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Discussion Starter #1
im thinking about putting an axel from an 83 trans am
(10 bolt),disc brakes, into a 79 z28 wich is origanally drums
what kind of problems will i run into and any advice will really help thanks

newton
 

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you have to think about a lot of things when you do a rear end swap. Like if it will bolt up. if the rear end itself can handle the power from the motor. the length of the drive shaft and brake lines. Disc brakes are the way to go tho.. Much better for stopping.
 

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Discussion Starter #3
hey thanks for the reply


but should i have to worry about pressure differences, like will i have to change the master, and whats better 12 bolt limited slip or a 10 bolt posi or should i say forget it and just keep the 10 bolt on the camero (drums)


thanx
 

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i say go with the posi i just did the same thing we took a rear off a 87 t.a. and put it on my 89 camaro we ran into one problem everything matched up perfect brakes from drum to disk was fine the only thing was the e brake was not long enough to connect but that was no big deal took us a total of 5 to 6 hours though but it was def worth it the car feels better i hpoe this helps a little
 

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The driveshaft length shouldn't give you any trouble. Suspension mounting points may have to be ground off and welded back on in different locations. The e brake for a disc setup is different than that for a drum. You'll need to make sure your cable can actuate the finger thing that flips over to squeeze the caliper when you pull on the cable. These things can be lengthened or shortened as your needs dictate. The flexible rubber brake line is something else to think about. You need to make sure your existing hard brake line will mate up to it properly. I suspect the fittings will be compatible, just that it might be on the wrong side of the car is all. No big thing, this is not insurmountable.


Also, drum and disc brakes all have a residual pressure kept on them when you let off of the brake pedal. Drums require 10 psi of pressure on them as they use springs and what not to pull the shoes back from the drum. Discs use two psi of pressure as they just rely on rotor runout and the contraction of the metals involved to seperate the pads from the rotor when you let off the brake pedal. What I'm getting at, is that this residual pressure valve may be in your proportioning valve, or it may be in your master cylinder and if you have 10psi residual pressure squeezing on your discs, they will start to heat up, which will cause the fluid to expand, which will press the pads into the rotor harder, which will create more heat, which will cause the fluid to expand more, etc...

Eventually you won't be able to turn your drive wheels until the brakes cool down. Make sure you get this detail sorted out. It will hurt your feelings to watch your brakes make that much smoke on the interstate (grin).
 

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First of all I don't think this swap is a good idea here is why

The 3rd gen f body's dif is a different width and has different mounting points

2nd switching to rear disk brakes probably will make little difference in your stopping ability how ever will require some fabrication and a different perportioning valve and master cyl very possibly

Another problem is is that the 3rd gen rear ends aren't terribly strong you are better to stick with an 8.5" from the 2nd gen with a good after market limitedslip.

All in all I don't think this axle is worth the trouble and would be taking a step back in some ways. Get a good 8.5" 10 bolt from a second gen and build it up lots of after market parts are available for it including rear disks.
 

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Look for a rearend out of a 78-81 Trans Am. It will have disc brakes, and you can get everything you need to make everything work properly with no fabrication or guesswork.

You will need at least the master cyl, and the combo valve, as well as everything you want to get with the axle, including the cables.

Going from a 2nd gen to a 3rd gen rear is not the best idea, or the easiest, IMO. You are going from an 8.5" ring to a 7.5" ring, a leaf spring axle to a coil spring axle, and the axle tubes are smaller on the 3rd gen. Using a weaker rearend, and going thru all that work for disc brakes is not worth it IMO. I think one of them is a tad wider too, but I dont know the dimensions offhand.

If it came down to it, you might be better off converting your current rear to disc, rather than making a 3rd gen rear fit.

IMO rear drum is fine. The tires limit your stopping no matter what you have for brakes anyway. I really dont care for the way 4wl disc feel, personally, but they do look good. 4wl drums feel great... till they heat up... then they suck.

Ooops. Robin beat me to it... and in less words. I gotta type quicker.
 

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Discussion Starter #8
thanks

thanks for all your help guys ....so if i have 10 bolt rear end on my 83 trans am and a ten bolt on the 79 z28 then can i just switch the spider gears... i really appreciate the time you guys are giving me i know alot about cars but my flaws is rear ends thanks again
 

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The 83 10bolt is a 7.5" rear, and the 79 10bolt is an 8.5". i dont think anything in them is a direct swap, although I have never tried to swap side gears around.
 
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