I have an 01 F150 SC 4x4 4.6L 4R70W Transmission 196,000 miles (Shooting for 300K+).

When going at a steady speed about ~40 mph +, I get a hard downshift (and sometimes a shudder). everything I have found in this and other forums points to replacing the shift solenoids and/or TCC solenoid. I plan on replacing BOTH of them soon (While I am in there). This brings me to a couple of questions:
1) In some places, I have found that there is also an EPC solenoid and others say not in this year. Can anyone tell me for sure? (If there is, I want to replace it also)
2) How hard are the shift & TCC solenoids to replace (I did the ones in my wife's 04 Intrepid without any problems)? Is there anything I should watch for when I remove the valve body?

I tried doing a search for a thread that steps you through it (To familiarize myself with the process) but could not find anything.

ANY help is GREATLY appreciated!!!

 

From what you said you found a lot of poor info.
As you surmise the transmission is electically operated by the computer.
These all have EPC solenoids.
This is the main solenoid that gates fluid from the front pump driven by the converter.
The rest of the solenoids use this gated fluid to supply the channels for each gear.
The reverse gear has no solenoid because it does not up or down shift
from that point because your shift selects the path mechanically at the transmission lever and internally.
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Going on, if you have no codes or a flashing OD light, there are no electrical issue with the solenoids.
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If you have shudder/missfire in OD at light throttle between 45 and 55 mph then the high possibility of the cause is one faulty coil not the transmission.
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Until you determine exactly what you have, do not begin replacing parts hopeing you get lucky.
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To review;.... codes and trouble indicators****** yes or no.
If yes then you have internal electric issues.
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Missfire in OD ******* yes or no. If yes with no code, you have to find which coil is the cause. It's not the transmission.
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If you experience sudden transmission actions with no other indicators then you need internal 'mechanical' service. Broken springs, worn parts etc.
The operating systems were layed out to be able to make a determinations as to the probable fault area by how it shows up.
Good luck.

 

OK... sorry for the delay.
I went by the place that fixed my Wife's transmission and he put his analyzer on it while we went for a drive. From what the analyzer told him, the hard "shift" was not a shift but the lock-in in the torque convertor locking 100%. He said the clunk I am feeling is the clutches in the torque convertor catching. During the test drive, at a steady speed, it would loose 100% lock-up.
He seems to think the torque convertor is going bad and recommended that since it has 196K miles on it, I should have the transmission rebuilt (About 2K) since if I replace just the convertor (About 1K), the rest of the clutches could go before too long and take the new convertor with it.
One question I have is: Once it locks up, why is it becoming unlocked? Is it just because it is not maintaining the pressure? If so, why? Or, are the clutches breaking loose due to variances in resistance while driving long.

 

It seems you didn't get any positive good outcome from the trans shops effort at diagnosis.
The lock up is an electrical operation controlled by the computer.
A lock/unlock usually is never harsh as you mention in the first post.
Reason is the lockup is just preventing the normal converter fluid slip which would be a 'soft' feeling along with an engine RPM change of about 300 +/-.
If the lockup friction becomes a ragged on/off engagement then it could feel a bit like a wash board feeling.
A harsh feeling can be an accumulator/servo slamming clutch paks or bands closed to engage gears when they should be under a more gradual control by a spring to dampen the engagement.
If spring is broken in a valve body location controling an accumulator or servo there will be harsh on engagements.
When valve body is reworked for more positive shifting as compaired to stock this is what is done. In race setups the harsh engagements are made intenional to minimize slipping under high HP application.
Valve control spring tensions are changed, orface hole sizes are changed, servo pistons are sometimes changed etc.
You can see from this that a broken spring for instance causes a loss of valve control when fluid pressure is gated to it through the EPC solenoid from the front pump..
I would agree if you value the truck enough to make the investment worthwhile, I would have the trans rebuilt.
A reminder that the solenoids are electric control and monitored by the computer.
If no codes are set, with harsh transmission actions it's usually the mechanics beyond/after the electric operation the computer cannot see except on a secondary basis or as a reaction to the fault.
It get's tricky to evaluate unless all the operations are understood and taken into acount.
Good luck with it..

