Speedometer sending unit adapter for 395/85R20 tires

[tcruwithme]

Ok. I ordered and received "Ratio Adapter, Speed Up Rate: 20%" that is part number 54RA2+20% from PATC Transmissions. Their phone number is 1-888-201-2066. The part cost $62 plus $8 in shipping with no tax. I have not yet got a chance to install it, as my tuck is parked an hour away. I make this post to share what the instructions look like and provide a photo of what arrived. There will not be such an opportunity once I attempt to get it installed. This is third on my list of projects right after marker lights and convoy lights. It's getting cold here, so I hope all goes well!

 

[peashooter]

Okay, I think the correct speedometer adapter for the deuce with 395 tires is going to be a 1:222 unit that has a part number scary close to the 939 trucks.
There is a SP-288 .222 unit (NSN 3010-00-740-9623). An alternative part number for it is 749623, but its NOT THE SAME AS 749623-1

http://www.parttarget.com/3010-00-740-9623_3010007409623_2520007409623.html

Well I mounted this one and tried it out today! It shows the correct speed when using 395's ! Mystery solved!

 

[rustystud]

Well I mounted this one and tried it out today! It shows the correct speed when using 395's ! Mystery solved!

Way to go Aaron !!!

 

[tcruwithme]

That's great Aaron! Can you tell us which specific part you got? There looks to be a few with the same model number but by different manufactures. I'll try installing the unit I have on Tuesday, and if that doesn't work, I'll know what my backup plan is. Thanks again.

Well I mounted this one and tried it out today! It shows the correct speed when using 395's ! Mystery solved!

 

[peashooter]

Sure, here are some pics... Looks like the one I got was marked "RELSP288 .222" as the part number although like you said there are several different part numbers. The unit did come with a rubber washer inside the female threaded part that I had to remove to make it fit correctly. (its the same housing as the other speedo adapters, the deuce just has a rubber seal on the transfer case so the rubber washer I removed must have been for a different application as these are also used on some planes according to the NSN).

 

[skinnyR1]

Anyone successfully order one of these lately? Anyone at that link is quoting me in quantity only, not just one.

 

[peashooter]

Anyone successfully order one of these lately? Anyone at that link is quoting me in quantity only, not just one.

I think you can get some used ones from boyce equipment. I had found mine on eBay a few months back but it was the only one listed unfortunately. I have to think that you could contact one of the manufacturers of these and have them make one. It's the same housing just with different combinations of gears inside to get the desired ratio.

 

[Jakelc15]

Okay, I think the correct speedometer adapter for the deuce with 395 tires is going to be a 1:222 unit that has a part number scary close to the 939 trucks.
There is a SP-288 .222 unit (NSN 3010-00-740-9623). An alternative part number for it is 749623, but its NOT THE SAME AS 749623-1

http://www.parttarget.com/3010-00-740-9623_3010007409623_2520007409623.html

I tried the 939 speedometer adapter on my 818. At first it spun the wrong direction and only showed speed in reverse. I took it apart and flipped the output to the correct side. Now it shows speed going forward but is way too fast. Second gear winds out to 60 mph and I know that's impossible!
My truck has stock size tires.
I guess I'll keep looking for the correct one. I have this 939 one if someone wants to try it.

 

[peashooter]

I tried the 939 speedometer adapter on my 818. At first it spun the wrong direction and only showed speed in reverse. I took it apart and flipped the output to the correct side. Now it shows speed going forward but is way too fast. Second gear winds out to 60 mph and I know that's impossible!
My truck has stock size tires.
I guess I'll keep looking for the correct one. I have this 939 one if someone wants to try it.

Right, the 939 uses the adapter with part # 749623-1, which is not the same as the correct adapter that will work on the deuce w/395's.... that part number is 749623 (doesn't have the "-1" at the end). The part number is nearly identical but it is completely the wrong part.... I learned that the hard way as well.

 

[DMaddox]

Ok. I ordered and received "Ratio Adapter, Speed Up Rate: 20%" that is part number 54RA2+20% from PATC Transmissions. Their phone number is 1-888-201-2066. The part cost $62 plus $8 in shipping with no tax. I have not yet got a chance to install it, as my tuck is parked an hour away. I make this post to share what the instructions look like and provide a photo of what arrived. There will not be such an opportunity once I attempt to get it installed. This is third on my list of projects right after marker lights and convoy lights. It's getting cold here, so I hope all goes well!

View attachment 519135 View attachment 519136 View attachment 519137

Did you ever install this part. Did it work for you. Was it correct.

 

[peashooter]

Did you ever install this part. Did it work for you. Was it correct.

I just saw some of the 3010-00-740-9623 correct ratio adapters on ebay but they were $99. If you are willing to spend $70 on an an add on conversion kit, then its probably worth spending a bit more for the correct ratio original style adapter thats a direct swap.

 

[Eliteweapons]

I just saw some of the 3010-00-740-9623 correct ratio adapters on ebay but they were $99. If you are willing to spend $70 on an an add on conversion kit, then its probably worth spending a bit more for the correct ratio original style adapter thats a direct swap.

I just ordered one from one of our vendors for $89. not sure if I am allowed to say who it is thou.

 

[gringeltaube]

... not sure if I am allowed to say who it is....

Yes, you are allowed.

 

[DMaddox]

I just ordered one from one of our vendors for $89. not sure if I am allowed to say who it is thou.

Could you PM me the vendors.

 

[Eliteweapons]

Big Mikes Motorpool has em.

 

[texas30cal]

Just to confirm as there are a lot of part no's in this thread, the one that big mikes has is the correct one, and is part no 3010-00-740-9623?

 

[Eliteweapons]

This is what it says on his page.

.222 RATIO SPEEDOMETER DRIVE FOR USE WITH CORRECTING THE SPEEDOMETER TO THE PROPER CALIBRATION WHEN UPGRADING THE TIRES ON YOUR 2.5 TON TRUCK TO THE 395 SIZE SINGLE TIRES.

[h=1].222 RATIO SPEEDOMETER DRIVE FOR 395 SIZE TIRES - 7409623[/h]
NOT FOR USE WITH STOCK TIRES, AS IT WILL MAKE THE SPEEDOMETER READ INCORRECTLY WITH STOCK SIZE TIRES.
PART # 7409623 NSN 3010-00-740-9623, 2520007409623

 

[USMCGunny]

I ordered one for the M800 series trucks from Seems to work fine. Im running G177 1100x20 tires on stock duece rims.

 

[montaillou]

I do the math in my head. Rather spend that money on bling.

 

[MrMikey4026]

Tacoma speedometer can build you a ratio adapter, just tell them how far off it is and the can calculate the correct adapter.
I used to build them in the truck shop I worked in, long ago out of business!

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Mike