Front Differential and Housing

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=90 BGCOLOR="#006633" TEXT="#F7F7FF" bgproperties="fixed" background="079005a0ddvuru.png"> <div> <A HREF="http://www.vernco.com/index.htm" TARGET="_top" TITLE="http://www.vernco.com/index.htm"><U><B>home</B></U></A><B>     |     </B><FONT SIZE="5" COLOR="#FFCC66" FACE="Arial" ><B>Vern</B><B>co.com</B></FONT></div> <div> back to<B>  </B><A HREF="index.htm" TARGET="_top" TITLE="Front Axle Rebuild"><U><B>Front Axle Rebuild</B></U></A></div> <bR> <div> <A HREF="http://www.vernco.com/id173.htm" TARGET="_top" TITLE="http://www.vernco.com/id173.htm"><U><B>Site Map</B></U></A></div> <div> </div> </td> </tr><tr> <td valign="top" width=150 BGCOLOR="#669966" TEXT="#080000"> <div> <B>Front Differential and Housing</B></div> <div> <A HREF="id404.htm" TARGET="_top" TITLE="Spindle Bolt Upgrade"><U>Spindle Bolt Upgrade</U></A></div> <div> <A HREF="id373.htm" TARGET="_top" TITLE="Kingpin Bearings"><U>Kingpin Bearings</U></A></div> <div> <A HREF="id374.htm" TARGET="_top" TITLE="Bendix Joints"><U>Bendix Joints</U></A></div> <div> <A HREF="id460.htm" TARGET="_top" TITLE="Spindles, etc."><U>Spindles, etc.</U></A></div> <div> <A HREF="id461.htm" TARGET="_top" TITLE="Hubs and Drums"><U>Hubs and Drums</U></A></div> <div> <A HREF="id495.htm" TARGET="_top" TITLE="Front End Alignment"><U>Front End Alignment</U></A></div> <bR> </td> <td valign="top" height=390 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> Procedures for the differential in the front axle are nearly the same as for the rear differential.  Just like in the factory service manual, the adjustment procedures for the front differential are in the <A HREF="http://www.vernco.com/rearaxle5/" TARGET="_top" TITLE="http://www.vernco.com/rearaxle5/"><U>rear axle section</U></A>.   One important distinction is that unlike the stock rear axle configuration, there is no <A HREF="http://www.vernco.com/rearaxle2/index_spacer_stock_config.htm" TARGET="_top" TITLE="http://www.vernco.com/rearaxle2/index_sp"><U>spacer</U></A> between the front axleshafts.</div> <bR> <div> One big surprise was finding the <A HREF="http://www.vernco.com/rearaxle5/index_carrier_preload.htm" TARGET="_top" TITLE="http://www.vernco.com/rearaxle5/index_ca"><U>carrier preload</U></A> was way too tight.  Without a case spreader, the only way I could remove the carrier was with a slide hammer.  In this picture, the two jaws of the slide hammer are gripping the edge of the carrier.  Normally the preload should never be this tight.  If you were disassembling a properly shimmed unit, a <A HREF="http://www.vernco.com/rearaxle5/index_removing_carrier.htm" TARGET="_top" TITLE="http://www.vernco.com/rearaxle5/index_re"><U>pair of wooden prybars</U></A> should be plenty:</div> <bR> <div> <A HREF="id359.htm" TARGET="_top" TITLE="Slide hammer on carrier"><U><IMG SRC="577af3b0.jpg" border=0 width="175" height="59" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <bR> <div>  <A NAME="cleaning_up_yoke"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="1" ALIGN="bottom" WIDTH="1" HSPACE="0" VSPACE="0" ></A></div> <div> The differential gears and bearings were okay, but the sealing surface on the yoke was pretty well gouged.  It would have destroyed the new seal in short order.  I used my lathe to clean up the seal land area.  A <A HREF="http://www.skf.com/portal/skf/home/products?contentId=242195" TARGET="_blank" TITLE="http://www.skf.com/portal/skf/home/produ"><U>Speedi-Sleeve repair</U></A> could be used if you don't have access to a lathe.   Because of the odd shape, it is hard to hold the yoke on the lathe.  During previous work on the rear axle and transfer case, I bolted the yoke to the lathe faceplate.  It was a slow, frustrating process to properly center the yoke this way:</div> <bR> <div> <A HREF="id369.htm" TARGET="_top" TITLE="Yoke on faceplate"><U><IMG SRC="5a07d4f0.jpg" border=0 width="125" height="79" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <bR> <div> The proverbial light bulb illuminated over my head with this yoke.  The yoke splines are the same as the outer axleshafts.  I was able to turn the axleshaft between centers, with the yoke bolted in place.  