9-bolt service
#1
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Car: Pontiac Trans Am GTA -87
Engine: 5.7 TPI
9-bolt service
My problem is, 9 bolt with worn out cones (bottomed). I have new cones, i was going to re-assemble the differential today. The new cones doesent seems to touch the "housing-wall" it just feels like its bottoms out. Can someone tell me how this posi works? Maybe my housing is worn out?
If i try to assemble it with the new cones it seems like they are too thick. Do i have to lath them down or something?
Please help me out. I have no experience in posi differentials.
,Mathias
If i try to assemble it with the new cones it seems like they are too thick. Do i have to lath them down or something?
Please help me out. I have no experience in posi differentials.
,Mathias
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Car: Pontiac Trans Am GTA -87
Engine: 5.7 TPI
Re: 9-bolt service
Thank you for the answer.
So i have to machine the "housing bottom" and the whole rised edge in bottom has to be removed?
Thanks for answer, really appreciate it.
So i have to machine the "housing bottom" and the whole rised edge in bottom has to be removed?
Thanks for answer, really appreciate it.
#4
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Re: 9-bolt service
you machine the step in the center, make it flush with the surrounding
That's what's hanging up your cones, the original cones have a step machined in them to clear that.
This step: (these are machined beyond factory specs to be able to reuse them)
That's what's hanging up your cones, the original cones have a step machined in them to clear that.
This step: (these are machined beyond factory specs to be able to reuse them)
Last edited by Twin_Turbo; 04-23-2012 at 01:57 AM.
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Car: Pontiac Trans Am GTA -87
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Re: 9-bolt service
Thanks again!
Just one question more, How do i know how much to shim behind the cone?
I think im going to machine the cones, because its much easier. But dont know how much i have to shim them.
Thanks
,Mathias
Just one question more, How do i know how much to shim behind the cone?
I think im going to machine the cones, because its much easier. But dont know how much i have to shim them.
Thanks
,Mathias
#6
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Re: 9-bolt service
shim the cones so that they are in there without play and the cross with the spider gears is flush in the case, no rocking and minimal to no play on the spiders. This will gie you a tight setting. If unsure go a little thinner on the shim for a little less tightness. Gear action will force the spiders out and press the cone in the carrier when the wheels turn at different speeds.
You do this shimming on both halves using the respective parts on their sides, do NOT mix them up after determining the shim pack. The only stuff you use on both sides is the cross and the spider gears and the cupped load washers (or whatever those are called)
Just make absolutely certain you do not have it too tight or it will hammer like crazy and will take stupid amounts of break away torque. I always shim mine a little tight, in some cases you will need to use posi additive to get the chattering to stop but it should go away fairly quickly. If you shim it loose I would run it without additvie and only add it if you hear poppinghammering noises.
check this pictorial
https://www.thirdgen.org/forums/tran...hese-posi.html
You do this shimming on both halves using the respective parts on their sides, do NOT mix them up after determining the shim pack. The only stuff you use on both sides is the cross and the spider gears and the cupped load washers (or whatever those are called)
Just make absolutely certain you do not have it too tight or it will hammer like crazy and will take stupid amounts of break away torque. I always shim mine a little tight, in some cases you will need to use posi additive to get the chattering to stop but it should go away fairly quickly. If you shim it loose I would run it without additvie and only add it if you hear poppinghammering noises.
check this pictorial
https://www.thirdgen.org/forums/tran...hese-posi.html
Last edited by Twin_Turbo; 04-23-2012 at 06:46 AM.
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