Clunking Sound Coming to a Stop

[BIGBAND39]

Hello Everyone,

 

It's been a long time since I've been on here, but I'm back with a new ride!  This time around I picked up a 1939 D-11 Luxury Liner.  I had a rear main seal leak which was taken car of by my usual mechanic.  Unfortunately, I forgot to mention to him that when I come to a stop I can clearly hear and almost feel a rhythmic clunking sound.  He told me that the clutch needed some adjustment and everything looked great when he reassembled it.  When we took the car for a test drive after the work was complete, he heard the sound and told me that the transmissions in this old vehicle are somewhat unrefined and that the noise was normal.  It seems to be getting somewhat worse and happens whether the car is in gear or in neutral.  Am I wrong that this could be u-joints?  I don't know how he would have missed that but I'm figuring the reason I don't hear it at higher speeds is that the joint has a load on it.  When I decelerate, it still has a load of the motor winding down and then clacks when the load is released at lower speeds.  Any ideas out there?  Thanks!

 

Jonathan

[TodFitch]

Check your universal joints. . .

 

Might not be a bad idea to inspect the rear brakes for anything out of order too.

[BIGBAND39]

Thanks for the quick response!  That's what I figured.  A transmission rhythmically clunking when in neutral didn't seem to make sense.  Sitting on a flat level road with the car in neutral, I don't feel it pulling at all.  What would I be checking for with regards to the rear brakes?

Edited July 1, 2016 by BIGBAND39

[TodFitch]

. . .What would I be checking for with regards to the rear brakes?

 

 

Anything that looks loose or wrong. Maybe a broken piece of lining, etc.

 

A quick check of the universals is the easiest: Without a load on them (parking brake holding the car from moving on even a slight slope would be a load) see if there is any rotational play that you can feel. There should be none.

[plymouthcranbrook]

You can also get underneath with a big pipe wrench and with the car in gear and the rear wheels on the ground, see if there is any play by trying to turn the shaft with the wrench.  If really bad, you probably can do it by  hand

[desoto1939]

I have u joints for the 39 Dodge they are the same that are used on my 39 Desoto.  This is the pin and trunion style. I have the complete kits with the metal housing.  Also have a lot of great cross reference catalogs and manuals for this car.

 

Send me your home email.  I live near Valley Forge PA.

 

Rich Hartung

Desoto1939@aol.com

cell 484-431-8157

[BIGBAND39]

The pipe wrench is a good idea.  I can likely get that done this weekend.  The last thing I want to do is be driving around for the holiday and have the driveshaft drop. 

 

Thank you Rich for the offer!  As of now, I have the manual for 1938 models with the D-11 supplement.  I've also been able to reference the 1936-1948 Plymouth manual that's available online too. I'm from Cranston, RI.  

Edited July 2, 2016 by BIGBAND39

[greg g]

I think when Rich asked for your particulars he was implying you use the personal message portion of this site rather than a broadcast on an open forum...

[BIGBAND39]

Makes sense. Considered he through his out open forum, I figured I'd do the same. Good looking out. Thanks!

Edited July 2, 2016 by BIGBAND39

[dpollo]

Ball and trunnion joints can  make a terrible noise when you are braking because the torque on the rear axle is causing the snout

of the  housing to move toward the road, stretching the driveshaft.  This movement is normally taken up by the U Joints  but if the grease has hardened or if there is rust in there, the joint balls are running in an area which may no longer be smooth.

 

If you clean and re lube the joints, the noise may persist for a while until the surface inside the bell smooths out.  It is a truly alarming noise but does little harm.

[Phil Martin]

Have you checked rear motor mounts?

[BIGBAND39]

Thanks for all the responses! My girlfriend had plans today that didn't include crawling underneath the Luxury Liner. I might wait until Tuesday, post holiday, when I can get her on a lift.

[soth122003]

A good test would be to coast on a flat strectch of road. Clutch in and coasting, if the condition is there might be the u-joints. If nothing lightly apply brakes, if there is a problem, I would look at the drums being out of round.

 

Joe

[BIGBAND39]

Sorry for the delay.  I finally got the car into the shop today and found that it is the front u-joint.  I have looked into the rebuild kits and I am wondering how I would know if I need to replace the outer metal housing.  How would I grease the existing joint to tell if the old grease has simply dried up?  It would be great not to spend $200 on rebuilding if it's not necessary. Thanks everyone!

Edited July 13, 2016 by BIGBAND39

[greg g]

Here is something you can try for free if you have the same type joint on both ends of the shaft. Remove it and swap it end for end. Some one also mentioned putting a couple washers under the springs just below the end caps. It may move the balls to a different location where wear in the slide portion is less. Might stop the clunking. Not a permanent fix, but give you time to consider other options. You can also have a new shaft made up of modern parts for the same cost as replacing the old stuff with nos parts. That would give you easily replaceable parts should further maintain be needed 30 or 40 years down the road....

[BIGBAND39]

I like the idea of keeping her original and Andy Bernbaum's is allowing me to buy the full u-joint setup and return the unused u-joint casing if I don't need it.  When I take it apart, will wear be noticeable inside the casing?  I feel like instead of jury rigging it, I would rather spend the $155 it would cost me for everything new. Besides that, considering I'm having a shop do it, I'd rather pay to have it done once and right.  Thank you for the suggestions though.   

[TodFitch]

In my limited experience (having only worked on one old Plymouth), by the time a thunk noise is heard due to u-joints the inside of the housing where the ball slides back and forth will have a worn spot that you can feel as you run your fingers across it.

 

It would not surprise me if the front and rear wear slightly differently which could then allow you to get some more miles by simply flipping the driveshaft but that is likely to be a short term fix.

 

Again, in my limited experience, it seems that if you keep the boots in good condition and follow the lubrication/maintenance schedule the u-joints will last a long, long time. Basically they are primitive CV joints and like CV joints seem go indefinitely as long as the boots are good but will fail rapidly if there is a boot issue.