I were to do this again, I'd assemble all that on the engine stand, then put the engine in. I think that would have fit OK. I'd put the water pump, exhaust manifolds, & oil pump on after insertion.

I still have to put the rest of the engine together (injectors, fuel rail, upper intake, drive belt accesories, harmonic balancer, etc. That should go quickly. I'll need to also put the exhaust back on. I think it is not much more work, one, maybe two weekends.

[tomj76]

I've now inserted the block with front cover, heads, and lower intake manifold.

If I were to do this again, I'd assemble all that on the engine stand, then put the engine in. I think that would have fit OK. I'd put the water pump, exhaust manifolds, & oil pump on after insertion.

I still have to put the rest of the engine together (injectors, fuel rail, upper intake, drive belt accesories, harmonic balancer, etc. That should go quickly. I'll need to also put the exhaust back on. I think it is not much more work, one, maybe two weekends.

[tomj76]

OK, the whole thing is back together and I've taken it for a short drive.

THe engine and the transmission seem to work good. It will take some time to see if the oil consumption is resolved. The transmission shifted all the way to fourth gear & the torque converter clutch engaged.

I'm having a few little problems. (1) The exhaust won't seal at the flange between the y-pipe and flex pipe. (2) The transmission seal on the passenger side is leaking a fair amount. (3) The brake lines rotted out near the fuel tank.

So, I have a little more work to do before I can get it on the road for real, but the rebuild has so far proven to work out. I don't know what was the real problem with the transmission, but I took a repair shotgun to it and apparently found the problem. I'll give another update after I have some road time on the whole thing.

[12Ounce]

Good for you. Sometimes its best not to overanalyze ... looking for the root cause ... just repair/refresh everything you come across. Fix all you know to fix.