Car specs are in my sig. My rear end is the stock one, drum brakes and no posi. I want to convert to a 4th-gen rear end since I'll get posi and disc brakes at the same time. A few questions for you all

1) Where's the best place to get a 4th-gen rear end? F-Body Motorsports is local to me but they are out of 4th gen rear ends. And how much would it cost?
2) What other parts would I need to convert everything over?
3) If anyone has does this, can you give me an idea of how hard it would be to install it? I am pretty much a novice to working on cars, a friend of mine can probably help me out, but I want to try and do most of it myself. Or maybe there are some good guides on this swap?
4) Since I also want to convert to some new wheels, I wouldn't need rear spacers if I have a new rear end, so where can I buy just the front spacers? I'm going to use my thirdgen wheels on the new rear until I buy new wheels, yes I know they'll stick out...

Thanks guys! I'd appreciate any and all answers.

 

Its rather easy. A friend of mine and I did it on his 91 RS. No other parts needed besides the rear end. We bought some brake lines from napa so we could utilize the rear disc. (which we never got working, but oh well)

Took us 2 days about 8-10 hrs a day. His underbody was rather rusty and we had to pretty much drill/cut every bolt off, and replace with new ones.

After you're done you will want to get an adjustable panhard bar so you can recenter your wheels.

Have fun!

edit: dont know about question 4. We just ran stock 91 RS wheels, yah gave it the bull dog look.

 

Thanks I dont know how much underbody rust my car has, but it's got 59K miles and has spent its whole life garaged, and in North Carolina...so I'm not imagining a whole lot but I'll manage with what there is. I will definitely replace the bolts though. What did you use to cut off the old bolts with?

So to get the rear brakes to work I would need new brake lines, OK...would something like this work? I am not looking to win any braking competitions (do they even have those? LOL), as long as it's better than my stock brakes...(if my stock brakes were a little better I wouldn't have gotten into a wreck )

How necessary is the panhard bar? I'd rather not spend the money...what would it give me as opposed to not getting one?

Oh, and if you have any pics of the 91 RS with the wheels sticking out, I'd like to see em I only saw one but it was too close up for me to get a good impression...

 

It is a very easy swap, I've done 5 3rd gen to 4th gen swaps and 15 rear end swaps on my brothers 96 T/A.

On my 88 Formula that I put the 98 Rear end on, I just went to Advance Auto and bought 2 lengths of brake lines, 20" and 26" I think, just measure from the "T" that is on the body (drivers side next to the fuel lines) to each caliper.

Stock panhard will work fine since they are the same as the 4th gens. If you lower your car, then you need the adjustable one to recenter the rear end.

I am not running an e-brake at the moment since I haven't found the right cables to use. My friend bought some GM cables for his swap but they are discontinued.

A lot of the spacer vendors will sell the spacers in pairs if you only need 2 which reminds me, I need to get another pair soon since I took my spacers from my Trans Am and put them on my Formula.

We have air tools at my house and it takes us about 2 hours to swap rear ends if none of the bolts are rusted on.

Here is a quick run down of the removal and installation.

Jack up the rear of the car and support the body with 2 jackstands.
Place 2 jackstands under each of the the axle tubes.
Remove the wheels
Remove the 2 long bolts the hold the torque arm to the pumpkin on the rear end
Move torque arm to the side or pull it off
Unbolt the driveshaft from the rear end, leave it in the tranny and lay the end on the ground being carefull not to damage it or knock the end caps off
unbolt the sway bar from the rear
you can leave the sway bar attached to the endlinks but it will make it harder to move the rear end out from under the car
remove the brake lines from the drums
unbolt the lower control arms from the rear end
unbolt the brake line "T" from the rear end, if you are changing the brake lines, remove the lines from the "T" before unbolting it
unbolt the shocks from the rear
using the jack under the rear end, carfully balance it and jack it up a bit and pull the shocks out of the rear end, shocks will just hang there.
move the 2 jackstands that were under the rear end.
As you carefully lower the rear end, grab the coil springs as they will start to fall out.
roll the jack with the rear end out from under the car and place it somewhere.
Put the 4th gen rear on the jack and roll it under the car.
jack it up about level with the shocks and place the jackstands under the rear.
Position the springs back on the perches and carefully jack the rear up
Bolt up the shocks
Bolt up the Lower control arms.
And just start bolting everything else back up.

