OK Sorry I missed the beginning but its been a long weekend of kids activities, theater and hockey while great discussion, Down to ONE Car almost out of nowhere a couple of weekends ago. Those who don't know I'm the shadetree mechanic version of Click and Clack with a downstate NY Bronx accent instead of a Baston (Boston) one.... (Red Socks SUX!!! Sorry now that Derek and I share the same dreaded injury and Gay-Rod is too busy flitter with chicks in the stands to give a rats behind about the F'ing Play-offs (AGAIN!!! Tweeeter!) us Yankee fans are a bit grouchy to say the least... A-Rod should have watched "Miracle" with Curt Russell as Team USA's 1980 Gold Medal Coach to learn what happens to athletes who are more concerned about flirting instead of staying focused on the game at hand.... "Craig, Again... Craig Blow the Freakin' Whistle!!" (Brookes) (In a German Accent) "But Herb this is maddness!!!" (Trainer Doctor) "Herb don't you think the boys get the message by now, they can hardly stand?" (Assist Coach Craig Partick) "AGAIN!!! Come on boys up on the goal line. Craig blow that freakin Whistle!!!" "Tweeeeeet" (As the team continues to slog thru another set of "Suicides" Wind Sprints, Stops and Starts...) That's what happens at least if they actually care and want to be champions and their coach is smart enough to know how to get them there that is...
Anyway, I have two completely Different Differential Diagnosis's for your Transaxle which is actually your transmission and your main front differential as it is one larger combined unit on a transverse mounted front wheel driver. So pardon the bad pun but it's too cool to resist here... So we really could refer to this as a Differential's Differential Diagnosis! (Ba dump, Baaaaah (crash) :o)
One: Your Cable theory, ala shift linkage may be sort of half valid but sort of right basic concept but wrong cause... The Clank, bang sort of thing that then lead to pretty much Nothing, be it park, drive or reverse gets me thinking about Dead, unbolted, missing, shreaded Engine, tranny mounts kind of thing. I am going here because you did NOT mention any continous noises or knocks while the car sat there idling away but unable to connect and transfer power thru her own powertrain. Cracked, broken fly wheels and torque converters, flex plates, bolts coming loose, tend to make noise, before during and after.... Many times after a crack or the stuff comes loose you have a deep, almost bad rod bearing kind of heavy parts Knocking down low... I was looking for one of those in the rain at 50 degrees soaking wet under my 2000 4.0 liter in-line six WJ Grand Cherokee while stranded at the US OTC in Lake Placid a couple of weekends ago now... Taking my lifetime certification seminar for Coaching. I'm a level 4 coach with a dead flippin' Jeep !!!!
But to get back to my first possible idea here is this. If your engine was able to get that loose to have one mount fail or come extremely loose, torn up (Solid piece of round rubber, used to be squares back around '72 and back, but they started to use circles with Bolt thru so even if the rubber Failed from stress and or Ozone and Engine Fluid degridation, there would still be this round piece of metal with a full bolt thru it to half hold things up. Also this is a safety feater to even as the rubber fails in a bad front end, head on collision, the mounts are less likely to completely allow the entire engine, tranmission assembly to come backward into and possibly thru the firewall and on to the front seat passenger and driver.... Imagine a 500 lbs small block V-8 sitting in your lap after you were luck enough to survive a head on with a delivery truck... Not good.
So now if you van is cable linkage controlled for its actual throttle body (ala gas pedal) control as well as what we in the Mopar Circles refer to the Throttle, Kick Down linkage, and the shift linkage cable, you now could have as many as three very important control signals and devices that all sort of are designed to work together thru all phases of throttle pressure to help the car keep all three of these things in sync so they all behave nicely whether you're standing still at a light, light part throttle cruising down the blvd, or kicking her down as you did to get into fast merging traffic or passing a large slow truck in a passing zone.... BOOM! Last few pieces of rubber went, last couple of treads on one of a few mounting bolts for that particular mount...
