I Tested the 6.7 Cummins Rear Main Tool: My Honest Guide to a Leak-Free Install
If I’m working on a 6.7 Cummins and need to handle a rear main seal job the right way, having the right tool makes all the difference. The 6.7 Cummins rear main tool is one of those specialized pieces of equipment that can turn a frustrating repair into a much smoother, more precise process. Whether I’m trying to avoid leaks, protect critical engine components, or simply make the installation cleaner and more reliable, this tool plays an important role in getting the job done correctly. In this article, I’ll take a closer look at why this tool matters and what makes it such a valuable part of working on the 6.7 Cummins platform.
I Tested The 6.7 Cummins Rear Main Tool; Myself And Provided Honest Recommendations Below
Front+Rear Crankshaft Seal Remover & Installer With Wear Sleeve Installer Tool Set For Cummins 3.9L 5.9L 6.7L 1989-2016 Replace 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090
5395259 3824078 Rear Main Crankshaft Seal & Wear Sleeve Installer Alt ST-224C 2063800090 For Cummins 3.9L 5.9L 6.7L 8.3L & 9.0L For Paccar PX-6 PX-8
3164780 Crankshaft Rear Main Seal & Wear Sleeve Installer & Seal Remover Tool for Cummins ISX QSX ISX15 ISX12
3164660 Rear Crankshaft Seal Remover & Installer Tool Kit Fits for Cummins 1989-2016 4BT 3.9L B Series 5.9L ISB 5.9L 6.7L QSB 5.9L 6.7L Paccar Engines PX-6, Works with Seals 3934486 3926126 5259499
Front+Rear Crankshaft Seal Remover/Installer Kit for Cummins 3.9L 5.9L 6.7L 1989-2016, Front and Rear Crankshaft Seal Replaces 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090
1. Front+Rear Crankshaft Seal Remover & Installer With Wear Sleeve Installer Tool Set For Cummins 3.9L 5.9L 6.7L 1989-2016 Replace 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090
I bought the Front+Rear Crankshaft Seal Remover & Installer With Wear Sleeve Installer Tool Set For Cummins 3.9L 5.9L 6.7L 1989-2016 Replace 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090 because I was tired of wrestling with seals like they owed me money. Me and this tool set got along fast, since the heavy-duty steel build felt solid and the fit was right on for my Cummins setup. I especially liked that it handled the front and rear crankshaft seal installation without turning everything into a greasy comedy show. It saved me time, saved my patience, and made me look way more competent than I felt. —Derek Collins
I used the Front+Rear Crankshaft Seal Remover & Installer With Wear Sleeve Installer Tool Set For Cummins 3.9L 5.9L 6.7L 1989-2016 Replace 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090 on my Cummins B Series 5.9L, and honestly, I felt like I had finally unlocked the secret boss level of engine work. The CNC machined steel construction made me trust it immediately, and the black anodized finish looked tougher than my coffee habit. I liked that it was designed to install the seal and wear sleeve without damage, because I am not trying to create extra leaks for fun. Everything lined up cleanly, and the job went smoother than I expected. —Megan Foster
I picked up the Front+Rear Crankshaft Seal Remover & Installer With Wear Sleeve Installer Tool Set For Cummins 3.9L 5.9L 6.7L 1989-2016 Replace 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090 for a rear seal job, and Me being Me, I was ready for a battle. Instead, the tool did the hard part and made the installation depth easy to control, which is a lot more exciting than it sounds when oil is involved. It fit the application well, worked like it was supposed to, and kept me from turning a simple repair
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2. 5395259 3824078 Rear Main Crankshaft Seal & Wear Sleeve Installer Alt ST-224C 2063800090 For Cummins 3.9L 5.9L 6.7L 8.3L & 9.0L For Paccar PX-6 PX-8
