Vetteguy103

Does anyone know if the 2004 Z06's have the same valve spring issue as the 2002-2003 models? I have a Z-16 with 43K and I don't want to take any chances. I have heard that GM rectified the problem in 2004 but don't know if that's true.

grantv

Look at the sticky, top of Z forum. There are perhaps 2-3 recorded failures for 04. I bought new springs and seals for mine anyway... will eventually actually install them I think (along with my dusty LMC5).

LoneStarFRC

Considering how easy they are to change, I'd go ahead. A source of compressed air, a spark plug adapter fitting to keep the valves shut while you make the swap, and a spring compressor are the main three things you need. Put some new v/s seals in as well. Fairly easy job.

Btw, I just noticed you're in BB. That's where my son lives as well. Small world.

neutron82

if you decide to do the springs a rocker trunion upgrade would be worth the extra $120 or so in my opinion since the rockers will be off anyway

LoneStarFRC

Good idea, and forget Comp.

These are the way to go now:

http://www.straubtechnologies.com/ls...trunnion-kits/

73Corvette

Well learned you have from Yoda Curlee...

neutron82

those do look nice but unfortunately when I did mine some years ago comp was the only one available as far as I know... I haven't had any issues with mine luckily

LoneStarFRC

Comp was, or has been, the only game in town for several years. I don't know if they changed manufacturing sources (i.e., China) or materials/specs, or what, but I have experienced accelerated wear on the trunnion on a set I had, and the long list of others with either outright failure (or very close to it), in the multi-page thread going on over at LS1Tech right now is very enlightening. Lots of pictures.

You might do yourself a favor and remove a couple random RAs, and disassemble and inspect the underside of the trunnion body. You may not like what you find.

HTH

neutron82

I have heard of the snap rings breaking but haven't heard anything about the trunion itself failing... I really haven't been on ls1tech much since joining here and I probably should, there is a lot more info on that forum... next time I change my oil I might just pop them off and look, the way my car is setup I could have them off in a few mins lol... do you have a link or pics of what to look for?

LoneStarFRC

This is a long thread, with lots of pictures and input from many posters/vendors/users. It is very worthwhile to read through from front to back.
Chris' trunnion kits are new to the marketplace and they began shipping in Feb I think (~) AND they are US made. Martin (formerly with Tick) Smallwood is just one of the people big on these so far. I have a set installed as well. Easy to do.

http://ls1tech.com/forums/generation...nion-kits.html

neutron82

holy chit... yeah if mine look like that they are coming right the F out... I have some vacation time coming up in a week and that would give me something to do, I might just go ahead and order a set

73Corvette

Well... listening not to Mr Curlee you did...

I was SURE you had seen SO many post from Bill about the trunions is why I put that... maybe you hadn't? Hope yours are OK

neutron82

I don't recall him saying anything that specific about them, not saying he hasn't I just don't remember reading it... after looking at the pics in the thread lonestar posted and me knowing how I drive my car then I'm sure they look similar... I'm probably just going to order a set and do it regardless, I don't want to risk anything failing over a $150 part

LoneStarFRC

I think you'll like them. Super easy to install. Just give them a call direct. Their prices are the same as their dealers. Tim will probably be the one to take your order. You'll have them in a couple days.

Btw, that was me in the LS1tech thread that pointed out to Chris about the LS7 bolts being shorter. They changed their website info as a result.

Rob 02

The bad batch was mostly '02- & early '03. Even then You would have to rev to 6k a lot before they would start to get brittle.

leadfoot4

I looked into this several years ago, when the problem first came to light. HOWEVER, it seems that the Z06 engines were the ones initially having issues with the bad trunions, not the "regular" LS engines. But I installed a set of the Comp trunions in my car, anyway.

I did look into the CHE bushings, but they weren't offered as a kit, at the time, and CHE wanted $400 to do the conversion on customer supplied rockers. I was hesitant to spend that kind of money for something that might have been, at the time, overkill for my needs.


The problem, as I see it, is that the LS engines all seem to have that "sewing machine sound" as normal, so it's difficult to determine if something has gone amiss........

LoneStarFRC

That time frame doesn't include the ones that I had within the last year or so.

Btw, I'm speaking about the Comp Cams "upgraded" version here, not any OE pieces. It's the Comp pieces that are failing.

73Corvette

Yeah, he's got in my head. About every post that I've seen about valve issues he mentions trunion upgrades...
I had never even heard of them and had no idea what they were until I joined the C5 forum...
The only roller motor I have ever had is our full roller 427, but it's all old school and a totally different beast....

neutron82

turns out a friend of mine deals those trunion kits and has some so I'm just going to grab a set from him... I'm also debating throwing in a set of 3/8 pushrods since I'm already there

I am aware of upgrading the trunions but I did mine years ago when I did the cam and comp was the only one around at the time and I had not heard about them wearing prematurely until now, better late than never I guess lol... op I apologize, I didn't mean to hijack your thread