Milwaukee Compact 3/8 M12 Fuel Ratchet

[Nezil]

Milwaukee "Compact" 3/8 M12 Fuel Ratchet

As is typical when I set about buying a new tool, I turn to forums and social media to influence my decision and do some background reading.

I'd ended up getting an M12 Fuel 3/8 stubby impact wrench recently and managed to get it at a bargain price with three batteries (CP 2.0, XC 4.0 and XC 6.0). With these spare batteries, I fancied adding to my M12 tool collection with a ratchet, and so started the research.

Reading and watching reviews, the general consensus seemed to be that the newer fuel models were a significant improvement in terms of strength (for manual ratcheting), power, build quality, run time etc. There are also extended reach models released even more recently, but at a price premium over the already expensive fuel models.

Most of my sockets are 3/8. I do have a full set of 1/4" drive as well, but 3/8 is kind of my go to size, so initially I picked up the 3/8 Fuel ratchet.... Damn that thing is heavy, and the head is MASSIVE... It's got a ton of power (55 ft-lbs), perhaps too much power, but the size and weight just killed it for me.

The original (non-fuel) models feel a bit flimsy in comparison, but the size and weight are so much better. I nearly went this direction, but inspired by a YouTube video that I can no longer find, I took a different path.

I picked up a 1/4" Fuel ratchet, and modified it to have a 3/8" anvil:

The 1/4" Fuel ratchet is similar in size and weight to the original 1/4" and 3/8" units, but is better built, slightly more powerful, brushless.

Here are the specs for comparison:

1/4" Non Fuel
- 10 3/4" / 27.3cm long
- 1.9 lb / 860g
- 30 ft-lb
- 250 rpm

3/8" Non Fuel
- 10 3/4" / 27.3cm long
- 1.9 lb / 860g
- 35 ft-lb
- 250 rpm

1/4" Fuel
- 10.39" / 26.4cm long
- 1.93 lb / 880g
- 40 ft-lb
- 250 rpm

3/8" Fuel
- 10.87" / 27.6cm long
- 2.43 lb / 1,102g
- 55 ft-lb
- 250 rpm

As I said, the 3/8" Fuel is a beast, both in terms of power and it's just huge. What I wanted was a 3/8" model with the size and features of the 1/4" Fuel... here is how I did it.

 

[Nezil]

So as I said, I was inspired by a YouTube video where someone else had done this mod, but didn't provide any details. The only clue he gave was that the end result was 100% Milwaukee, so I took a look at the parts diagrams for the non-Fuel ratchets and the Fuel ratchets:

2556-20 1/4" Fuel Ratchet Parts Diagram
2457-20 3/8" Non-Fuel Ratchet Parts Diagram

You can see from these diagrams that the anvil head assemblies look remarkably similar between the old Non-Fuel 3/8" ratchet and the new 1/4" ratchet. The main difference seems to be that the Non-Fuel anvil assembly pushes through from the back, and is held in with a C clip around the anvil at the front, whereas the Fuel anvil assembly pushes through from the front and is held in with a large C-clip around the outside.

Armed with this information I placed an order for the Non-Fuel 3/8" anvil service kit, part number 42-06-1030.

Once the service kit arrived, I took it all apart to inspect the pieces. Most of the parts are 100% identical, including the selector, the spring that pushes the pawl, the pawl itself, the springs and the pins on the top of the assembly that push on the friction plate. Here is a photo of the parts of both the Non-Fuel 3/8" assembly and the Fuel 1/4" assembly:

A close up of the head parts:

And a side by side view that shows the only real differences between these assemblies:

The only two differences between these assemblies is that the Non-Fuel has a groove for the C clip that holds it in place in the Non-Fuel head, and the Non-Fuel body is slightly longer.

Using a micrometer I measured the body length of the 3/8" Non Fuel assembly as 14.7mm, and the 1/4" Fuel assembly as 13.6mm. Because of the design change of the main body of the head, the selector switch sits slightly proud of the anvil assembly on the Fuel models, and is recessed on the Non-Fuel. Obviously it was necessary to grind off the additional 1.1mm, and thankfully this was only the outside ring that made the selector switch recessed in the Non-Fuel.

