Had a 2004 E-250 (5.4L/4R70W) towed to me over the weekend. Owner of the Van runs a local painting/remodeling business, says his crew "drove it until it stopped pulling".

The transmission had no engagement in ANY Forward gears, not even low 1, however reverse worked perfectly. The owner dropped the pan and replaced the filter/fluid, before he towed to me, he claims there was little to no debris in the pan.

Knowing vans in general are a pain to work on, I feared the worst. I was pleasantly surprised to find most of the transmission bolts and the wire connectors were easily accessible from the top, once the engine cover was removed;





Once the transmission was out, I found the OD band was burned and almost worn to the rivets. The forward clutch pack was burned because the outer piston seal was ripped in multiple places. No forward clutch engagement = No go forward!





I found NO other problems with this transmission. The direct, reverse and intermediate clutches had minimal wear, even with 100K on the odometer.
Going back together I discarded the wave plate in the forward clutch pack and increased it to 6 clutches. All the clutch pistons got new seals installed and I upgraded to OD band to the latest Ford unit, which uses a Hi-Energy carbon material that resists burning. Ford part # 7L3Z-7F196-A.

The OD servo return spring was updated to a softer spring, this allows the OD band to apply faster and hold more firmly. Ford part # F2VY-7F201-A.




To aid in better shifting I enlarged several holes in the valve body separator plate and installed updated shift valves from Sonnax.

 

I can rebuild a manual mixer , sit all day and work on electronics , and replace a set of Duramax injectors in no time flat ! The old ones ain't no fun ! But an auto mixer ain't my thing . More power to ya !

 

Sonnax makes good stuff. They also make a kit to replace the snap-ring with a spiral-lock ring on the Intermediate one-way clutch retainer. Many of these rings expand and fly off on squads and performance cars, not as much on vans. However I would caution you that the forward engagement may be more abrupt than you would expect with the wave removed. I once pulled a C-6 back out and replaced the wave after I tired of the "improved" engagement. The fwd lip seal being torn indicates that the piston over traveled in the drum, probably due to the clutch plate wear, but make sure the top of the drum is not cracked at the retaining ring groove. Also, I advise replacing the two molded accumulator pistons in the case corners, above the valve body. They often become worn and can fail to seal. Make sure as you assemble, that the OD servo catches the band, I do this before installing the Intermediate clutch and pump body, so I can see that it's engaged. I'll have the case up on end and since that servo spring can be difficult to compress, I use a home-made tool that bolts onto the case VB surface, and pushes the servo in with a screw and holds it while I get the snap ring in.

Have fun and good luck!

 

Yes, I know about the spiral snap ring and I usually install them. This van barely has enough power to get out of its own way, I doubt it will see the kind of RPM needed to rip the snap ring off. The stock snap ring shows NO evidence of wear.

I replaced both molded pistons.

yes, I make sure the OD band catches when I put it together using this tool.

 

Very Good, ^^ that's the tool I copied to save $. How is the fwd engagement? I never did the extra clutch thing on a 4R70W.

 

I bought the tool for $25 on Ebay.

 

When I made the tool there was no Ebay , besides that, I'm cheap.

So how is the engagement with out the wave? Not being critical, I'm really interested.

 

I get NO 1-2 upshift. I am pretty frustrated at this point. I think I damaged to front pump.

https://www.ford-trucks.com/forums/1...1-2-shift.html

 

I don't know about the 4R70W, but I had the same Problem on my AOD.

At the AOD there is a Spring on the TV-Lever inside the Transmission.
If this Spring isn't hooked to the Seperator plate, the Transmission doesn't shift into second gear anymore.

 

When you installed the intermediate clutch did you install the steel spring support ring with the inner lip up first and then the wave spring before installing the pump?

Maybe if it installed wrong it might keep the piston from appling.

 

Good call...... Yes, I installed the spring support with the inner lip up against the top steel plate on the clutch pack, then the wave spring then the pump. which is exactly as the picture shows it in the ATSG update manual.

what do you think about the front pump or torque converter being damaged?

 

There is a seal inside the converter for the TCC that is pretty tight when its new, sometimes I have to push really hard to get the converter to seat before installation. If reverse and forward wont slip I think you should be able to get second and the pump concern is not the issue. So maybe you just felt the seal seating, worse case here is the seal damaged and there will be a TCC problem, but I have never had that happen.

Second gear in this thing is both solenoids off, so if you unplug the case connector it should start in second, this should tell you that the trans is capable of having second. Note obviously this will set all internal trouble codes.

If you have second then its a control problem, speedo work?, did you replace the rear ring gear?

If no second then I would start looking at the valve body first like stuck valves or wrong gaskets covering holes, loose plates, the small one seals the intermediate circuit, did you install a shift kit?. Air check before pulling the unit.

Inside the unit it could be the assembly of the clutch plates or piston in the pump, pump gasket, intermediate sprag.

 

BINGO.... 1-2 shift valve was stuck. polished a few small burs on the valve with some 1500 grit cloth, put it together and its shifting perfectly.

all the up shifts and down shifts are firm and noticeable, but not objectionable or back breaking. the 4-3 down shift fast is very firm, but again, not objectionable.

 

The help is very good around here! Glad it's working right.