Will try and keep this brief.. so my C5 Z pinion is pooched, broken teeth, is an RPM diff and transmission.. trying to locate ring and pinion locally, find one freshly rebuilt with 3.73, no big deal i have 3.90, doesn t matter much to me. so shop goes to jam the transmission in and find out the spline is different size, the rebuilt has smaller spline than trans. rebuilder is a track guy with cars and does lots of work on others, tells me c5 and c5z have different sizes, rpm tells me they are all the same. so i need the 30 spline diff, rpm tells me no one makes it, they will sell me a stock one and have it machined for $350 + $400 for gear set, NO thanks. Have read that could be a C6 internals in the case, not sure can t find anything on the spline count on C6 or C6z.. and am understanding that the C6 z is 9" opposed to C5 8.5". I am at a total loss as what i can do, maybe try and source a stock c5z diff and trans, no idea. rpm tells me the 30 was an upgrade from stock,if it is an upgrade, someone one must produce them without sending them out to be machined.
any input would help..

 

So you broke the RPM dif? Man I just put one in w 390s.

Now I'm worried. I can't help ya sorry but good luck.

 

C6 Z06 is 30 spline. C5 Z06 is 27 as are the coupe and FRC MN6. I direct swapped an '02 Z06 diff into my '99 coupe. Base and vert C6 is 27 spline, GS and ZR1 are 30 spline.

You bought yourself a C6 Z06 diff.

Right churn wrong pew.

 

PS...stop listening and going to your "rebuilder track guy".

 

that is who i went to..

 

it is not a C6 diff.
from what i understand no one makes a 30 spline for the c5z. the c6z is 8.75 and c5z 8.25 so i am guessing it won t fit in the c5 housing

 

It’s very simple, you have an rpm trans/diff that has been upgraded to a 30 spline shaft, both the c5 and c5z have a 27 spline shaft, so you can either have rpm mod the new diff to accept 30 spline or replace the transmission with a stock 27 spline

 

yea that is simple.. 400 + 350 for a crown and pinion.. ridiculous

 

I glazed over the fact that your trans spline count was bigger than the diff. I had the opposite scenario in my head. Multitasking and poorly I might add.

493ls is spot on and it is that simple. To your point though that cost is a bit steap. But it is what it is. You don't want to go backwards on the trans upgrade. If it were me I'd just cough up the $750 and move on.

 

you will be fine.. mine is 18yrs old.

 

yea.. i don t see many options.. C6z is 30 spline, and Summit told me is 8.25 ring gear, i m sure I found it was 8.75.
if it is 8.25 not sure if i can just stuff the c6z ring and pinion in my carrier and housing..
not matter what i do.. i have to add on another %42 to the price of anything.. thats what hurts.

 

Hey Walleye, this should help you solve that mystery.

https://www.corvetteforum.com/forums...-z06-guts.html

 

thanks.. i bit the bullet and ordered new crown and pinion,, . only ones that can help with 30 spline..
and
he said he would send a free tube of ky jelly for me

 

Aaahahaha! I hope it's the water based KY. The other stuff ruins your sheets. And sheets are expensive to replace.