 

Bluegrass, Thank You for all the help!!!

I was looking back through my original post and noticed I left something out. It only happens when accelerating. I don't think this makes much of a difference but I thought I would throw it out there. I do get a shudder occasionally.

I have read in one post that this transmission is notorious for having a spring in the accumulators break. Do you know if this is true? If so, based on what you said, it could explain a lot.

As for rebuilding the transmission, Unfortunately, this is not much of an option at this time. If it is possible to fix myself, I would rather go that route.

I do want to keep this truck but need to try and get the transmission to last another year or so.

Any more thoughts?

 

You will have to drop the fluid out of the pan.
Take down the valve body for inspection of all the valves and springs.
The servos may need inspection if you don't find a small spring broken.
Watch all check ***** that are in the channels at various places and where they are.
Keep the body level as you lower it so the check ***** don't fall out.
Above the valve body should be a seperator plate with a lot of holes in it.
This plate is most of the calibration along with the springs and their tensions on the various valves.
Best to search for the valve body layout so you see what is in them.
Or get a copy of a transmission repair book for you unit showing where everything is.
You should have a special low value inch pound torque wrench to put the body back to proper torque.
You goin become expert quickly.
I just got a job to repair a 94 Buick with a basterd OBDI terminal nobody knows anything about. It's not in any book and not found it on the internet yet and I need the codes!
Hope you have good luck.

 

Bluegrass:
Sorry for the delay. It's that time of year.
One of the posts I found with a similar problem said that the accumulator spring could be broke.
Do you know if there is such thing as a valve body rebuild kit?
I am thinking about getting one of those (If they exist) and springs for the accumulators (Since they are cheap).
I would like to have as much of a chance as possible of only having to tear into it once.
Any thoughts?

 

Good question.
Most of the time you just have to wing it and find a source of the springs.
A trans shop is the best source otherwise you not sure what your getting from anyone or from a yard source of transmissions that are bad for other reasons.
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An update on the Buick as if anyone cares.
The alternator was locking up, slipping the belt and loading the motor down. Never saw that before.
The fuel pressure was low from a faulty fuel regulator causng less than good throttle response plus servicing other sensors and testing..
Runs like a top now.
Never was able to read any codes but CEL is no longer on.
Good luck.

 

AODE 4R70W transmission parts Aode transmission rebuild kits

I guess you could look at the sonnax specialized parts to see if any fit your situation.



Bluegrass, I've had alt's and pulley's seized but they usually smoke or shred the belt.

 

Bluegrass:
At one time, I found a post that told you how to install a jumper and then you could read the flashes of the check engine light but I have not been able (Or had much time) to find it. I think Autozone has a data base that might tell you. You should be able to go by there and maybe they can tell you.

I have been looking around and found WIT Transmission Parts ( https://www.wittrans.com/default.aspx? ) and they have quite a few rebuild kits.

I am going to find a transmission repair book and go from there.

 

On the Buick, the year 94 was a transition to OBDI.
The data link has a rectangle socket with only three active leads. The rest are vacant. Otherwise known as a ' basterd' deal.
I have yet to find any reference to this on the internet or in a manuel.
Looked at Buick boards and see many had found out the same thing.
This takes a special cable and reader to output the data.
At this point only a couple diagnostic tools are still available to read this setup using a specific cable.
It's not worth the cost to buy for one use.
I got the car running very good again so the owner might try Advance Auto to see if they have a scanner and cable to access it otherwise it will be left as is as long as the motor starts and runs as well as it does.
It looks like a paper clip deal to read the CEL flashes but isn't.
Thanks for the replies.
Good luck.

 

Check out this link, Bluegrass....

Innova OBD I Code Readers - SummitRacing.com

also....

 

What you shows is for Ford from 1985 to about 95 EEC sytems.
OBD1 and GM for 94 is totally different.
Thanks.

 

Check out the link provided, they have the GM one also, I believe.