I could have also used the pinion gear shaft, but I had already pressed it back in place in the axle housing:</div> <bR> <div>  <A HREF="id370.htm" TARGET="_top" TITLE="Yoke on axleshaft between centers"><U><IMG SRC="5a2af430.jpg" border=0 width="175" height="67" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <div>  <A NAME="inboard_seals"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="1" ALIGN="bottom" WIDTH="1" HSPACE="0" VSPACE="0" ></A></div> <div> The axleshaft seals are located at the inboard ends, another important <A HREF="http://www.vernco.com/rearaxle2/index_stock_axleshaft_seal.htm" TARGET="_top" TITLE="http://www.vernco.com/rearaxle2/index_st"><U>difference</U></A> from a rear axle.  This cross section scan, from a 1948 Owner's Manual, shows the seals as item #14:</div> <bR> <div> <A HREF="id364.htm" TARGET="_top" TITLE="Front RP Scan"><U><IMG SRC="58d4b7d0.jpg" border=0 width="75" height="125" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <bR> <bR> <div> Immediately outboard of each seal is a hat shaped steel spacer.  These spacers are not shown in the image from the owner's manual.  The neck of the spacer is a slip fit inside the axletube.  The inner diameter of the spacer doesn't quite touch the axleshaft.  It has a funnel shape and helps guide the axleshaft through the seal during installation.  It might also help minimize damage to the axletube if the inboard end of an axleshaft were to break at the splines:</div> <bR> <div> <A HREF="id360.htm" TARGET="_top" TITLE="Hat spacer and inner seal"><U><IMG SRC="579af480.jpg" border=0 width="175" height="72" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <bR> <div> I thought the spacer and seal were all one unit and hammered the first one free with a long pipe inserted from the outer end of the axletube.  Since the seal and spacer have nearly the same inside diameter, I couldn't catch the seal by itself.  A seal puller or slide hammer wouldn't fit inside the case.  A big old screwdriver couldn't get enough leverage to budge the seal, either.  From the Better Late Than Never Department, I figured out an easier method on my '51 wagon's front differential.  Drive a thin prybar behind the seal, inboard of the spacer.  (A slight deformation of the spacer is not a problem, but don't go overboard as spacers are not included with the new seals.)  Next, insert a pipe from the outboard end, which will contact the prybar blocking the opening.  Hammer the pipe inwards, and the pressure against the prybar will drive out the seal.  A third hand would be helpful to keep the prybar in place while hammering on the pipe.  For best results, use the largest diameter pipe which will fit inside the spacer.  Once the seal is removed, the spacer will slide out:</div> <bR> <div> <A HREF="id361.htm" TARGET="_top" TITLE="Removing The Inner Seal"><U><IMG SRC="c90c8650.jpg" border=0 width="200" height="101" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <bR> <div> When it comes time to reinstall the new seals, the manual calls out for a fancy seal installer.  The illustration is from the rear axle section of the manual.  All of the front axles over the years would have these seals, but only the <A HREF="http://www.vernco.com/rearaxle1/" TARGET="_top" TITLE="http://www.vernco.com/rearaxle1/"><U>23-2 full-floating rear axle</U></A> would have had them.  By turning this tool with a wrench, it expands to push the two seals away from each other and into the axletubes:</div> <bR> <div> <A HREF="id362.htm" TARGET="_top" TITLE="Inner oil seal tool scan"><U><IMG SRC="58664810.jpg" border=0 width="100" height="129" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <bR> <div> But fear not, that tool is not needed.  I used a long pipe and a mandrel from a <A HREF="http://www.vernco.com/rearaxle6/index_bearing_seal_driver_set.htm" TARGET="_top" TITLE="http://www.vernco.com/rearaxle6/index_be"><U>bearing driver set</U></A>.  The flat end of a large socket would work well, too.  Just give a few love taps to the other end of the pipe to install the seal, and then repeat for the opposite side.  Use caution that you don't damage the first seal while installing the second one.  