Year-over-year backlog increased 13% and was up 3% sequentially. On a rolling 12-month basis, our book-to-bill for our Aerospace segment remained strong at 1.1. Moving on to our Vehicle segment on Page 12. In the quarter, total revenue was up 2%, all from favorable foreign exchange. Vehicle end markets were down 500 basis points year-over-year but the business was able to deliver outgrowth, primarily driven by higher aftermarket sales, stronger share in heavy-duty transmissions and a new product launch of electrical vehicle gearing in China. Operating margin came in at 17.9%, 270 basis points above prior year, driven by effective management of price cost and improvement in manufacturing efficiency. Throughout 2023, we’ve demonstrated the ability to execute on operational improvements as shown by our 270 basis point improvement in segment margins from the first half to the second half of the year.
On Page 13, we show results for our eMobility business. We generated another quarter of strong growth, including an all-time sales record. Revenue was up 19%, 18% organically and 1% from favorable foreign exchange. Driven by the ramp-up of new product launches, we outpaced the market which grew 7%. However, due to program start-up costs, the operating loss increased by $14 million when compared to the prior year. On a full year basis, eMobility posted 18% organic growth on slightly lower margins as we continue to invest in the business. We remain very encouraged by the profitable growth prospects of the eMobility segment. In 2023, we won new programs with more than $1 billion of mature year revenues. Through these wins, we continue to find opportunities to leverage expertise and differentiated technologies across segments.
Moving to Page 14. We show our Electrical and Aerospace backlog updated through Q4. As you can see, we continue to build backlog with Electrical stepping up to $9.5 billion and Aerospace reaching $3.2 billion for a total backlog of $12.7 billion. Both businesses have increased their backlogs by significantly more than 100% since Q4 2020, with Electrical growing almost 200%. Versus prior year, our backlogs have grown by 15% in Electrical and 13% in Aerospace which exceeded our expectations as we began the year. As noted earlier, both Electrical and Aerospace have book-to-bill ratios above 1.1. Our strong backlog to close the year gives us continued confidence in our growth outlook for 2024 and beyond. In addition to our strong backlog growth in 2023, the next page shows the acceleration in growth of our negotiations pipeline which supports our expectation for stronger markets and structurally higher organic growth rate.
In Electrical Americas, the pipeline doubled over the past 3 years and increased a further 29% and in 2023. This is even stronger than the 19% organic growth in our Electrical Americas business which suggests continued strength going forward. For 2023, we saw $6.2 billion of projects in our negotiations pipeline in Electrical Americas alone. Now, I’ll pass it back to Craig to walk through the guidance and wrap up the presentation.
Craig Arnold: Thanks, Tom. Turning to Page 16, we lay out our end market assumptions for 2024. You’ll recall that we provided an early look at our 2024 assumptions during our Q3 earnings call at the end of October. Today, we’re updating those assumptions. And with the exception of residential markets where we have increased our outlook from down slightly to flat in commercial vehicles where we have decreased our outlook from slightly declining to declining, all of our assumptions have remained the same. In contrast to what we’re seeing in the macro economy, we continue to expect growth in about 80% of our end markets. And much of this growth is supported by large backlogs. Turning to Page 17. As you’ve read, we’re announcing a new multiyear restructuring program to reduce fixed costs and enhance our efficiency.
While we’re structurally positioned to deliver higher levels of organic growth, we also have a vast number of opportunities to improve the way we run the company. And we’re at a point in time where we have the organizational capacity to take on a number of these efficiency projects that have been in our pipeline for some time. The program will focus on reducing structural costs through the consolidation of rooftops, increasing shared services and deploying digital technologies. These actions will also free up time and resources in our businesses, allowing them to focus on growth and driving operational improvements. Overall, we expect $375 million of restructuring costs over the next 3 years with $325 million of mature year savings in 2027.
This includes approximately $175 million of charges in 2024 and $50 million of savings, both of which are included in our 2024 guide and I’ll cover those in the next several slides. While the company is performing well, we see these actions as an important part of how we’ll continue to do so for years to come. Moving to Page 18. We summarize our 2024 revenue and margin guidance. Our organic growth for 2024 is expected to be between 6.5% and 8.5%, with particular strength in Electrical Americas and Aerospace, both expected to be up between 9% and 11% while eMobility is expected to grow some 30% as new programs are launched and the electric vehicle market continues to see solid growth. And I’d also add that the healthy end markets, combined with our large backlog provides actually better-than-normal visibility for our 2024 outlook.
For segment margins, our guidance range of 22.4% to 22.8% is an improvement of 60 basis points at the midpoint from our 2023 all-time record of 22%. As we’ve communicated earlier, incremental margins of about 30% are what you should assume and that’s what’s reflected in our guidance. These incrementals are consistent with our plan to step up investments in R&D and with the investments we’re making to expand our manufacturing capacity, all done to ensure future growth. On the next page, we have the balance of our guidance for 2024 and Q1. For 2024, our adjusted EPS is expected to be between $9.95 and $10.35 a share, $10.15 at the midpoint and up some 11% from 2023. And for operating cash flow, our guidance is between $4 billion and $4.4 billion, up 17% at the midpoint.
The key drivers here are really a combination of higher earnings and improved working capital. We also expect to repurchase between $1.5 billion and $2.5 billion of our shares outstanding. And given our cash position at the end of the year, at the end of ’23 and our strong cash generation this year, we’ll still have plenty of room for strategic M&A. For Q1, we expect organic growth to be between 6% and 8%, segment margins between 21.3% and 21.7% and adjusted EPS in the range of $2.21 and $2.31 per share. Let me just close here on Page 20. As we transition into 2024, I think we can all conclude that Eaton has proven that we’re a changed company, a company that delivers higher growth, higher earnings and does so consistently. And we’re proud of our team’s record performance in 2023.
