winfred
10-26-2009, 08:25 AM
here is a repost from another board of my install of a obx ripoff of a torsen into my e24 shark, i autocrossed it last weekend and it works great with none of the unloading of the inside tire and smoke shows that i was getting with the stock LSD on hard maneuvers, video of first cold run from said event (http://www.youtube.com/watch?v=03d1eV683e4) with seals and spacers i am at a little under $500 installed and so far i love it, ill likely try it in my e30 as the diff's are a direct swap but i am not sure if it will do anything for it, i have yet to have the 230k mile factory LSD unload on it as the e30 is a good bit lighter then da shark and doesn't have that big of a weight transfer, when it breaks loose it breaks both loose
ok.....
all da insidie bits
http://i792.photobucket.com/albums/yy201/wdixon27/obx6.jpg
measuring the back lash of the ring gear you will want to set the lash as close to this reading at possible on reassembly, you set it with the shims that are between the diff housing and the two side pieces that have the 6 13mm bolts
http://i792.photobucket.com/albums/yy201/wdixon27/obx10.jpg
http://i792.photobucket.com/albums/yy201/wdixon27/obx11.jpg
those side pieces have the outer races of the bearings that are on either side of the carrier, you will need a puller to get those bearings off the carrier which is the big black one from harbor freight, i tried a snap on of the same size class and it would not grip the bearing at the correct spot to pull it off without damaging it, the puller was just too thick and id rather buy a new cheap puller and grind it if needed (and it wasn't) then **** up a expensive snap on
http://i792.photobucket.com/albums/yy201/wdixon27/obx12.jpg
and a big two jaw to work with the clamp, but you could use a shop press at the risk of dropping the carrier
http://i792.photobucket.com/albums/yy201/wdixon27/obx13.jpg
you need to heat up the speedo chopper to get it off the carrier and if you are quick drop it right onto the obx carrier, mine once cool was only snug and not tight because they cut the step a cunt hair too small, i didn't try to measure the difference but it will be so small it may come down to manufacturing differences on if yours fits tight, i popped mine a few times with my dc tig, i didn't even add filler and just let it flow together
http://i792.photobucket.com/albums/yy201/wdixon27/obx16.jpg
you will need to grab the one per side snap ring out of the old carrier and put them into the obx, these are what keep the axle drive flanges from sliding out, i had to run my pick around the grooves to clear out a burr or two so the ring could fit clean
http://i792.photobucket.com/albums/yy201/wdixon27/obx14.jpg
nice snug fit on the ring gear as it should be, i used a couple pieces of plastic but wood would work too to protect the ring gear from damage, booger that up and you are ****ed
http://i792.photobucket.com/albums/yy201/wdixon27/obx15.jpg
while it is apart inspect the worms and other gears for burrs, about half of mine had little things like this, i used the edge of a fiber wheel on a dremmel at a near flat angle to the surface to knock the defects off (i have been doing this for a long time of various items including to sharpen drill bits, you can **** up quickly and put a nasty mark on the gear, if you are not comfy use needle files and do it by hand) after cleaning up the burrs i lightly buffed all the obx gears on a bench grinder with a wire wheel just to smooth them a little, i don't have a post buffing pic
http://i792.photobucket.com/albums/yy201/wdixon27/obx8.jpg
http://i792.photobucket.com/albums/yy201/wdixon27/obx7.jpg
i used a fan clutch tool and couple bolts to torque the carrier to 29ftlb, to torque the ring gear i clamped the carrier in a vice (can't remember the torque but i found it online, it is recommended to replace the bolts but i suspect that they come preloaded with locktight and that is why they want new ones, i hit everything with red)
http://i792.photobucket.com/albums/yy201/wdixon27/obx9.jpg
the "large" spacer set, there is a small set and it is a crap shoot what you will need, you gotta measure that back lash and see what it comes out with and measure the spacers with vernier calipers to see where you stand, i took several diffs down looking for spacers to get it together so i wouldn't need to wait a week for them to come from germany and bust out $50-60 for em and found them all to be in the .065 range with only a few thousandths variation (biggest one i found was .070 and smallest was .060) the biggest spacer being .077 in my set (they ran .067 to .077 on couple thousandth steps
http://i792.photobucket.com/albums/yy201/wdixon27/obx17.jpg
all done, in the end i could only go the backlash to .002-.003 which is likely close enough to the .005 it started with, if i couldn't get it closer i would of needed to pull the bearings and file the seats a little to get the bearings to seat deeper as i used the two thickest spacers a .076 and .077 (thicker increases your clearance) i tossed new o-rings and seals into the side pieces for the last time together and sealed up the rear cover with ultra gray sealer and no gasket (been doing it that way for years with no leakers)
get the replacement hardware for the obx from this guy http://rbryant.freeshell.org/obx_washers
ok.....
