TR4/4A Horn button and brush assistance

[Chasman3]

I found an original steering wheel for my 61 TR4. It wasn’t complete so I ordered clip, brush and button assembly from Moss. The replica assembly wouldn’t fit without some modification so I sent it back to Moss.

I bought what I thought was a decent Lucas button from EBay. However the brass wire is pulled out. It is spring like in that it will push down against the rim of the plastic. It fits nice and snug without the brush but as soon as I include the brush, it will pop off. Good news my horns will work. I’m thinking this button is defective. The moss replacement, I was certain, the wire was not pulled out but adjacent to the plastic housing. Or the horn brush Moss )560-430) provided is too long? Uncompressed it measures ~ 2.5”. I’ve asked the seller for a refund but if this is the brush I am wrong. Thanks for your help.

 

[TRopic6]

C3, The button should fit into the steering wheel hub with that wire pushed in. The spring action keeps it in contact with the hub, which provides the ground for the horns (after passing through wires connecting across the steering couplers). The button should be held in place by a 3-prong spring steel clip that attaches under the nut that holds the wheel (ha ha). 2.5" is the correct brush; there is a longer one, for Spitfires maybe. Here is a picture of one I have for the later TR6 with the same wire.

Jeff

 

[Chasman3]

All correct and I know but as soon as I put the brush in, it will pop it off the spring steel clips. Note the difference in your button and mine. The brass wire is pulled out farther. I think that’s the problem?

 

[TRopic6]

Yes, you have to push and hold it in while pushing the button into the 3-prong clip. If it won't go in easily, try pushing the wire in with a thin screwdriver while you push the button into the clip. I thought maybe the repro clip wasn't made to the right dimensions, but yes, if that wire sticks out it won't let the button drop down far enough. I have a clip somewhere if you need to compare.

 

[Chasman3]

I’ve done that. I guess I’m not be clear. The button will go in flush and stay in place without the brush. And yes the wire is spring like and will depress while the spring steel clips connect to the button but it won’t remain fastened with the load from the the brush pushing up on it. My thought was the wire has been bent out causing it to misalign.

 

[charleyf]

I’ve done that. I guess I’m not be clear. The button will go in flush and stay in place without the brush. And yes the wire is spring like and will depress while the spring steel clips connect to the button but it won’t remain fastened with the load from the the brush pushing up on it. My thought was the wire has been bent out causing it to misalign.

It sounds to me like your brush may be either to long or the spring in it is to strong. I can not verify the length needed as I use after market steering wheels. But I have found some brush sets that were to long and was able to grind off some of the bottom contact to shorten it.
Just a thought.
Charley

 

[TRopic6]

The later TR6 replaced the 3-prong clip with a couple of side clips to hold it in. I found a horn button with one still attached, maybe a combination of the two would hold it in. I pushed the button I have into a 3-prong clip, and it didn't hold it in as tightly as I expected. And you can't bend the prongs in too much or they be open enough for the button to pop in.

 

[Chasman3]

Thanks. TRopic6. The wire on yours is much closer. I suspect mine was pulled out to give better contact. And I have a new spring steel clip.

 

[Chasman3]

I found an original steering wheel for my 61 TR4. It wasn’t complete so I ordered clip, brush and button assembly from Moss. The replica assembly wouldn’t fit without some modification so I sent it back to Moss.

I bought what I thought was a decent Lucas button from EBay. However the brass wire is pulled out. It is spring like in that it will push down against the rim of the plastic. It fits nice and snug without the brush but as soon as I include the brush, it will pop off. Good news my horns will work. I’m thinking this button is defective. The moss replacement, I was certain, the wire was not pulled out but adjacent to the plastic housing. Or the horn brush Moss )560-430) provided is too long? Uncompressed it measures ~ 2.5”. I’ve asked the seller for a refund but if this is the brush I am wrong. Thanks for your help.

A follow up. I took the after market brush and ground ~ 0.2 mm off the end. It seems to be enough to keep the button secure. I need to test drive for sure. The horn works. My guess is the aftermarket brush spring is more robust than NOS. And the ground wire stretched both confounded and compounded the problem. I will say this, the horns are loud! My ears were ringing after tooting it in the garage! My wife’s too! Thanks for the help and wish me luck with oncology tomorrow.

Charlie

 

[TRopic6]

Jolly good! Our cars are pretty small compared to what's on the road today, so working horns are a must. All the better when both H & L sound off to get attention, maybe even bring a few smiles. Yes - wishing you all the best tomorrow.

Jeff

 

[TR Tom]

I have been having the exact same problem on my TR4. My horn button is OEM and looks exactly like yours, with the spring sticking out like that (not close in, like picture in post #2). With the brush assembly not in place, it stays on just fine, but when installed occasionally pops off, usually when I’m honking frantically at some moron in an SUV trying to cut me off.

I often suspected that the aftermarket brush was too long or the spring too strong as Charley F said. Always meant to grind a little off, but never got around to it. Will now give it a try. Thanks to both of you for inspiring me to finally fix this. Nothing worse than having the horn button fall off in your hand when some inconsiderate driver is trying to kill you.

Thanks
Tom

 

[Chasman3]

I have been having the exact same problem on my TR4. My horn button is OEM and looks exactly like yours, with the spring sticking out like that (not close in, like picture in post #2). With the brush assembly not in place, it stays on just fine, but when installed occasionally pops off, usually when I’m honking frantically at some moron in an SUV trying to cut me off.

I often suspected that the aftermarket brush was too long or the spring too strong as Charley F said. Always meant to grind a little off, but never got around to it. Will now give it a try. Thanks to both of you for inspiring me to finally fix this. Nothing worse than having the horn button fall off in your hand when some inconsiderate driver is trying to kill you.

Thanks
Tom

It will work. I used a Makita grinder took off a little and tested them a little more. I think it’s fixed but really need some good driving for sure. It was a simple fix. Charlie

 

[Chasman3]

Another update.

It will work. I used a Makita grinder took off a little and tested them a little more. I think it’s fixed but really need some good driving for sure. It was a simple fix. Charlie

Important! Don’t use the grinder. Too hot. I ground more today, It got too hot and liquified the solder and ruined the brush. Need to use a hack saw or possibly a file to avoid the heat.

 

[Chasman3]

I took it for a spin. The cap popped off. So got out the grinder. I got it too hot. It liquified the solder and ruined the brush. I decided to order a new repro horn button again from Moss and modify to fit. That button at least the first one I got, had a v shaped plastic on its hub that needs to be removed to fit into the wheel. I think it will be more snug than the Lucas cap that I have. I’ll let you know.

 

[Chasman3]

I purchased a reproduction again from Moss. It definitely requires modification to work on the original TR4 banjo steering wheel. I should have photographed before modifying. Anyway the plastic base where the flat brass tab lies, has a pointed tip of plastic about 1.5 mm projecting from it. That plastic tip will not allow the reproduction cap to fit into the steering wheel hub. I used a flat file, carefully avoiding contact with the outermost plastic of the button. I took the spring steel clip and wheel nut off to test. Once I filed enough that it would snuggly fit into the hub, I reinstalled the clip, wheel nut, tightened the nut, installed the brush and finally pushed the cap on. It’s snug and the horn works! It’s not Lucas but it’s acceptable. The Lucas cap simple is too loose. The grounding side wire on the repro is definitely closer to the body than the one I purchased on eBay. Perhaps I can modify but for now the repro fits and works.