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Big Problem With New Rear End

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Old Feb 3, 2002 | 11:33 AM
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Big Problem With New Rear End

Ok well we got the rear mounted but the cv joint and the driveshaft bolts are different....this rear is a lsd from a 1987 gxl...mine is an 1986 sport...is there a reason these are different...they are slitghly widder...on the rear end...can i take the axels from the 1987 and mount them on my car...and take the knuckle off the drive shaft and swap them????

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Old Feb 3, 2002 | 11:48 AM
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Sounds like you got the rear from an 87 turbo. ALl NA rearends hav teh same flange diameter and axle width. Both these items are bigger on teh t2 rearend. IF you did get this, there is nothng that can be done except to use the t2 halfshafts and driveshaft and transmission and everything else unless you wanna get a custom driveshaft.
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Old Feb 3, 2002 | 05:52 PM
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Well

If i keep the turbo rear, which i am guessing thats what it is...I can get the halfshafts for it and swap those but i cant afford a tranny...plus i have a stage 3 clutchmaster clutch in mine...is there a way i can use my drive shaft...maybe swap the flange at the end joint of the propeller shaft???

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Old Feb 3, 2002 | 09:21 PM
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Perhaps a good auto mechanic shop with an experienced welder could hook you up?
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Old Feb 3, 2002 | 09:30 PM
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I ran into that problem when converting my 88SE to a GTX Turbo....there really is nothing you can do. Even if you swap the halfshafts and all...you'll still need a T2 driveshaft and tranny. Check w/ a driveline shop and see what they can do for you. They should be able to custom make a driveshaft for you.
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Old Feb 3, 2002 | 10:11 PM
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Is the length in the t2 driveshaft the same?
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Old Feb 3, 2002 | 10:53 PM
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NOPE> Length, diameter, rear flange diameter, and front yoke diameter are all different.
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Old Feb 3, 2002 | 11:54 PM
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Ok well call me crazy but i am going to give it a shot...i am going to get the half shafts tomorrow and then i am going to use my n/a drive shaft (propeller shaft) i am going to open up the holes on the flange alittle with a drill...to fit the flange on the differential....its such a slight difference i wont have to do much...but i am going to give it a try!

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Old Feb 4, 2002 | 07:48 AM
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I've seen on posts where it is suggested to redrill the flange on the differential. Just drill b/t the existing holes. Preferably with a well setup jig. A local driveshaft shop should be able to take your existing driveshaft and put a matching yoke on the end to fit the differential
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Old Feb 4, 2002 | 12:41 PM
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Please note that dropping a driveshaft at high speed/rpm can kill you. I don't think that it's worth risking your life to modify that driveshaft. Go back to the salvage yard and trade that TII rear end for an NA rear end.

Some measurements so you don't do this again:

2Gen RX-7 Differential Flanges - Ref Grannys Speed Shop
NT 3.786" Bolt Center Dia
TII 4.120" Bolt Center Dia

2Gen RX-7 Propeller Shaft Lengths (Including U-Joints) - Ref 1988 FSM
38.03" MT TII
38.07" MT NT
35.94" AT NT
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Old Feb 4, 2002 | 01:17 PM
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Very good advice.
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Old Feb 4, 2002 | 02:58 PM
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So i have a TII tranny, driveshaft and differential. I was thinking of swapping it into my gxl.
Will the TII tranny bolt right to my n/a motor? and will the diff bolt right up?

is there any other problems i might have/

thanks

Action RT
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Old Feb 4, 2002 | 03:35 PM
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Originally posted by ACTION RT
So i have a TII tranny, driveshaft and differential. I was thinking of swapping it into my gxl.
Will the TII tranny bolt right to my n/a motor? and will the diff bolt right up?
OK, first of all note that the TII drivetrain is heavier. Heavier means that it can handle more torque, but it also means that the car will weigh more which will slow the car down, especially when you consider the additional rotational mass and friction of the TII driveline components. I would recommend keeping the NA drivetrain unless you have over 220hp.

Yes, all those TII components will fit, but you will also need a TII clutch & flywheel, TII starter, and TII halfshafts. It is easiest to just unbolt the entire rear subassembly from a TII, and bolt it on your car; brakes, shocks, rear end, halfshafts, and all.
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Old Feb 5, 2002 | 01:49 AM
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Originally posted by HAILERS
I've seen on posts where it is suggested to redrill the flange on the differential. Just drill b/t the existing holes. Preferably with a well setup jig. A local driveshaft shop should be able to take your existing driveshaft and put a matching yoke on the end to fit the differential
I would drill the driveshaft, not the diff. The differential has "notches" in the flange that hold the bolt heads to keep them from turning. Just drilling holes is NOT gonna help you. You MIGHT get away with drilling the driveshaft though... MAYBE.
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Old Feb 5, 2002 | 01:50 AM
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Originally posted by Evil Aviator

OK, first of all note that the TII drivetrain is heavier. Heavier means that it can handle more torque, but it also means that the car will weigh more which will slow the car down, especially when you consider the additional rotational mass and friction of the TII driveline components. I would recommend keeping the NA drivetrain unless you have over 220hp.

Yes, all those TII components will fit, but you will also need a TII clutch & flywheel, TII starter, and TII halfshafts. It is easiest to just unbolt the entire rear subassembly from a TII, and bolt it on your car; brakes, shocks, rear end, halfshafts, and all.
Don't forget the clutch slave cylinder, and that you have to extend the wires on the tranny. And the flywheel is a PITA. I've done this swap, see sig.
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Old Feb 5, 2002 | 01:59 AM
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if the diff does not work, i will buy it!
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