Automatic goes "Bang"

[xirdneh]

My aunt drives an '87 tercel that I aquired and fixed up for her. It has about 160,000 orig miles on it and she has been driving it for the last four and a half years. She started it up one morning last week , put it in drive and began to pull away from the curb. She says the car kind of lunged forward and went bang. After that it would not move. The engine runs fine but the car does not move. She also mentioned hearing some tapping sounds off and on during previous days.
She had someone take a quick look at the front axles which seemed to be fine.
Anyone had an automatic go out this way?

[splatterdog]

Is it "locked up" or just wont move itself foreward or back?

If it's locked or binds up when pushed, you probably blew the differential.

[keith]

Might just be the torque converter or even the flex plate, if you've been good and deserve some good luck.

[xirdneh]

I finally made it over to my aunts to check out the problem. I started the car and kicked down the idle to normal. I moved it into Reverse and the car did not move. There was a whirring sound that sounded like something was very close to engagement but just couldn't quite do it. Moving it into Drive produced the same sound as did the two optional speeds below .
I pushed the button to put it into 4WD and that produced a clunk sound. I could now move forward in 4WD and the whirring sound had stopped. I pushed the button again taking it out of 4WD and I could still move forward but when I moved to Neutral then back to Drive the whirring sound began and the car would not move.

[keith]

Now it sounds more like the front differential. I suppose she could use it as a RWD car for awhile. It could also be one of the CV joints. If an inner joint went, you might be able to drive it, but not if an outer joint went. If an outer joint went, the axle will flop around and do a lot of other damage.

[xirdneh]

I forgot to check the fluid level so I did that last night. Under the circumstances I can only check it cold. Instead of registering in the "COLD" area the level is about 2 inches above the hot level. I wonder if this could be the problem.

Re-cap: Car will not move in Reverse, Drive or any of the forward speeds. Makes whirring sound as though something is trying to engage. Will move forward and backward if put in 4WD. Will continue to move when taken out of 4WD until shift lever is moved, then it's back to where it started (whirring sound and not engaging).

[Petros]

It moves normal if in 4wd, and still normal after you shift out of 4wd? That could be a loose or out of adjustment linkage issue. That should be an easy fix but better have a trans shop you trust look at it (one familiar with these kinds of transmissions).

On most cars with auto trans you have to have the engine idling with trans in neutral to check fluid level, when off it all drains back to the sump and shows a high level. So you level is likely normal, you just have to check it with the engine idling.

[xirdneh]

i'm still messing around with the automatic now and then. I shoved a hose down the tranny dip stick tube as far as it would go and siphoned out over a gallon and a half of fluid. I slowly refilled the tranny with fluid till it showed up on the dipstick at the "cold" mark. I started the car and it shifed just fine. i drove it up and down the street and moved the shifter to low, 2nd and drive. stopped put it in reverse backed up. when i thought the tranny was warm i rechecked the fluid with engine running and in park. nothing showed on the stick so i added fluid till it reached the hot level. Still had about 1/2 to 3/4 gallon left in the siphon bucket. Car drove fine.
i stopped and with car idling pushed the 4wd button, instantly the whirring sound returned and a loud cluck occurred. it was engaged and moved back and forth in 4wd. when i pushed the button to take it out of 4wd the whirring sound and loud clunk happened again.
i talked to two transmission repair shops about it. they both thought something had to be broke inside the tranny.
i have to wonder if the last oil change person (she takes it to one of those fast lube places) topped off the tranny a bit to much?