gsl-se part swapping gs
08-19-19, 06:38 PM
#1
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Thread Starter
gsl-se part swapping gs
hi guys, im looking at a roller gsl se for 700 right now, by the looks of it it has pretty much everything but the engine (damn) my question is, how hard would it be to switcfh the whole rear axle assemlby (for lsd and rear disc) and from it and the front struts as well. it has the transmission and drive shaft in it as well. so it should pretty much just transfer over right?
would you guys say a roller like that is worth the 700? seems high to me. but id like to have an LSD at some point and rear discs.
would you guys say a roller like that is worth the 700? seems high to me. but id like to have an LSD at some point and rear discs.
08-19-19, 07:04 PM
#3
Last week I would have paid $500 for the rear alone, so I think $700 sounds good. If your GS is '84 or '85 the entire rear axle will swap right in, except you will need new parking brake cables. The leading part is the same, but the end cables that go to each rear wheel are different than the drum cars. The axle will bolt right into earlier cars too but the pinion flange might be different (not sure).
Up front everything will go right in. The OE strut cartridges were valved a little firmer for the heavier engine, but the springs and mounting points are all the same. The Strut tubes and spindles are identical to the GS but use different rotors and dust shields.. Wheels are different bolt pattern and offset.
If the roller has a solid body it would be easier to just put a motor in it.
Up front everything will go right in. The OE strut cartridges were valved a little firmer for the heavier engine, but the springs and mounting points are all the same. The Strut tubes and spindles are identical to the GS but use different rotors and dust shields.. Wheels are different bolt pattern and offset.
If the roller has a solid body it would be easier to just put a motor in it.
08-19-19, 07:12 PM
#4
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Thread Starter
the body is kinda in pieces, but he has everything for it. and the paint is kinda messed up. its been sitting for lord knows how long. it has alot of stuff missing too, for example, tail lights. as for the pinion flange, what is that? if i went through with this, id most like just put the transmission, driveshaft, rear axle and front strut tower. christ, thats like a week of work :/
the interoir looks gone, bare metal. but it does have its title. i figure if im determined enough id eventually electric swap it, ya know, when i win the lottery.
also my car is an 82. needs a damn paint job.
the interoir looks gone, bare metal. but it does have its title. i figure if im determined enough id eventually electric swap it, ya know, when i win the lottery.
also my car is an 82. needs a damn paint job.
08-19-19, 07:20 PM
#5
Pinion flange is where the driveshaft bolts to the rear end. I think the early cars have a smaller bolt pattern, but if you are getting driveline with the new car you could use that. The GSL-SE has a larger bolt pattern than the Non-SE cars. It is a more common pattern and is generally more desirable (most first gen's have 4 x 110mm wheels, like yours. SE's have 4 x 114.3mm wheels, like a 4 bolt mustang)
08-19-19, 07:25 PM
#6
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Thread Starter
yes, i remember those sexy wheels you have >.>
can you just swap the GSL SE drivesaft into the GS transmission? instead of pulling a tranny for no reason? i found out he has a second rx7 hed throw in for another 100, but its on blocks, and i have no way to move it, plus its STRIPPED almost nothing of value.
can you just swap the GSL SE drivesaft into the GS transmission? instead of pulling a tranny for no reason? i found out he has a second rx7 hed throw in for another 100, but its on blocks, and i have no way to move it, plus its STRIPPED almost nothing of value.
08-19-19, 08:44 PM
#7
Post pics and we can tell what;s good and not good.
You'll also want to swap the brake booster, master cylinder, and proportioning valve.
The driveshaft is the same on all manual 1984-1985 as far as I know. For the front brakes, if you don't want to change the entire struct, you can just change the backing plate, rotor, caliper and bracket. The struct tube is basically the same.
You'll also want to swap the brake booster, master cylinder, and proportioning valve.
