of late my clutch pedal has been feeling a little wierd and today i started having problems shifting. went to leave work, got down the street and heard the pop noise and mu clutch pedal was on the floor. limped the car back to the shop and started tearing it apart to find the dreaded broken firewall plate.

anyone have a how to on changing this? and what way does it go in, from the engine bay or from the interior?

 

broken firewall plate?

 

subd

 

You have any pics... I kinda want to see what the carnage looks like

 

I'll get some pics when I get home. It's a nightmare of a job

 

first off, this is whats needed to even get a proper look at the firewall plate from the inside



that was around 4 hours work to get to that point. to actually remove the firewall plate id have to remove the hvac box, that required recovering the a/c refrigerant and draining the coolant. the brake booster also needs to be removed. basicly another hour or 2 of work just to remove the plate.

now for the carnage


thats it from the inside. all cracked and bent. no wonder these things fail, there is not very much contact area and a lot of pressure is being put on very little surface area.

now for the bad part, as if it wasnt bad enough, the plates are not available. local dealer said no stock in canada, i called tom at crate engine depot this morning and he had no stock, and gm didnt show any either, but gave me numbers for the only 2 dealers in the USA showing stock. one dealer couldnt find it, the other refused to sell it to me. so the end result is no new plates. i can get a used one from a wrecker for 3x the new cost (if i could get one), but they cant get it out of the car till mid next week. welding it isnt really an option, i could tig weld the plate in place, but its gonna break again.

so im working with a local machine shop on a fix. ive got an idea, going to draw it in cad tonight and hope they can cut it out tomorrow. itll be a way thicker and stronger piece and it wont require removing the firewall plate to complete the repair. only downside will be the car still needs to be disassembled to the point i have to be able to install it.

 

Holy hell.... That's a lot worse than I could have imagined.

 

I heard rumor that the lnf had a stronger plate, but I'm not sure how much truth there is to that

 

That's what i heard too. Crate engine depot lists it but none anywhere

 

Damn that crazy that's alot of work for sure

 

Holy crap.... In for the fix.

That would prob put me over the edge to dump my car. Proud of ya for sticking through it.

 

well what choice do i have? its still worth $5k, and its my only running car. not running/driving its worth $500 at most, or take $100 for it at the junkyard. not gonna happen.

 

Yeah, I prob wouldn't either, although the rare parts on my car would prob net me just enough to possibly justify saying screw it, lol.

Even though it wouldn't be close to the actual value of the car running.

 

Even so, who wants to part there car out because they have to do some work to fix it? This sucks, but it's not that bad.

The machine shop has a drawing made up and is hoping to have one spit out today for me. Crossing my fingers on that

 

I need to pull my dash to that extent and finish gutting some things. Maybe this summer

 

In for solution. What clutch are you running?

 

Didn't know lsjs had this problem, I've had many 07/08 wrx's break pinch welds on the firewall and it makes an awful noise everytime you hit the clutch pedal

 

Holy fuhq I'd probably just roll my car off a cliff...

x2 on the LNF, I've heard GM secretly knew this was an issue and made the LNF plates stronger

 

^^I did hear or read that somewhere as well or I wanna say it was firewall flexing/bending, But I am drawing a blank on where and it was probably a while ago.

In for a solution.

 

If someone can cite a source to show this issue was fixed for the '08+/LNF cars I'd sincerly appreciate it being linked.

 

as far as i can find the original part number for the plate is 15258000, however i had found a parts site that showed that part and under description said "replaced by 20858564". as far as i know, the 2nd number is the lnf plate.

gm performance clutch. kinda interesting, its rumored that gm upgraded the firewall plate for the lnf, and i broke my firewall plate on what is essentially the lnf clutch. coincidence?

 

I wish I can reply with pictures, but just my two cents, wire wheel the surface area, then find a washer with the same dimensions and tack weld it in place, I say just tack weld because if you put too much heat into that plate it will become brittle and break again. just my two cents, if this is not the fix you hoped for just take whatever info and run with the idea.

 

IDK if this helps but I think theres some info about the clutch plate in this thread
https://www.cobaltss.net/forums/prob...rewall-301420/

According to powell in that thread, the lnf's was double what we have

 

i did have a look at that. imo, not a very good option. the metal in that whole area is fatigued already. a reinforcement piece (washer, a home made plate, etc) would have to be larger than the hole, the flange on the master cylinder is roughly 3/8" larger diameter than the hole, so there is still a lot of damaged metal there that would remain unsupported. you would have to put the reinforcement on the outside, however that still leaves the studs pulling against the plate, and as you can see its cracked near the studs, wouldnt take long till that cracks all the way around them and they break off. imo the only way to repair that plate would be to clean it up and tig weld all the cracks then put something on the reinforce it. the problem with that is like you said, itll be hardened and brittle. would work for a while but not a real good fix.

what im working on is a machined piece that will sandwich between the firewall plate and the clutch pedal bracket. the piece will have much thicker tabs (roughly 2.5x thicker) and the piece itself will end up pushing on a large area of the firewall plate, well outside of the damaged area. so not only will it be a repair, it will be an upgrade. should be able to handle the stiff pressure plates people have tried running.

unfortunately the machine shop didnt get it done today, so i wont get it till monday.

 

stock clutch or a heavy pedal pressure clutch?