X25

I am only left with the rear LCAs to install for my T1 suspension kit. In the service/instructions manual, it tells me to refer to "Rear Crossmember Replacement" instructions to lower the crossmember enough, so that we can remove the long LCA bolts by the chassis, and clear the fuel tank. However, when I looked up the document, I was literally horrified by the amount of special tools needed, as well as the necessary steps listed:
https://www.corvetteforum.com/forums...post1587325405

So my question is simple: I am very much hoping I don't need to do 99% of these steps, since I am not removing, but only trying to lower the crossmember enough to get the LCA bolts out. Has anyone done this before? Do you know what it takes to do so?

Thank you very much in advance.

X25

Any takers? I need help : )

X25

Did no-one do this?

descartesfool

When I looked at the rear lower control arm bolts on my Z51 with the hope of using plates to set the alignment between track and street, I came to the conclusion that that was not possible as one cannot simply pull out the lower bolts as there would be interference, requiring dropping the sub-frame to get the bolts out. Seemed like really poor design to me.

X25

This was the case for my Camaro as well, but all I needed to do was to lower the rear subframe an inch or so to clear the bolts. This was fairly easy on the Camaro, since it has a two piece shaft allowing high angles, and I can see everything I lower, so I don't break anything.

I don't have the same confidence on this car. The rear is very much packed with stuff, and I can't see all the interferences. The service manual is literally horrific that it uses special tools in many steps, not to mention it's meant to remove the subframe, not lower it.

I'm just wondering if there's an easy way for this. For instance, could I just loosen the bolts for 1-2" drop without breaking anything?

descartesfool

Perhaps you could check on the SCCA racing forum for the T1 class where people race C7's for which this suspension was designed, as confirmed to me by a GM engineer at the SEMA booth where I first saw the parts. I assume you would need to register to post questions if a search doesn't yield an answer. Some guys who have done it for their SCCA racing might get you an answer. I know on my GT-R, to change the front lower A-arms you can just lower the sub-frame a bit and get the A-arm bolts out without actually removing the whole sub-frame, but not having done it on a Corvette, I can't answer.

X25

You can do the same for the Corvette as well, and it tells you to just lower it, but the procedure referenced in service manual is for removal, and it is VERY complicated, also involving custom tools to keep your diff in place, etc. I fear I might break something if I don't follow it to the teeth, but at the same time, it is definitely overkill; if only I knew which steps to 'ignore'

Honestly, I will just do it slowly and carefully, and if something breaks (since it's hard to see through such a tightly packaged backend), I'll replace it. Call me stupid, but I just don't want anyone else (like a dealer) to touch my car.

I had the very same problem with the Camaro, but it was so easy to do so on that car with its two-piece shaft that can bend, and almost empty space around the diff.

descartesfool

For those curious about the T1 suspension install, you can find the instructions here:

http://www.crateenginedepot.com/pdfs/23336064.pdf

X25

I have carefully read the full rear cross membership removal instructions again, and it looks like I don't really need to do much as long as I can secure the transmission in its place with a transmission jack (which I just ordered). Long story short, unlike what I thought, if the transmission is secured by a jack, the cross member will come down by itself.

Anyway, long story short, I will be doing this install in off-season, and will document it.

X25

I also asked Anthony from LG Motorsports for his advice on how to replace the rear LCAs, which require lowering the whole rear subframe, and he had this brilliant idea!
Will do, thanks!!!!!!

0Anthony @ LGMotorsports

Yes sir! Done that during all of the drag conversion kits (we send new bolts with it), and will be sending bolts for the camber kits too.

No clue why someone didn't look at this and say "hey if we have to service the car you can't get the control arm out without the bolt hitting the fuel tank".

X25

Thanks again, it was a nightmare waiting to happen, since I don't even have the $1000 special tool to hold the transmission in place, and I really didn't want to go to service for just a control arm replacement.

Now, looking forward to hearing back from you regarding the email I've sent you for the coilovers : )

0Anthony @ LGMotorsports

Sorry, got caught up in the shop.. Writing a reply to you right now.

0Anthony @ LGMotorsports

FYI, thought you might like this one.

greendot

Can you provide the PN for this bolt?

Dane@LGmotorsports

gm 11611443

Keihin39

Easiest way is cut head off bolt, and buy new bolts and reinstall from opposite side,

X25

Yeah, this thread was resolved as such by post #10. Since this thread, I did the cutting for my second C7 (Z06), too : )

Keihin39

Sorry I just missed that post my bad 🤦‍♂️