The driveshaft is the same on all manual 1984-1985 as far as I know. For the front brakes, if you don't want to change the entire struct, you can just change the backing plate, rotor, caliper and bracket. The struct tube is basically the same.
Last edited by KansasCityREPU; 08-19-19 at 08:55 PM.
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Maxwedge (08-19-19)
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08-23-19, 08:11 PM
#8
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Thread Starter
ok, so pics are coming, but i have new questions.
my power goal for my car is a streetport 13b. so from what i gather, that gets about 190hp at the flywheel from my digging around. BUT. idk if the GSL SE can take the ammount of torque i have from my secret sauce, preliminarly calculations show that at times i can suddely get an extra 100lb/ft of torque, if not more. HOW much can this GSL-SE diff take? secondly. it seems like if ANYTHING is wrong with the LSD its either a pain in the *** to rebuilding, or expensive?
if the GSL-SE diff cant take this ammound of torque, what are my options? i want discs at all 4 corners. and..... is indepenant suspension possible? i had an experience with snap back the other day. and im curious as to what suspension upgrades are possible here, and the associated cost if i DONT want to go the GSL-SE route.
my power goal for my car is a streetport 13b. so from what i gather, that gets about 190hp at the flywheel from my digging around. BUT. idk if the GSL SE can take the ammount of torque i have from my secret sauce, preliminarly calculations show that at times i can suddely get an extra 100lb/ft of torque, if not more. HOW much can this GSL-SE diff take? secondly. it seems like if ANYTHING is wrong with the LSD its either a pain in the *** to rebuilding, or expensive?
if the GSL-SE diff cant take this ammound of torque, what are my options? i want discs at all 4 corners. and..... is indepenant suspension possible? i had an experience with snap back the other day. and im curious as to what suspension upgrades are possible here, and the associated cost if i DONT want to go the GSL-SE route.
08-23-19, 09:40 PM
#9
Wait a minute.... in post 4 you didn't know what a pinion flange was, and now you're contemplating an independant rear swap? What is this 100 lb/ft secret sauce you're drinking down there in the "land of entrapment"?
LSD rebuild is about $430 in parts from Mazdatrix. 2 cone springs for $40 each, 4 outside finger plates for $40 each and 4 inner finger plates for $45 each.
LSD rebuild is about $430 in parts from Mazdatrix. 2 cone springs for $40 each, 4 outside finger plates for $40 each and 4 inner finger plates for $45 each.
Last edited by Maxwedge; 08-23-19 at 09:55 PM.
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Zenobia K'ael (08-23-19)
08-23-19, 09:47 PM
#10
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Thread Starter
hehe. secret suace i say! (ill probably make a post around this idea at a later point)
and im yes. im curious about my options, like i said. potential expense of fixing a GSL-SE rear end seems... high. and im not sure how easy it would be to break.
and im yes. im curious about my options, like i said. potential expense of fixing a GSL-SE rear end seems... high. and im not sure how easy it would be to break.
08-23-19, 09:57 PM
#11
ok, so pics are coming, but i have new questions.
my power goal for my car is a streetport 13b. so from what i gather, that gets about 190hp at the flywheel from my digging around. BUT. idk if the GSL SE can take the ammount of torque i have from my secret sauce, preliminarly calculations show that at times i can suddely get an extra 100lb/ft of torque, if not more. HOW much can this GSL-SE diff take? secondly. it seems like if ANYTHING is wrong with the LSD its either a pain in the *** to rebuilding, or expensive?
if the GSL-SE diff cant take this ammound of torque, what are my options? i want discs at all 4 corners. and..... is indepenant suspension possible? i had an experience with snap back the other day. and im curious as to what suspension upgrades are possible here, and the associated cost if i DONT want to go the GSL-SE route.
my power goal for my car is a streetport 13b. so from what i gather, that gets about 190hp at the flywheel from my digging around. BUT. idk if the GSL SE can take the ammount of torque i have from my secret sauce, preliminarly calculations show that at times i can suddely get an extra 100lb/ft of torque, if not more. HOW much can this GSL-SE diff take? secondly. it seems like if ANYTHING is wrong with the LSD its either a pain in the *** to rebuilding, or expensive?
if the GSL-SE diff cant take this ammound of torque, what are my options? i want discs at all 4 corners. and..... is indepenant suspension possible? i had an experience with snap back the other day. and im curious as to what suspension upgrades are possible here, and the associated cost if i DONT want to go the GSL-SE route.
