Tranny "BANGS" into reverse occasionally

[mjt73]

Got another one for you. My '96 XLT with the 4.0 liter Pushrod V-6. Occasionally, but mostly in the fall and winter months, my tranny when shifted into reverse to back out of the garage or a parking stall, BANGS into reverse gear like a grenade went off. Then the O/D light blinks at me and the thing almost dies like it's running on 3 of the six cylenders. BUT, if I shut it off and re-start it, the light goes away, runs tip-top, and it shifts as smooth as ever (still allowing the normal 5-7 second hesitation). I'm guessing some sort of solonoid on/in the tranny, but am looking for a little more info. Thanks for any info.
Mark

 

[BuffaloXplorer]

There have been a few recent posts similar to your issue and the consensus had been "possible U-joint" problems.

I've been shown that i've got 2 (out of 3) bad u-joints in my rear split shaft and mine will occasionally "clunk" when going into reverse. Not nearly as bad as an explosion, but a clunk nonetheless. I had provided the assumption that, depending where your driveshaft came to a rotational stop, the "clunk" may occur if your u-joint has become so loose that it roates a bit before actually catching...

I'm not sure about your OD light issue, though.

 

[mjt73]

This actually started happening last winter. It doesn't bother in the warmer, summer temps. I did replace the u-joints this past summer, the same time I changed tranny fluid and filter. But it still does it...just yesterday in fact. There again, it hesitates a little (as usual) then BAM! into reverse and it barely stays running. If you give it gas it "shudders" and there's no power, so I shut it off and restarted it and it's fine, just like clockwork. It probably won't do it again for a month or so until it gets cold, then it's almost every day. The one reputible Tranny shop I've gone to scanned it three times last winter, even when the O/D light was flashing, but no codes come up. Back to hunting up an intermittent solonoid I guess.

 

[BuffaloXplorer]

does it sound like the 4wdLO transfer case "lockup" ???

 

[mjt73]

No, nothing like that. It definately comes from the tranny. I'm told it could be a shift solonoid or some sensor of some sort.