TECH: Fix a stuck Radio Pushbutton

This tech will descibe the most common reasons for push****ons to be stuck/ hard to push /hard to set on old car radios

For those of you who dont know. To set your cl***ic radio push****ons, tune to desired station using the tuner knob, pull out on the push****on you want to set that station to. Pulling ou ton the ****on should extend the ****on farther out then the rest of the push****ons. To set, simply plress the ****on all the way in. In a workign radio, the station is now set to this push****on. This post describes what to do if this doesnt happen.

For the majority of this post I will be using a delco radios tuner for pictures and description but push****on tuners are mostly all the same and the ideas here should carry over to most push****on radios from 1935-1985

The main problems you will see are:

1: Push****ons that dont set the station you tuned to correctly/ at all

2: push****ons that are very hard to push and dont move the dial.

in the next posts we will discuss each one.

 

Problem #1- Push****ons that dont set the station you tuned to correctly/ at all


This is usually caused by rust in the tuner shafts. This can be fixed easily by removing the bottom cover only on most radios. No electronic knowledge needed

To understand what to do, you first need to know how the tuner works.

As you tune the radio with the tuner knob, the mechanism moves the dial pointer and tuning coils usually through a gear. The gear connects to a long shaft . The shaft connects to a boxed shape section that runs through the push****on ***embly. See the picture below which shows the boxed shape area outside of a tuner and inside of a tuner.

 

Again- I am right now describing how the push****on tuner works- Dont worry you wont need to take it apart for this fix...

Moving on.

Each push****on shaft is made up of multiple parts. 2 sliding plates, one arm, a clutch plate and a spring. See the picture below.

When the push****on is in its normal closed position (Pushed in) the clutch plate is pinched by arm and held in one position.

When the push****on is pulled out, the arm is loosened and the clutch plate can move freely. Again, see the pictures.

 

Now lets look at how it works in the tuner-

With the tuner all put together you can see in the picture below where the bixed section is

in the second picture, the #2 push****on has been pulled out to set it and is now being pressed half way back in. note the location of the clutch plate.

the thrid picture shows the push****on pushed almost all the way in. notice how the clutch plate has has become flash against the boxed section of the tuner. At this point the push****on shaft will lock the clutch plate in this position.

With the push****on set, and you tune to a new station with the tuning knob or another push****on the boxed section has moved. When you press the push****on in again, the NOW LOCKED clutch plate will push the boxed section into the same location it was in when you set it.

 

Now that you know how it works- the most common problem is that the clutch plate and surrounding areas of the push****on shaft become rusty.

With the bottom cover off the radio, pull out ALL the push****ons (might as well work on them all at once). looking at the bottom of the tuner you can see holes in the botom plate allowing access to the clutch plates. with a small screw driver or needle nose pliers, try to move the cltuch plate back and forth. It will most likely be very tight and you will need to put some pressure on it to get it to move. Once it moves add some oil to the clutch pivot point and continue to try to move it back and forth until it is loose. Once it is loose, the problem is fixed.

On a side note- if the radio is really rusty, the retaining spring may be broken- if it is, the clutch may not stay in place. the spring will need to be replaced. Last picture shows the spring

 

Now onto problem #2

If you try to push any of the push****ons and they are very hard and dont move the dial, most likely the radio clutch is seized up.

Dont mistake the clutch with the clutch plate discussed earlier- They are different.

The clutch it there to connec the tuner shaft to the tuner ***embly. Whn you tune the radio using the knob, the dial moves. When using the push****ons, the clutch separates the tuning knob from the rest of the ***embly.

There are two tyoes of clutches- All metal (used mostly in Delco radios) and rubber clutches (used mostly in Ford and Mopar radios)

First lets show the delco clutch (Sorry its so dirty). The clutch is the area directly under the worm gear

 

When you push in a push****on, the clutch should separate slightly. Please view the below pictures closely (it doesnt separate much but its easy to see while pressing the push****on in person)

 

If the clutch doesnt separate- hold the push****on in and stick a small screwdriver into the clutch and twist it- Thos should separate the clutch and get it working again. Its a good idea to spray the clutch with contact cleaner to remove some of the built up crud. NEVER SPRAY A CLUTCH WITH LUBE for obvious reasons. If you do this, you will turn the tuning knob but the dial pointer will slip and not move.

Now your problem shoudl be solved.

NExt lets look at the ford/Mopar unit

 

Here isa picture of the Ford/Mopar unit.

As you can see, this clutch sandwiches a rubber pad between 2 metal plates. Sometimes this rubber pad STICKS to the pad its not supposed to and seizes the ***embly.

I have attached pictures of the ***embly closed and open

 

If the clutch doesnt open like shown above, you need to separate it yourself. Look closely to determine which side should not be connected. pushing the clutch with your finger can help you determine. using a small screw driver, gently pop the rubber pad off the side its not supposed to be connected to. Now the clutch is loose.

You may find that there is rust and a glazing stuck on the rubber pad. Use some sand paper to remove this. It can also help to use a co**** sand paper on the metal mating surface. Now your clutch should be fixed.


In the event that you accidentally pop the rubber off of both metal parts, you can reattach by spraying spray glue onto a q-tip and carefully applying it to ONE side of the rubber. Put the rubber in place and let the clutch hold it until its dry.

So thats it. You can now fix some very common ailements of cl***ic car radios.

Any questions?

 

I'm doing this now for a buddies radio. Got new capacitors, cleaned out the push ****ons. My clutch is not stuck. It slips so manual tuning doesn't work. Need to fab or find some new parts.

 

I have a question. Whatever happened to Radio Joe?

 

This article launched his career as a professional proof reader.

 

Im still around- But dont get over here too much- Anyone who needs help is welcome to email me joescl***iccarradio@yahoo.com

Nope- Still building radios...