I am upgrading a site from Gold that has a Manufacturer dropdown on the category page that shows only the manufacturers for the products in the category, like only two or three out of 15 manufacturers in the site. When a customer selects the manufacturer, it filters the page to show only products in the category for that manufacturer. That is working OK. The issue comes with paging. The ManufacturerId shows up in the querystring, but not in the pager links. I've added the manufacturerId to the paging links, in the view for the category, but it isn't showing up when I hover over the paging link.
<div class="pagination-wrapper">
@Html.PagedListPager(Model.Products, page => Url.RouteUrl("AbleRoute", new { page, Model.SortExpression,Model.ManufacturerId, Model.PageSize }), new PagedListRenderOptions { DisplayEllipsesWhenNotShowingAllPageNumbers = false })
</div>

I see that on the search page, it is
<div class="pagination-wrapper">
@Html.PagedListPager(Model.Products, page => Url.RouteUrl("AbleRoute", new { page, CategoryId = Model.CategoryId, Keywords = Model.Keywords, manufacturerId = Model.ManufacturerId, shopBy = Model.ShopBy, pageSize = Model.Products.PageSize, sortExpression = Model.SortExpression }), new PagedListRenderOptions { DisplayEllipsesWhenNotShowingAllPageNumbers = false })
</div>

Is there somewhere else I would need to change?
Thanks