The rear end on my 87 Trans Am went out last night. How hard is it to change the whole rear axel? My car is a 5-spd with posi and I found a rear axel at a junk yard out of a 91 with 3.23 gears and a posi with 80,000 miles for $325.00 Does this sound like it's worth it? Will this 91 rear end work on my 87? My car has rear drums and so does this one. Thanks, Jason

 

It's cake! It should take you a couple hours to swich the axle, most of which will be fighting rusted bolts. You'll need 18mm and 21mm sockets for the track bar (panhard rod) and lower control arms. That time excludes any brake work...

For the brakes, since both have drums, all you need to do is hook up the lines & bleed the rear brakes. Don't let the "frontmost" reservoir of the master cylinder drip dry when you unhook the body-to-axle hose! Now's a great time to replace that 13-year-old body-to-axle hose; it's probably deteriorating internally. If you replace the hose, you can cut your old one in half and plug it with a screw to keep the m/c from draining while you finish the swap.

Oh; and if you shop around you should be able to do better than $325. I bought my 1984's 3.73/posi/disc axle for $150.

You might want to replace the rear axleshaft bearings (misnamed "rear wheel bearings") and seals while you're doing the switch. It cost me $34 total for the rear bearings/seals.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

TomP,
I guess that 34 dollars is just for the bearings right. You have to have a bearing puller to replace them right? I'm doing this swap in about two days so.......What happens if you let the "Frontmost" resovoir drip dry. How do you stop it. Just plug the lines I assume, Stupid I know.
bsa

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"If they do not run, Then they will die." - Stonewall Jackson

'87 IROC, 355 TPI,700R4, Trick Flow Heads, Comp Cam, Comp 1.6 Rockers, Lucas 23# injectors, Edelbrock headers, Flowmaster 3'' exhaust, gutted cat,
Mallory coil, Mallory HyFire IV ignition box, Mallory Sidewinder 8mm wires, Autolite platinum plugs, K&N filters, Transgo Performance Shift Kit, Corvette Servo, 2,000 Torque Converter

 

Are you sure its 3.23 ratio? Most drum rears in 91 cars are 2.73 or 3.08 ratio.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

Irocbsa, yeah, the $34 was just for the bearings & seals. I made my own bearing puller for under $10! I used the following, all from Home Depot except the first:

(1) 10 pound plate from my weightlifting set
(1) 20 inch long, 1/2 inch threaded rod
(3) 1/2" nuts (to fit threaded rod above)
(1) 8 inch long, 1/2" diameter steel pipe (plumbing)
(4) 5/8" fender washers (outside diameter = 2 inches, matched against rear bearings)
(4) 1/2" fender washers (to reinforce 5/8" washers)

The 5/8" washers were large enough to get a grip on the metal ring surrounding the bearing, not the actual rollers.

I cut two "sides" of the the 5/8" washers, which turned them into a rectangularish shape. I then did the same to the smaller washers. The idea was to be able to slide the washers thru one side of the bearing and out the other. Both the 5/8" and 1/2" washers I bought had holes in the center large enough to allow them to tilt on the threaded rod (to be shoved thru the bearings).

Next comes the "slide hammer section": I then put a nut on the end of the the threaded rod. I dropped two small "cut" washers onto the rod, followed by two large "cut" washers. Next, I spun another nut onto the free end of the rod. I spun it down far enough so it would allow for the pipe to go over the rod. (This keeps the pipe from sliding on the rod.) Next, I put the 10 pound plate over the rod/pipe combo. Finally, I put another large washer onto the rod, followed by the two small washers and the final nut.

So, now, the tool looks like:

nut---small cut washers---large cut washers----------------------*nut-----"slide hammer section"

I pushed the "cut washer" end into the bearings, and pulled it so the washers pulled against the bearing cage. Then, while holding the puller against the bearings, I yanked the 10 pound plate back. Pop!

Another idea I had later would be to use another large washer, and another nut, as a "lock" device to hold the tool on the bearings. The tool would be modified to be:

nut---small cut washers---large cut washers-------*large washer--*nut-----"slide hammer section"

Now, when the tool is slid into the axle, and pulled back out so the cut washers are against the bearing, the extra washer & nut can be spun down towards the axle, to lock against the outside of the bearing. See what I mean? That leaves both hands free to yank the weight back.

I bent a few washers; you might want to buy more as spares.

I bet that's more than you wanted to know, eh? I hear you can rent pullers too.

And yeah just plug the brake line up with something. If the "frontmost master cylinder reservoir" (for the rear brakes, yes, it's backwards) goes dry, you'll have to bench-bleed the master cylinder. It's just one more headache you can avoid...

You could "flush" half of the master cylinder of old fluid by doing this right before hooking up the new axle-to-body brake hose:

1. Place container under rear of rear brake line
2. Remove cap from master cylinder
3. Have a friend pull the plug out of the rear brake line
4. Pour new brake fluid into the FRONTMOST reservoir of the m/c to keep it from running dry.
5. Have your friend tell you to stop when new, clear brake fluid comes out of the rear line
6. Switch places with your friend, tell him to watch the frontmost reservoir
7. Put on the new body-to-axle brake hose

I keep stressing "frontmost" m/c reservoir because I confused the two twice... I kept checking the wrong reservoir for the rear brakes. Anyway next, you'd bleed the rear brakes as normal. Everything's detailed in that Haynes 82-92 book... except my $8 puller.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

[This message has been edited by TomP (edited December 14, 2000).]

[This message has been edited by TomP (edited December 14, 2000).]

 

Kevin91Z, 3.23 was a pretty common gear ratio for 91 cars. I have owned 3 91 Z28s, and all 3 had the 3.23 gear ratio.

 

That sure is a bunch of hassle to pull those bearings. An inventive way to make a puller, but altogether too much work.

All you need is a piece of 3/4" water pipe about 6' long. Stick it through from the left and bonk the right bearing out, and vice versa. 30 seconds to do both sides, counting walking around the car.

I hate work...

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"So many Mustangs, so little time..."

 

TomP, Thanks for all the info buddy, that sure is one way to make a bearing puller. I may have to make one of those just to see if it works. You're gonna be my go to guy if I run into problems on Friday.
bsa

 

Yes, 3.23's are common in disc rears, but this is a drum rear he's talking about. I've only heard of Glenn's car coming with a 3.23 drum rear in 91-92. Just making sure before he buys it and then its not what he thought it was.

 

Heh, good luck, BSA.. since you don't have to screw with the master cylinder/prop valve, the swap should be pretty easy- especially since I bet it's warm in Georgia. Thinking about doing that swap here now makes me shiver...


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

Two of the three 3.23s that I have had were drum brakes.

 

Not to add confusion, but if I recall from many other posts on this board, the 2.73 were standard ratio. 3.08 were optional in Auto trans. 3.23 were optional in Manual trans.
The type of rear brakes had nothing to do with the ratio.

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Chuck Rini
Perry Hall MD
91 Z28 305TPI Convertible Black
92 RS 305TBI T-Top White

 

With the V6 and an automatic tranny, the 3.23 was the standard ratio. An L98 with the G92 option you could get the 3.23.
The v6/auto combination was pretty common, so chances are you have that one. Which is good, because the v6 could not hurt the rear-end much.

Update: All L98's supposedly had to get the G92 option.

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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

[This message has been edited by 82camaro (edited December 17, 2000).]