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Engine locks up with transmission in gear

Posted: Fri Sep 17, 2021 12:48 pm
by MikeNTexas
I'm going to start from the beginning. I acquired a 1976 project in pieces and the first thing I did was to rig the engine up on a test stand so I could see if and how good it ran. I ran it for a while and all was good so I cleaned it up, repainted it, replaced the water pump and installed new timing belts and idlers. After replacing the belts I pulled the spark plugs and turned the engine over with a wrench on the crank bolt. It only turned about 90 degrees and stopped. I double checked the cam timing and all looked good. I found out that the tranny was in gear so I found neutral and now the engine turned freely. I found out that the higher gear I put it in the less the engine would turn. In 5th gear it would only turn about 10 degrees. That has led me to believe something is loose inside locking up the output shaft. Suspecting something might have fallen in through the filler hole I rolled the motor over upside down and turned the crankshaft. It turned freely without locking up! So I rotated it back to right side up and when I turned the crank it locked up again. After a few times of rotating the engine to different angles to see when it locks up I now can't get it to lock up. The crank turns freely all the time. What the heck could be causing this?

Re: Engine locks up with transmission in gear

Posted: Fri Sep 17, 2021 1:35 pm
by Whiskerfish
Take off that little cover by the output shaft and look in there

Re: Engine locks up with transmission in gear

Posted: Fri Sep 17, 2021 1:46 pm
by gltriker
Remove the rectangular engine oil strainer screen cover on the bottom right side edge of the crankcase, too.
A Best Practice to remove and inspect the screen anyways. tumb2

Re: Engine locks up with transmission in gear

Posted: Fri Sep 17, 2021 10:02 pm
by Don R
Was the starter installed? The drive gear hangs on a chain and can swing around in there.

Re: Engine locks up with transmission in gear

Posted: Sat Sep 18, 2021 7:09 am
by Whiskerfish
The output shaft just pulls out of that gear inside the case. The shaft is what centers that gear and holds it in place. If the shaft was removed and the engine moved around then it would have allowed that gear to move around. Need to remove that little side cover and realign the gear and the output shaft and see if the problem is resolved. "If" that is the problem then it is a very easy fix.

Re: Engine locks up with transmission in gear

Posted: Sat Sep 18, 2021 7:16 am
by MikeNTexas
Whiskerfish wrote: Fri Sep 17, 2021 1:35 pm Take off that little cover by the output shaft and look in there
I'll give that a look.

gltriker wrote: Fri Sep 17, 2021 1:46 pm Remove the rectangular engine oil strainer screen cover on the bottom right side edge of the crankcase, too.
A Best Practice to remove and inspect the screen anyways. tumb2
Had it out to clean it. I'll pull it back out and take a look in there.
Don R wrote: Fri Sep 17, 2021 10:02 pm Was the starter installed? The drive gear hangs on a chain and can swing around in there.
Starter is still installed

Thanks for the suggestions. There has got to be something floating around inside. Even though I can't get it to lock up now I'll to everything I can to find the offending party. I had ran it a while and went through the gears with it on the test stand with no problems but when I had it upside down to replace the water pump whatever is in there must have fallen into the gears.

Re: Engine locks up with transmission in gear

Posted: Sun Sep 19, 2021 11:38 pm
by Don R
That sucks.

Re: Engine locks up with transmission in gear

Posted: Mon Sep 20, 2021 1:00 pm
by MikeNTexas
I pulled out the oil strainer and looked inside and found this broken off piece Anyone recognize it?
14A8A443-E19A-4BC5-B314-099F16124306.jpeg
14A8A443-E19A-4BC5-B314-099F16124306.jpeg (273.33 KiB) Viewed 212 times
51AE91DE-7BDC-4EA0-B740-6D07276E4A62.jpeg
51AE91DE-7BDC-4EA0-B740-6D07276E4A62.jpeg (251.67 KiB) Viewed 212 times
A5DD2B87-B01A-4CDE-94F9-A642070ADF5C.jpeg
A5DD2B87-B01A-4CDE-94F9-A642070ADF5C.jpeg (288.48 KiB) Viewed 212 times
F27F9770-ED29-453C-A0A6-137FF095FF5E.jpeg
F27F9770-ED29-453C-A0A6-137FF095FF5E.jpeg (237.64 KiB) Viewed 211 times

Re: Engine locks up with transmission in gear

Posted: Mon Sep 20, 2021 3:03 pm
by Rat
Nope, was chipped off a thick something or other, looks like the edge of a hole in a case or somesuch ...

Gord :roll:

Re: Engine locks up with transmission in gear

Posted: Mon Sep 20, 2021 3:26 pm
by Whiskerfish
Interesting shape but no I have no idea right now.

Re: Engine locks up with transmission in gear

Posted: Mon Sep 20, 2021 3:59 pm
by Old Fogey
Did you only find two pieces, as there is just about 180 degrees of the hole, so another 180 somewhere either still attached or stil floating around in there. I don't remember (from my travells) how big a one cent coin is. Can you put a ruler beside them? Also try to size the hole with a drill on the larger piece.

Re: Engine locks up with transmission in gear

Posted: Mon Sep 20, 2021 4:23 pm
by gltriker
Is it attracted to a magnet?

Re: Engine locks up with transmission in gear

Posted: Mon Sep 20, 2021 4:28 pm
by Old Fogey
Oh, my mistake, reading the post again. There's only one piece?

Re: Engine locks up with transmission in gear

Posted: Mon Sep 20, 2021 4:32 pm
by Old Fogey
I can't think of anything like that, but assuming it actually belongs in the engine, regardless of what it is, something had to have hit it to break it off which means there has got to be other faults inside.

Re: Engine locks up with transmission in gear

Posted: Mon Sep 20, 2021 5:30 pm
by MikeNTexas
Old Fogey wrote: Mon Sep 20, 2021 3:59 pm Did you only find two pieces, as there is just about 180 degrees of the hole, so another 180 somewhere either still attached or stil floating around in there. I don't remember (from my travells) how big a one cent coin is. Can you put a ruler beside them? Also try to size the hole with a drill on the larger piece.
There only the one piece. one cent is about 19MM in diameter.
gltriker wrote: Mon Sep 20, 2021 4:23 pm Is it attracted to a magnet?
It's aluminum. Not attracted to a magnet.

I have another engine that had some bad rust in one cylinder so today I took it apart. So far I can not find any of the casting that has the shape of this piece.