Don't forget to reinstall the spacers with the seals, too:</div> <bR> <div> <A HREF="id363.htm" TARGET="_top" TITLE="Installing inner oil seal"><U><IMG SRC="588af4c0.jpg" border=0 width="175" height="76" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <div>  <A NAME="bushings_and_thrust_washers"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="1" ALIGN="bottom" WIDTH="1" HSPACE="0" VSPACE="0" ></A></div> <div> With the differential squared away and new seals installed, let's move on to the outboard end of each axle tube.  A bushing supports the inboard axleshaft half and a thrust washer controls end play.  At some point in production, it was decided that the bushing was no longer needed.  With the outboard half of the axleshaft supported in the <A HREF="id460.htm" TARGET="_top" TITLE="Spindles, etc."><U>spindle</U></A>, the inboard half would stay more or less centered within the axletube all by itself.  This is similar to how a driveshaft, running between a transfer case and axle, is supported only by the universal joints at each end.  I'm not positive, but would guess the elimination of the bushing coincided with a change in the knuckle castings.  When changed so that <A HREF="id373_knuckle_changes.htm" TARGET="_top" TITLE="Kingpin Bearings"><U>kingpin shims were used only on the top</U></A>, this meant the spindle may not always be vertically aligned with the bore of the axle tube.  By eliminating this bushing, it wouldn't matter if the axle shaft was slightly offcenter relative to the axle tube.  As far as the thrust washer, it was only needed to keep the inboard half of the <A HREF="id374.htm" TARGET="_top" TITLE="Bendix Joints"><U>Bendix Joint</U></A> from moving away from the outer half.  With Rzeppa or Spicer joints, the axle halves won't separate so there was no need for the thrust washer.  Even though the bushing was eliminated, the thrust washer was still installed at the factory in case Bendix Joints were ever retrofitted. </div> <bR> <div> <A HREF="id382.htm" TARGET="_top" TITLE="Front axle thrust washer and bushing"><U><IMG SRC="5df7d4a0.jpg" border=0 width="125" height="74" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <bR> <div> The old bushings were not too bad, but the Bendix Joints had worn the thrust washers to about half of their original thickness.  The bushing was easy to remove using a <A HREF="http://www.vernco.com/rearaxle6/index_slide_hammer.htm" TARGET="_top" TITLE="http://www.vernco.com/rearaxle6/index_sl"><U>slide hammer</U></A>.  The thrust washer was a bit harder to pull, as it is not easy to get a grip under the thin edge.  A hook type seal puller did the job fairly well.  You will have to hammer the seal puller in from the edge to get a good grip.  Another option is to carefully cut it away with a small cold chisel.  If you look closely in this picture, you can see how the bushing is recessed behind the thrust washer:</div> <bR> <div> <A HREF="id384.htm" TARGET="_top" TITLE="Seal Puller on thrust washer"><U><IMG SRC="5e4af490.jpg" border=0 width="175" height="73" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <bR> <div> Considerable force is required to install the new bushings and thrust washers.  Expect the bronze material to get slightly shaved around the edges.  My trusty air hammer came in handy, in conjunction with a mandrel from the bushing driver set.  This picture shows the bushing being driven in place.  Don't forget to clean up any bronze shavings when done.  Note the recess for the thrust washer.  Pay close attention when you drive in the thrust washer as it is thin and easy to distort.  Do you want to guess how I know this?:</div> <bR> <div> <A HREF="id383.htm" TARGET="_top" TITLE="Driving in front axle bushing"><U><IMG SRC="5e67d560.jpg" border=0 width="125" height="86" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <bR> <div> Remember, it would be okay to leave out the bushings if desired.  The bushings might even cause interference if <A HREF="id373_knuckle_changes.htm" TARGET="_top" TITLE="Kingpin Bearings"><U>later style knuckles</U></A> are used.  The thrust washers, however, are mandatory for Bendix Joints, regardless of bushing or knuckle configuration.</div> <bR> <bR> <bR> <bR> </td> </tr></table></body>