Gear Ratio mismatched

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Walter Joy

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My first ever thread, so I hope it's a good one. I'm a teenager who has a fair bit of knowledge of mechanics and cars, and has been gifted with a 1989 Dodge W250 that has been in the family since 1992. I have just started working on the truck this past week with my family in order to get it on the road for me to go to school and work. Today we decided to put some new RTV on the front differential because it seemed like it was leaking. When we took the cover off I found the tag, and discovered the front axle, a Spicer 44-8F 3500lb, has 3.54:1 gearing. Now I had remembered looking at the build sheet and seeing it was supposed to have 4.10:1 gears. So I checked the rear tag (Spicer 60HD 5800lb) and saw it had a 4.10 in it. Is there supposed to be that much of a difference between front and rear? The driveline is a 360 V8 (throttle body) with a 727 Torqueflite and an NPG241 transfer case. I have read other forums across the web but they only discuss axles that are .01 or so off, not .56. Thank you so much
 

DaKing

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That is too much of a difference.

Maybe one of the axles was replaced? Or maybe someone upgraded to 4:10's and did not change the tag?

You can check by jacking up each axle, rotate a tire and count how many times the drive shaft turns. 1 full rotation of the tire, count turns of drive shaft.
 
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Walter Joy

Walter Joy

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I will try that the next time we have the front jacked up (replacing the brakes now). The build sheet said it should have 4.10 and I assume it means front and rear. Just seems odd. The build sheet also specified I had 12x2.5 rear drums but when we measured them (after buying all the stuff for new 2.5 drums) they were 3 inch. So somewhere there are things not lining up
 
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Walter Joy

Walter Joy

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Yet the odd thing is it seems alright when in 4wd (or I think. The light doesn't come on so either it's blown or something else)
 

Jimmy68

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Take off your covers. Verify your gears. If you do not have a match set do not use 4x4 till you do. Be fine to drive and be fine to use 4x4 in the mud. Front will spin faster which actually will help. I'm talking deep mud, like a foot or more. Chances are as a daily driver your not abusing your truck like that anyway.
 

Rustycowl69

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counting driveshaft revs has been kinda hit or miss for me, and tags can be swapped. But removing the covers and reading the numbers stamped on the ring gear or counting the teeth on the gears is foolproof.
 
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Walter Joy

Walter Joy

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Thanks. I bet it just is a mismatched tag (probably from factory too. Who knows). As dad was saying, he's driven the truck 300 miles round trip in 4wd during snow once and it hasn't blown up. So I would expect it to have done so between 1989 and now
 

crazzywolfie

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I will try that the next time we have the front jacked up (replacing the brakes now). The build sheet said it should have 4.10 and I assume it means front and rear. Just seems odd. The build sheet also specified I had 12x2.5 rear drums but when we measured them (after buying all the stuff for new 2.5 drums) they were 3 inch. So somewhere there are things not lining up
the drums are the same for both 2.5 and 3 inch wide shoes. also since you are doing the brakes and lines this would be a good opportunity to swap to 3" shoes and the larger 1-1/8" bore wheel cylinders. both should cost about the same as the smaller parts.
 
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Walter Joy

Walter Joy

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the drums are the same for both 2.5 and 3 inch wide shoes. also since you are doing the brakes and lines this would be a good opportunity to swap to 3" shoes and the larger 1-1/8" bore wheel cylinders. both should cost about the same as the smaller parts.
Next time around. Right now I just want to get the truck on the road again after 10 years of it being idle (to put it in perspective, 3 or 4 years ago we took it on the road and the odometer rolled to 44,000 miles. Today it sits at 44,035 miles.)
 

crazzywolfie

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it would likely cost more to do those upgrades next time if you decided to do them since you would have to have the drums machined back to full width again.

also the truck could possibly have more than 44,000 miles on it. with my knowledge of these truck i know the odometers on an 89 are only 5 digits so it would never have over 99,999 before it would roll over.
 
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Walter Joy

Walter Joy

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it would likely cost more to do those upgrades next time if you decided to do them since you would have to have the drums machined back to full width again.

also the truck could possibly have more than 44,000 miles on it. with my knowledge of these truck i know the odometers on an 89 are only 5 digits so it would never have over 99,999 before it would roll over.
Nope. This is a true 44,000 mile truck. Been in my family since 1992. When we were trying to diagnose why only 5 of 8 cylinders were firing earlier this year and the rough idle, we replaced the original distributor cap and spark plug wires. (Rough idle was due to Fuel Pressure Regulator going bad and led to gas in oil)
 

crazzywolfie

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you just never know with older trucks. sometimes people just forget when they roll over. i changed mine to reflect how many miles i have personally put on the truck. 44,000 is just really low mileage for an older truck. most usually roll at least once
 
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Walter Joy

Walter Joy

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you just never know with older trucks. sometimes people just forget when they roll over. i changed mine to reflect how many miles i have personally put on the truck. 44,000 is just really low mileage for an older truck. most usually roll at least once
The reason it has so few miles is it is barely driven. My grandfather bought it and drove it for a while, but it was too big for him. It occasionally went out into town to pick me up from preschool and to go to the dump (this was 12-13 years ago) but we took it off the road and drove it around our property doing stuff. Plus 9 miles per gallon and a 30 gallon tank isn't the most cost friendly setup the past 10 years
 

CVX20

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If the ratio's aren't the same it would just bind up and not want to move at all in 4wd(unless maybe you're on glare ice).Believe me you could tell just by driving it in 4wd(providing the t-case and frt axle are working properly).
 

Sniper X

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Many who drive a lot in snow or mud intentionally do a taller ratio in front so the front spins faster. On a regular 4x4 I would not do this but I am also one who is thinking the tag is probably wrong. Check the ring and pinon on both just count the number of teeth on both front and rear. I'll bet they are the same.
 
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