DRIVER456

Did a search couldn't find much.What is needed to swap a C6 cradle & Diff into a C5 auto

BLOWNBLUEZ06@RKT Performance

Change the tail housing and output shaft and then add the RKT56 offset mounts. If you changed torque tubes, it would be the proper length to not use offset mounts, but will cause you other fitment issues.

Patches

Curious - does using the C6 cradle on the C5 change the wheels base?

TRINIC5

It will only change the alignment and camber but the wheel base will stay the same, a visit to the alignment shop will get everything right. I did the same to my C5 for the purpose of the C6 Zo6 rear and the 4L80E transmission.

BLOWNBLUEZ06@RKT Performance

Good point, I forgot about the suspension aspect.

Your C5 spring won't work. Your C5 lower control arms will only work if you use coilovers. Using C6 lower control arms will move your wheel center back but I don't recall how much. I prefer the new wheel position over the original.

robert miller

Yes it does, it push the wheel base back 5/8 of a inch. But that really centers the wheel more to the center point of the cut hole the car has for the wheel.

Before with a 28 inch tall tire on the car it would rub in the front. Now it don't at all in the front or back. Bret has told you what you have to do are use to make it work in the c5 now above.

BLOWNBLUEZ06@RKT Performance

Doesn't change the camber, it changes the caster and it does change the wheelbase.

always faster

Exactly 5/8 inch
Edit: Robert was quicker on that one

DRIVER456

I didn't change the TT,I have coil overs,Also I have an auto (4L60E)Will it work with an auto?Anybody have any picture's? Can you explain alittle more please,What year C6 cradle & diff will work? I think RPM sells an adapter plate and I think I need a 30 spline output shaft,Is that correct?

robert miller

I also have a auto trans you will need the plate from RPM to get it to marry up to the rear. That little puppy was 550.00 from them. Call them will fix you right up Great group of guys to work with.....

DRIVER456

OK thank you,What about output shaft?

DRIVER456

Just called RPM they do have the adapter and he said I can go with a base C6 rear diff so the 27spline will work

robert miller

Call rick the guy that BLOWNBLUEZ06 said I got my 500 mm 30 spline from him and got both at a good price. Rick is also a great guy to deal with on these parts for a rear end set up... Robert

DRIVER456

Can't I just stay with the 27 spline? Obviously the 30 spline is stronger.What C6 rear has the 30 spline,The ZO6? Also does it matter what type of C6 the rear cradle comes out of BASE or ZO6?

torkmonstr

So could we use the c6 lower control arm on the c5 cradle to gain that 5/8 movement to center the rear wheels then?

CamminC5

You can use a cradle from a 2006-up Cadillac XLR. I got one for $75 at a junk yard. It's the same part number as the C6's.

The Z06 and ZR1 are 30 spline, and use a larger ring a pinion. That and the extra ribbing in those cases make them more stronger and more desirable.

DRIVER456

Yea I was just searching around,I'm going with the 30 spline and C6 ZO6 diff,Alot stronger.Thanks for the tip on the Caddy xlr cradle

DRIVER456

Not sure,but you need the C6 lower control arms if you still have the leaf spring,If you have coil overs you dont need the C6 lower control arms from what Im reading

4DRUSH

Not sure if the triangle of the C5 & C6 lower control arms are the same, just the mono spring mounting point is different?

But I can tell you the lower A arms mount to a C6 cradle 1" farther back than the C5 in relationship to the cradle mounting bolts.

That 1" difference might be what makes the 5/8" difference mentioned above, since the upper A arm location don't change.

Which means the spindle is at a different angle from stock.

What we need is conformation of the C5 & C6 lower A arm triangular points.

robert miller

You are correct, I used my c5 uppers & lowers with the coilover in my set up. Plus had to buy the ALUMINUM 5/8 inch plate from RPM to make the c5 auto trans fit correct.