1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Questions about rear end's

Thread Tools
 
Search this Thread
 
Old Sep 13, 2010 | 03:16 PM
  #1  
fupersudge's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jan 2010
Posts: 38
Likes: 0
From: North Carolina
Questions about rear end's

I know alot of parts like the diff and gears are throughout years of the rx-7. One thing ive never seen mentioned is if you can put drum brakes on a disc break axle.

The main reason I am asking this is because I may have found a GSL rearend for sale super cheap but its brakes are super rusted.

Is it possible for me to use my current drum brakes on this rear end? since they both have the 4x110 bolt pattern? I do plan on using the discs but I just dont have the money to rebuild calipers and buy rotors at the moment :P
Reply
Old Sep 13, 2010 | 03:38 PM
  #2  
john smack's Avatar
Rotary Enthusiast
Tenured Member 05 Years
iTrader: (12)
 
Joined: Oct 2007
Posts: 871
Likes: 0
From: Fort St John B.C. Canada
I cannot answer your question but food for thought... Why not pick up the GSL axle and while it is out sand it down and paint it make it look nice.. then throw some new parts on it as you can afford it.. Then when it is done it will be nice and function prroperly..
Reply
Old Sep 13, 2010 | 07:40 PM
  #3  
Rx-7Doctor's Avatar
Lives on the Forum
Tenured Member 10 Years
iTrader: (13)
 
Joined: Jul 2004
Posts: 10,584
Likes: 12
From: Oregon
The answer is no.

Just buy the set up and then when you have enough money for the rest of the parts install it.
Reply
Old Sep 13, 2010 | 07:50 PM
  #4  
bumpstart's Avatar
talking head
Tenured Member 05 Years
 
Joined: Apr 2008
Posts: 2,775
Likes: 15
From: Perth, WA, OZ
disc brake rears have a 3 bolt flange at the axle end of the tube
drum brake rears have a 4 bolt flange at the axle end of the tube

that should answer things nicely
Reply
Old Sep 13, 2010 | 08:54 PM
  #5  
fupersudge's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jan 2010
Posts: 38
Likes: 0
From: North Carolina
good to know, guess ill roll around with a welded diff for a bit then :P
Reply
Old Sep 13, 2010 | 08:56 PM
  #6  
IanS's Avatar
Ricer
Tenured Member 15 Years
iTrader: (4)
 
Joined: Jun 2004
Posts: 4,424
Likes: 1
From: Washington, Iowa
However, you COULD (if correct years on both rears) swap in the 3rd member from GSL rear into the open rear currently on your car and then have drum brakes and limited slip. Just like mine. Rear disc brakes are overrated - rebuild and have your drums turned and BAM back in business.
Reply
Old Sep 13, 2010 | 09:15 PM
  #7  
Siraniko's Avatar
RX for fun
Tenured Member 15 Years
iTrader: (13)
 
Joined: Aug 2001
Posts: 15,926
Likes: 25
From: Socal
Originally Posted by fupersudge
I know alot of parts like the diff and gears are throughout years of the rx-7. One thing ive never seen mentioned is if you can put drum brakes on a disc break axle.

The main reason I am asking this is because I may have found a GSL rearend for sale super cheap but its brakes are super rusted.

Is it possible for me to use my current drum brakes on this rear end? since they both have the 4x110 bolt pattern? I do plan on using the discs but I just dont have the money to rebuild calipers and buy rotors at the moment :P
just install the GSL 3rd member on your drum brake set-up and save up for a new/rebuilt rear calipers and brake rotors.
Reply
Old Sep 17, 2010 | 01:14 AM
  #8  
fupersudge's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jan 2010
Posts: 38
Likes: 0
From: North Carolina
Originally Posted by IanS
However, you COULD (if correct years on both rears) swap in the 3rd member from GSL rear into the open rear currently on your car and then have drum brakes and limited slip. Just like mine. Rear disc brakes are overrated - rebuild and have your drums turned and BAM back in business.
what years need to be correct for this to work?
Reply
Old Sep 17, 2010 | 03:28 AM
  #9  
Rx-7Doctor's Avatar
Lives on the Forum
Tenured Member 10 Years
iTrader: (13)
 