My advice, swap what you can and keep it stock for now. Once you have achieved that goal and everything is running good, then reevaluate goals v.s. cost. This will be a good learning experience without braking the bank right now.
08-23-19, 10:02 PM
#12
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Thread Starter
the plan was an s5 13b. streetport and mathing exhuast, from what i can tell, the full racing beat exhuast system for the 12a and 13b are the same except for the headers, so i can buy it (which im close too if i decide to not go the GSL SE route right now)
sadly my dumb butt was unwilling to drive 5 hours 1 way to get a full 13b+tranny+ecu and wiring harness for 300 a couple of months ago, well. i partially didnt becuase my s10 had a leaking radiator. but still. i shouldve went for it. just bring like 20 gallons of distilled water lol.
sadly my dumb butt was unwilling to drive 5 hours 1 way to get a full 13b+tranny+ecu and wiring harness for 300 a couple of months ago, well. i partially didnt becuase my s10 had a leaking radiator. but still. i shouldve went for it. just bring like 20 gallons of distilled water lol.
08-23-19, 10:05 PM
#14
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Thread Starter
whats the cost like to fix a worn out LSD clutch? im really hoping the GSL SE parts car im wanting to get DOESNT have a worn out clutch system, any tests i can do before i buy it to see?
Last edited by Zenobia K'ael; 08-23-19 at 10:08 PM.
08-24-19, 09:42 AM
#15
ancient wizard...
You can,with a helper,perform a basic wear test on LSD. If wheels still on car,jack up and support car with wheels off ground. Transmission in neutral,have your helper hold tire on his side of car not letting it turn while you attempt to turn tire forward on your side of car. An LSD in good condition will let you turn the tire with a fair amount of resistance. The better the condition,the more the resistance,opposite wheel should yield similar results. Not much or no resistance to turning wheel,LSD will need some attention.
For an axle out of the car,supported on stands,using long screwdrivers or prybars wedged into lug studs have your helper hold his axle in position while you turn your side forward,same as testing using wheels on car.
If you're intending to "work" the SE diff with an engine making more power,have the LSD built to GSL specs,it will work better and last longer. Never agreed with Mazda's thinking with their SE 3+1 clutchpack orientation vs GSL 2+2 orientation.
Their reasoning,the SE 13B 6 port engine had higher hp and tq #s than 12A and they were concerned the SE would be wagging it's tail more than GSL cars and drivers' losing control of the car so they set the diff up with only 1 friction disc on one side of LSD. Any type of enthusiastic driving eventually overpowers the weaker setup.I have done it in 2 days of taking possession of a 65k miles SE,on stock size tires. 6 passes at local drag strip and LSD was done.
People that don't run their cars hard,the LSD will remain in good working order into triple digits with timely gear oil change intervals using proper friction modifier to keep clutches happy.
Until diff is out and and apart,LSD disassembled and thrust washers,clutch discs measured,costs to bring back to spec won't be known. Cost for LSD parts could be @ $200 depending on the level of wear. Mazda does have "thicker" clutch discs available besides the oe dimension friction discs and the two can be mixed/matched with proper measuring to build a tighter LSD to give rear axle more bite. FSM has all test/clearance specs.If you're not doing work yourself,taking car to a shop...expect to pay $500-$700 labor for this work. If you remove 3rd member and take that to shop,you'll lower your labor costs a bit.
