1984 Evinrude 140 - Crankshaft Binding

[hoeser]

I am currently rebuilding my 1984 Evinrude 140 Crossflow V4 and I have run into an issue after joining the crankcase halves. I carefully aligned all the connecting rod caps, installed new seals on the upper and lower crankcase heads and joined the two halves together using gel seal.

After hammering in my taper pins, tightening the crankcase screws to torque, and also tightening the crankhead screws both upper and lower to torque I installed my flywheel and checked for binding, there was virtually no resistance and I was quite pleased with how smooth it was turning. The only thing I had left to do was tighten the 4 screws which retain the lower crankshaft bearing retainer plate. These were already installed but only finger tight. After tightening them to a modest 3 or 4lb I checked for binding again before going up to the manual-suggested 84-120in/lb of torque. At this point there was enough resistance on the crankshaft that I couldn't really turn it easily anymore even using both hands.

I have picked my brain on this one for a while now but I can't figure out why the plate is causing the crankshaft to bind. Can you offer any ideas? I'm 99.9% sure I am using the correct screws for the plate - they are about 1.5" in length, have lock washers and are a finer thread than most of the screws in use on the rest of the engine.

Hope you experts can help me out on this. Thanks in advance.

-Dave

 

[ezeke]

Re: 1984 Evinrude 140 - Crankshaft Binding

Might be the kind of thing that Rodbolt is mentioning in this thread:

http://forums.iboats.com/showthread.php?t=95377&highlight=binding+crankshaft

 

[hoeser]

Re: 1984 Evinrude 140 - Crankshaft Binding

I don't think we are having the same issue. I am confident the main bearings are lined up correctly. What bothers me most is that it turns over really easily with the 4 lower bearing plate screws finger tight, and as soon as you add any degree of torque to those particular screws it starts to become hard to turn, but I don't feel any odd resistance, it is very linear and smooth... it just becomes way more resistant to rotation.

 

[Chinewalker]

Re: 1984 Evinrude 140 - Crankshaft Binding

Is it possible the lower main bearing is worn a bit (did it get replaced?) and when you are finger tightening them it is twisting the outer race enough to bind the bearing? The bottom main cap screws need to be torqued evenly to prevent the bearing plate from pulling harder on one side than the other...
- Scott

 

[hoeser]

Re: 1984 Evinrude 140 - Crankshaft Binding

The lower main bearing was not replaced but it felt excellent on installation... extremely smooth and easy to spin. I don't believe I am binding the bearing when finger tightening, also, when I did my "pre-torquing" to 3lb they were all of even torque and I could barely even turn over the engine from the flywheel with both hands.

Is it possible to remove the lower crankhead assembly from the crankcase with the crankcase joined together so I can inspect it? I'd really like to avoid breaking it apart again and resealing it.

Also, I've noticed that there are *5* holes in the bearing retainer plate, 4 for the screws, and one extra, I can't remember if it was threaded but I don't believe so. should this hole be oriented in any particular direction, and could this be the issue if its not in the right place?

Thanks again for your replies.

 

[Joe Reeves]

Re: 1984 Evinrude 140 - Crankshaft Binding

It really doesn't matter where that unthreaded hole is positioned but I usually have it facing the forward portion of the engine.

There are four seal equipped bolts that secure the lower main bearing retaining plate to the lower crankcase head. On that engine (84 140hp) they are part number 317763.

Assuming that you do have the bearing retaining snap ring installed, your explanation of the problem, in my opinion, could only result from having the wrong bolts installed (too long) which would allow them to actually contact the crankshaft surface.

 

[Walker]

Re: 1984 Evinrude 140 - Crankshaft Binding

Is it possible that the index pin is missing or misaligned in the lower bearing.

 

[Joe Reeves]

Re: 1984 Evinrude 140 - Crankshaft Binding

The bottom main bearing has no index pin retainer. The inner race is a pressed fit upon the crankshaft.

 

[hoeser]

Re: 1984 Evinrude 140 - Crankshaft Binding

Joe - that is the same conclusion I came too. I did not remove any of the snap rings or bearings from the crankshaft during the rebuild, I basically just removed the connecting rods and set it aside and then put it back in when I got back to actually rebuilding the engine. I have searched my workspace neurotically for over an hour in search of 4 potential candidate bolts and believe me my search turned up nothing.

The 4 bolts I had set aside with it are the ones I am using (or attempting to use, if you prefer). They are, like I said, about 1.5" long and more of a machine screw thread than a standard thread. This engine was rebuilt in the early 1990's and I believe when they did the rebuild they did not put the o-ring seals back on the bolts... as the bolts I have for this didn't have any seals on them nor do I recall removing any bolts with seals on them. The engine always leaked from this plate so I'm assuming thats why, but that is a different story altogether. I do have new o-rings that came in my crankshaft seal kit which I am using with these bolts.

This would be a lot easier if I could actually see if the bolts were, in fact, touching the crank but as I said I already sealed it up. I am hoping someone just posts one of those "super easy fixes" that is just a result of me missing something easy but it's sure looking like I'm going to have to break this damn thing open, again.

 

[R.Johnson]

Re: 1984 Evinrude 140 - Crankshaft Binding

The thread on the lower bearing retaining plate is a 1/4-28. The retaining pin's on the upper, and middle bearing can be a real chore to align. the only thing I can think of is that one of those pin's is not in it's seat. Pulling down that lower bearing retainer is pulling the crank into contact with the bearing shell. That crank must roll smoothly when all bolt's are pulled down to spec.

 

[hoeser]

Re: 1984 Evinrude 140 - Crankshaft Binding

I recall the middle bearing retaining pin being a real chore to align, and I eventually got it and confirmed by attempting to roll the bearing. I also noticed that when it wasn't seated perfectly the engine would only rotated about 180 degrees and then stick... so it's in place. The upper bearing has a retaining pin? I never removed it from the upper crank head so I guess I wouldn't know.. like I said I never replaced any of the crank bearings as they were all in good working order.

 

[Joe Reeves]

Re: 1984 Evinrude 140 - Crankshaft Binding

Hoeser..... If any of the pin alignments were not to specifications. tightening the crankcase bolts would cause the crankshaft to actually twist/bend, and in doing so..... that alone would cause the crankshaft to bind. Your description of the problem states that with those bolts tightened, the crankshaft is still free.

However, the fact that you did not know that the upper main bearing also had a locking alignment pin makes one wonder.

I'd suggest that you order the proper bolts, compare them with what you have, and take it from there.

 

[72SideWinderSS]

Re: 1984 Evinrude 140 - Crankshaft Binding

Hoeser,
The bolts are 1/4-28 as Joe stated and I just measured mine (since I happen to be in a rebuild) and they are 1 1/8" long with a 3/8" Hex washer head and star washer under the head.

Hope this helps

 

[hoeser]

Re: 1984 Evinrude 140 - Crankshaft Binding

Well it turns out the issue was with the lower crankshaft seal, the new one I just installed. I didn't install it deep enough into the crank head. As the crank was getting pulled in by the retainer plate, it was pushing up against the seal... making it increasingly more difficult to turn as bolts were brought up to torque. I had to separate the crank halves and basically start over, fully removing the crank but I got it... Everything is back together now after a long night and it's not binding at all.