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4th Gen Rearend Swap

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Old Oct 29, 2013 | 11:56 AM
  #1  
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From: Westfield, Indiana
Car: 1984 Camaro
Engine: built 305 V8
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4th Gen Rearend Swap

Hey fellas, just got my 1984 sport coupe camaro back from a friend who swapped a built 305 into it, and i wanna upgrade my rearend to a posi. How do i swap a fourth gen rearend into mine, im not that mechanically savvy, and any help would be wonderful. cheers!
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Old Oct 29, 2013 | 12:24 PM
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Car: 1984 Trans Am L69
Engine: Sniper EFI Powered 355
Transmission: WC T5 w/ Steel Support Plate
Axle/Gears: 3.42 10 Bolt Posi
Re: 4th Gen Rearend Swap

Originally Posted by XxSLeEPyJuiCExX
Hey fellas, just got my 1984 sport coupe camaro back from a friend who swapped a built 305 into it, and i wanna upgrade my rearend to a posi. How do i swap a fourth gen rearend into mine, im not that mechanically savvy, and any help would be wonderful. cheers!
Unbolt 3rd gen rear end, bolt in 4th gen rear end.

They are a direct swap.
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Old Oct 29, 2013 | 12:40 PM
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From: Yorktown, VA
Car: 1989 IROC-Z
Engine: L98
Transmission: 700R4
Axle/Gears: 4th gen rear with 3.42
Re: 4th Gen Rearend Swap

At most will need custom e. cables and you if you end up with an ABS rear you will have to swap one of the hard lines from the old rear to the new one. other than that I swapped mine in about 3 hrs.
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Old Oct 29, 2013 | 12:59 PM
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Re: 4th Gen Rearend Swap

Just as a heads up, 4th gen rear is wider than 3rd. Except for that all you need to do to swap them is undo brake lines. Unbolt torque arm, 2 bolt, control arms, 1 bolt for each side. panhard rod, 1 bolt and sway bar, 2 u bolts. and take out the driveshaft. Pretty easy swap
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Old Oct 29, 2013 | 03:12 PM
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Re: 4th Gen Rearend Swap

4th gen rear ends have disc brakes. You probably have drum brakes. That's probably going to be your biggest issue.
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Old Oct 29, 2013 | 07:16 PM
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From: stallings,n.c.
Car: 1989 camaro rs convertable
Engine: 305 tbi
Transmission: 700r4
Axle/Gears: 7.5"3.42 gears forth gen 2000 camar
Re: 4th Gen Rearend Swap

Originally Posted by big gear head
4th gen rear ends have disc brakes. You probably have drum brakes. That's probably going to be your biggest issue.
to me this was a plus.i swapped in a 2000 disc brake rear and the brakes seem to work fine.i got park brake cables from flynbye.im in the process of swapping in the lsi front brakes.
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Old Oct 29, 2013 | 07:24 PM
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Re: 4th Gen Rearend Swap

a plus
No doubt!!

But, it does take a certain amount of "custom" engineering to get that handled.

I'd agree though, the rear end swap itself is beyond eeeezy. Almost doesn't even qualify as a swap. (like 305 ->350) It's the brakes and the wheels, getting em PERFECT, is where the finesse is.
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Old Oct 30, 2013 | 09:02 AM
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Car: 88 IROC
Engine: 97 5.7 Vortec LT4 hotcam
Transmission: 700 r4
Axle/Gears: 3.73
Re: 4th Gen Rearend Swap

Swap the proportion valve. If you dont, your rear brakes will barely be doing anything.
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Old Oct 30, 2013 | 11:02 AM
  #9  
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From: Westfield, Indiana
Car: 1984 Camaro
Engine: built 305 V8
Transmission: 5 Speed
Re: 4th Gen Rearend Swap

okay well i do understand the swap part, the only yhings im no good at is the ebrake, how does it connect to the rear. and where is the proportion valve located at. Thanks guys.
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Old Oct 30, 2013 | 11:07 AM
  #10  
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From: Westfield, Indiana
Car: 1984 Camaro
Engine: built 305 V8
Transmission: 5 Speed
Re: 4th Gen Rearend Swap

Alright well as an update, my rearend is drums and i think it might be easier to just find a posi out of an iroc or something, problem is i know that some 3rd gen rearends are not posi track, just like my friends 5.0 89 RS. So what rearends are posi, how would one check? thank you all for your patience im not a more mechanically inclined third gen owner. in other news , how does the emergency brake work lol
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Old Oct 30, 2013 | 01:41 PM
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Re: 4th Gen Rearend Swap

Originally Posted by kcaalarcon
Just as a heads up, 4th gen rear is wider than 3rd. Except for that all you need to do to swap them is undo brake lines. Unbolt torque arm, 2 bolt, control arms, 1 bolt for each side. panhard rod, 1 bolt and sway bar, 2 u bolts. and take out the driveshaft. Pretty easy swap

How much wider?
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Old Oct 30, 2013 | 01:48 PM
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Re: 4th Gen Rearend Swap

I never actully measured but I think 2.5 inches maybe. Just a guess tho cuz it was almost the same as my stock axel with 1.5 spacers
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Old Oct 30, 2013 | 03:28 PM
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Re: 4th Gen Rearend Swap