Interview the shop/technician as to their familiarity with Mazda LSD units from that time period. Any good driveline shop should be able to do this work. A shop specializing in older Mazdas or Japanese cars would have more working knowledge on the product and likely do a better job a bit cheaper. Do your homework.
You can rebuild LSD without having to do anything else to differential,to have a long lasting rebuild,consider renewing all pinion/carrier bearings while chunk is out of axle housing(they have same amount of miles) and to further strengthen the 3rd member and help pinion bearings keep proper preload much longer under aggressive driving,replace the stock crush collar that maintains pinion bearing preload with a crush collar eliminator kit. It requires a few more steps to setup differential but worth the time/trouble for longer life of components it insures.
You could also swap in a Torsen type LSD from a later Miata. These have no clutches to wear out,not many wear parts at all so have a longer service life. Expect to pay @$500 for a used Torsen LSD in good condition. I have one for my SE,not installed yet. When my modified LSD begins to wear to the point of needing freshening,i'll swap the Torsen in. I have a 4wd Ramcharger i have this type differential in front and rear axles,called Detroit Locker True Tracs. They work very well and their presence is not noticeable till one tire begins to slip and unlike an LSD or a Locker in front axle,there's no handling quirks on turns.
For an axle out of the car,supported on stands,using long screwdrivers or prybars wedged into lug studs have your helper hold his axle in position while you turn your side forward,same as testing using wheels on car.
If you're intending to "work" the SE diff with an engine making more power,have the LSD built to GSL specs,it will work better and last longer. Never agreed with Mazda's thinking with their SE 3+1 clutchpack orientation vs GSL 2+2 orientation.
Their reasoning,the SE 13B 6 port engine had higher hp and tq #s than 12A and they were concerned the SE would be wagging it's tail more than GSL cars and drivers' losing control of the car so they set the diff up with only 1 friction disc on one side of LSD. Any type of enthusiastic driving eventually overpowers the weaker setup.I have done it in 2 days of taking possession of a 65k miles SE,on stock size tires. 6 passes at local drag strip and LSD was done.
People that don't run their cars hard,the LSD will remain in good working order into triple digits with timely gear oil change intervals using proper friction modifier to keep clutches happy.
Until diff is out and and apart,LSD disassembled and thrust washers,clutch discs measured,costs to bring back to spec won't be known. Cost for LSD parts could be @ $200 depending on the level of wear. Mazda does have "thicker" clutch discs available besides the oe dimension friction discs and the two can be mixed/matched with proper measuring to build a tighter LSD to give rear axle more bite. FSM has all test/clearance specs.If you're not doing work yourself,taking car to a shop...expect to pay $500-$700 labor for this work. If you remove 3rd member and take that to shop,you'll lower your labor costs a bit.
Interview the shop/technician as to their familiarity with Mazda LSD units from that time period. Any good driveline shop should be able to do this work. A shop specializing in older Mazdas or Japanese cars would have more working knowledge on the product and likely do a better job a bit cheaper. Do your homework.
You can rebuild LSD without having to do anything else to differential,to have a long lasting rebuild,consider renewing all pinion/carrier bearings while chunk is out of axle housing(they have same amount of miles) and to further strengthen the 3rd member and help pinion bearings keep proper preload much longer under aggressive driving,replace the stock crush collar that maintains pinion bearing preload with a crush collar eliminator kit. It requires a few more steps to setup differential but worth the time/trouble for longer life of components it insures.
You could also swap in a Torsen type LSD from a later Miata. These have no clutches to wear out,not many wear parts at all so have a longer service life. Expect to pay @$500 for a used Torsen LSD in good condition. I have one for my SE,not installed yet. When my modified LSD begins to wear to the point of needing freshening,i'll swap the Torsen in. I have a 4wd Ramcharger i have this type differential in front and rear axles,called Detroit Locker True Tracs. They work very well and their presence is not noticeable till one tire begins to slip and unlike an LSD or a Locker in front axle,there's no handling quirks on turns.
