Made another step in the right direction. 
Got the .020" pinion shim in and everything reassembled with the larger carrier shim on the right (as it was). I checked backlash and it is sitting nice at .010". I checked my wear pattern again and I think it looks pretty good, could maybe use a little more gear meshing (larger pinion shim) but I don't have enough experience reading wear patterns to know:
Got the .020" pinion shim in and everything reassembled with the larger carrier shim on the right (as it was). I checked backlash and it is sitting nice at .010". I checked my wear pattern again and I think it looks pretty good, could maybe use a little more gear meshing (larger pinion shim) but I don't have enough experience reading wear patterns to know:
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Nice job!!! Ok, if you did nothing else you will most likely be ok, however, what other size pinion shims do you have??? 0.025" might be the sweet spot, and I would like to see the back lash closer to 0.008" to reduce the chance of clunking. If you want clean the ring with brake clearner and reinstall the pinion with another 0.005" of shim, and recheck baklash and gear pattern, and see what you get. If it is better then you need to set the pinion beaing preload, but don't do that yet....... let us know.
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If I haven't mentioned, this would be a great time to drill and tap the bottom of the diff center section for a drain. The flat spot make a great place, drill and tap for 3/8th-20 NTP and you can get an aluminum plug from summit racing. Don't worry about the second hole, it is for a temp probe for the gear oil pump on a road race application.
http://store.summitracing.com/partd...906705+4294906728+4294906750+115&autoview=sku
http://store.summitracing.com/partd...906705+4294906728+4294906750+115&autoview=sku
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Ok, I'll check my shims in a bit. Great idea for the drain as well. I'm assuming the plug needs to be aluminum to prevent corrosion/seizing? I should maybe think about that for my diff cover as well, seeing as I just had to remove the broken vent and tap it for an npt fitting... What do you think? Should I try to track down an aluminum fitting for that as well?
As for the preload, I think I'm straight on that (there's actually a great vid on youtube about getting the crush sleeve crushed and preload set. I also just got my 1/4" to 3/8" and 3/8" to 1/2" adapters for my in/lb torque wrench! Either way, I'll wait to see if you have any important tips I may have missed!
As for the preload, I think I'm straight on that (there's actually a great vid on youtube about getting the crush sleeve crushed and preload set. I also just got my 1/4" to 3/8" and 3/8" to 1/2" adapters for my in/lb torque wrench!
Either way, I'll wait to see if you have any important tips I may have missed!I always use aluminum fittings with the cobra diff center sections due to the high heat it generates and the expansion rates, steel will leak. As far as the vent don't wory about it as it won't see much oil, do you have the stock vent tubing?? It is hook shaped.
Ok, good, I just want to make sure you get the preload right, it should be the last step, and you have only once shot at it if you use a new crush sleeve. Just go slow and in small increments and check it often, 180-210ft/lbs on the pinion nut, with a new crush sleeve should get you in the ball park, if you are using the old beaings shoot for 16inch/pounds or so, if the bearings are new shoot for 20inch/lbs.
Good luck, you are almost there!!!
When you reseal the cover use gray RTV sealant, as the black stuff leaks, and make sure the mating surfaces are clean, and 25-ft/lbs on the cover bolts. Let it sit over night before you install and use it so you won't get any leaks. Run it for 20-30 mins at normal speeds, then let it cool down, drain and refill and run it as you will.
BTW do you have an IRS cover brace like the Billetflow, Steeda, or Motoblue one??? IMHO, cheap insurance on these covers FWIW!!!
Ok, good, I just want to make sure you get the preload right, it should be the last step, and you have only once shot at it if you use a new crush sleeve. Just go slow and in small increments and check it often, 180-210ft/lbs on the pinion nut, with a new crush sleeve should get you in the ball park, if you are using the old beaings shoot for 16inch/pounds or so, if the bearings are new shoot for 20inch/lbs.
Good luck, you are almost there!!!