Joined: Jul 2004
Posts: 10,584
Likes: 12
From: Oregon
http://www.mazdatrix.com/g5.htm

Covered for the Hmmmm upt time! :-)
Reply
Old Sep 17, 2010 | 06:20 AM
  #10  
Kentetsu's Avatar
Lives on the Forum
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 11,359
Likes: 14
From: Grand Rapids Michigan
Check over at www.rockauto.com

I bought discs for about $14.00 each. They've held up great for over 20,000 miles and still going strong.

Calipers are pretty cheap there too.

Also, the upgrade you are considering is a very worthy effort. The LSD makes a big improvement in handling, slides that are easy to initiate and even easier to control. And disc brakes are so much easier to work on than drums.





.
Reply
Old Sep 17, 2010 | 11:12 AM
  #11  
fupersudge's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jan 2010
Posts: 38
Likes: 0
From: North Carolina
Originally Posted by Rx-7Doctor
http://www.mazdatrix.com/g5.htm

Covered for the Hmmmm upt time! :-)
i never noticed that on their site...

but from what i notice, 83 will match a 85 due to the size change in 83?

Last edited by fupersudge; Sep 17, 2010 at 11:15 AM.
Reply
Old Sep 17, 2010 | 04:46 PM
  #12  
Rx-7Doctor's Avatar
Lives on the Forum
Tenured Member 10 Years
iTrader: (13)
 
Joined: Jul 2004
Posts: 10,584
Likes: 12
From: Oregon
No it will not. ^

Searching with the terms "Doff interchange" would answer your questions. :-)

Last edited by Rx-7Doctor; Sep 17, 2010 at 04:50 PM.
Reply
Old Sep 17, 2010 | 07:12 PM
  #13  
fupersudge's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jan 2010
Posts: 38
Likes: 0
From: North Carolina
Originally Posted by Rx-7Doctor
No it will not. ^

Searching with the terms "Doff interchange" would answer your questions. :-)
So if the 3rd members interchange what has to be done to the propeller shaft? that's right i call it propeller shaft, it just sounds cooler. Also i read a couple things about a miata torsen diff working in FB's also by swaping the 3rd member?
Reply
Old Sep 17, 2010 | 08:43 PM
  #14  
flight_of_pain's Avatar
its supposed to do that
Tenured Member 20 Years
 
Joined: Jan 2003
Posts: 1,352
Likes: 2
From: PNW
81-82 = small driveline flange, small axle
83 = big flange, small axle
84-85 = big flange, big axle

The miata pumpkin works in 84-85 rears with a small bit of grinding (for watts link clearance IIRC)

The drum rear is lighter by a small amount fyi.


Isaac
Reply
Old Sep 18, 2010 | 07:47 AM
  #15  
IanS's Avatar
Ricer
Tenured Member 15 Years
iTrader: (4)
 
Joined: Jun 2004
Posts: 4,424
Likes: 1
From: Washington, Iowa
If you have an 83 (like me) here are your options:

83 GSL 3rd member
81 GSL or 82 GSL 3rd member AND driveshaft (those also have easier to replace u-joints) - this is what I did
84 or 85 complete rear end

Cant remember about parking brake lines and brake hydraulic lines. Im sure a quick search would tell you what you need to do.
Reply
Old Sep 21, 2010 | 11:33 PM
  #16  
GordiniRX7's Avatar
Senior Member
Tenured Member 10 Years
iTrader: (10)
 
Joined: Aug 2007
Posts: 742
Likes: 0
From: Savannah, GA
So, how about an 85 gs rearend with drum brakes onto an 85 gsl? can I use the rearend and drive shaft?
Reply
Old Sep 22, 2010 | 10:24 PM
  #17  
Rx-7Doctor's Avatar
Lives on the Forum
Tenured Member 10 Years
iTrader: (13)
 
Joined: Jul 2004
Posts: 10,584
Likes: 12
From: Oregon
The answer to that question is here in this thread.

