LS7 Rocker Arm Failures

[TODD L GRIFFITH]

Have their been any failures on 06 Z'S?
59-62USNVET

I really don't have any information on that. Maybe someone here does and will chime in.

 

[TODD L GRIFFITH]

TODD, great advise. This is NOT your daddy's Chevrolet. (I seem to recall some OLD marketing) I keep my Z in a heated garage and it is babied until I reach an oil temp of at least 165. Nothing over 2500 on the tach until then.

Thanks for the kind word. Yes, not your Daddy's Chevrolet at all, but very close to a production race engine, minus the higher valve lift and some forgings. What gets better than that to drive on the street? I spent alot of time researching the subject awhile back when building my own high performance valvetrain for my C5Z, and during the time when some guys here and on the other forums were talking about valvespring failures on their 06Z's. I was also able to determine through different dyno sessions and different valvespring combinations that if you want to winde these motors up way above 6000 rpm, naturally aspirated, you are better off using a single rated beehive valvespring. If you are using a Procharger, go with the insurance of a dual spring, because rpm isn't as important above 6000 rpm your already making a ton of power below that. Dual springs tend to have valvefloat above 6000rpm alot sooner. The latest trend seems to be the LS7's going to 8000rpm, so part selection is alot more critical. Shaft mounted rockers are a sure way of getting there, with single beehives. Just pay attention to the numbers so there is no coil bind, and the valvelift specification on the springs isn't into the safety factor. It's all way too cool and interesting to me. My wife isn't as excited about my hobbies, but it sure is alot of fun.

 

[Ken Olson]

rocker arm bearings in pan

Well, when I found 3 or 4 bearings on the magnet, man, I thought it was a bad deal. But, the engine had 6000 miles, so I had no way of determining when these guys worked loose. The good news, when they were banging around in the pan, the engine ran perfectly fine, no miss, click, noise, or anything. Plus, I got it to 6 grand on the tach a few times, no problem.

Bottom line, maybe it is not such a big deal. Famous last words?

Ken Olson

 

[NORTY]

I remember seeing some pics of rocker bearing cage failure. Is there "that much" thrust load to cause these failures? Are we looking at a "material" failure or a design failure? I am in contact with GM occasionally, and they are VERY interested in this issue. The rockers are sub-contracted form a supplier.

Speaking of GM info, they are currently "in developement" with the C7. It is scheduled for the 2012 MY. They are looking for owner input/ideas on various websites as well as directly to GM. GM does watch these sites as they are the largest "database" for end user information.

 

[maxrevs85]

I believe Jesel makes rogker arms for these . Top of the heap for rockers.

 

[maxrevs85]

I beleive "Jesel" makes rockers for these. They are top notch .

 

[TODD L GRIFFITH]

I beleive "Jesel" makes rockers for these. They are top notch .

Todd L. Griffith said above:
I just received my Feb. issue of Vette magazine. On the featured procharged ZO6 build by MTI Racing, it indicates Jesel shaft mounted rockers on LS7 heads.

 

[Ken Olson]

My 07 Z has just over 6k on the clock and NO needle bearings in the 3 oil changes I've done so far. I'm not going to worry about it until it actually happens. It's covered by warranty if it does happen. I would like to see some actual numbers of failures. The internet is a great thing but can sometimes make a mountain of of a molehill.

Well, after finding 3 or 4 bearings on the magnet when oil was changed, the dealer replaced 3 rockers. Have driven it 2,000 miles since, and no problems. Actually, when the rollers were in the oil pan, the car still ran great, no missing or noise. I beleive there are slightly more than 40rollers per rocker,so maybe 2 or 3 or so is not the end of the world. Still scary.

I sure do like the car, though. First "vette I've owned.

Ken Olson

 

[johnm]

HI there,
It is simply a preliminary document and not a TSB.
It tells us to replace only the bad rockers, based on ticking noises from the engine.
Allthebest, c4c5

I have not heard of this problem before. My 07 Z06 with roughly 1000miles makes a slight ticking sound at idle that can only be heard when standing next to the car. Under heavy throttle the sound is exacerbated and easily heard from inside the cabin. Could this be a symptom of rocker arm failure?

 

[augydog]

I have not heard of this problem before. My 07 Z06 with roughly 1000miles makes a slight ticking sound at idle that can only be heard when standing next to the car. Under heavy throttle the sound is exacerbated and easily heard from inside the cabin. Could this be a symptom of rocker arm failure?

What month was your '07 built?

From the information I've seen, the one's with the rocker arm problems seem to fall between
January '07 thru June '07 build dates. There is a list of rocker arm failures on another forum that shows 23 Z06's so far. All are 2007's.

I think I would do 1 of 3 things if you think there might be a problem.

1. Take it to the dealer and tell them about the rocker arm problems on the 2007 Z06's and let them listen to the engine.

2.. Get the oil changed and look for needle bearings on the drain plugs.

3.. Remove the valve covers and inspect the rockers for problems.

