LOW/INTERM. Servo Explosion

[Plata]

Hi there, well, here I'm with new stories about the "mommy-van" alias my windstar

Well, in my ealier post, i told you about the failures and all the stuff with the transmission (i doesn´t rebuilt it in the correct way), well, after the second rebuild of the tranny (by myself) the tranny worked perfectly, perfect shifting, no delays, no heating, it was like a dream becoming true.


But, nothing its perfect, and then when i was trying to park the van inside the garage, something exploded and about a quart of oil were disposed into the ground. By the position of the oil leak, I supose it was the low/interm. servo, because also 2 of the 3 bolts were on the ground.


Now i think my van its crazy or she hates me hahaha. This time the rebuild were under specifications, all bolts were properly torqued, all pistons were properly inserted, well, this time it was well done the rebuild job, but i think that the servo cover was damaged, cracked or something or the bolts threads were damaged, really i dont have checked it because its raining outside, so i only pushed the van to park it in the correct way, and i collected the bolts.


Tomorrow i will update with more information, because i actually haven't see any failure like this, the servo cover explodes, that is a very rare failure LOL (i have to take the failure with humor otherwise i would be kicking the van )

Also i will upload photos, and well, use the DIY post for replacing the servo and the cover without droping all the transmision again

Greetings

[12Ounce]

I have heard of the pistons splitting ... or, you may have the arteries plugged up that are supposed to return the piston by-pass fluid back to the reservoir. For some reason, you are getting high pressure under the cover ... and that should not be.

[northern piper]

you also could have a broken c-clip which has jammed the piston in some way. Take a look at the servo posting I did a while back (mid Feb) The c-clip is a common failure I learned and there's an aftermarket rebuild kit. I too doubt that the servo cover would fail... the bigger thing is, if the bolts have been pushed out, you're likely faced with tapping the hole larger as I'd doubt the threads will hold. this job likely could be done with the trans in place but would be tight.

[Plata]

hi, thank you for answering, well, i haven't checked out the van today, becuase the exhaust of my other vehicle was broken and making awful noises, so i have to repair it until i can get the windstar again to the roads.

Well, i could see in older posts that this servo was a little problematic because it doesn't apply the correct pressure causing the low drum to slip, i think my case was different because in my case the low drum stays stopped, so i think that the servo was aplying pressure always, and well, the pressure that controls the servo, for disengage it could be acumulated and also the excesive pressure could cause the bolts threads to break out.

Well, i need to verify how is the servo, and in all case replace it, i see that sonnax make the C-Clip for replacing the OEM clip, but well i first nedd to verify how is the servo piston and cover

thank you

Greetings

[Plata]

hi friends, well, just for updating this posts, i see under the van, and i found that the servo cover was broken from one bolt retainer, so, the normal presure for applying first gear in the servo, finally break the other two bolts threads.


I havent take photos of the procedure, but have photos of the brroken pieces, i will upload it later.


So finally, the total cost of the reparation was 50 USD aprox. the cover cost $30, and i wanted to buy a new jubilee clip for the piston (because it was broken) but they give me a used piston with all clips and all necesary just for mounting it for $20 so i preferred that way because my piston was slightly damaged because of the pieces of the broken jubilee clip.



oh, i was forgeting it, the bolts threads, well, it was easy, the old thread was unusable, so, i bought some "thread adapters" in the exterior it have a 8mm male thread, in the interior it have a 6mm female thread. i don't know the name of that things, but i will upload a photo of the pieces, also i've to use a 8mm thread maker, by the position it was slighly difficult, but not so much.



CONCLUSION the cover was previosly damaged because of a rock, or i dont know what, but i see that it has previous damage on it, so it only takes to the tranny a little pressure to broke it, but well, know i'm so happy with my windstar again in the roads, and with rebuild tranny LOL. I expect to have the minivan for much years.


Greetings

[MarPac]

This is a nice story :-) Lucky you are that you might drive your van outside the "winter areas" so enjoy the Win for a long time. Mine starts to be a little bit rusty by using a lot of salt on our ways during winter time :-(

I'm going to rebuilt my 2000 Windstar's AX4S trans due to Overdrive band slippage. I took the OD servo out of the trans and welded the piston to enlarge it by 5mm. It works now, but better to place overhaul kit on it. Did you make some special operations when rebuilding? Using some bore kits, Accumulator overhaul kits etc?

Thanks for your hints, my brother just finished his Volvo's S80 Aisin Werner AW5550 tranny and there was quite a lot of stuff to proceed using CNC machine.

[12Ounce]

Wow, MarPac ... you folks are serious with your repair efforts! You increased the diameter of the piston to increase the force? I salute your skills.

If you have road-salt, watch that rear axle and front sub frame for dangerous rusting/breakage.

Hope you and your family are keeping dry! Good luck!

[Plata]

Yeah, fortunetly it actually works fine, that AX4S really gave me some headaches LOL.

Well, when i rebult i used the "Transtec" AX4s seals kit, that kit includes all the necessary O-Rings, pan gaskets, servo gaskets and orings, new orings for the pistons (i only use the oring of the reverse piston because my pistons were not the oring interchangeable type), also it has the valve body gaskets, and all new stuff like the plastic balls, the nylon filters that goes inside valve body.

Other things that i replaced were the pistons, the transtec kit comes with the "LIP WIZARD" its a thin plastic disc that you can use for putting on the pistons in their place, its very useful for not damaging the seals of the pistons. Search youtube for a demo-video.


Also if you going to open it, i recommend to change ALL the nedle bearings, the kit coast me aprox 60 USD and change all the plastic washers, all the washers coast me aprox 50 USD.

Well, the necessary thing its the OD Band, i get both (FORD OEM) for 100 USD aprox, in my local transmission suplier.

I also recommend to change all discs, at least the friction ones, because they comes in "packages" inside the drums and it goes "metal disc-Friction disc-metal disc-friction disc" the metal disc in my case were damaged because the tranny fails in higway and i continue driving it to home, but normally it doesn't have damage, just the friction ones should have a little damage.

Each kit (because is one kit of metal disc and one of friction disks) coast aprox 70 USD.


And well you should replace all that you see damaged, in my case, the planetary gearset were damaged because of a broken retainer of the low servo, so i had to change the planetary gearset that coats almost 100 USD or more.

Last thing i could say if that if you could get a remanufacutred valve body, you should change it, it will save you from much problems, in my case, i replace it because the sonnax individual valves (Boost vale for example) coast aprox 70 USD, and all the valve body with new actuators seals and everything, just coast me 120 USD, so by that price i preferred the entire valve body.



PS: If you want some manuals, i have bought the "ATSG Rebuild manual for the AXOD & AXOD-e" basically its the same that the AX4S but with the "Servo kind" speed sensor, and the ax4s has a "hall effect" output sensor, but that is'nt the speed sensor the ECU or PCM takes the speed from the ABS sensors (trust me i unplugged the output sensor and the tranny works just a little hard but indicates properly the speedometer), so if you want it send me an email and i will respond you with the PDF file of the manual.

My email is: platae@live.com.mx

i forgot to take many photos of the procces, that should be really useful for a DIY rebuild AX4S post, but well, its hard to take photos with oiled hands. But the rebuild process is not so hard as it apper, its very easy compared to the process of puting the tranny again in its place LOL,


Greetings