"Rocky" - 1981 F250 Restoration

[taskswap]

I don't know if OP is still looking for a lug solution but just to put a pin in that, I did replace my (stock/left-side) lugs on both my discs (front) and drums (rear). I used these:

Dorman 610-228 Rear 9/16-18 Serrated Wheel Stud - .625 in. Knurl, 2-25/32 in. Length Compatible with Select Ford Models, 10 Pack

https://www.amazon.com/gp/product/B0011N1K7C

The listing is misleading, this is for a box of 10 (they aren't $22ea!). But they installed quite easily, I thought. I didn't need a press for removal or installation. I just set the disc and drum over a cinder block and used a 2lb sledge to drive them out and the new ones in. To seat them fully I used a pair of washers with a small dab of grease between them as a temporary bearing and an open-end lug nut plus a deep socket impact to draw them fully in. It was really fast an easy.

Guys can I revive an old and horse-beaten topic? Rear lockers. But maybe with a twist?

I've had a health setback (stroke) and I'm reprioritizing some projects. Everyone in the family loves Rocky and I have no plan to sell it, but figuring out what to do with it has been a challenge. I'm the only person who can drive stick (very well) and I don't really want to think about an automatic conversion. It's also obviously never going to be a show truck.

We have a homestead here in CO where it can while away its years (just like me LOL) but the most useful thing I'd do with it aside from runs into town is plowing. Not a lot of plowing, mind, but we have a dirt access road with two spots that collect snowdrifts, each about 30' long. It's enough to be a barrier for most vehicles in winter, but as you can imagine this is no great workload for even an entry level plow setup. It's a straight "push it to the side to make a path" type of work effort.

The trouble is, Rocky is 2WD. All the other specs are great - '81 F-250, 6.6L V8 351M that starts instantly even in the dead of winter, etc. I've got some chunky hybrid-mud tires on there, too and I can keep chains on it full time because it's all a dirt road from the property out to the main highway. But it's still very tempting to try to do something about the stock rear axle (a Dana 61 at 3.73).

I know lockers come up in discussion a lot but all the past threads I've seen have focused on daily drivers, people wanting "hunt trucks with highway manners" and so on. But what would you do if you had the opposite situation? Suppose you wanted the fastest, simplest option to give something like Rocky more grip in snow and mud, and on-road behavior was almost never important? I'm not super driven by cost here but mostly because I figure the most costly options are probably not the first choice anyway... I do have some skill at welding but only moderate so I'm not sure I'm up to welding the spider gears properly.

Everything I see seems to mostly focus on Dana 60's. I know the 61 is essentially similar but with a few clearance/spacing differences but I don't exactly have a machine shop in my garage. And given my health issues I just can't see trying to pull old axles from junkyards at this point. Is there a purchasable, bolt-in option of some kind that a shade-tree mechanic could pull off that would at least add some snow/mud grip for this kind of occasional use?

[grumpin]

Guys can I revive an old and horse-beaten topic? Rear lockers. But maybe with a twist?

I've had a health setback (stroke) and I'm reprioritizing some projects. Everyone in the family loves Rocky and I have no plan to sell it, but figuring out what to do with it has been a challenge. I'm the only person who can drive stick (very well) and I don't really want to think about an automatic conversion. It's also obviously never going to be a show truck.

We have a homestead here in CO where it can while away its years (just like me LOL) but the most useful thing I'd do with it aside from runs into town is plowing. Not a lot of plowing, mind, but we have a dirt access road with two spots that collect snowdrifts, each about 30' long. It's enough to be a barrier for most vehicles in winter, but as you can imagine this is no great workload for even an entry level plow setup. It's a straight "push it to the side to make a path" type of work effort.

The trouble is, Rocky is 2WD. All the other specs are great - '81 F-250, 6.6L V8 351M that starts instantly even in the dead of winter, etc. I've got some chunky hybrid-mud tires on there, too and I can keep chains on it full time because it's all a dirt road from the property out to the main highway. But it's still very tempting to try to do something about the stock rear axle (a Dana 61 at 3.73).

