how far off is my speedo-larger than stock tire

[bobehud]

I have seen on the net a way to figure it.My Burban began like as a K1500..PO
Turned it into a 1 ton and i bought 33x12.5x16.5 yes 16.5...
The truck had 235/75R15 ,i ask because as i cruise along at 60mph on the speedo it seems to run up on traffic quickly.

 

[crazy4offroad]

Need to post gear ratio, t-case and trans type. I know you did it in your intro thread but you should include it in your question, or put those details in your signature like mine is. You can use this gear ratio calculator
http://www.grimmjeeper.com/gears.html
to find expected speed at certain rpms. The reason there are 2 columns is to do side-by-side comparison, like if you wanted to see what to expect with different size tires, or different gears, t-case, trans, etc.

If I remember correctly you have a TH400, NP205 and 4.09 gears (which I've never heard of, maybe 4.11s??). Anyway, it looks like at 60mph you'll be turning 2,640 rpms. The foolproof way to figure out how far off your speedo is, is to take a GPS with you for a test drive. Recently I did the same thing and found out with my gears and tires, I'm close enough that I wont be getting pulled over.

 

[bobehud]

yeah the 4.09 gears threw me off,need to get a tach.

 

[crazy4offroad]

4.09s were common in Dana 44s, you for sure that front is indeed a Dana 60? They look very similar except the D60 has the extra thick webbing on the 3rd member top and bottom, and it should have "60" on the lower right webbing, looking at it from the front.

 

[bobehud]

Positive about the Diff's these are aftermarket gears so who knows how many aftermarket gear sets there are.

 

[crazy4offroad]

Yeah I know that's why I started looking for 4.09s and all that was coming up was sets for the Dana 44. The 14 bolt could have 4.11s and that would be close enough not to have any real bad binding on the blacktop but I still would refrain from driving it on dry blacktop in 4WD. Still, I'm curious about that front axle. Next time you're snappin pics get a good one of the front diff and post it up.

 

[bucket]

Yeah I know that's why I started looking for 4.09s and all that was coming up was sets for the Dana 44. The 14 bolt could have 4.11s and that would be close enough not to have any real bad binding on the blacktop but I still would refrain from driving it on dry blacktop in 4WD. Still, I'm curious about that front axle. Next time you're snappin pics get a good one of the front diff and post it up.

He's got a pic of the front wheel in his other thread... it's got the big fat manly hub poking through the center of the wheel.

 

[bobehud]

Bucket is correct it is a Dana 60 with a 4 bolt Ball joint buddy got under it and just chuckled when i asked if it might be a 44. to be honest 4.09/4.10
dont care just when i set up gears in diff's most have been 4.11's but that was 10 years ago who knows now