I ended up putting the anvil assembly into the chuck of a drill, and using a Dremel with a grinding bit to take most of the material off and bevel the edges slightly, then finished with some sand-paper and metal polish. The end result of the modifications looks like this:

Once assembled back together, it works perfectly. Here are some photos comparing the size of the official 3/8" ratchet, and my more compact version:

Obviously just buying the Non-Fuel version would have been far cheaper, and achieved 90% of my goal... but it wouldn't have been as fun for sure. Now I have something unique, and something that I got enjoyment out of making.

 

[MrNatural]

That’s a really impressive course of adaptation. Do you feel limited in how much you can manually wrench on the hybrid and in regard to where it should be used?

For example by extrapolation: A standard long neck 1/4” m12 ratchet will take you up to 16mm around the engine bay - great.

A long neck 1/4” m12 hybrid breaking loose an 18mm nut
tucked away above an axle?

I guess having designed a 1/4” - 3/8” hybrid you also have to set your own common sense limits in regard to breaking fasteners loose?

Great idea and thanks for sharing.

 

[M635_Guy]

I've got the (1/2") Stubby and the Fuel (3/8") ratchet and they're a fantastic combo. I never use it with anything other than the 2.0 battery, and don't find the weight or size an issue at all so far.

Given the significant savings offered to Milwaukee by commonizing the 1/4" and 3/8" tooling/housing/parts/etc., I have to think they made them different for a reason. I guess if it fails you can pop the original head back in for warranty coverage, but that kind of mod isn't something I'd personally do.

I've kinda considered getting a non-FUEL 1/4" since I enjoy the 3/8" so much, but the 1/4" swivel head ratchets work so well/fast for me I sorta doubt it will happen...

 

[Nezil]

That’s a really impressive course of adaptation. Do you feel limited in how much you can manually wrench on the hybrid and in regard to where it should be used?

For example by extrapolation: A standard long neck 1/4” m12 ratchet will take you up to 16mm around the engine bay - great.

A long neck 1/4” m12 hybrid breaking loose an 18mm nut
tucked away above an axle?

I guess having designed a 1/4” - 3/8” hybrid you also have to set your own common sense limits in regard to breaking fasteners loose?

Great idea and thanks for sharing.

To be honest, I'm new to power ratchets of any sort, but don't necessarily think that they'll replace manual ratchets for me in all applications. Aside from speed, the main benefit of a power ratchet is in situations where you cannot simply keep moving back and forth, or the swing distance is very small.

The 3/8" Fuel ratchet is so powerful at 50 ft-lbs that I was concerned about accidentally over-torquing smaller fasteners, or crushing knuckles. The 1/4" at 40 ft-lbs max reduces that chance, but I'm sure you could get used to the 3/8" power given time.

I'm pretty sure that anything above 16mm I'd probably break loose with a manual ratchet or breaker bar first, then maybe use the power ratchet to remove.

 

[Nezil]

Given the significant savings offered to Milwaukee by commonizing the 1/4" and 3/8" tooling/housing/parts/etc., I have to think they made them different for a reason. I guess if it fails you can pop the original head back in for warranty coverage, but that kind of mod isn't something I'd personally do.

If you already have the 3/8" Fuel and you're happy with it, I can totally understand your point.

As for making them different for a reason, I've now looked at and disassembled the heads of the non-Fuel and the Fuel and found them to be quite different in a few areas.

Firstly, the cast heads on the Fuel are much stronger, even the 1/4" model which has similar dimensions to the Non-Fuel.

Secondly, the anvil assembly is installed from the back on the Non-Fuel, and secured with a C clip around the anvil which turns with it. There have been reports that the C clip can pop off, and I can see why with that design it might happen. Any pressure applied to the anvil, which is natural when pushing to hold a socket on a fastener, will put pressure on the C clip and if that does pop off, the anvil will fall out the back of the head. The Fuel version has the anvil installed from the front and is secured with a large C clip around the outside, pressure against the anvil puts no load on the C clip and only to the back of the head.

