Transmissions and Drivetrain Need help with your trans? Problems with your axle?

Rear end question

Thread Tools
 
Search this Thread
 
Old 09-08-2012, 04:15 PM
  #1  
Junior Member
Thread Starter
 
mark crooks's Avatar
 
Join Date: Sep 2012
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Rear end question

Will a 1984 rear end fit in my 1989 IROC? Is there a difference in the disc brake sizes between the two? Thanks.

I just got a Camaro and know nothing about them
Old 09-08-2012, 04:51 PM
  #2  
Member

iTrader: (9)
 
Whoboy580's Avatar
 
Join Date: Feb 2004
Location: NJ
Posts: 176
Likes: 0
Received 0 Likes on 0 Posts
Car: 1986 Camaro
Engine: 383 Stroker
Transmission: Powerglide
Axle/Gears: 4.10
Re: Rear end question

They should bolt right in and if you have complete rears just swap them over and connect the brake lines up. You can also install a 4th gen rear on the car but you will need to get a adjustable Panhard bar to center the rear up.
Old 09-08-2012, 05:34 PM
  #3  
Supreme Member

iTrader: (8)
 
TTOP350's Avatar
 
Join Date: Oct 2001
Location: Il
Posts: 11,709
Received 756 Likes on 512 Posts
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: Rear end question

84 rear brakes are junk compared to the stock 89s,
Old 09-09-2012, 08:37 AM
  #4  
Supreme Member

iTrader: (1)
 
stealtht/a's Avatar
 
Join Date: Aug 2008
Location: Short Summer, VT
Posts: 1,485
Likes: 0
Received 2 Likes on 2 Posts
Car: 1985 Trans Am T-Top
Engine: 305 TPI
Transmission: T-5 5 Speed
Axle/Gears: 3.42 posi 1LE 10 bolt
Re: Rear end question

And the shafts of the 84 are weaker and the ebrake lines are different and I think the fittings on the 84 are SAE where the 89 is metric.
In other words, an 84 axle is a poor swap choice for an 89 iroc.
What ratio gears are in the 84? Posi?
I think you would be much better off fixing the 89 rear.
Old 09-10-2012, 07:00 PM
  #5  
Senior Member
 
Derek The Great's Avatar
 
Join Date: Dec 2004
Location: Warren, MI
Posts: 627
Likes: 0
Received 2 Likes on 1 Post
Car: 1989 Firebird Formula
Engine: 305 T.B.I. (Vin tag "E" = LO3)
Transmission: THM-700-R4
Axle/Gears: 10 bolt posi 3.23
Re: Rear end question

While the 84's rear end will have 26 spline axles in place of the 89's 28 as long as it has disc brakes I say swap the rear end over. I just swapped a 10 bolt from an 83 pace car into my 89 Formula and couldn't be happier. The car will most likely never make more than 450 ftlbs of torque and the disc set up works better than my old drums did. The ebrake cables from the 84 will hook right up but you might have to re use the brake line fittings that run into the rubber line with the "Y" block. You'll also want to buy a the correct proportioning valve for the brakes. If you don't and you currently have drum brakes you'll notice the rear brakes will be a bit on the grabby side and might drag a little like mine did.
Old 09-10-2012, 08:18 PM
  #6  
Supreme Member

iTrader: (8)
 
TTOP350's Avatar
 
Join Date: Oct 2001
Location: Il
Posts: 11,709
Received 756 Likes on 512 Posts
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: Rear end question

[QUOTE=Derek The Great;5375605]While the 84's rear end will have 26 spline axles in place of the 89's 28 as long as it has disc brakes I say swap the rear end over. [QUOTE]

We really need more info as to what rear is in his 89.
If its a performance 305 or a 350 car it will have a 11.65" rear disc with aluminum single piston calipers on a 9bolt with 3.27 gears.
If he has a drum rearend in his 89, I sure wouldn't want the 88 and older iron rear disc rearend. Id keep the drums and wait for a good rearend for it..
Old 09-10-2012, 09:01 PM
  #7  
Senior Member
 
Derek The Great's Avatar
 
Join Date: Dec 2004
Location: Warren, MI
Posts: 627
Likes: 0
Received 2 Likes on 1 Post
Car: 1989 Firebird Formula
Engine: 305 T.B.I. (Vin tag "E" = LO3)
Transmission: THM-700-R4
Axle/Gears: 10 bolt posi 3.23
Re: Rear end question

More info on his car is indeed necessary.. I'm not sure but I think those 11.65" brakes only came with the 1LE package otherwise yeah he should wait like I did until something better turned up. I prefer the 10bolt and I know I could always upgrade the brakes if I want. Right from the get go though I can tell the discs out perform my drums buy a significant margin.
Old 09-10-2012, 09:26 PM
  #8  
Supreme Member

iTrader: (8)
 
TTOP350's Avatar
 
Join Date: Oct 2001
Location: Il
Posts: 11,709
Received 756 Likes on 512 Posts
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: Rear end question

Nope, not just 1LE cars. Fronts, yes(kinda) rears nope they were standard on 89-92s with performance options
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
hectre13
Engine/Drivetrain/Suspension Parts for Sale
2
12-11-2023 08:14 AM
TreDeClaw
Theoretical and Street Racing
11
06-22-2021 08:21 PM
hectre13
Engine/Drivetrain/Suspension Parts for Sale
7
08-26-2015 08:17 AM
AkDrifted
Engine/Drivetrain/Suspension Parts for Sale
6
08-17-2015 07:45 PM
BlackBoulder
Suspension and Chassis
2
08-11-2015 11:15 PM



Quick Reply: Rear end question



All times are GMT -5. The time now is 08:09 PM.