I know lockers come up in discussion a lot but all the past threads I've seen have focused on daily drivers, people wanting "hunt trucks with highway manners" and so on. But what would you do if you had the opposite situation? Suppose you wanted the fastest, simplest option to give something like Rocky more grip in snow and mud, and on-road behavior was almost never important? I'm not super driven by cost here but mostly because I figure the most costly options are probably not the first choice anyway... I do have some skill at welding but only moderate so I'm not sure I'm up to welding the spider gears properly.

Everything I see seems to mostly focus on Dana 60's. I know the 61 is essentially similar but with a few clearance/spacing differences but I don't exactly have a machine shop in my garage. And given my health issues I just can't see trying to pull old axles from junkyards at this point. Is there a purchasable, bolt-in option of some kind that a shade-tree mechanic could pull off that would at least add some snow/mud grip for this kind of occasional use?

I had a Detroit True Trac installed in my 98 GMC. I really like it.

Good road manners, always there, no special lube requirements and very stout. And it makes me giggle when it chirps on a faster take off!

https://www.eaton.com/us/en-us/catalog/differentials/eaton-detroit-truetrac-differential.html

[Gary Lewis]

I had a Detroit True Trac installed in my 98 GMC. I really like it.

Good road manners, always there, no special lube requirements and very stout. And it makes me giggle when it chirps on a faster take off!

https://www.eaton.com/us/en-us/catalog/differentials/eaton-detroit-truetrac-differential.html

Sorry about the stroke! Please take appropriate cautions from now on.

As for the diff, while your application might be ok with welding, I've not done that and don't know what needs to be done to make that happen. But at the very least I'd think the diff needs to be out or, if you weld like me, you'll have spatter in the gears that will cause horrible problems.

And if you are going to take it out then I think I'd want to go back with something "good". I, too, have a True Trac and love it. The thing just works when it needs to and doesn't cause any problems otherwise. No need for a way to engage it. Just install and enjoy.

[taskswap]

Sorry about the stroke! Please take appropriate cautions from now on.

As for the diff, while your application might be ok with welding, I've not done that and don't know what needs to be done to make that happen. But at the very least I'd think the diff needs to be out or, if you weld like me, you'll have spatter in the gears that will cause horrible problems.

And if you are going to take it out then I think I'd want to go back with something "good". I, too, have a True Trac and love it. The thing just works when it needs to and doesn't cause any problems otherwise. No need for a way to engage it. Just install and enjoy.

Thanks, guys.

So this Eaton... Their application guide is a little confusing. It's been a year since I verified these notes but last summer I spent some time figuring out exactly what I have and my notes say "Axle 42 = Dana - Capacity 6250 - Ratio 3.73 Dana (Spicer) 30 Spline 10 bolt cover 9.75" ring gear Looks Like A Standard Dana 60, But Has A Different Offset For The Carrier". Any of that sound any alarm bells for you?

From Eaton's application guide if I choose Rear, 30 Spline, "3.73 and Down" plus "3.73 and up" (because I have no idea what the diff is I get two results:

913A315: DETROIT TRUETRAC® DIFFERENTIAL; GM 8.875 IN.; 30 SPLINE; 3.73 AND UP

913A589: DETROIT TRUETRAC® DIFFERENTIAL; DANA 44 FRONT; 30 SPLINE; 3.73 AND DOWN

Neither screams "this is the one" and their detail pages are unhelpful too. One has notes like "For use with non-thick ring gears only." and the other says "All Eaton differentials made for General Motors 8.5" and 8.6" axles require special bearings. For axles with small bearing bores (race O.D. or 2.89"), usually found on vehicles prior to 1999, bearing LM102949 and race LM102911 are required. For axles with large bearing bores (race O.D. of 3.06"), usually found on vehicles from 1999 to present, bearing LM603049 and race LM603012 are required.".

And they list different ring gear sizes of 8.875" and 8.5" neither of which match mine.

Do you happen to have any idea what part numbers y'all might have installed?

[Gary Lewis]

Thanks, guys.