 

Thanks Zepher...OK, I won't get another panhard bar, there is no way in Hell I am lowering this car...hard enough to jack it up and go over speed bumps as it is

This might be a stupid question, but do I HAVE to get new brake lines when converting from drum to disc? I dont' know much about brakes

We also have air tools so it should be fairly quick assuming nothing is rusted on..

Where are some places to buy spacers at? F-Body Motorsports is the only place I've found, but they only sell in pairs...

And also, does anyone know where I can get the rear end at? Thanks

 

the only thing that isnt a bolt in deal is the ebrake cables.

for that to work, you need to make a bracket to hold the cables to the top of the trans tunnel.. thats all.

or leave em off.




for a rear, start talking to local clubs, looking in junkyards, ect... the most expensive way to do it, is to call some specialty place..... but thats also the easiest.

 

Can anyone point me in the direction of how to make or where to buy such a bracket?

 

OK, well being that I think I found a few nice rear ends on eBay...with 3:23 gears, posi, and disc brakes...I'm going to give this thread a bump for an answer for the e-brake thingy and if anyone knows where to get e-brake cables that would also be a plus

 

you have a PM man

 

OK, here's an update. My rear end is on the way via eBay, it's got 3.23 gears, posi, and disc brakes. It's from a 93-97 F-body.

Two questions:
1) Do I NEED new brake lines? If so...what measurements will I need, and can someone recommend some cheap ones? I don't really need new front ones, but if it makes financial sense to buy all 4 lines at once, then I might as well. Cheap as possible, please, especially considering that the rear brakes don't handle most of the load. Also, if anyone can find an e-brake line, that'd be great.
2) While I realize this is unrelated to drivetrain type stuff, I also want to upgrade my sway bar while I have the rear end apart. Can anyone point me in the right direction, and also will I need a sway bar specifically made for 93+ F-bodies?

 

in regards to the brake lines.

Wait and see what is on the axle. it may be little more than just attaching what you have.

and with the swaybar... you really can't upgrade the rear without also upgrading the front swaybar as a mismatched pair will lead to dangerous handling.

 

OK, I should be getting it towards the end of next week, so I'll see what I have...I'm looking to do the swap over Thanksgiving break so I want to get this all in by then...

As for the swaybars...thanks for telling me that how hard is it exactly to change out the front sway bar?

 

really easy to change the front.

you just need a matching set.

what's on it now?

 

Not sure what you mean? If you mean what sway bars are on now...whatever the stock ones are, I have a 91 base Firebird.

OK, I'll try to find a matching set, and if anyone can brief me on front sway bar installs, that'd be great. Thanks

 

I'm going to do this swap REAL soon dudes. But what the HECK is the Ebrake? Is that for the anti-lock? Also, the hyrdrualics (master cylinder/booster/etc.) can be left alone right? I know this is a lame question, but since I have Eibach lowering springs, do I have to worry about anything flying apart "abruptly" when I take this sucker loose? Also, I have the stock panhard right now. Will going to the 4th-gen require the adjustable unit? If so, where is the best source or will one from a 4th-gen work? Remember, I'm lowered 1.8" back there. Thanks a TON, fellow f-body FREAKS!

EDIT - the pic is before the Eibach 1.8" drop...

 

I thought when you went from drum to disc you had to change out the master cyl. Please clarify, yes or no

 

I didn't have to change my propotioning valve...some drum prop valves work on the disks. I think its a wait and see sort of approach. I had a summit adjustable prop valve just in case it didn't work but it was unnecessary. I have an 87 iroc with aluminum drums.

A 4th gen rear will bolt on with the exact same hardware (LCAs, PANHARD ROD) as the third gen rear. THough i'm not sure, shouldn't you have an adjustable panhard rod if you are lowered anyway?

Nothing is under any extra pressure from being lowered...you didn't install the springs yourself i take it.

 

