Driveshaft/Trans Coupler...Stumped!

[OK-944]

This one has me completely, utterly stumped.

Dropped the engine 18 months ago…with no drama.

Dropped the transmission ten months ago…again - no drama. During the drop, I slid the trans to driveshaft coupler back onto the trans, and left it there.

Fast forward to yesterday. Raised the trans. (engine is still out) and secured all the bolts. Trans case and TT bell housing lined up perfectly (both top alignment collars functional), and torqued everything down. So far so good.

Then, sliding the driveshaft/trans input shaft coupler forward…I’ve discovered that I cannot get the recessed collars on the two shafts to align simultaneously with the two threaded holes in the coupler. I can slide the coupler forward enough to allow for smooth entry of the front bolt…or I can slide the coupler backward to allow for smooth entry of the rear bolt (also lines up with the old paint/reference mark) - but the shafts are now somehow too far apart to for the unimpeded entry of both bolts. How can this be?

BTW…the trans shaft face to driveshaft rear face distance is about .35” Does this sound correct?

Furthermore…if I slide the coupler back so that I can insert the rear lock bolt, I can only tighten this bolt with the aid of a U-joint. In other words, the bolt is just a bit too far back to allow for straight access. This would seem to indicate that the trans input shaft has somehow migrated backwards.

Also, if I slide the coupler forward enough to insert the front lock bolt, it seems that the bolt is a bit forward of where it should be…although I can lock this bolt without using a U-joint.

Again…I removed the engine prior to removing the tranny, and tranny removal was uneventful, with the recessed shaft collars in perfect alignment with both bolt holes at that time. I cannot think of any possible way that these collars could now be too far apart.

This morning, I slid the coupler backwards so that I could tighten the rear coupler bolt, and then tried to pry the coupler forward…thinking that this whole issue might relate to some amount of fore and aft freeplay of the input shaft…but this shaft did not budge.

From here, it looks like the transmission input shaft has somehow retracted (by about 3/16”) into the trans case.

While the trans was out, I resealed the axle shaft inputs and replaced the shift mechanisms with a short shift kit and shift arm linkage. I did rotate the shifter collar about a bit, getting it to click into different gear locations, just out of curiosity. Question: could my doing this (clicking around) have made the trans input shaft vulnerable to “resetting” itself to a slightly (about 3/16”) retracted position? And if so…is there a way to reset back to a correct position - without dropping the trans?

Any other ideas? In a perfect world this would just be another one of my numerous “the fix is easy/obvious…I’m just a complete idiot” scenarios, but I gotta say its a real head scratcher!

[OK-944]

Solved!

Lying under the car (phone at my side, had just left a message with George Buselink), peering up through the tranny access holes...I think "I should lock the front bolt, and try prying the driveshaft backward...and see if the rear hole lines up."

Just then, the phone rings...and its George - explaining to me exactly what I am doing in real time just as I'm finding out the driveshaft moved just enough...unreal!

So glad that that my "I am a complete idiot...this is obvious!" scenario played out once again!

At any rate...great timing George - thanks!

[azbanks]

You are only an idiot if you make the same mistake three times.
Unless you are over 50 and then every time is like the first time.
I think...

I can't really remember.

[OK-944]

...but what about four times?

And I'm 66 - and am finding that "every time is like the first time" can actually be pretty refreshing!

...that much I can remember!