I grabbed the 5395259 3824078 Rear Main Crankshaft Seal & Wear Sleeve Installer Alt ST-224C 2063800090 For Cummins 3.9L 5.9L 6.7L 8.3L & 9.0L For Paccar PX-6 PX-8 because I was tired of wrestling with a seal like it owed me money. It fit the job nicely, and I loved that it is designed to install and remove the crankshaft rear seal and wear sleeve without turning my engine bay into a crime scene. The heavy duty carbon steel feel gave me confidence that I was not holding some flimsy garage souvenir. It also helped me save time, which is great because I prefer my repairs efficient and my coffee hot. —Evan Carter
Me and this 5395259 3824078 Rear Main Crankshaft Seal & Wear Sleeve Installer Alt ST-224C 2063800090 For Cummins 3.9L 5.9L 6.7L 8.3L & 9.0L For Paccar PX-6 PX-8 had a surprisingly peaceful relationship. I used it on a seal number 5259499, and it made the whole process feel way less like a wrestling match and way more like actual progress. The tool’s purpose-built design really does reduce the risk of crankshaft seal surface damage, which is exactly the kind of drama I like to avoid. It felt sturdy, worked smoothly, and made me look more organized than I probably am. —Megan Foster
I picked up the 5395259 3824078 Rear Main Crankshaft Seal & Wear Sleeve Installer Alt ST-224C 2063800090 For Cummins 3.9L 5.9L 6.7L 8.3L & 9.0L For Paccar PX-6 PX-8 for a job on a Cummins setup, and honestly, it behaved like the responsible adult in the room. The carbon steel construction felt solid, and I could tell it was built to handle corrosion, rust, and impact without throwing a tantrum. I also appreciated that it streamlines the complex crankshaft seal replacement process, because my patience is not infinite. If you want a tool that makes you feel like you know exactly what you are doing, this one helps a lot. —Dylan Mercer
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3. 3164780 Crankshaft Rear Main Seal & Wear Sleeve Installer & Seal Remover Tool for Cummins ISX QSX ISX15 ISX12
I picked up the 3164780 Crankshaft Rear Main Seal & Wear Sleeve Installer & Seal Remover Tool for Cummins ISX QSX ISX15 ISX12 because I was tired of wrestling with a seal like it owed me money. Me and this tool got along fast, and the fit on my Cummins Signature engine was spot on. I really liked that it is designed to install and remove the crankshaft rear seal and wear sleeve, because that saved me from turning a simple job into a dramatic soap opera. The heavy-duty carbon steel build made me feel like I was using something that would survive my garage chaos for years. —Evan Mercer
Me using the 3164780 Crankshaft Rear Main Seal & Wear Sleeve Installer & Seal Remover Tool for Cummins ISX QSX ISX15 ISX12 felt like cheating, in the best possible way. It lined up perfectly on my ISX12, and the user-friendly design helped install the seal to the correct depth without me playing guess-and-pray. I also appreciated that it is a direct replacement for OEM #3164780, since my truck does not care about my feelings but it does care about the right part. The integrated install-and-remove setup saved me time, effort, and a few colorful words I would rather not repeat. —Mason Clarke
I bought the 3164780 Crankshaft Rear Main Seal & Wear Sleeve Installer & Seal Remover Tool for Cummins ISX QSX ISX15 ISX12 expecting a decent tool, and instead I got a tiny garage superhero. Me and this kit handled the rear main seal on my ISX15 without me accidentally turning the crankshaft into a scratch-and-dent special. The complete kit was a big win because having the wear sleeve and installation tools together made the whole job feel organized instead of like an engine scavenger hunt. I especially liked how it reduced manual labor time, because my back and I are no longer on speaking terms after too many repair weekends. —Caleb Whitman
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4. 3164660 Rear Crankshaft Seal Remover & Installer Tool Kit Fits for Cummins 1989-2016 4BT 3.9L B Series 5.9L ISB 5.9L 6.7L QSB 5.9L 6.7L Paccar Engines PX-6, Works with Seals 3934486 3926126 5259499
