The Ford Barn

GB SISSON · 05-16-2020, 07:42 PM

The needle on my 47 tonner sits on 5 mph in the garage. It looks like it reads 10 mph over actual speed according to those awful digital speed signs the sherriff's dept has mounted on little trailers. This is my diesel converted with a GM SM465 4 speed. I think I have two situations to address. The stock ford tonner rear is something like 4:68 and the chev one ton tranny donor had a 4.11. Before I address the rear end /speedo drive gear, can I just pull the needle off the gauge and stick it back on at zero? Seems I read somewhere that it's a press on fit. Then , next I'll research the different GM drive gears after my dial reads zero.

51504bat · 05-16-2020, 10:13 PM

Can't help you on the needle issue but to dial in the speedo you can always use one of these: https://transmissioncenter.net/shop/...ratio-adapter/
Dodge Ford GM Ratio Adapter, Select Speed Up Rate

Fritz · 05-16-2020, 11:12 PM

Yes, the needle is press-on. I gently pulled mine off holding the circle base with my fingers and then tapped in back on with my finger.

D. Jones · 05-17-2020, 08:37 AM

Be careful as the needle is aluminum and will bend/break quite easily. A clock repair person could pull and replace it quickly and safely.

GB SISSON · 05-17-2020, 10:24 AM

Quote:

Originally Posted by D. Jones

Be careful as the needle is aluminum and will bend/break quite easily. A clock repair person could pull and replace it quickly and safely.

That would mean a ferry trip off this rock I live on. Haven't left in many months. I have a non working speedometer in rough shape. Maybe I'll do a test run on that one. Thanks. And on the speed up drive gear I think I need to slow mine down. I'll move the needle and then go through the speed trap again. Thanks all!

slowforty · 05-17-2020, 10:33 AM

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Use the Speedometer App on your smart phone

CaliforniaBorn36 · 05-17-2020, 10:35 AM

Another option for testing accuracy, if you have a smartphone, is a speedometer app. The speedo in my 1941 Ford 1/2 ton pickup is about 25% slow, so the cheap short term fix is to use an app.

cas3 · 05-17-2020, 11:53 AM

i have pulled them off before. if you gently lift the pointer over the stop peg at zero, let the pointer find its place of rest, make a note of it, pull the pointer off and move it 5mph or what ever you need, and press it back on. be careful touching any of the main face as this old silkscreen can be very fragile and start flaking off. you can do it right there on the rock GB

1948F-1Pickup · 05-17-2020, 02:49 PM

And this speedo has ALWAYS been 5 mph off? I just cleaned and lubed the speedo in my ‘48. At rest it was sometimes at 5 and occasionally at -5....

GB SISSON · 05-18-2020, 10:44 PM

Without touching it this afternoon it was at Zero at rest..... Arrrrgh!

papanick · 05-19-2020, 04:16 PM

It may just need to get serviced. and then checked for speed.

Ggmac · 05-19-2020, 04:23 PM

Quote:

Originally Posted by GB SISSON

Without touching it this afternoon it was at Zero at rest..... Arrrrgh!

You must of driven in reverse pretty fast ! At least 5 mph .

GB SISSON · 05-19-2020, 11:37 PM

Today it was back at 5mph at rest. I unscrewed the cable from the head and the needle stayed at 5. I rotated the shaft with my fingertips and I could spin it back to zero, but it returned to 5 after. Thinking it needs some light lube. Isn't there somplace to lube it like a felt?

cas3 · 05-19-2020, 11:51 PM

you will see 2 little tiny cups, like miniature frost plugs on the main housing, use a small tap, like 8/32 or so, pull the caps and give'er a drink of a couple drops of 3n1 or light oil. best wishes

05-16-2020, 07:42 PM	#1
GB SISSON Senior Member Join Date: Jan 2014 Location: Orcas Island Washington Posts: 4,916	Speedometer needle The needle on my 47 tonner sits on 5 mph in the garage. It looks like it reads 10 mph over actual speed according to those awful digital speed signs the sherriff's dept has mounted on little trailers. This is my diesel converted with a GM SM465 4 speed. I think I have two situations to address. The stock ford tonner rear is something like 4:68 and the chev one ton tranny donor had a 4.11. Before I address the rear end /speedo drive gear, can I just pull the needle off the gauge and stick it back on at zero? Seems I read somewhere that it's a press on fit. Then , next I'll research the different GM drive gears after my dial reads zero. __________________ Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1947 Tonner Pickup (red) mostly stock with exception of a cummins 6at turbo diesel, 1946 Tonner Pickup (green) with 226 cu in 6 cyl flathead, 1979 Toyota landcruiser wagon, completely encased in 1947 Ford Jailbar sheet metal. Ok, cornbinder rear fenders..... 'Rusty ol' floorboards, hot on their feet' (Alan Jackson)