So now you Van can not get into any gear, the tranny does not have any idea where your foot is in terms of how deep, hard into the pedal for shift points and the like. And you many or may not have much or any control over your throttle, engine speed. I get the feeling that all seems in the driver's seat to sort of work, but no response. I mean that you can throttle the throttle, gas pedal, you can shift the shifter and the like but NO response as though you are doing such especially the shifter to get in and out of all the gears and park position. This could have Busted off the cable from its bell crank assembly which is basically a modest few inches long lever with a bike brake like cable going to it, with a tear drop shaped plastic clip that pops on and off of a short post with a round ball on it that allows the wire to actuate the tranny thru all its positions and yet does not bind up because this ball and clip set up allows it to smoothly move in an arc like pattern. sort of like a trailer hitch. Same thing with the throttle if it is still a wired throttle instead of the newest "Fly By Wire" like throttles...
So blown or almost gone motor, tranny mount is possibility #1.
2) That last loud clunk Bang you heard was the last legs on something inside your tranny itself, that allows it to auto shift and move thru it's "Gears", ala the main input, output, main drum, a band or two, or an entire set of clutch packs that ride and firm up according to the inputs from the forementioned throttle lever, kickdown linkage that speaks to your tranny about how far down into the gas pedal you are... DO you want to cruise, get a good Kick Down from drive to lets say 3rd or 2nd gear to pass, climb and the like.... This is a good time and place for such things to fail because this is exactly when they are spinning fast at the crank, slower at the output, wheels, the motor is winding up, perhaps in her better part of the her torque band, power range and everything is loosening up and coming back together, and in general getting pushed around under higher loads and demands. Clutch packs, bands, and the like...
I'm just not sure that this would take out your "Park" position though unless there is no longer any direct connection from other solid spinning parts, output to the drive wheels back to the main "Sprag" or whatever it is they call it. There is a large, very old fashioned looking "Gear Cog" thing attached to the main drive output near the tail of rear wheel drive cars and trucks that a large rod, lever engages to literally hold the rear driveshaft from spinning or moving and that is what is engaged when you put your vehicle in park position to hold it in place. Great Reason to use your "E" Brake on hills and other inclines or places where letting go is NOT an option.
So if unless there was a good internal drive failure and that could take out the parking sprag and engagement rod part of a front driver which is where my knowledge gets a bit shakey, I'm gonna say I believe that your have a pretty bad, loose, even half gone motor mount, which again failed while under stress in the in demand all the time direct which makes sense, as this is how motor mounts tend to fail, in the direction of power, demand rotation. Pretty much the same idea, if your chassis has a rear tranny cross member like pick point, or some other body to frame to motor Pick Point, the bang could have been that connect the mount mount to the body frame like place and again now your drive train in out of wack and the inputs you are able to do are not anywhere near where they need to be to make anything happen, cables could be bound up, shear off or cut, so on and so forth....
Can you at least press down on the gas and make the engine change speed normally like revving the engine? If you place the shift selector into any position does it seem to do that "engaged" thing regardless of whether or not your shifter is in the wrong place for such a thing? If You can get it to engage in any position, I would say open the hood and with foot firmly on the brake, "E" Brake on kind of thing (you don't want to move) Put it into any gear possible and see if the engine starts to move A LOT, like Comes UP and OUT of the Engine bay because it is not Securely held in place enough. When not so far gone as you still can shift around, and get proper engagement of forward gears, we do this as a test on rear drivers and some front drivers, too, looking for excessive Movement, engine RISE in the direction of engine stress and stain against the motor mount that is attempting to sheer it off in an upward direction, passenger side I believe. The mounts on the downward force side don't tend to get a beat up because in general they are in a "Compression" like state most of the time when the engine is flexing its muscles where as the UP side is being pulled apart and sheared more. To some extent this was half eliminated by the modern, crash safer mounts that are very resistant to catistrophic failure the way the old sandwich flat, sqaure mounts where....
I would love to hear how this all plays out and what the final answer is.... Good Luck and hopefully you only need an engine mount of two, some loc-tite and perhaps a clip or shift cable and the like....
Paul
