help diagnosis klunk broken drums?

[Dave_Kriegel]

greetings from my previous post after 65 years engine started when put into low gear heard loud klunk klunk and low band stopped. Pulled inspection plate. Other contributors suggest sounds like a broken drum ( yuck) before I take off hogshead ( difficult for me) any suggestions like what I am thinking here ? how to diagnosis a broken drum. My understanding and what I can see is two -3 smooth drums connected to the bands and planetary gear. By slow,y hand cranking the engine I should be able to see cracks ( broken chunks) from these drums causing the loud clunk sound? When I remove the hogshead can I get to the bottom and sides to remove any foreign objects that may be rotating causing the thump?

[John kuehn]

Dave if the clunking sound is as pronounced as you say it is you probably can hear it by turning the engine over by hand and listening for it. If you can hear it with the inspection cover removed have someone turn the hand crank while you watch what’s going on inside the transmission.
The clunking could be caused by several things besides a broken drum. If it can’t be diagnosed the alternative besides pulling the engine is to remove the transmission cover so you can see things better.

[Steve Jelf]

Sometimes sounds that seem to be from the transmission are really traveling from the rear axle. Has the one in this car been rebuilt? If the drums look OK when you turn them, check out the rear end.

[Charlie B in N.J.]

First off DO NOT START PULLING THINGS FURTHER APART !! You said you engaged low and heard a clunk and low stopped. Does that mean the car doesn't move in low? Explanation is needed because if it's so it may, as Steve said, be somewhere else. Like the rear end. The trans cover is off so look at the drums by all means but we need further information to be able to help. Please re-read and follow the first line in this post.

[Dave_Kriegel]

Thank you all for your advice The car WAS traveling in low then klunk no low The low band looks good I will be turning the engine over with high gear engaged and a back wheel elevated I HOPE something minor !!!!! Never have rebuilt a rear end !!!

[Steve Jelf]

If I understand your situation correctly, this is the first startup after 65 years. That suggests original thrust washers and possibly original band linings. Babbitt thrust washers crumble with age, and cotton rots with time. You could have trouble with both, but I'm guessing washers. Don't worry about the rear end if that's it. Just get the MTFCA axle book and follow Glen's directions. It ain't rocket surgery.

[Loftfield]

A little logic here! If the thrust washers are gone then you won't have low speed, reverse, OR high speed engagement. Very easy to tell if the problem is in the differential or the transmission.Very good advice above, don't tear things apart until all avenues of non-invasive investigation have been exhausted.

[babychadwick]

A clunk and then what? Was the car still freewheeling or did things lock up? Jack up one wheel and see if you can turn the other by hand in high. If it turns something is broken in the driveline. If you can't jack up the other wheel so both are off the ground and rotate one by hand listening for noises as the other rotates in reverse. Rotate the engine by the crank and see if both wheels are turning, block one then block the other. Drain the engine oil, see if there is any bits in it. Check the differential oil and see what it looks like. All relatively easy checks before you tear things apart.