Author Topic: 8 3/4" differential rebuild  (Read 1250 times)

Offline john h

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8 3/4" differential rebuild
« on: February 26, 2016 - 02:20:08 PM »
guys, I'm finally in the tear down stage of the rear end. Pulled the tires, driveshaft and axles last night.  pulled most of the bolts and proped the pig out so it could drain over night.  Have not pulled it out of the housing yet.  Now for the question....  do you always have to add a new Tru Track or Eaton unit to it?  is it possible to use the old Cone type unit with a fresh set of bearings and and ring&pinion?  just curious if it's one of those things like you have it all apart may as well use all new parts?  was just wondering if I can save myself $350-450 in parts.

looking for all opinions.
Thanks
John
John
73 Cuda
360 Crate motor
FiTech Fuel injection
727 Trans (wishing it had Over Drive)




Offline crash340

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Re: 8 3/4" differential rebuild
« Reply #1 on: February 26, 2016 - 05:02:43 PM »
First point of call would be to Cass at Dr Diff, out and out good guy. cone cores can be re used if they are still servicable and not worn out, clutch units can be rebuilt, i would definitely put a full bearing kit in it if its out just for peice of mind. I personally would not use the Eaton TrueTrac in an 8.75, I did and while it worked great it was problematic, thats just my experience, other have had the same if you google noisy TrueTrac, ultimately your choice though
Greg

73 Cuda
Brisbane, Australia

Offline HP_Cuda

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Re: 8 3/4" differential rebuild
« Reply #2 on: February 26, 2016 - 05:04:27 PM »

Clutch units are more serviceable as once the cone style is worn out it's pitch time.
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Offline brads70

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Re: 8 3/4" differential rebuild
« Reply #3 on: February 26, 2016 - 09:01:18 PM »
When your adding up all the costs keep in mind a brand new Dana is $2150 bolt in.....
http://www.doctordiff.com/strange-60.html
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
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Offline john h

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Re: 8 3/4" differential rebuild
« Reply #4 on: February 26, 2016 - 10:26:04 PM »
First point of call would be to Cass at Dr Diff, out and out good guy. cone cores can be re used if they are still servicable and not worn out, clutch units can be rebuilt, i would definitely put a full bearing kit in it if its out just for peice of mind. I personally would not use the Eaton TrueTrac in an 8.75, I did and while it worked great it was problematic, thats just my experience, other have had the same if you google noisy TrueTrac, ultimately your choice though
how can you tell if the cone type core is still serviceable? I don't know about its use from 71-88, (salvage yard purchase) but since 1988 it's seen only street driving and about 10K miles.  I have replaced the the gear oil 1 time since 1988.  It still lays 2 thick black stripes :bigsmile:  I think if I need to replace it, I will go with the "power Lok"  unit. 

Thanks, John
« Last Edit: February 26, 2016 - 10:39:46 PM by john h »
John
73 Cuda
360 Crate motor
FiTech Fuel injection
727 Trans (wishing it had Over Drive)

Offline Chryco Psycho

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Re: 8 3/4" differential rebuild
« Reply #5 on: February 26, 2016 - 10:39:09 PM »
if the cones are worn to the point where thay are bottomed out inside the case it is shot , cone type are the worst , 4 pinion clutch type are far superior & the true trac are a perfect design if they work properly

Challenger - You`ll wish You Hadn`t