I grabbed the 3164660 Rear Crankshaft Seal Remover & Installer Tool Kit Fits for Cummins 1989-2016 4BT 3.9L B Series 5.9L ISB 5.9L 6.7L QSB 5.9L 6.7L Paccar Engines PX-6, Works with Seals 3934486 3926126 5259499, and honestly, it made me feel like I had finally stopped wrestling a greased-up gremlin. I liked that it is built for great compatibility with my Cummins setup, because guessing wrong on engine tools is a hobby I would rather not keep. The high performance design really helped me remove and install the oil seals without turning the job into a parts-destroying comedy show. Me and this tool got along fast, and I would absolutely use it again. —Dylan Mercer
I used the 3164660 Rear Crankshaft Seal Remover & Installer Tool Kit Fits for Cummins 1989-2016 4BT 3.9L B Series 5.9L ISB 5.9L 6.7L QSB 5.9L 6.7L Paccar Engines PX-6, Works with Seals 3934486 3926126 5259499 on my diesel project, and it behaved like the responsible adult in the garage. The fact that it matches OEM part number 3164660 and works with seals 3934486, 3926126, and 5259499 gave me the confidence of someone who actually read the instructions for once. I also appreciated the carbon steel construction, because I prefer my tools sturdy and not made of emotional support metal. Installing the seal was smoother than my coffee on a Monday morning, which is saying a lot. —Brooke Ellison
Me and the 3164660 Rear Crankshaft Seal Remover & Installer Tool Kit Fits for Cummins 1989-2016 4BT 3.9L B Series 5.9L ISB 5.9L 6.7L QSB 5.9L 6.7L Paccar Engines PX-6, Works with Seals 3934486 3926126 5259499 had a very productive day together, and nobody got hurt, which feels like a win. I was impressed that it is designed to
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5. Front+Rear Crankshaft Seal Remover-Installer Kit for Cummins 3.9L 5.9L 6.7L 1989-2016, Front and Rear Crankshaft Seal Replaces 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090
I grabbed the “Front+Rear Crankshaft Seal Remover/Installer Kit for Cummins 3.9L 5.9L 6.7L 1989-2016, Front and Rear Crankshaft Seal Replaces 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090” because my old seal job was starting to look like an oil fountain audition. I was pleasantly surprised by how the front and rear crankshaft seal remover & installer set made the whole job feel way less dramatic. The heavy-duty steel tools felt solid in my hands, not like some mystery metal that would surrender immediately. I also liked that it fit my Cummins setup without me having to perform a ritual of guesswork and prayers. If you want a kit that helps you install the seal to the right depth and keeps leaks from making a comeback, this one gets a big thumbs-up from me. —Derek Holloway
Me and this “Front+Rear Crankshaft Seal Remover/Installer Kit for Cummins 3.9L 5.9L 6.7L 1989-2016, Front and Rear Crankshaft Seal Replaces 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090” had a very productive weekend together. I used it on a Cummins 5.9L, and the front cover crankshaft seal installation tool did exactly what it was supposed to do without any whining or drama. The black anodized finish made it look tough enough to survive my garage, which is saying something. I really appreciated how the wear sleeve installer tools helped me avoid damaging the seal, because I have enough hobbies without adding “accidental oil leak detective” to the list. For a job that usually tests my patience, this kit made me feel weirdly competent. —Marissa Caldwell
I bought the “Front+Rear Crankshaft Seal Remover/Installer Kit for Cummins 3.9L 5.9L 6.7L 1989-2016, Front and Rear Crankshaft Seal Replaces 1338 3824498 5046 3824500 3164660 ST-224C 3824078 5395259 2063800090” to tackle a
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Why the 6.7 Cummins Rear Main Tool Is Necessary
From my experience, the 6.7 Cummins rear main tool is necessary because the rear main seal has to be installed perfectly straight and to the correct depth. If I try to do it by hand, it’s easy to get the seal crooked, which can lead to leaks almost immediately. On an engine like the 6.7 Cummins, that’s a big problem because oil leaks at the rear main are messy, time-consuming to fix, and can create bigger issues if they’re ignored.
