How to Determine Replacement Bearings and Seals for 1970s Popup Camper

Question:

Im have a old 1970s popup camper frame Im working on. Im not sure the exact make but it is a coleman. Only one of the existing bearings had any markings so Im having trouble finding what I need. I measured the existing items with a digital caliper. Seal - ID: 1.524inch OD:1.985inch - It looks like a double lip so I believe RG06-020 will work here. It seems closest. I did pull these seals out so the ID might be larger than a new seal : Inner Bearing - This was marked with 44649 so that gives me L44649 bearings and L44610 races. Outer Bearing - ID: 0.751inch OD: 1.516 - It looks like LM11949 is the only one with a ID of 0.750inch but Im not sure the OD matches. Perhaps I measured the OD wrong. This would give LM11910 races. Are these the right parts? Do you have a matching hub? It is a 4 bolt pattern.

asked by: Kevin

Expert Reply:

You are correct that the process of removing old grease seals can distort their shape and make it tougher to measure their inner and outer diameters. Part numbers from the originals are the preferred way to find replacement parts but the other option is to measure your spindles at the various points where the seal and bearings ride. The linked diagram shows you these points on the spindle that you can measure with your digital caliper. This is more reliable than measuring the old parts since the spindle is less likely than the seal to have been distorted from use.

Based on your seal dimensions your choice of seal set # RG06-020 looks to be right on. Since you have the inner bearing number 44649 you're good with the # L44649 bearings and # L44610 races. Outer bearing # LM11949 is indeed the only option for a 0.750 inner diameter and this works with race # LM11910. Please feel free to provide your race number for the outer bearing.

We do offer hubs but none that matches your bearing set L44649 and LM11949. All of the 4-on-4 hubs we offer use bearing # L44649 as both inner and outer bearing. A new hub or hub/drum must use the exact bearing set in place now or it will not fit your spindles. Given the age of the trailer it is quite possible that you will need to replace the axle.

The linked page will show you our axle kits for the 4-on-4 bolt pattern. You can use the filters on the page to select the required capacity (check you existing axle for a plate or sticker), axle length, spring center length and hub type. You may want to consider the axle-less suspension systems from Timbren, such as their 2000-lb-rated kit # A20RS440 which bolts (or welds) onto your trailer frame. Eliminating the axle helps with both ground clearance and reduces the trailer's overall weight.