Calling All Brains

[clawrence1994]

Okay guys here is what we have.
1994 XLT Elxplorer 4 door, 4WD.
4.0 Liter V6
a4ld automatic transmission.

Problem #1: The acuator motor on the transfer case is not locking the transmission into gear.
Example: Driving along and on an incline; or where high torque/power is used, it feels like the truck slips out of gear. I found out that if I turn on the 4wd, the truck will go back into gear. The best I can explain it is that the actuator motor turns the transfer case to four different positions. they go as follows. 4wd (low), 2wd, neutral, 4wd high. So as I'm driving the shifter is slipping out of 4wd (high) into the neutral position. And stays there, unless I turn the 4wd on and off. So the question is How do I fix this?

E-mail me at cmlawren@mtu.edu.

Problem #2: When put the truck into drive it will start moving, shift into second, then at 3000 rpms and 20-25 mph when the truck should shift into third gear it just stays in second. Doesn't shift.
What I've done so far is change the vacuum module up on the passenger side of the trans.
A couple of key things. The truck will manually go into all gears including reverse, neutral, overdrive, drive, 2 and 1. Its bugging the hell out of me and I need my rig back on the road.

Come on now guys, anything will help at this point.

 

[BrooklynBay]

Did you read the sticky thread on rebuilding the shift motor? As for the other problem, did you adjust the kickdown cable linkage?

 

[Glacier991]

3rd gear applies the High Reverse clutch and releases the intermediate band. The High/Reverse clutch is also applied in reverse, so the fact you have reverse probably means that component is ok. All other components for 3rd are used elsewhere as well.... but the high reverse is first applied in forward gears in 3rd.

I suspect your 2-3 shift valve is stuck or the 2-3 backout..... ot both. I'd pull the VB and rebuild it along the lines of the A4LD Valve Body Rebuild Diary.

 

[Bent Bolt]

I'm Back !!!!

Anyway, it is possible to have a bad direct clutch operate in reverse and not in 3rd due to higher pressures in reverse. If that is the case here, there should be a slip or a more than normal delayed reverse engagement.

The sealing rings on the center support for the direct clutch are famous for leaking.

Also, if the intermeditae servo piston is hard and leaking, that can cause a no 3rd condition .

 

[Glacier991]

Welcome back Bent Bolt. I try and figure out possible scenarios that might get a fix without removing the tranny.... and I HAVE seen stuck 2-3 valves before.

[Note: For others less familiar than Bent Bolt and I - I should point out that the names for various clutches vary in transmissions.... and the direct clutch in the A4LD and the Low/Reverse are the same, just as are the OD clutch and the Coast Clutch.]

I certainly understand the higher boost in reverse might get reverse but not 3rd... but wonder why if the intermediate band is being released for the 2-3 shift we don't have a no gear scenario. That was why I was suspecting the 2-3 backout and the 2-3 shift....in any event we can at least check the VB without a teardown was my thinking....

Thoughts on mine?

 

[clawrence1994]

I'm back

Did I mention that I changed the vb modulator. So its brand new. I put the pin back inside and reconnected the hose. Does the vb need any pressurizing or adjustment?

Another question. Could the motor that activates the transfercase into 4wd affect the performance of the trans. Like if it wasn't fully engaged into gear, could that confuse the computer and not allow it to shift properly?

Thanks for the help guys!!!

 

[NHale623]

Could the motor that activates the transfercase into 4wd affect the performance of the trans. Like if it wasn't fully engaged into gear, could that confuse the computer and not allow it to shift properly?

No. The transmission knows nothing about the transfer case. 4wd range has no impact on the shift strategy.

The A4LD is only electronically shifted into overdrive. Other shifts are mechanical.

 

[gijoecam]

Indeed, I suspect a trans issue, not a t-case issue... In order for the transfer case to shift into neutral, it has to pass through 4high first anyways... If it tried to do that without synchronizing the front driveshaft first, it would make a horrendous clunk when it engaged 4high...

The other guys are on the right path, although I can't contribute much on that front... My name is Joe and I'm auto-trans illiterate.

-Joe