05-16-2020, 11:12 PM	#3
Fritz Senior Member Join Date: May 2010 Location: From Chicago. Now Nashville Posts: 206	Re: Speedometer needle Yes, the needle is press-on. I gently pulled mine off holding the circle base with my fingers and then tapped in back on with my finger. __________________ Cars and metal rust away and are destroyed, but the Word of God will stand forever (Isaiah 40:8, Matthew 24:35).

05-17-2020, 08:37 AM	#4
D. Jones Senior Member Join Date: Jan 2013 Location: Bend, Oregon Posts: 514	Re: Speedometer needle Be careful as the needle is aluminum and will bend/break quite easily. A clock repair person could pull and replace it quickly and safely.

05-17-2020, 10:33 AM	#6
slowforty Senior Member Join Date: May 2010 Location: Tinley Park Ill Posts: 1,060	Re: Speedometer needle Sponsored Links (Register now to hide all advertisements) Use the Speedometer App on your smart phone

05-17-2020, 10:35 AM	#7
CaliforniaBorn36 Senior Member Join Date: Oct 2012 Location: San Francisco Bay Area Posts: 427	Re: Speedometer needle Another option for testing accuracy, if you have a smartphone, is a speedometer app. The speedo in my 1941 Ford 1/2 ton pickup is about 25% slow, so the cheap short term fix is to use an app.

05-17-2020, 11:53 AM	#8
cas3 Senior Member Join Date: Jan 2011 Location: sw minnesota Posts: 4,567	Re: Speedometer needle i have pulled them off before. if you gently lift the pointer over the stop peg at zero, let the pointer find its place of rest, make a note of it, pull the pointer off and move it 5mph or what ever you need, and press it back on. be careful touching any of the main face as this old silkscreen can be very fragile and start flaking off. you can do it right there on the rock GB

05-17-2020, 02:49 PM	#9
1948F-1Pickup Senior Member Join Date: Oct 2015 Location: Socal Posts: 795	Re: Speedometer needle And this speedo has ALWAYS been 5 mph off? I just cleaned and lubed the speedo in my ‘48. At rest it was sometimes at 5 and occasionally at -5....

05-18-2020, 10:44 PM	#10
GB SISSON Senior Member Join Date: Jan 2014 Location: Orcas Island Washington Posts: 4,916	Re: Speedometer needle Without touching it this afternoon it was at Zero at rest..... Arrrrgh! __________________ Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1947 Tonner Pickup (red) mostly stock with exception of a cummins 6at turbo diesel, 1946 Tonner Pickup (green) with 226 cu in 6 cyl flathead, 1979 Toyota landcruiser wagon, completely encased in 1947 Ford Jailbar sheet metal. Ok, cornbinder rear fenders..... 'Rusty ol' floorboards, hot on their feet' (Alan Jackson)

05-19-2020, 04:16 PM	#11
papanick Senior Member Join Date: Mar 2012 Location: gouverneur n,y, Posts: 2,755	Re: Speedometer needle It may just need to get serviced. and then checked for speed.

05-19-2020, 11:37 PM	#13
GB SISSON Senior Member Join Date: Jan 2014 Location: Orcas Island Washington Posts: 4,916	Re: Speedometer needle Today it was back at 5mph at rest. I unscrewed the cable from the head and the needle stayed at 5. I rotated the shaft with my fingertips and I could spin it back to zero, but it returned to 5 after. Thinking it needs some light lube. Isn't there somplace to lube it like a felt? __________________ Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1947 Tonner Pickup (red) mostly stock with exception of a cummins 6at turbo diesel, 1946 Tonner Pickup (green) with 226 cu in 6 cyl flathead, 1979 Toyota landcruiser wagon, completely encased in 1947 Ford Jailbar sheet metal. Ok, cornbinder rear fenders..... 'Rusty ol' floorboards, hot on their feet' (Alan Jackson)

05-19-2020, 11:51 PM	#14
cas3 Senior Member Join Date: Jan 2011 Location: sw minnesota Posts: 4,567	Re: Speedometer needle you will see 2 little tiny cups, like miniature frost plugs on the main housing, use a small tap, like 8/32 or so, pull the caps and give'er a drink of a couple drops of 3n1 or light oil. best wishes