My trucks not stock? Gearing concerns...

[Rembrant]

This is the only stamps I have found on that differential. These are all on the forward side of the differential. Very hard to read.

Well, nothing that is cast into the housing will tell you what's inside it. The data tag may have been removed or rusted away.

Are there any tags on the front differential? Or any way to ID it to confirm what gears are in it?

I'm assuming with the 11,000 lb GVWR that this thing had dual rear wheels...but I'm just guessing. There must be a cut off somewhere in that rating where DRW are required. Gary or Lebaron may know...

If the gearing was changed in this thing, then it would have had to be changed both front and rear. Maybe the transmission was changed...or the speedo cable driven gear. There are a couple things that could cause the speedo to be off.

Transmission change...

Gears changed...

Cable driven gear changed...

[Rembrant]

This is the only stamps I have found on that differential. These are all on the forward side of the differential. Very hard to read.

One thing to try...

Jack the rear end up, and then mark the tire and the driveshaft. If the truck still has the factory spec 4.56 gears, then the driveshaft will have to make 4.5 revolutions for one complete rotation of the rear wheels. That should be pretty easy to see.

[86-350-460-dually]

One thing to try...

Jack the rear end up, and then mark the tire and the driveshaft. If the truck still has the factory spec 4.56 gears, then the driveshaft will have to make 4.5 revolutions for one complete rotation of the rear wheels. That should be pretty easy to see.

I could definitely do that truck with the rear end up and check for the rotations, however, my buddy who has all the jack stands is on vacation until next weekend. So that will have to wait til then unfortunately.

[Nothing Special]

I could definitely do that truck with the rear end up and check for the rotations, however, my buddy who has all the jack stands is on vacation until next weekend. So that will have to wait til then unfortunately.

Generally I think the Sterling is considered an upgrade from the Dana 60. Not sure if it's a huge difference, but I certainly wouldn't be worried that my truck had a Sterling.

(edit to add that I wasn't thinking clearly when I wrote the following. Look down a few posts to read something that isn't garbage.)

Without jack stands but with 4WD you can leave the transfer case in 2WD, lock the right front hub and turn the driveshaft by hand while counting the turns on the left axle shaft (look at the U-joint in the steering knuckle). It's a little harder to count because you are seeing so many caps go by, but put a mark, or some masking tape on one cap and it's not that hard to count.

Because the front diff is almost certainly an open diff, in this test the axle shaft will turn two revs for every turn of the ring gear. So if it turns 9 times for one driveshaft rev you have 4.56. If it turns 8.2 times you have 4.10 and if it turns 7 times you have 3.55. (Those are the stock ratios. It could also be 3.73 = 7.5 turns or maybe other possibilities too if the gearing isn't stock.)

On the off chance that you have a limited slip or aftermarket locker in the front diff you won't be able to turn the front driveshaft with one hub locked. In that case unlock the other hub and do the same test, but don't multiply by two. So 4.5 turns is 4.56, a little over 4 turns is 4.1, about 3.5 turns is 3.55 and so on.

And of course this is assuming that the ratios in the front and rear axles (essentially) match. But assuming you've used 4WD, then they must match, or else you'd be asking why it feels like your truck is broken when you drive in 4WD

[Gary Lewis]

Generally I think the Sterling is considered an upgrade from the Dana 60. Not sure if it's a huge difference, but I certainly wouldn't be worried that my truck had a Sterling.

(edit to add that I wasn't thinking clearly when I wrote the following. Look down a few posts to read something that isn't garbage.)

Without jack stands but with 4WD you can leave the transfer case in 2WD, lock the right front hub and turn the driveshaft by hand while counting the turns on the left axle shaft (look at the U-joint in the steering knuckle). It's a little harder to count because you are seeing so many caps go by, but put a mark, or some masking tape on one cap and it's not that hard to count.

Because the front diff is almost certainly an open diff, in this test the axle shaft will turn two revs for every turn of the ring gear. So if it turns 9 times for one driveshaft rev you have 4.56. If it turns 8.2 times you have 4.10 and if it turns 7 times you have 3.55. (Those are the stock ratios. It could also be 3.73 = 7.5 turns or maybe other possibilities too if the gearing isn't stock.)

On the off chance that you have a limited slip or aftermarket locker in the front diff you won't be able to turn the front driveshaft with one hub locked. In that case unlock the other hub and do the same test, but don't multiply by two. So 4.5 turns is 4.56, a little over 4 turns is 4.1, about 3.5 turns is 3.55 and so on.

And of course this is assuming that the ratios in the front and rear axles (essentially) match. But assuming you've used 4WD, then they must match, or else you'd be asking why it feels like your truck is broken when you drive in 4WD

I agree that the Sterling was considered an upgrade to the Dana 60. And, good thinking on how to figure out the gear ratio.

[Ford F834]

I agree that the Sterling was considered an upgrade to the Dana 60. And, good thinking on how to figure out the gear ratio.