Last edited by GSLSEforme; 08-24-19 at 09:54 AM.
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08-24-19, 02:43 PM
#16
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Thread Starter
awesome! what usually breaks under heavy load on these? the axles right? are there better stronger after market options? (for the axles)
Last edited by Zenobia K'ael; 08-24-19 at 03:07 PM.
11-09-19, 03:04 PM
#17
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Thread Starter
Post pics and we can tell what;s good and not good.
You'll also want to swap the brake booster, master cylinder, and proportioning valve.
The driveshaft is the same on all manual 1984-1985 as far as I know. For the front brakes, if you don't want to change the entire struct, you can just change the backing plate, rotor, caliper and bracket. The struct tube is basically the same.
You'll also want to swap the brake booster, master cylinder, and proportioning valve.
The driveshaft is the same on all manual 1984-1985 as far as I know. For the front brakes, if you don't want to change the entire struct, you can just change the backing plate, rotor, caliper and bracket. The struct tube is basically the same.
also i scored. this car has tokico illuminas
not blues like he thought. and they appear to be in good working condition.
11-09-19, 03:16 PM
#19
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Thread Starter
ok, well i have the entire brake cable set up from the donor car all the way up to the e brake itself. so ill just swap the entire thing over.
thanks!
thanks!
11-10-19, 01:31 PM
#20
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Thread Starter
So, im still wondering what typically breaks on the rear diffs? also what year miata torsen LSD works on our diff? and are there other kinds of miata diffs that work in our cars?
11-10-19, 09:21 PM
#23
ancient wizard...
I answered all your pertinent questions in post15 of this thread.
Pretty sure your secret sauce is nitrous and that answers question about what you’re going to do with the car.
Have done what you’re planning on several 1st gens, have a 125hp shot on my current car for the rare occasion I get an urge to use it.You never know,lol...
In the past have destroyed several engines,gearboxes and LSD diffs and axles using juice to excess,used parts availability/cost wasn’t a big factor. Today this is not the case.
Today if I were to build a car for the track where slicks and power adders were intended,I would go with an 8” Toyota axle from a truck 1st choice and Ford 8.8 axle 2nd. Toyota axle can stand up to more abuse than the Ford in stock configuration other than an LSD upgrade.
Detroit True Trac is my choice for LSD unit.
It’s a Torsen Diff and near bulletproof and no clutches to wear out.
Putting in a used LSD diff of any type without going thru it,for one to see what you have and the other to freshen it or upgrade its internals for what you intent to do with it is not a good idea if longevity is desired.
Pretty sure your secret sauce is nitrous and that answers question about what you’re going to do with the car.
Have done what you’re planning on several 1st gens, have a 125hp shot on my current car for the rare occasion I get an urge to use it.You never know,lol...
In the past have destroyed several engines,gearboxes and LSD diffs and axles using juice to excess,used parts availability/cost wasn’t a big factor. Today this is not the case.
Today if I were to build a car for the track where slicks and power adders were intended,I would go with an 8” Toyota axle from a truck 1st choice and Ford 8.8 axle 2nd. Toyota axle can stand up to more abuse than the Ford in stock configuration other than an LSD upgrade.
Detroit True Trac is my choice for LSD unit.
It’s a Torsen Diff and near bulletproof and no clutches to wear out.
Putting in a used LSD diff of any type without going thru it,for one to see what you have and the other to freshen it or upgrade its internals for what you intent to do with it is not a good idea if longevity is desired.
Last edited by GSLSEforme; 11-10-19 at 09:28 PM.
04-16-20, 11:31 PM
#25
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Thread Starter
Does the gauge cluster swap from one car to the other relatively easily? Also i'd like to transplant the power sterring box to my GS as well since it has a nicer 15:1 ration versus the 20:1, is it easy to do?