Why would you want to do this anyways?


Originally Posted by GordiniRX7
So, how about an 85 gs rearend with drum brakes onto an 85 gsl? can I use the rearend and drive shaft?
Reply
Old Sep 22, 2010 | 10:38 PM
  #18  
GordiniRX7's Avatar
Senior Member
Tenured Member 10 Years
iTrader: (10)
 
Joined: Aug 2007
Posts: 742
Likes: 0
From: Savannah, GA
The GSL that Im buying(from a junk yard, thats right, Im saving it) doesnt have a rear end. But the GS thats sitting next to it has one. and Id need something to at least roll around on, unless I can find a GSL rearend for the same price.
I saw a track oriented FB on car domain that had a whole miata IRS on it. I was wondering how hard that would be...
Reply
Old Sep 22, 2010 | 11:19 PM
  #19  
flight_of_pain's Avatar
its supposed to do that
Tenured Member 20 Years
 
Joined: Jan 2003
Posts: 1,352
Likes: 2
From: PNW
Originally Posted by GordiniRX7
The GSL that Im buying(from a junk yard, thats right, Im saving it) doesnt have a rear end. But the GS thats sitting next to it has one. and Id need something to at least roll around on, unless I can find a GSL rearend for the same price.
I saw a track oriented FB on car domain that had a whole miata IRS on it. I was wondering how hard that would be...
Hard.
Reply
Old Sep 23, 2010 | 08:45 AM
  #20  
GordiniRX7's Avatar
Senior Member
Tenured Member 10 Years
iTrader: (10)
 
Joined: Aug 2007
Posts: 742
Likes: 0
From: Savannah, GA
Originally Posted by flight_of_pain
Hard.
Would it be worth it in the end?
Reply
Old Sep 23, 2010 | 10:42 AM
  #21  
Kentetsu's Avatar
Lives on the Forum
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 11,359
Likes: 14
From: Grand Rapids Michigan
Find a GSL rear end. If you are going through this much work, it should result in an upgrade (or at least not a downgrade) in performance. Spend a little more time now to find the right rear end, and you won't spend the next 10 years wishing you had...
Reply
Old Sep 23, 2010 | 12:17 PM
  #22  
fupersudge's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jan 2010
Posts: 38
Likes: 0
From: North Carolina
I had someone tell me a FC 3rd member works in a 85 live axle. Any one ever see anything about this?

If this is true, what in all needs to be done to get it to fit. Cause im getting a free FC 3rd member

Last edited by fupersudge; Sep 23, 2010 at 12:25 PM.
Reply
Old Sep 23, 2010 | 07:25 PM
  #23  
GordiniRX7's Avatar
Senior Member
Tenured Member 10 Years
iTrader: (10)
 
Joined: Aug 2007
Posts: 742
Likes: 0
From: Savannah, GA
Originally Posted by Kentetsu
Find a GSL rear end. If you are going through this much work, it should result in an upgrade (or at least not a downgrade) in performance. Spend a little more time now to find the right rear end, and you won't spend the next 10 years wishing you had...
Well I mean, I would eventually. I just need something to help get this thing out of "the yard". And theres an '85 GS thats sitting next to it with a rearend that I could swap on in like an hour or two.

But if I could find a GSL before then, for around $60-70, then Ill just do that.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Th0m4s
Build Threads
25
Feb 26, 2019 02:04 AM
mazdaverx713b
Build Threads
48
Apr 21, 2016 06:45 AM




All times are GMT -5. The time now is 02:52 AM.