Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: Jim Miller on October 11, 2017, 05:46:05 PM

Title: Occasional pop noise under my '41 62
Post by: Jim Miller on October 11, 2017, 05:46:05 PM
Once in a while moving slowly forward I will hear a single pop under the car. Sounds  toward the rear end. Sounds like when you run over a piece of gravel that pops from the edge of the tire or running over a walnut on the street. Usually after shifting from reverse to forward and after traveling 20 or 30 feet - like maneuvering around to get into the garage or pulling out of a parking spot. Checked rear axle nuts and suspension nuts for proper tightening and checked u-joints. Rear bushings and pads are atrophied, but not sure that would do it. Any suggestion of things to check?
Jim Miller
Title: Re: Occasional pop noise under my '41 62
Post by: The Tassie Devil(le) on October 11, 2017, 06:14:14 PM
Have a look at your universal joints.

Bruce. >:D
Title: Re: Occasional pop noise under my '41 62
Post by: V63 on October 12, 2017, 08:26:15 AM
My guess would be bushings..but also could be a brake shoe. Check wheel nuts and studs. Rear Axle fluid level ?
Title: Re: Occasional pop noise under my '41 62
Post by: Steve Passmore on October 12, 2017, 12:18:21 PM
I would remove all 4 brake drums and check everything. Had some similar noises on my 41, turned out a back brake was sticking in reverse and would suddenly 'pop' off when moving forward.   Both return springs had broken and the broken pieces were jamming up under the lining.
Title: Re: Occasional pop noise under my '41 62
Post by: Jim Miller on October 12, 2017, 02:56:30 PM
Thanks guys - I appreciate the feedback. Recently had all the drums off - shoes, cylinders, and springs were good. I was concerned about the rear drums after reading the forum, but a friend had a very old giant puller and they came off easily. Didn't need a BFH. Re packed front bearings and rear are sealed, but the area was very clean. The rear were Timkens, but I don't know their age. I did order but not put on yet new rear bearings and seals from George at Olcar. Checked u joints when we did the pinion seal. This is why I'm at a loss. It's occasional and I've stopped worrying about it, but it's like an itch you can't scratch.
Jim
Title: Re: Occasional pop noise under my '41 62
Post by: Bob Schuman on October 12, 2017, 03:33:33 PM
Jim,
It looks like Bruce, Steve, and W. Link have covered about everything, but I can suggest one more. Each brake shoe rests against three smooth pad surfaces on the brake backing plate. With wear, those pads can become slightly grooved by the motion of the brake shoes. That can cause slight sticking of the smooth movement of the shoes, and possibly a popping when the shoe overcomes the groove. Checking will require again removing the rear drums, prying the shoes away from the backing plates or maybe removing the shoes to inspect, and grinding those pads smooth if necessary.

The above is a long shot, with my vote still going to a U-joint, even though they have been checked before.
Bob Schuman
Title: Re: Occasional pop noise under my '41 62
Post by: Jim Miller on October 12, 2017, 03:49:26 PM
Thanks - before the weather turns I think we can tackle the dried up rubber components and that's an opportunity to check the u joints and your brake suggestion.