When you reseal the cover use gray RTV sealant, as the black stuff leaks, and make sure the mating surfaces are clean, and 25-ft/lbs on the cover bolts. Let it sit over night before you install and use it so you won't get any leaks. Run it for 20-30 mins at normal speeds, then let it cool down, drain and refill and run it as you will.
BTW do you have an IRS cover brace like the Billetflow, Steeda, or Motoblue one??? IMHO, cheap insurance on these covers FWIW!!!
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No, the vent tube was broken off and missing along with all the other problems the seller failed to mention when he said no to the question "Is anything wrong with the unit besides the bad DS bearing?" Thanks! Anyway, I was thinking I could somehow replace it with shaped brake line but I'm not sure how to attach it to the npt fitting so it'd stay upright...
Good note on the RTV. I bought black as all the tutorials said black. And yes, I have a Steeda brace. Makes putting the filler plug back in a massive PITA!!
Good note on the RTV. I bought black as all the tutorials said black. And yes, I have a Steeda brace. Makes putting the filler plug back in a massive PITA!!
That sounds much better!!
Ok, backlash looks good but now my pattern is off. Looks like the "needs a smaller pinion shim" picture on the chart.
I also have a .012" shim so I think I'll try that plus the .010" and see what I get... Sound like a good idea?
I also have a .012" shim so I think I'll try that plus the .010" and see what I get... Sound like a good idea?
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So close!!! 0.022" should do it. I always try to get backlash as close to 0.008" as possible.
I think you could be on the road tomorrow!!!!
I think you could be on the road tomorrow!!!!
Sweet! I'm back out there... I'm determined to have this thing sealed up tonight so I can (maybe) get it back up in there tomorrow. Then I still have to reinstall my catbacks (which are really just flow tubes, series flows and dumps before the LCA's - no cobra catback system for the 'bird yet), reinstall the axles, knuckles, suspension and wheels!! If I'm lucky I can do a test drive tomorrow and see if I fixed the problem!
That look good to me!!! I would be real comfortable running this shim set up!!
It is your call, but the 0.020" shim you used with a 0.010" backlash will make more noise than you want and the 0.025" shim with 0.007" is a little too tight.
It is your call, but the 0.020" shim you used with a 0.010" backlash will make more noise than you want and the 0.025" shim with 0.007" is a little too tight.
No worries!!! That is the only problem with shims, unless you have every size, you sometime have to go with the stack that make the best setup, and IMOH it is the 0.022" pinion stack with 0.008" backlash!!
BTW, is this the first diff/rear end you have ever rebuilt??? If so you are doing a great job!!! It realy is not that bad of a job, just need som time and a few special tools.
BTW, is this the first diff/rear end you have ever rebuilt??? If so you are doing a great job!!! It realy is not that bad of a job, just need som time and a few special tools.
Yeah, the tools part killed me: dial indicator, base, in/lb torque wrench, digital caliper, etc. I also have to go pick up an extraction kit. Plus all the parts for an IRS unit that was supposed to be all good, ready to install!! I also forgot to mention the dude that put the gears in before selling me the unit snapped a cover bolt off and instead of extracting it and replacing it he put the cover on and gobbed it up with RTV. Nice!
Anyway, yes, this is my first and I can't thank you enough for the help!! It's been fun even through all the repetition!! Another skill. Love it!
Anyway, yes, this is my first and I can't thank you enough for the help!! It's been fun even through all the repetition!!
Another skill. Love it!
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You are more than welcome!! If it were not for others helping me at some point I would have been stuck along the way too, in fact many times!!
On the cover bolt that broke, can you remove it with needle nose pliers?? Post a pic if you can??
On the cover bolt that broke, can you remove it with needle nose pliers?? Post a pic if you can??
No, it was flush. Added a set of extractors to the tool list. Drilled it, spun it out and replaced. Crush sleeve is in, preload set, caps torqued and RTV is setting up! I probably won't get it in tomorrow though. I have lots of other things to get done. As another side note, I think I'm gonna get my crown vic interceptor alum DS cut down, balanced and installed while the car is up. I'm gonna look for a shop on Monday!
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