Propshaft coupler issues 68 Mustang
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=7128
Printed Date: October-31-2024 at 9:32pm
Topic: Propshaft coupler issues 68 Mustang
Posted By: Spievy
Subject: Propshaft coupler issues 68 Mustang
Date Posted: June-18-2007 at 2:48pm
| 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. |
Replies:
Posted By: Spievy
Date Posted: June-18-2007 at 2:52pm
My mistake it is a 1968 Mustang with the original 318 Chrysler in it, and it roars! 
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Posted By: gigem75
Date Posted: June-18-2007 at 11:08pm
| 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. |
Posted By: 8122pbrainard
Date Posted: June-19-2007 at 6:31am
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Spievy, What we fell you are looking at is the stuffing box. It should look like the picture below. The hose clamps and short length of hose are indeed factory. The stuffing box is to keep water out and it does not contain a bearing. The design has been used since the late 1800's although there have been improvements in the actual rope stuffing that goes inside. The large hex cap with the jam nut next to it is screwed in to expand the packing against the shaft to make a near water tight seal. It should drip slightly since the rope packing is water lubed. The new style teflon rope packings (available from Skidim) run cooler even with less water.
You should remove the old packing so you can check the shaft for scoring (it should be smooth) and then repack with the teflon. 
Taking technology one step farther, you can replace the stuffing box with a no drip seal. They are a water lubricated high tech carbon and teflon faced seal assembly. They are also available from Skidim. If you haven't found Skidim yet, Follow the link on the top of this page. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: gigem75
Date Posted: June-19-2007 at 9:39am
| nice pipes! |
Posted By: TRBenj
Date Posted: June-19-2007 at 9:54am
Thanks! ------------- |
gigem75 wrote:Posted By: 8122pbrainard
Date Posted: June-19-2007 at 10:19am
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. http://www.correctcraftfan.com/forum/forum_posts.asp?TID=6888&PN=3 - Tims pipes ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Spievy
Date Posted: June-19-2007 at 11:06am
Like I said I am awful at terminology but that picture is on the money. My problem however, is where the shaft at the point where the four bolts meets and connects with the other side (up closer to the back of the engine, right where the shaft enters). I took off the two set screw bolts ( with the allen heads ) and undid the four bolts and seperated the two cylinder-like pieces. What I saw was where one of the set allen bolts seats it had worn a groove in the shaft and was pivoting left to right. I am guessing I need a new shaft unless that can be fabricated. I have a good friend that thinks he could do the job. Again, I apologize on the lack of part names. Nice pipes too!! 
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Posted By: 8122pbrainard
Date Posted: June-19-2007 at 11:26am
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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. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Spievy
Date Posted: June-19-2007 at 11:42am
I agree and that was what I heard and saw on the lake was the shaft spinning in the coupling. Quite the disturbing noise! Is this something that I could find on Skidim? I haven't been on there yet to see what all they have. It is a real bummer though to have an hour of fun with my new boat and have this happen  . Also, the boat is a '68 Mustang with the original 318 Chrysler. Engine is in pretty good condition. The hour meter only reads 819 hours, not saying that it could have been unhooked at one point but I do know I am only the third owner so not too bad either way.
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Posted By: gigem75
Date Posted: June-19-2007 at 12:04pm
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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! |
Posted By: 8122pbrainard
Date Posted: June-19-2007 at 12:24pm
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75, We have a complete pictorial thread on alignment. It's better than PCM's!! Do a search if you want to take a look. It was done by our resident trans specialist (his business) Erik. Here's it.
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=6037&KW=alignment - alignment ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: boat dr
Date Posted: June-19-2007 at 1:40pm
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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 ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: eric lavine
Date Posted: June-19-2007 at 2:23pm
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if the shaft is worn inside of the coupling and is really lose its a good indication of mis-alignment but it also could be just normal wear and tear over the years. Be sure to check the alignment anyways ------------- "the things you own will start to own you" |
Posted By: Spievy
Date Posted: June-19-2007 at 2:27pm
| 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? |
Posted By: boat dr
Date Posted: June-19-2007 at 2:33pm
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Spievy, Put the coupler in the oven and the Drive shaft in the freezer,leave the shaft in overnight.Set the oven to 425 and bake until a tooth pick comes out clean...ooopppps wrong recipe.425 for 45 min,should warm it up enough to slip right on,,,,,,,
That the way the boat dr does it....... ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: 8122pbrainard
Date Posted: June-20-2007 at 5:27am
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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. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Spievy
Date Posted: June-20-2007 at 11:01am
| Thanks, I appreciate the heads up on that I was hoping it wouldn't be a pain to find. Another quick question is on the torque of the bolts, any specific or just snug? I don't want to tighten too much and cause damage when adjusting the mounts. |
Posted By: Spievy
Date Posted: June-20-2007 at 11:05am
| 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. |
Posted By: 79nautique
Date Posted: June-20-2007 at 7:06pm
thithen them as tight as you can get them they should be grade 5 or 8 bolts to start with so the odds of you snapping one is slim if the are not grade 5 or 8 then get grade 5 or 8 bolts to replace the wrong bolts you have. Look for at least three dash marks on the head of the bolts to tell if it is a grade 5 or not. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Spievy
Date Posted: June-21-2007 at 10:40am
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79 Nautique small world I see you are on Wawasee, I am in Angola on Snow , I appreicate the advice.
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Posted By: 79nautique
Date Posted: June-21-2007 at 6:21pm
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used to live there not any more. Need to update diary ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |