I have a question for some of you guys that know more about the differences between the GSL and GSL-SE suspensions than I do. I have a 1985 GS (named Gus) that I am in the process of modifying/restoring. Since my GS has the despised drum brake rear end, I bought a complete LSD rear end out of a 1985 GSL that I am planning to swap in (pumpkin, axle housing, axles, brake rotors, calipers, e-brake cables, the whole deal). The only problem with the assembly that I bought is that is needs a good thorough freshening up. I am going to disassemble it, sand blast the axle housing, paint it, reinstall the pumpkin, and replace the brake rotors and calipers before I install it under the car. Which got me to thinking...

Is there anything stopping me from switching over to GSL-SE rotors and calipers in the back and having the much preferred 4x114.3 bolt pattern from that point forward? Sort of a hybrid GSL and GSL-SE rear end? The rear end is out of an '85 so it is a big bearing rear end for sure. I'm going to be replacing the rotors and calipers anyway since they are junk, so why not just buy new GSL-SE parts instead of GSL parts when I reassemble everything? Is this possible? I realize that I'll have to buy SE spindles for the front of the car to switch that to 4x114.3 and make it match, but will my scheme for the back work?

I attached a picture of the rear end in question just because. Let me know what I'm overlooking here. It seems too easy....

Thanks,
Jamie

 

Off the top of my head I can tell you that you will have to swap the axles themselves to GSL-SE axles to change the lug pattern...plus buying the calipers,rotors, etc....I dont know of any reason the swap wouldnt be possible using what you have, assuming you can get the axles....

 

you need the GSL-SE axles too. the pumpkin/diff and actual axle housing are the same between an 84-85 gsl and a gsl-se

 

j9fd3s is right, the axle housings are the same. You will need gslse axles, rotors, calipers, and pads.

For the front, since you already have an 85 with the larger bearings, you don't need new spindle. You do need gslse front rotors, calipers, pads, and caliper mount/back plates.

 

Could I just have someone re-drill the back brake rotors to 4x114.3? Or is that dangerous/not possible? I'm talking machine shop here, not some bozo with a Craftsman drill.

 

rotors yes, axles no.

 

i had my axles and rotors drilled on al four corners. not with a drill tho. i used a conventional mill for the axles and fot the rotors a cnc mill. also pressed in some ARP studs on the rear.

 

here are some pics of my redrilled axle[ATTACH]456911[/ATTACH]

 

Do you have a picture of the rotors you drilled? I'd like to see those too! Looks great though! Thanks for the pictures.

 

ill post pictures tomorrow of the front and back asembled

 

Awesome! Thanks for posting the pictures. I really appreciate it. Is there a way that I could re-drill the axles and rotors and still use the stock lug bolts instead of the ARP studs like you used?

 

I imagine you would just need to get a tap the same size and thread pitch as the bolts and tap the new holes.

 

Man you are going the cheapest possible route! Just get some fancy arp studs. Its safety!

 

So if you use the ARP wheel studs, do you thread the holes in the axles and the brake rotors still? Or not? I guess I just don't understand how you keep the rotor and the axle concentric to each other without threading the lug bolts thru them both.

 

The rotor is drilled to slide over the studs. The axle's center hub keeps it in place and concentric. Thats at least the way I have always seen it done when a conversion was done...

 

ok i got some pics. on the rear the rotor has to be drilled slightly oversize so it will slide over like 83limited said. on the front i used mazdatrix screw in studs,on the rear i used mazdatrix arp press in studs like $4.63 each or you can thread the axle and use the threaded studs.hope you enjoy

my new wheels

front

front

rear

 

The studs will either press in from behind the hub, or thread in (use locktite) from the front. I believe the ones I used just threaded in. I used locktite, and haven't had any issues.



.

 

Kentetsu, did you change your bolt pattern or just change from lug bolts to studs/nuts?

 

Thanks for the pictures Lilmazda! Just to finish off the thread, what size wheels and tires are you using in that picture? What offset are the wheels? Did you roll the fenders? Any rubbing issues anywhere?

After seeing this, I don't understand why more people don't do this setup? It seems every bit as easy to me as switching over to the GSL-SE suspension. If I started with a GSL I would definitely do this! Since I started with a GS I'm going to be swapping in a GSL differential, and THEN drill everything for 4x114.3.

 

I would do exactly what you are doing, but since i have an 83 LE and the LE wheels are 4 x 110 I cant....best I can do is swap to a GSL rear....

 

I too dont understand why more people don't do what i did. It gives you a huge selection of wheel options. like xxr has the 522,527,513,002 and 501 series that would fit also rota has a few and also drag wheels has some

the wheels are xxr 527 16X8.25 with a 0 offset. 195/50/16 tires
i have no rubing issues with my setup. Its all stock except for racing beat springs
i did roll the inner lip of my fenders but i didnt make them wider. i used a body hammer and a hot air gun to massage the inner lip of the fenders.

heres a pic of my previous wheel and tires
15x8 0 offset steel wheel 195/50/15 tires

 

I agree with you guys, any competent machine shop can redrill the axles so it's not overly difficult.
Good looking car lolmazdarx7!

 

No pattern change, just bolts to lugs.

 

Where is this machine shop in socal if you dont mind sharing. i cant find a shop to do the task

 

You can call cooks machine works he does bolt pattern changes not sure how much tho.
Give him a call

4845 Telegraph Road
Los Angeles‎ CA‎ 90022
United States
(323) 268-6571