Posi Rear Dillema
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all trs came 3.42 and 8.5 , what you have in there today may not be what it was sold with , unless you bought it new and know its history its best if you verify what you have because the 7.5 bolts right up and you wouldnt be the first TR owner to find a 7.5 rear under his car
if going eaton, which is a good choice for a posi there are some things to be aware of
stock axles are 28 spline going into the center section , if you buy an eaton you will need to get one that is 28 spline
you can get an eaton with 30 spline but youll need to replace the axles with aftermarket 30 spline c-clip axles.
stock carrier for 3.42 gears is whats called a 3 series carrier , youll need to get an eaton with 3 series posi carrier , a 2 series carrier wont work as it would require a ring gear spacer and at the hp level of the TR a spacer isnt a wise.
the eaton also uses larger side bearings than stock on the carrier so youll need to get the carrier side bearings
you need to check your gears to see if they are damaged , if they arent you can reuse the ring gear but replace the ring gear bolts with new ones
if your doing the work yourself you should pick up a rear diff install kit which will have new carrier bearings (specify for eaton if thats what you go with) , shim kit to set the carrier for proper backlash and will also include the ring gear bolts, locktite for the bolts ,new cover gasket , and marking compound to check the tooth contact .
i would get a magnetic base dial indicator as well to set the backlash to spec (approx .008")
youll also need a torque wrench to torque the ring gear bolts and the carrier cap bolts and two quarts of diff lube
cheap and easier is find a used stock GM posi , they swap right in and usually are close enough to install without a shim kit using the OE cast shims (be sure to check backlash anyway), only downside is if the used is worn out and requires a rebuild , clutch kits run about 150 and if you need other parts like spider gears you'd have been better off going with a new eaton
if going eaton, which is a good choice for a posi there are some things to be aware of
stock axles are 28 spline going into the center section , if you buy an eaton you will need to get one that is 28 spline
you can get an eaton with 30 spline but youll need to replace the axles with aftermarket 30 spline c-clip axles.
stock carrier for 3.42 gears is whats called a 3 series carrier , youll need to get an eaton with 3 series posi carrier , a 2 series carrier wont work as it would require a ring gear spacer and at the hp level of the TR a spacer isnt a wise.
the eaton also uses larger side bearings than stock on the carrier so youll need to get the carrier side bearings
you need to check your gears to see if they are damaged , if they arent you can reuse the ring gear but replace the ring gear bolts with new ones
if your doing the work yourself you should pick up a rear diff install kit which will have new carrier bearings (specify for eaton if thats what you go with) , shim kit to set the carrier for proper backlash and will also include the ring gear bolts, locktite for the bolts ,new cover gasket , and marking compound to check the tooth contact .
i would get a magnetic base dial indicator as well to set the backlash to spec (approx .008")
youll also need a torque wrench to torque the ring gear bolts and the carrier cap bolts and two quarts of diff lube
cheap and easier is find a used stock GM posi , they swap right in and usually are close enough to install without a shim kit using the OE cast shims (be sure to check backlash anyway), only downside is if the used is worn out and requires a rebuild , clutch kits run about 150 and if you need other parts like spider gears you'd have been better off going with a new eaton
this is the one you want:
GM Chevy GMC 8.5" 10-Bolt Posi Carrier - 28 Spline -NEW - eBay (item 390270805641 end time Dec-17-10 05:28:41 PST)
part # is 19557 010
its listed as a 3 series,buts its for 2.73 and up
very easy to install.
http://www.jegs.com/InstallationInstructions/300/362/362-19557-010.pdf
GM Chevy GMC 8.5" 10-Bolt Posi Carrier - 28 Spline -NEW - eBay (item 390270805641 end time Dec-17-10 05:28:41 PST)
part # is 19557 010
its listed as a 3 series,buts its for 2.73 and up
very easy to install.
http://www.jegs.com/InstallationInstructions/300/362/362-19557-010.pdf
turbofabricator
Well-Known Member
- Joined
- Mar 7, 2004
- Messages
- 4,261
Also one VERY important thing when replacing the carrier (Posi).......THe ring gear bolts are REVERSE thread. Don't try and break them loose counter clockwise, or you REALLY will be breaking them loose.
In other words....tighten them to loosen them.
Easy mod for an average mechanic with good tools and a dial indicator as stated above. If the extra $250-$300 won't kill you, go with 30 spline. Randy's Ring and Pinion has both Eaton and Yukon brand carriers. (They claim the Yukon is better, but that is their company brand, so go figure) They can set you up with everything you need, along with DTS, Moser, ect. Call around for best price.
I've found that the stock shims work about 90% of the time.
In other words....tighten them to loosen them.Easy mod for an average mechanic with good tools and a dial indicator as stated above. If the extra $250-$300 won't kill you, go with 30 spline. Randy's Ring and Pinion has both Eaton and Yukon brand carriers. (They claim the Yukon is better, but that is their company brand, so go figure) They can set you up with everything you need, along with DTS, Moser, ect. Call around for best price.
I've found that the stock shims work about 90% of the time.
why does the ad say ......Eaton-STYLE.........
is this an Eaton or an offbrand????????
just asking
scott
I believe it is an Eaton as an Auburn is a cone style posi
So "Eaton style" means it is a clutch type not a cone.
Also,I would rather reuse the original GM ring gear bolts because most of the installation kits I have seen have cheezy Chi-com made bolts I wouldn't use on a lawnmower.
So "Eaton style" means it is a clutch type not a cone.
Also,I would rather reuse the original GM ring gear bolts because most of the installation kits I have seen have cheezy Chi-com made bolts I wouldn't use on a lawnmower.
