Change out rear end?
#1
Member
Thread Starter
Join Date: Jun 2006
Location: Colorado
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Trans Am/1993 Trans Am
Engine: 305 .030 over built/ LT1 Bolt Ons
Transmission: t5/700r4
Axle/Gears: 3.43 Posi/3.23 Posi
Change out rear end?
So what would be the easiest way to change my rear to either 3.43 posi disc or 3.73 posi disc? I know how to pull the rear from the car but is there specifics i should stay with? like 9 bolt or 10 bolt and whats the diff in 9,10 and 12?
#2
Supreme Member
9 bolt was the borg warner rear
10 bolt is the 7.5 and 7.625
12 bolt never came in these cars and was gone after '72 in cars and '80 in trucks
there was a dana 44 under a few of these cars i have heard
a direct fit axle- from a third or fourth gen f body is what to use
3.42 and 3.73 posi are common under these cars, especially in the 84 85 86 years, see them all the time
good luck
10 bolt is the 7.5 and 7.625
12 bolt never came in these cars and was gone after '72 in cars and '80 in trucks
there was a dana 44 under a few of these cars i have heard
a direct fit axle- from a third or fourth gen f body is what to use
3.42 and 3.73 posi are common under these cars, especially in the 84 85 86 years, see them all the time
good luck
#3
Member
Thread Starter
Join Date: Jun 2006
Location: Colorado
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Trans Am/1993 Trans Am
Engine: 305 .030 over built/ LT1 Bolt Ons
Transmission: t5/700r4
Axle/Gears: 3.43 Posi/3.23 Posi
How do i tell if i get an axle at a junk yard, ya turn a tire and if the other side goes same way its a posi, what about gears?
#4
Moderator
Join Date: Jan 2000
Location: Mercedes Norte, Heredia, Costa Rica
Posts: 20,981
Likes: 0
Received 9 Likes
on
8 Posts
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
The only way to know what's inside it, whether you're worried about posi or gears, is to take the cover off and actually look.
#5
Member
Thread Starter
Join Date: Jun 2006
Location: Colorado
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Trans Am/1993 Trans Am
Engine: 305 .030 over built/ LT1 Bolt Ons
Transmission: t5/700r4
Axle/Gears: 3.43 Posi/3.23 Posi
Thats the only way to check the gears???
#6
Moderator
Join Date: Jan 2000
Location: Mercedes Norte, Heredia, Costa Rica
Posts: 20,981
Likes: 0
Received 9 Likes
on
8 Posts
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
The only way to check with any certainty.
You might also want to know additional trivial little details like are the gears damaged at all, which you'll only find out if you actually look inside.
You might also want to know additional trivial little details like are the gears damaged at all, which you'll only find out if you actually look inside.
#7
here's how to tell:
1)rotate the wheel one full turn (use the valve stem as a guide)
2)count the turns of the pinion or driveshaft
3)if the driveshaft turns 3-1/4 turns it's a 3.25:1 rear
3-3/4 turns- 3.73
2-3/4 -probably the 2.79
3-1/2 - probably the 3.42 (or if it's the 9 bolt - 3.45)
etc, etc.
1)rotate the wheel one full turn (use the valve stem as a guide)
2)count the turns of the pinion or driveshaft
3)if the driveshaft turns 3-1/4 turns it's a 3.25:1 rear
3-3/4 turns- 3.73
2-3/4 -probably the 2.79
3-1/2 - probably the 3.42 (or if it's the 9 bolt - 3.45)
etc, etc.
Trending Topics
#8
Moderator
Join Date: Jan 2000
Location: Mercedes Norte, Heredia, Costa Rica
Posts: 20,981
Likes: 0
Received 9 Likes
on
8 Posts
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Yeah, but you're still buying a pig in a poke. You don't know if you're buying a bunch of broken teeth and shavings.
#9
TGO Supporter
Join Date: Oct 2002
Location: Saskatoon, SK, Canada
Posts: 9,067
Likes: 0
Received 1 Like
on
1 Post
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Dana 44 was an over the counter deal, unless you bought a Firehawk from SLP.
The 9-bolt is the strongest of the 3rdgen rear ends (rare Danas aside) but are still far from bulletproof. The 10-bolt would be a better choice, because they are much easier to find parts for than the 9-bolt, and the 9-bolt isn't stronger by a whole lot.
The 9-bolt is the strongest of the 3rdgen rear ends (rare Danas aside) but are still far from bulletproof. The 10-bolt would be a better choice, because they are much easier to find parts for than the 9-bolt, and the 9-bolt isn't stronger by a whole lot.
#11
Member
Thread Starter
Join Date: Jun 2006
Location: Colorado
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Trans Am/1993 Trans Am
Engine: 305 .030 over built/ LT1 Bolt Ons
Transmission: t5/700r4
Axle/Gears: 3.43 Posi/3.23 Posi
Just looking at grabbing one from a junk yard!
#12
Member
Join Date: Apr 2004
Location: Calgary, AB
Posts: 156
Likes: 0
Received 0 Likes
on
0 Posts
Car: 89 GTA
Engine: 5.7L
you always have the option of gutting yours out and putting a posi carrier and new gears in. that way you'll know exactly what you have. i know its obvious but its always an option
#14
Supreme Member
iTrader: (2)
Join Date: Feb 2005
Location: West Warwick RI, postal code: 02893
Posts: 4,337
Received 55 Likes
on
41 Posts
Car: Building LS3, T56 Z28
Engine: LS3
Transmission: T-56
Axle/Gears: Moser/ 4.11
if you are looking at jusnkyard prices, then stick to the yards and hope for the best. If you are not gonna open it up and see what you get, then there is not much anyone can do for you. Just dive in an cross your fingers.... or you could just open it up...
The next best thing would be new gears, but then istalling them would run you some more $....
Let us know what you end up goin' with.
The next best thing would be new gears, but then istalling them would run you some more $....
Let us know what you end up goin' with.
#16
Member
Thread Starter
Join Date: Jun 2006
Location: Colorado
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Trans Am/1993 Trans Am
Engine: 305 .030 over built/ LT1 Bolt Ons
Transmission: t5/700r4
Axle/Gears: 3.43 Posi/3.23 Posi
goin to look at junk yard tomorrow and checkin if anyone has a cheap one here
#20
Member
Thread Starter
Join Date: Jun 2006
Location: Colorado
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1986 Trans Am/1993 Trans Am
Engine: 305 .030 over built/ LT1 Bolt Ons
Transmission: t5/700r4
Axle/Gears: 3.43 Posi/3.23 Posi
found crap at junk yard and for 500,no.
#21
Supreme Member
iTrader: (5)
so did almost every Z28 or T/A from 84-87 that was carb'd, most 5 speeds got this rear end too. In fact the 9 bolts which were posi and had disc brakes don't even go for more than $400 TOPS and those are much stronger than the 10 bolt ever could be. Swap out the price to $200 and it might sell. 4th gen rear ends with bigger brakes on them only go for $250 all day.
Thread
Thread Starter
Forum
Replies
Last Post
hectre13
Engine/Drivetrain/Suspension Parts for Sale
2
12-11-2023 08:14 AM
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