3rd gen limited slip rear ends had the Auburn differential. If you find one it is probably going to be worn out, and they can not be rebuilt, so you would be no better off than you are now. Installing a new Eaton Posi or Yukon Dura Grip would be a better idea.
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Old Oct 30, 2013 | 03:48 PM
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Re: 4th Gen Rearend Swap

Originally Posted by big gear head
3rd gen limited slip rear ends had the Auburn differential. If you find one it is probably going to be worn out, and they can not be rebuilt, so you would be no better off than you are now. Installing a new Eaton Posi or Yukon Dura Grip would be a better idea.
He is right, it would probly be smarter to do that if all you're trying to achieve is having posi. Plus a new locker would probly be stronger
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Old Oct 30, 2013 | 09:19 PM
  #15  
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From: Westfield, Indiana
Car: 1984 Camaro
Engine: built 305 V8
Transmission: 5 Speed
Re: 4th Gen Rearend Swap

Originally Posted by kcaalarcon
He is right, it would probly be smarter to do that if all you're trying to achieve is having posi. Plus a new locker would probly be stronger
Alright, ive seen plenty used rearends on the local classifieds for like 250 bucks but they are the stock ones out of 3rd gens, do you guys think i could find a 4th gen rear for cheap? or could i find an aftermarket one for cheap used
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Old Oct 30, 2013 | 09:40 PM
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Re: 4th Gen Rearend Swap

I got mine for 300 and it came setup with ls brakes, 3.42 and a still pretty well working possi that's not worn out to the point of not functioning, out of a 4th gen. I could be wrong but I think some of the 4th gens, maybe ws6 had a stronger steal diff. As far as getting an axel out of a third gen they can very so widely from having no locking diffs, drum brakes, and some 2.73 gears. If you could find a 4th gen rear for cheap that's not super well used then go for it. Otherwise I would just buy a posi unit or save up to buy and aftermarket rear cuz the stock 7.5 inch 10 bolts are kinda weak
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Old Oct 30, 2013 | 09:46 PM
  #17  
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From: stallings,n.c.
Car: 1989 camaro rs convertable
Engine: 305 tbi
Transmission: 700r4
Axle/Gears: 7.5"3.42 gears forth gen 2000 camar
Re: 4th Gen Rearend Swap

the six cylinder cars usually have lower gearing and are the same strength.
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Old Oct 30, 2013 | 09:53 PM
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Re: 4th Gen Rearend Swap

Originally Posted by zenish
the six cylinder cars usually have lower gearing and are the same strength.
From my understanding anything ranging from a Chevy truck to a 3rd. Or 4th gen f body all have the same exact axle. Different gears and lockers but overall same. Didn't one of the 4th gen anniversary bird have a hardened steal diff tho?Could be wrong tho
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Old Oct 31, 2013 | 06:44 AM
  #19  
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Engine: 350 HO Deluxe (350ci/330hp)
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Re: 4th Gen Rearend Swap

Check the 10-bolt sticky at the top of the page.

JamesC
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Old Oct 31, 2013 | 07:21 AM
  #20  
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Re: 4th Gen Rearend Swap

If you do a 4th gen rear end get a '98 to '02. They have the Torsen differential which is far better than the Auburn.
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Old Oct 31, 2013 | 11:11 AM
  #21  
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Car: 85 Trans Am
Engine: LB9
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Axle/Gears: 3.27
Re: 4th Gen Rearend Swap

Originally Posted by kcaalarcon
From my understanding anything ranging from a Chevy truck to a 3rd. Or 4th gen f body all have the same exact axle. Different gears and lockers but overall same. Didn't one of the 4th gen anniversary bird have a hardened steal diff tho?Could be wrong tho
I believe (based on some research, and having both) F-bodies got the 7.5" 10 bolt, the trucks got the stronger/larger 8.5" 10 bolt. Parts will not interchange.
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Old Oct 31, 2013 | 03:02 PM
  #22  
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Re: 4th Gen Rearend Swap

S series trucks used the 7.5 rear end.
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Old Oct 31, 2013 | 03:19 PM
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Re: 4th Gen Rearend Swap

I have a Sonoma and a full size blazer that ik for sure have the 7.5 but idk about the other full size trucks. He is most likely right and they have the 8.5 but I couldn't tell just from glancing at them
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Old Oct 31, 2013 | 05:55 PM
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Re: 4th Gen Rearend Swap

Full size Blazer and full size trucks did NOT have 7.5 rear ends. The smallest rear end that they had was the 8.5.
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Old Oct 31, 2013 | 11:20 PM
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Re: 4th Gen Rearend Swap

Not to argue, in most cases your probly right but I have an od-ball one and have replaced the diff in it and it is defiantly a 7.5. Sorry
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Old Nov 1, 2013 | 06:17 AM
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Re: 4th Gen Rearend Swap

Not to argue, only to state facts...

Then you have the only one in existence like that.

Either your truck isn't a full-size (which it isn't if it's a Trailblazer, S, Colorado, etc.), or it wasn't a 7.5" rear. That's the only 2 possible explanations.
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