Mechanics

WHAT WOULD CAUSE A 4R44E TO NOT HAVE A REVERSE AFTER A RE-BUILD

1999 Ford Ranger • 15,500 miles

I JUST REBUILT A FORD 4R44E IN A 4X4 RANGER 3.0L, THE TRANS HAD STARTED SLIPPING FWD AND REVERSE & FLUID WAS BURNT. UPON DISASSEMBLY I FOUND THAT THE O/D CLUTCHES WELDED TOGETHER & O/D BAND WORN THIN, & VALVE BODY GASKETS BLOWN OUT. AFTER A THOROUGH DISASSEMBLY, CLEAN, & REBUILD KIT WITH BANDS, EPC, REVERSE BAND NOT CHANGED(LOOKED GOOD). RESULT, NO TO LITTLE SLIPPING REVERSE, FORWARD WAS OK SO I INSTALLED A TRANSTAR SHIFT IMPROVER KIT, REVERSE SERVO EXTENSION, & SONNAX VALVE BODY END PLUG KIT. NOW SLIPPING FORWARD & REVERSE. CAN YOU PLEASE SUGGEST A NEXT STEP B/C I AM STUMPED.
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Stangman01
July 9, 2012.




Everything was good till you installed the trans star valve body kit plus sonnax upgrade?

Saturntech9
Jul 9, 2012.
Forward was fine except for a flare between second to 3rd. But reverse would clunk but not pull, now reverse will delay clunk then pull some with high revs.
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Tiny
Stangman01
Jul 9, 2012.
Forward is acting the same as reverse now, I am re checking the fwd band servos tmw morning to make sure no problems. They were not replaced.

Tiny
Stangman01
Jul 9, 2012.
The first thing I would do is check the line pressures in the transmission to rule out a pressure issue. Also thats the first thing I check when diagnosing a transmission before taking it apart. Nothing worse then not know you had a pressure problem that caused the problem your taking the transmission apart to fix. Then after the repair you find the pressure problem on the test drive.

Saturntech9
Jul 9, 2012.
Ok I will try that, what should the next step be if it has high or low pressure?

Tiny
Stangman01
Jul 9, 2012.
So you did a trans star valve body upgrade with sonnax upgrades?If so I would suspect that as being a problem some where in the valve body. If the pump is good and there is a too high or low pressure issue then something going on in the valve body that regulates and directs the flow of the pressurized fluid. Let me know what you find.

Saturntech9
Jul 9, 2012.
The sonnax kit was just the o-ringed end plugs& new check balls.

Tiny
Stangman01
Jul 10, 2012.
What was in the trans star shift improver kit?Also what was the cause for the burnt clutches?Leaking piston?Low fluid pressure?

Saturntech9
Jul 10, 2012.
The burnt o/d clutches were burnt from valvebody separator plate gasket blowout. The trans star kit consisted of improved springs & end cap forthe main pressure booster valve, a rivit on separtaor plate, a new hockey puck, drilled hole in casting of v/b & a insert in direct band in fluid passage of trans. The 4r44e is prone to the v/b gaskets blowing due to high pressure. I changed the epc solinoid & filter prior to any other repairs. That is when I found the pan full of friction material.

Tiny
Stangman01
Jul 10, 2012.
So the valve body gasket blew out pressure dropped then burnt the clutches from the low pressure allowing the clutches to slip?Also how are the pressures now?What are the readings?

Saturntech9
Jul 10, 2012.

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