If the truck had a Dana rear with DRW, wouldn’t it be a D70 or D80? I know that the Sterling is a beefier axle, but After seeing what happened with my short yoke version I would hesitate to rank it above a D60 😬.

Bill, are you saying that the later DRW axles for pickup trucks place the inner wheel track directly behind the front wheels? And do you know if DRW ever came in a 3.55 ratio?

[Nothing Special]

Generally I think the Sterling is considered an upgrade from the Dana 60. Not sure if it's a huge difference, but I certainly wouldn't be worried that my truck had a Sterling.

(edit to add that I wasn't thinking clearly when I wrote the following. Look down a few posts to read something that isn't garbage.)

Without jack stands but with 4WD you can leave the transfer case in 2WD, lock the right front hub and turn the driveshaft by hand while counting the turns on the left axle shaft (look at the U-joint in the steering knuckle). It's a little harder to count because you are seeing so many caps go by, but put a mark, or some masking tape on one cap and it's not that hard to count.

Because the front diff is almost certainly an open diff, in this test the axle shaft will turn two revs for every turn of the ring gear. So if it turns 9 times for one driveshaft rev you have 4.56. If it turns 8.2 times you have 4.10 and if it turns 7 times you have 3.55. (Those are the stock ratios. It could also be 3.73 = 7.5 turns or maybe other possibilities too if the gearing isn't stock.)

On the off chance that you have a limited slip or aftermarket locker in the front diff you won't be able to turn the front driveshaft with one hub locked. In that case unlock the other hub and do the same test, but don't multiply by two. So 4.5 turns is 4.56, a little over 4 turns is 4.1, about 3.5 turns is 3.55 and so on.

And of course this is assuming that the ratios in the front and rear axles (essentially) match. But assuming you've used 4WD, then they must match, or else you'd be asking why it feels like your truck is broken when you drive in 4WD

It must be too early in the morning. I was an idiot and no one called me on it. I had the ratio backwards. The method was right, but the numbers were all wrong.

Assuming an open diff, lock the right hub, mark the left U-joint and turn the driveshaft by hand. But count the number of DRIVESHAFT revolutions as the axle makes 2 full revolutions. And the number of revs will be the ratio. ~4 1/2 is 4.56, a little over 4 is 4.10, about 3 1/2 is 3.55.

And if it's a limited slip or locker unlock the right hub and count driveshaft revs for 1 turn of the axle. Again, 4 1/2 = 4.56 etc.

(A Truetrac limited slip will act like an open diff in this test.)

[Gary Lewis]

It must be too early in the morning. I was an idiot and no one called me on it. I had the ratio backwards. The method was right, but the numbers were all wrong.

Assuming an open diff, lock the right hub, mark the left U-joint and turn the driveshaft by hand. But count the number of DRIVESHAFT revolutions as the axle makes 2 full revolutions. And the number of revs will be the ratio. ~4 1/2 is 4.56, a little over 4 is 4.10, about 3 1/2 is 3.55.

And if it's a limited slip or locker unlock the right hub and count driveshaft revs for 1 turn of the axle. Again, 4 1/2 = 4.56 etc.

(A Truetrac limited slip will act like an open diff in this test.)

There's a man that takes the blame. You could have edited your post. But, instead you took the blame.

[85lebaront2]

If the truck had a Dana rear with DRW, wouldn’t it be a D70 or D80? I know that the Sterling is a beefier axle, but After seeing what happened with my short yoke version I would hesitate to rank it above a D60 😬.

Bill, are you saying that the later DRW axles for pickup trucks place the inner wheel track directly behind the front wheels? And do you know if DRW ever came in a 3.55 ratio?

Yes to the tracking and yes to the 3.55 ratio. Darth came with an open 3.55 gear Sterling 10.25" rear, when I redid the rear because of a spun left rear wheel bearing I took the guts from a 3.55 SRW traction lock and put it in an originally 4.10 DRW open housing (4.10 set had water damage to the ring and pinion). I wanted the limited slip 3.55 gear and needed it to have the ABS tone ring for the 1992 up speedometer so I used the innards from the parts truck SRW 3.55 limited slip Sterling and put them in the junkyard 4.10 DRW open Sterling.

[86-350-460-dually]

Yes to the tracking and yes to the 3.55 ratio. Darth came with an open 3.55 gear Sterling 10.25" rear, when I redid the rear because of a spun left rear wheel bearing I took the guts from a 3.55 SRW traction lock and put it in an originally 4.10 DRW open housing (4.10 set had water damage to the ring and pinion). I wanted the limited slip 3.55 gear and needed it to have the ABS tone ring for the 1992 up speedometer so I used the innards from the parts truck SRW 3.55 limited slip Sterling and put them in the junkyard 4.10 DRW open Sterling.

Thank you all. I must give this a test to find out. I personally have been afraid to give it a go in 4wd, because of my fears of breaking things haha. However, we shall find out shortly. Thanks for all the info.