So this Eaton... Their application guide is a little confusing. It's been a year since I verified these notes but last summer I spent some time figuring out exactly what I have and my notes say "Axle 42 = Dana - Capacity 6250 - Ratio 3.73 Dana (Spicer) 30 Spline 10 bolt cover 9.75" ring gear Looks Like A Standard Dana 60, But Has A Different Offset For The Carrier". Any of that sound any alarm bells for you?

From Eaton's application guide if I choose Rear, 30 Spline, "3.73 and Down" plus "3.73 and up" (because I have no idea what the diff is I get two results:

913A315: DETROIT TRUETRAC® DIFFERENTIAL; GM 8.875 IN.; 30 SPLINE; 3.73 AND UP

913A589: DETROIT TRUETRAC® DIFFERENTIAL; DANA 44 FRONT; 30 SPLINE; 3.73 AND DOWN

Neither screams "this is the one" and their detail pages are unhelpful too. One has notes like "For use with non-thick ring gears only." and the other says "All Eaton differentials made for General Motors 8.5" and 8.6" axles require special bearings. For axles with small bearing bores (race O.D. or 2.89"), usually found on vehicles prior to 1999, bearing LM102949 and race LM102911 are required. For axles with large bearing bores (race O.D. of 3.06"), usually found on vehicles from 1999 to present, bearing LM603049 and race LM603012 are required.".

And they list different ring gear sizes of 8.875" and 8.5" neither of which match mine.

Do you happen to have any idea what part numbers y'all might have installed?

I didn't install this one, so don't have a part number. Besides mine is a 10.25" axle.

Summit didn't find any Truetrac for your truck, saying "There are no results for your 1981 FORD F-250 that match your search criteria." And the Eaton application guide doesn't show any either from what I can see. Bummer!

[taskswap]

I didn't install this one, so don't have a part number. Besides mine is a 10.25" axle.

Summit didn't find any Truetrac for your truck, saying "There are no results for your 1981 FORD F-250 that match your search criteria." And the Eaton application guide doesn't show any either from what I can see. Bummer!

That seems to be my experience so far. Lots of "this is an easy install!" threads and videos from guys that seem to tear down and build diffs and axles as a weekend hobby (not me) and not so much "this is your truck, we know your truck, buy this and it will work..."...

[mat in tn]

That seems to be my experience so far. Lots of "this is an easy install!" threads and videos from guys that seem to tear down and build diffs and axles as a weekend hobby (not me) and not so much "this is your truck, we know your truck, buy this and it will work..."...

I have a similar truck although an automatic. I can see the value of having a traction lock if available. mine is an 81 f250 ranger camper special with 351m and c6. it's a great farm truck etc. I have not looked into what options are available for a dana 61 so I'm interested to see what info comes up.

[taskswap]

I have a similar truck although an automatic. I can see the value of having a traction lock if available. mine is an 81 f250 ranger camper special with 351m and c6. it's a great farm truck etc. I have not looked into what options are available for a dana 61 so I'm interested to see what info comes up.

Well I haven't got a definite answer yet. But I'm LEANING toward welding the spiders. If I do turn this into a plow vehicle it will live out its days almost completely on dirt roads and typically only be driven to plow - with snow on the road. So the usual drawbacks like being terrible on paved roads wouldn't apply. I'm not 100% sure this is a good idea, yet. Small ATVs with plows come up on Craigslist all the time pretty cheaply and for light duty like this would be fine. My daughter loves Rocky and is insisting on keeping it set up the way it already is.

I'll report back once I decide either way

[Gary Lewis]

Well I haven't got a definite answer yet. But I'm LEANING toward welding the spiders. If I do turn this into a plow vehicle it will live out its days almost completely on dirt roads and typically only be driven to plow - with snow on the road. So the usual drawbacks like being terrible on paved roads wouldn't apply. I'm not 100% sure this is a good idea, yet. Small ATVs with plows come up on Craigslist all the time pretty cheaply and for light duty like this would be fine. My daughter loves Rocky and is insisting on keeping it set up the way it already is.

I'll report back once I decide either way

I would think that an ATV would be quite handy where you are, and one with a plow even more so.