| C4 Corvette Chassis |
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| 1957 Corvette RestoMod Project - Page 15 Bearing Replacement in the Dana 36 Carrier The 1995 C4 rear end I purchased came from an automatic transmission Corvette. Only the Dana 36 carrier was offered in the C4 Corvette automatic cars. The Dana 44 was for manual transmission C4's, and it's a little beefier. My plan was to replace the stock 3.07 gear ratio with the lower ratio of 3.54. That's right - in gear-speak, the higher the ratio number the lower the gearing. With my Keisler Engineering T-56 overdrive manual transmission, the 3.07 ratio would have my rpm's near idle at highway speeds - not good. And since this rear end has been sitting a long time, and I already have the carrier off the car, I decided to replace all the bearings and seals as well. Read along as I take you into the spooky world of Pumpkins! |
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| A quick way to know if your carrier is a Dana 36 or a Dana 44 is the top center bolt. The 36 has one, the 44 does not. Pictured here is the batwing carrier cover removed. It's nicknamed the batwing because of the support arms integrated into the cover. |
| At right, also notice the stub axles that come out each side of the carrier. These mate up to the axle shafts via u-joints. The center of the carrier contains the differential, called the "case". Many people confuse the carrier with the differential - but think of it like this: the carrier holds all the gearing, while the differential transfers power to the axles. |
| One of the hardest jobs is to remove the snap rings that hold the stub axles in place - but only if you don't have the correct tool. The snap rings fit around the ends of each stub axle inside the differential, as seen in the above left photo. I tried on-and-off for 3 weeks to remove the snap rings until I finally gave up and bought the correct tool from Hands On Tools for $30 plus shipping. You can see in the above middle picture that the ends of the pliers are large enough to fill the holes in the snap rings - very important. I went through three generic sets of pliers that could not hold the snap ring long enough to remove it off the stub axle. The plier's ends are also at 90 degrees - straight pliers will never work. |
| Once the snap rings are removed, the stub axles are a snap to remove (sorry, couldn't resist). The ends of each axle have splines (above right). The shaft of the stub axle goes through the carrier and bearing, into the center of the case. The case contains side gears and clutches - these are what the axle's splines mate to. |
| The differential is held in place by main bearing caps - and as the name suggests, bearings allow the case to spin inside the carrier. Once the caps are removed, you can pry the case out of the carrier, as seen left. It may be difficult to dislodge the case from the carrier, so you need to secure the carrier. I clamped the pinion yoke in my bench vise. When the case is out, the fun begins! |
| Chapter 9 of my book covers the rebuilding of the carrier, including final setup, with great detail. While it's not too difficult, it does take a lot of patience. Chapter 9 is available from the Bookstore now. I highly recommend you purchase the package of Chapters 9 & 10. |
| At some point after the case is removed, you'll need to clean the carrier. I used brake cleaner for the inside - what a greasy mess. At right, a Roloc disk and die grinder quickly remove the gasket material from the carrier cover flange. Be careful with power tools though - the carrier is cast aluminum and you can easily grind away carrier material - not good! |
| The axle seals need to be removed to get at the axle bearings - both seen at left. Axle bearings are a roller pin-type and allow the stub axles to rotate. All the bearing replacement steps in Chapter 9 use a small 12-ton shop press I picked up at Harbor Freight for $125. It might be the best tool purchase in the entire project. Get one, or life will be miserable. In addition to the axle bearings, my carrier rebuild also replaced the pinion bearings, cups (or races), and the differential bearings and cups. Below is a photo of one of the new axle bearings in place. The Dana carriers have unique lips everywhere and it's important to know how these bearings are best removed and new ones installed - or you will be buying a new carrier! I used original replacement bearings by Timken. The only place I found these were at AutoZone. |
1957 Corvette RestoMod
| There are other bearing makers besides Timken, but I found their fitment to be troubling. Also, when you buy full kits to rebuild your carrier, be careful of what you get. The Dana 36 is such a rare piece that sometimes the replacement parts are not correct. The Dana 44 was used in many vehicles besides Corvette, so replacement parts for it are probably all good. |