Ratio Adapter Maintenance - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**jeffahart** · 02-26-2019, 02:50 PM

Funny the things you take forever to get around too. My speedo has been off by 20% since I got the truck. Last week I decided it was time to change out the adapter. I have an upper and lower cable. So I was measuring for a one length long cable to determine my speed without the adapter. I wasn't wanting to buy a cable. I studied the adapter and figured what the heck. I flipped it, and now the speed is right on the money with my GPS. Nice, why didn't I try that sooner!

Anyone know if I can pop those ends off and grease them. I'm kind of skeptical about messing with it. An if it works don't fix it type thing. But at the same time, I think if I could grease it somehow maybe I could extend its life.

Also, anyone know what the etched in numbers are?

Here's a couple pics of the adapter. Thoughts appreciated.

j

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B. W. · 02-26-2019, 03:25 PM

I believe it's a custom made ratio box that can be assembled from a kit. The etched numbers are the part numbers for the gears used. You would think that the ratio would be etched on it also, guess not.

**jeffahart** · 02-26-2019, 03:39 PM

Quote:

Originally Posted by B. W.

I believe it's a custom made ratio box that can be assembled from a kit. The etched numbers are the part numbers for the gears used. You would think that the ratio would be etched on it also, guess not.

Thanks for the info. Any idea if I can or should pull those ends off and try to grease the gears?

j

B. W. · 02-26-2019, 04:11 PM

I think you can drive the pin out & separate the two halves. Grease it & re-assemble. Some of the heavy duty ones have grease fittings. While it's apart you might see a good spot to put a grease fitting in it.

**jeffahart** · 02-26-2019, 04:19 PM

Quote:

Originally Posted by B. W.

I think you can drive the pin out & separate the two halves. Grease it & re-assemble. Some of the heavy duty ones have grease fittings. While it's apart you might see a good spot to put a grease fitting in it.

Sounds like a plan. I'll take some pics if I can get it apart.

Thanks,

j

**jeffahart** · 03-04-2019, 01:15 PM

Just like B.W. said. Case split nicely. Aluminum case with steel gears. Here's the inside. Cleaned and lubed only took a couple minutes. Grease was hard and dry. Glad I spent a couple minutes on maintenance.

j

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weq92f · 03-04-2019, 09:49 PM

.
That is very cool, thanks for sharing!

-klb

AcampoDave · 03-05-2019, 10:02 PM

Wow, i wasn't expecting it to be so well made. It must be old

02-26-2019, 02:50 PM	#1
jeffahart Senior Member Join Date: May 2012 Location: Scottsdale, AZ Posts: 1,883	Ratio Adapter Maintenance Funny the things you take forever to get around too. My speedo has been off by 20% since I got the truck. Last week I decided it was time to change out the adapter. I have an upper and lower cable. So I was measuring for a one length long cable to determine my speed without the adapter. I wasn't wanting to buy a cable. I studied the adapter and figured what the heck. I flipped it, and now the speed is right on the money with my GPS. Nice, why didn't I try that sooner! Anyone know if I can pop those ends off and grease them. I'm kind of skeptical about messing with it. An if it works don't fix it type thing. But at the same time, I think if I could grease it somehow maybe I could extend its life. Also, anyone know what the etched in numbers are? Here's a couple pics of the adapter. Thoughts appreciated. j __________________ White K20

02-26-2019, 03:25 PM	#2
B. W. Registered User Join Date: Nov 2014 Location: Bigfork, Montana Posts: 1,137	Re: Ratio Adapter Maintenance I believe it's a custom made ratio box that can be assembled from a kit. The etched numbers are the part numbers for the gears used. You would think that the ratio would be etched on it also, guess not.

02-26-2019, 04:11 PM	#4
B. W. Registered User Join Date: Nov 2014 Location: Bigfork, Montana Posts: 1,137	Re: Ratio Adapter Maintenance I think you can drive the pin out & separate the two halves. Grease it & re-assemble. Some of the heavy duty ones have grease fittings. While it's apart you might see a good spot to put a grease fitting in it.

03-04-2019, 01:15 PM	#6
jeffahart Senior Member Join Date: May 2012 Location: Scottsdale, AZ Posts: 1,883	Re: Ratio Adapter Maintenance Just like B.W. said. Case split nicely. Aluminum case with steel gears. Here's the inside. Cleaned and lubed only took a couple minutes. Grease was hard and dry. Glad I spent a couple minutes on maintenance. j __________________ White K20

03-04-2019, 09:49 PM	#7
weq92f Registered User Join Date: Oct 2016 Location: Dallas Texas Posts: 2,885	Re: Ratio Adapter Maintenance . That is very cool, thanks for sharing! -klb __________________ 67 C10 fleet fuel injected '70 402, 700r4, 3.73 posi 07 335 sport turbo 6sp 94 Trans Am GT LT1 6sp posi -- sold after 22yrs 99 540 sport V8 6sp -- sold 73 240z L24 4sp -- given to friend 68 C10 step 350/350 3.73 open -- sold

03-05-2019, 10:02 PM	#8
AcampoDave Registered User Join Date: Feb 2013 Location: central California Posts: 2,727	Re: Ratio Adapter Maintenance Wow, i wasn't expecting it to be so well made. It must be old



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