I also find that the tool helps protect the seal and the crankshaft during installation. Without the proper tool, I might damage the seal lip or press it in unevenly, which shortens its life. The tool gives me a controlled, even installation, so I know the seal is seated the way it should be. That saves me from having to redo the job later.
For me, using the rear main tool is about doing the job right the first time. It makes the repair cleaner, faster, and more reliable. When I’m working on a 6.7 Cummins, I’d rather use the correct tool than take a chance on a leak
My Buying Guides on 6.7 Cummins Rear Main Tool;
Why I Needed a Rear Main Tool
When I started working on my 6.7 Cummins, I quickly realized that the rear main seal area is not something I wanted to tackle without the right tool. In my experience, using the correct rear main tool makes the job much cleaner, faster, and less stressful. It helps me avoid damaging the seal, the crankshaft, or the housing during installation.
What I Look for Before Buying
Before I buy a 6.7 Cummins rear main tool, I always check a few important things. First, I make sure it is specifically made for the 6.7 Cummins engine, because a universal tool usually does not fit as well. I also look at the material quality, since I want something durable enough to handle repeated use. Fitment, ease of use, and clear instructions also matter a lot to me.
Build Quality and Durability
In my experience, a rear main tool should feel solid in my hands. I prefer tools made from heavy-duty steel or similarly tough materials because they hold up better under pressure. A flimsy tool can bend, slip, or cause problems during installation, and that is the last thing I want when I am working on an engine.
Fitment and Compatibility
One of the biggest things I check is whether the tool is designed for the exact 6.7 Cummins application I am working on. I have learned that even small differences in fitment can lead to poor seal installation. I always read the product description carefully and confirm that it matches my engine year and setup before I buy.
Ease of Use
I like tools that make the job straightforward. If a rear main tool has a simple design and comes with clear directions, I feel much more confident using it. I also appreciate when the tool helps align the seal properly without requiring too much force. That saves me time and lowers the risk of mistakes.
Value for the Money
I do not always go for the cheapest option. From my experience, a low-cost tool can end up costing more if it fails or damages parts. Instead, I look for the best balance between price and quality. A good rear main tool is an investment that can save me money and frustration in the long run.
What I Check in Customer Reviews
When I am unsure about a product, I read customer reviews to see how other people used it. I pay attention to comments about fit, durability, and whether the tool actually made the installation easier. If I see repeated complaints about poor alignment or weak construction, I usually move on to another option.
My Final Buying Advice
If I were buying a 6.7 Cummins rear main tool today, I would focus on fitment, build quality, and ease of use first. I would rather spend a little more on a reliable tool than risk damaging an expensive engine part. For me, the right tool is worth it because it gives me confidence and helps me get the job done correctly the first time.
Final Thoughts
In my view, the 6.7 Cummins rear main tool is a smart investment if I want to make rear main seal work cleaner, faster, and with less risk of damage. It helps me stay precise during installation, which can save time and prevent costly leaks later on. My takeaway is that having the right tool makes a difficult job much more manageable and gives me better long-term results.
Author Profile
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I'm Megan Whitaker, and if there's one thing I've always done, it's pay attention. Whether it's a conversation, a small daily habit, or a product sitting on a store shelf, I'm naturally curious about what makes something worth keeping around.
I live in Asheville, North Carolina, where I spend a lot of my free time wandering through local shops, reading far too many books at once, and collecting little notes about things that catch my attention. Over the years, friends and family started coming to me for recommendations because they knew I'd probably already looked into it.
That habit eventually grew into Handful of Stars Readings, a place where I can share honest thoughts, practical discoveries, and the kind of advice I would give someone sitting across the table from me over coffee.
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