Overall, I think the 3/8" Fuel was beefed up to handle users applying a huge amount of torque with it. I think I read somewhere that the hand applied torque can be up to 200 ft-lbs with the Fuel 3/8" ratchet, which is a lot... like truck lug nut torque. I wouldn't expect to apply that much torque with any power ratchet, but if they were getting abuse like that, you can see why the 3/8" got beefed up so much.

So the 1/4" Fuel is beefed up quite a bit from the 3/8" Non-Fuel, but I won't be putting 200 ft-lbs of torque on it, even with the retrofitted 3/8" anvil.

 

[Nezil]

Just a quick update to the thread...

I've now used the modified rather a few times for actual work om cars, and found it to be great. It has enough power to break away most bolts that aren't suspension or mounts, and the head is nice slim and small. The only thing I wonder is if I should have got the extended reach 1/4" to start with. I was a lot more expensive though, so I think I'm happy with my decision.

 

[darkzero]

I never thought to do this like they do with hand ratchets. If I didn't own the 3/8 Fuel already I'd probably consider doing this.

Nice job. Now you need to buy yourself a lathe.....

 

[Nezil]

I never thought to do this like they do with hand ratchets. If I didn't own the 3/8 Fuel already I'd probably consider doing this.

Nice job. Now you need to buy yourself a lathe.....

Judging by the fact that you’re a Garage Journal forum member, you’ll understand when I say that I was VERY tempted to do just that when I started this project.

I think it’s safe to say that the only reason I didn’t investigate lathes, is that I wanted to finish the project and felt comfortable that the tools I had, whilst not 100% ideal, would work acceptably well.

Welding is the next skill I’d like to master, so I I’ll likely spend money on that rather than machining... but I’ve been known to change my mind... often!

 

[darkzero]

Judging by the fact that you’re a Garage Journal forum member, you’ll understand when I say that I was VERY tempted to do just that when I started this project.

I think it’s safe to say that the only reason I didn’t investigate lathes, is that I wanted to finish the project and felt comfortable that the tools I had, whilst not 100% ideal, would work acceptably well.

Welding is the next skill I’d like to master, so I I’ll likely spend money on that rather than machining... but I’ve been known to change my mind... often!

Haha. Was just messing with ya really. But also going along with the nature of GJ or any tool related forum.... to try & help others spend their money whenever possible.

I too would like to get into welding. I was sucked into the world of machining & while I do own more affordable import stuff it's by far the most expensive hobby in my life that I have gotten into. It's also my favorite though. It's the tooling that gets expensive, especially for the quality stuff which adds up quick.

 

[itwnexus]

1. How much does the 3/8" non fuel anvil cost?
2. How much would it cost to have a machine shop shave off the metal on the 3/8" non fuel anvil with an industrial lathe?

 

[Tuc04]

Does anyone know how the selector switch is removed? I bought this and I am going to try it in my 1/4" extended reach ratchet.

I need to shorten the 3/8 anvil and it seems best to remove the switch first. Maybe the clues are in the first picture which is missing?

 

[Tuc04]

I'm going to answer my own question in case anyone needs this for future reference.

The 1/4" anvil was .535 inches and the new 3/8" anvil was .580. So .045 needs to be removed. The area being removed is thin and it goes fast so be careful. I put mine in a drill and carefully put it onto a belt sander. My final readings were between .5345 and .536 so that is acceptable run out for me in this situation.

Disassembly:
On the new anvil remove the four plungers and four springs so they don't get lost. Then tap socket end on something hard so the pawl pin starts sliding out. Grab it with a needle nose pliers and remove it. Use the same pliers to reach in and remove the selector plunger and spring. Pull the selector out.

Thanks OP for this idea. The 3/8 anvil in the long 1/4 ratchet seems like it will be a real winner. Now I have to decide if I want to by another 1/4" ratchet or pull the snap ring and swap anvils.

Here are some pics that I think will be helpful.

 

[nomadicbohunk]

Thanks!

 

[pbon]

Good job! Maybe one day I will need to do this; so far I am doing OK with my 1/4 nonfuel and 3/8 fuel but I think you created a good compromise of size and power.