OK, some minor advice--in a long-ago life I was a front end and brake man: first, when dealing with brake lines, what you need to fabricate will be very obvious once you have the new rear end in the car, no harder than making a picture frame--but you've got to make sure your flares are sound, that you don't crimp or crack the line and that you don't cross-thread any fittings, so even though it looks simple make sure you know about bending up lines or have somebody experienced in this do it with you. One mistake in this area and you lose your brakes at speed--project over.
Second, most suspension systems are easy to figure out once you get under there and see how things work--the thirdgen F-body is my favorite because the torque arm and control arms eliminate twist in the rear end and locate it solidly front to rear while the panhard bar locates it side-to-side (we used to have to add this stuff on with earlier cars). IRS handles a bit better but it goes out of alignment and is a lot more complex.
So when you get under there, if you're not sure about springs flying out at you and such (a reasonable consideration), see what holds them in and release the pressure slowly, like unbolt the shocks and panhard bar and see if the rear end comes down far enough on your floor jack to get the springs out. If not, unbolt the control arms and see. There are only a few parts to deal with under there, no matter how confusing it looks at first.
Upgrading sway bars should be done in pairs, as advised above, because they are engineered in front and rear sets to stabilize the car through turns, transferring body lean into downforce on the inboard wheels. A mismatched set will cause mismatched traction between the front and rear inboard wheels, putting you into a spin. Upgrading means stiffer swaybars giving more transfer of force. Using those hard plastic bushings on the swaybars makes a feelable difference, doesn't cost much and is easily done.
Last, an Ebrake is an emergency brake, no?

 

SWWAAAYTTT!! Sounds easy enough. I gotta buddy that'll let me use his lift and transmission jack to lower out the rear-end. Naw...I didn't put the Eibach's on myself, that's for darned sure! I've just heard horror stories about green-horn wrench-heads (like myself) dismantling springs and having them fly out and smackinng some dude's head clean off, but it's pretty obvious that once the car's suspended all the compressed weight will be relieved anyway. I'm still unclear about the necessity of the panhard...the car has the stocker on it right now, but will installing the 4th-gen rear-end require me to replace the panhard bar? Thanx again!

 

if you're runnign the stocker now, then you can leave the stock panhard rod on.

And don't post a picture of your car in every post (especially the same pic) or you'll tick the moderators off.

 

Thanks for the info, Nightrider! And thanks for the tip...I didn't know they cared, but then again, I didn't read all the guidelines and it probably does take up bandwidth. My Bad!

 

did anyone give a part number for the cables? or what application they are from?
TIA
Chris

 

If you don't want to **** mods off, you probably shouldn't say that you didn't read the guidelines either.

As mentioned, 3rd and 4th gen rears are identical in all mounting dimensions (hub-to-hub 4th gen is wider). So if you didn't need adjustable panhard bar till now, you should be good. The thing you may want to do is determine whether or not you need one now.

The problem is that when you lower the car, panhard bar swings on a radius and lowering the car shifts the entire rear end slightly to the driver's side. So when you lower the car you want an adjustable PHB, so you can make rear end centered again. On some cars this shift is worse than on others because of factory tolerances. Go check out your car and see if rear end is centered in the car right now. If it is, I wouldn't worry about adjustable PHB.

 

Sweet enough, chief...what'sa good source for adjuctable phb's? I'll check the rear-centering while I got it up on the lift tomorrow. It looks easy enough to change out, so if it's even "iffy," I'm swappin' the sucker.
BTW, I didn't say I didn't read ALL the guidelines, I just kinda fliped through 'em. Boy I'm just gettin' in deeper....APOLOGIES TO ALL MODERATORS!!! I'M SORRRAYYYY!!!

 

The only stuff that goes on my car is red and says "SPOHN" in nice blue letters. www.spohn.net is where you find them, or talk to brian at schoch performance. email him at schochperf@triad.rr.com . he's a great guy, and sells everything that you see on the Spohn website. all in all, the 4th gen swap can be done very easily. here's some more things to remember:

1) if you lowered the car, get an adjustable PHB, an d re-adjust your center. if you want to know how to re-adjust it, PM me. Otherwise, use the stocker for now.

2) the 4th gen rear is 3.8" wider from hub to hub. if you plan on custom wheels, this it not an issue, and if you plan on 4th gen wheels, you just need spacers from www.skulte.net for the front.

3) if you have a 93-97 rear, go to advance auto, or Kragen, or Schuck's, or checker, of who the f*** ever you like best, (there's so many...) and ask for e-brake cables for a 91 camaro with rear discs. this will give you the right cables. you'll need 2.

4) 9 out of 10 times the rear brakes lines from the junction block to the calipers are the same size fittings as on your 3rd gen. i have a 97 T/A rear in an 82 T/A. I screwed them in and they worked great. still no leaks.

good luck. I've helped people out with these swaps a lot, both finding parts and troubleshooting the install. PM m if you have more questions.

 

SWWWAAAAYYTTT....Thanx for the info!

 

OK, after a long wait, I think I'm finally getting my rear end today. I'll be installing it next week with my friend, along with new front/rear sway bars, and new shocks/struts.

I do have a question though, will I need to recalibrate my speedometer with these new gears, and if so, how could I do this? Car specs are in my sig/profile.