Propshaft coupler issues 68 Mustang

Hello all, I have been attempting to get some pics up of my new beauty.....still working on it. At any rate, I did some searching on other posts and didn't see anything on what problem I have so I figured I can ask. I also am not good with terminology so if it is the wrong name I apologize. Had it out this past weekend for the first time. Ran excellent fluid levels good, engine temp, etc. While in gear though I was hearing a nasty noise.....Pulled the hood and where the propshaft meets a ( bearing of some sort )right before the coupler there is first a hose clamp ( which I know isn't factory...looks like they tried a temporary fix for a deeper problem, then the bearing or what not... it is two cylinder pieces bolted to each other and then two bolts that appear to tighten in on each side to hold the propshaft in place or gear. I am guessing something is stripped but have yet to get any further on it. Any advice or tips would be excellent. Again, I apologize for the terminology. Also, checked propshaft and is not bent, nor is prop they are in perfect shape.

Not sure what kind of noise you are talking about or where but if it's a high pitched noise it could be coming from the packing. There is a rubber boot hose clamped on one end to the hull and the other end to a bronze (looks like one when tight) two piece fitting. If the packing is to tight it can dry out and score the driveshaft and ruin it. You can loosen the bronze lock nut off the bronze fitting then loosen the fitting until just a drip of water comes out and retighten the bronze lock nut. The little drip of water will help lubricate the packing and avoid scoring the driveshaft. Hope this helps.

nice pipes!

TRBenj wrote: gigem75 wrote: nice pipes! Thanks!

75, Yes they are nice pipes but I can't take the credit for them because I stole the picture from Tim (TRBenj). They are his pipes. You should look at the compleat thread of him installing the Hi-Tech manifolds with dual exhaust.

Tims pipes

Spievy, It sounds like you lost a key in the coupling half to the prop shaft. You haven't mentioned what the boat is but there are two types of couplings / shafts. One is a straight shaft and a straight bore in the coupling. The other uses a taper between the two. The straight type is a very close fit. I have always thought it to be .001" max but recently heard refference to a press fit. (no clearence) I'm just telling you this so your friend knows. You will need a new shaft and coupling half.

The noise you heard was probably the shaft spinning in the coupling.

By the way, to check for a bent prop shaft it can be done with feeler gauges (thin piece of metal) between the coupling halves. It then should be removed from the boat, placed in V blocks and a dial indicator is used. You can't just go under the boat and look and turn the shaft.

Edit: You did mention that it's a 68 Mustang. It has a straight shaft and not the taper I mentioned.

Sounds like a new shaft is in order. You'll need to drop the rudder to to install the new shaft. If the old coupling slides eaisly onto the new shaft it should be replaced as well. It is a very tight fit and there is a special tool that hammers the new shaft into the coupling. It's that tight. The shaft I got didn't have the recesses drilled into it for the set screws and they've got to be exactly in relation to the keyway slot. You can probably use your old coupling to line up on the new shaft then center punch the shaft so you can drill detents for the set screws in the right location.
I would also line up the drive shaft with the tranny/engine. It's done with feeler guages and motor mounts. The procedure is outlined better than I could ever do in the pcm .pdf service manual. I am not sure if the mustang motor mounts are the same as a pcm but the therory should be pretty much identical. Maybe someone can clarify that for you. Click on the references tab at the top of this website. It's absolutly critical to have the engine/trans lined up within a couple of thousanths of an inch to the driveshaft. Otherwise you'll have major transmission problems down the road/lake. Good luck!

gigem, good trouble shooting on the stuffing box and the gland nut being too tight. I have never heard that type of squeel from there, dry cutlass bearing yes, stuffing box no.
Your reputation for giving sound advice is slipping into the realm of BS........
Read some of these older posts , there is a lot of info there.There are members here that actually do this stuff everyday, and make a living doing it..
The new coupler will have the holes in a different place, Murphys Law...........boat dr

Thank you for the advice. Could you or anyone else direct me to the feeler guages I need to check the alignment once I have the new shaft in there? I read the thread by 8122pbrainard, and it looks pretty easy to follow other than just playing with the mounts to get it in just the right spot. I also wanted to ask if there is a tool I need to get the one half of the coupler off of the existing shaft as it seems pressure fitted? And likewise to put on the new?

Spievy, A auto parts store or even a hardware will have the feeler gauges. I've seen some old timers use a strip of old beer can. The important thing is to get the coupling halves parallel and concentricly aligned.

One other quick question. I found a shaft from a 65 Mustang 40" long 1" diameter should be the same size as far as I have measured, just checking if anyone knows. I can get it cheap and it's in perfect shape, thought I would get an additional spare.

79 Nautique small world I see you are on Wawasee, I am in Angola on Snow , I appreicate the advice.