all da insidie bits
http://i792.photobucket.com/albums/yy201/wdixon27/obx6.jpg
measuring the back lash of the ring gear you will want to set the lash as close to this reading at possible on reassembly, you set it with the shims that are between the diff housing and the two side pieces that have the 6 13mm bolts
http://i792.photobucket.com/albums/yy201/wdixon27/obx10.jpg
http://i792.photobucket.com/albums/yy201/wdixon27/obx11.jpg
those side pieces have the outer races of the bearings that are on either side of the carrier, you will need a puller to get those bearings off the carrier which is the big black one from harbor freight, i tried a snap on of the same size class and it would not grip the bearing at the correct spot to pull it off without damaging it, the puller was just too thick and id rather buy a new cheap puller and grind it if needed (and it wasn't) then **** up a expensive snap on
http://i792.photobucket.com/albums/yy201/wdixon27/obx12.jpg
and a big two jaw to work with the clamp, but you could use a shop press at the risk of dropping the carrier
http://i792.photobucket.com/albums/yy201/wdixon27/obx13.jpg
you need to heat up the speedo chopper to get it off the carrier and if you are quick drop it right onto the obx carrier, mine once cool was only snug and not tight because they cut the step a cunt hair too small, i didn't try to measure the difference but it will be so small it may come down to manufacturing differences on if yours fits tight, i popped mine a few times with my dc tig, i didn't even add filler and just let it flow together
http://i792.photobucket.com/albums/yy201/wdixon27/obx16.jpg
you will need to grab the one per side snap ring out of the old carrier and put them into the obx, these are what keep the axle drive flanges from sliding out, i had to run my pick around the grooves to clear out a burr or two so the ring could fit clean
http://i792.photobucket.com/albums/yy201/wdixon27/obx14.jpg
nice snug fit on the ring gear as it should be, i used a couple pieces of plastic but wood would work too to protect the ring gear from damage, booger that up and you are ****ed
http://i792.photobucket.com/albums/yy201/wdixon27/obx15.jpg
while it is apart inspect the worms and other gears for burrs, about half of mine had little things like this, i used the edge of a fiber wheel on a dremmel at a near flat angle to the surface to knock the defects off (i have been doing this for a long time of various items including to sharpen drill bits, you can **** up quickly and put a nasty mark on the gear, if you are not comfy use needle files and do it by hand) after cleaning up the burrs i lightly buffed all the obx gears on a bench grinder with a wire wheel just to smooth them a little, i don't have a post buffing pic
http://i792.photobucket.com/albums/yy201/wdixon27/obx8.jpg
http://i792.photobucket.com/albums/yy201/wdixon27/obx7.jpg
i used a fan clutch tool and couple bolts to torque the carrier to 29ftlb, to torque the ring gear i clamped the carrier in a vice (can't remember the torque but i found it online, it is recommended to replace the bolts but i suspect that they come preloaded with locktight and that is why they want new ones, i hit everything with red)
http://i792.photobucket.com/albums/yy201/wdixon27/obx9.jpg
the "large" spacer set, there is a small set and it is a crap shoot what you will need, you gotta measure that back lash and see what it comes out with and measure the spacers with vernier calipers to see where you stand, i took several diffs down looking for spacers to get it together so i wouldn't need to wait a week for them to come from germany and bust out $50-60 for em and found them all to be in the .065 range with only a few thousandths variation (biggest one i found was .070 and smallest was .060) the biggest spacer being .077 in my set (they ran .067 to .077 on couple thousandth steps
http://i792.photobucket.com/albums/yy201/wdixon27/obx17.jpg
all done, in the end i could only go the backlash to .002-.003 which is likely close enough to the .005 it started with, if i couldn't get it closer i would of needed to pull the bearings and file the seats a little to get the bearings to seat deeper as i used the two thickest spacers a .076 and .077 (thicker increases your clearance) i tossed new o-rings and seals into the side pieces for the last time together and sealed up the rear cover with ultra gray sealer and no gasket (been doing it that way for years with no leakers)
get the replacement hardware for the obx from this guy http://rbryant.freeshell.org/obx_washers