If it was my car, I would immediately get the oil changed, or pull the valve covers before putting many miles on the car.

Good luck and let us know what the problem is.

augydog

 

[catbert]

Changed my oil yesterday. Happily nothing but Royal Purple came out.

 

[johnm]

What month was your '07 built?

From the information I've seen, the one's with the rocker arm problems seem to fall between
January '07 thru June '07 build dates. There is a list of rocker arm failures on another forum that shows 23 Z06's so far. All are 2007's.

I think I would do 1 of 3 things if you think there might be a problem.

1. Take it to the dealer and tell them about the rocker arm problems on the 2007 Z06's and let them listen to the engine.

2.. Get the oil changed and look for needle bearings on the drain plugs.

3.. Remove the valve covers and inspect the rockers for problems.

If it was my car, I would immediately get the oil changed, or pull the valve covers before putting many miles on the car.

Good luck and let us know what the problem is.

augydog

Thanks augy, I think i will have the oil changed next weekend and check the plug. I will update you then. thanks again

 

[Marlar]

Have there been any similar problems with the 2006 Z06?

:eyerole

 

[steveM]

Just joined the cac so interested to read about the rocker arm issues-I'm the proud owner of an '07 victory red ZO6 with 11k on the clock and it's ticking! I'm in England and this is my 4th 'vette but never experienced this problem before-I'm taking the car into the dealer on Monday so will keep you posted!

 

[TODD L GRIFFITH]

Again, just to let you know, Jesel makes a set of shaft mounted rockers for the LS7 head. I don't have a price, but I get this awful feeling that they are not cheap. It may be worth it to ease any fears during high rpm research which could be tomorrow and the next day, and the next day, and the next day!!!!

 

[johnm]

What month was your '07 built?

From the information I've seen, the one's with the rocker arm problems seem to fall between
January '07 thru June '07 build dates. There is a list of rocker arm failures on another forum that shows 23 Z06's so far. All are 2007's.

I think I would do 1 of 3 things if you think there might be a problem.

1. Take it to the dealer and tell them about the rocker arm problems on the 2007 Z06's and let them listen to the engine.

2.. Get the oil changed and look for needle bearings on the drain plugs.

3.. Remove the valve covers and inspect the rockers for problems.

If it was my car, I would immediately get the oil changed, or pull the valve covers before putting many miles on the car.

Good luck and let us know what the problem is.

augydog

Not sure what month car was built. Is there a way to tell? I never did see the window sticker on this car. When I asked about it the dealer said some bull like the sticker was damaged. Anyway changed the oil yesterday, no bearings on the drain plug, just a few very fine metal shavings. I am guessing these are normal. thanks for the advice johnm

 

[motorman]

Not sure what month car was built. Is there a way to tell? I never did see the window sticker on this car. When I asked about it the dealer said some bull like the sticker was damaged. Anyway changed the oil yesterday, no bearings on the drain plug, just a few very fine metal shavings. I am guessing these are normal. thanks for the advice johnm

the build month is on the door sticker. any GM dealer can pull up all info just by using your VIN

 

[Ed Doyle]

Fix for LS7 Rocker Arm needle bearing failures

I am the General Manager of a company called CHE in southern California.
We have been converting LS1 thru LS7 rocker arms to a bushed assembly with a our own rocker trunion. We have done this for LS2 stock car crate engines and street LS1 thru LS7 engines for some time now and have had no failures to date. Our fix completely eliminates the roller bearings all together.
What we do is have you send your stock rocker arms to us, we disassemble,mag and reinstall our bushings and trunions in your rocker arms and then send them back to the you in about one work week. We have also purchased new rocker arms, if the client does not want to use his used rocker arms. If the customer then wants to send us his old rocker arms after installing our new ones, we give him or her a $100.00 core reimbursement when we recieve the used rocker arm cores
If you have any questions or are interested in our product, call me at 805-499-8885 or look at our web sight: www.cheprecision.com
My e mail address is: edd@cheprecision.com
Thank you and good luck
Ed Doyle

 

[Hib Halverson]

(snip) We have done this for LS2 stock car crate engines and street LS1 thru LS7 engines for some time now and have had no failures to date.

Could you post:
1) Some information detailing the durability testing (particularly duty cycle and duration of testing) in which you've had no failures to date.

2) Details on the bushing design used to replace the roller bearings.

Thanks.

 

[RevMatt]

Next victim....

Reports continue to pour in about LS7 rocker arm needle bearings showing up on the magnetic oil plugs. I checked my rocker arms and they appear to be fine, right now.

This is so frequent, that I was wondering if there had been a TSB generated about this?

ad
I had three needle bearings attached to my drain plug @ oil change #3. (15k)
The dealer replaced the BROKEN ROCKER! It was missing 16 of the 33 needle bearings. I too was told the remainder will come out in the oil changes. My car was built 05/07! Since most of these seem to be LS7s built between 12/06 and 05/07, why are they not recalled?
I am not happy! I love my Vette but am very disappointed!
;squint: