broke 3 rocker arm shafts???

[fasterfaster]

206/206 cam,heads worked 2 new postons rocker shafts,new melling push rods #308 which are .038 shorter than stock, stock size is 8.686 .pass shaft broke at 2000 mi put old one back in. driver side broke at about 4500 mi,put the other old one back in. sent both new broken back to postons they gave me refund.three days ago(at 8500 mi) i broke drivers side of course every time i have broken them i bent push rods.which i replace. two days ago i ordered 2 new HD ones from nick mcale.Question is ,what is my problem?? I was at WOT when all 3 broke. Tow jobs are killing me
thanks jerry
Bruce I could not sign in as old hot rod,I had to registure under this new name,call you later.

 

[Race Jace]

well part of the problem is there is a design flaw with the stock fastners and shafts. That is why we designed the Rocker Shaft Braces. The stock setup does not have any kind of support washer or anything, just a bolt through the shaft. Our braces are actually a press fit so they "snap" into place and support the shaft on the top half. These combined with the the support from the bosses in the head make for almost 360 deg. of support. here is a link to pictures of what i am talking about.

Rocker Shaft Braces

hope this helps.

 

[Pat Adkins]

Do they come with a longer bolt?

 

[TurboBob]

I have a set of Billet shafts with NEW GM rockers if you're interested.

Actually I drove them for a little while, so they are Like New.


Bob

 

[MSDGN]

This is no offense to Jason's products because I think he makes quality ones and I use several of them but I had a rocker shaft break even with the shaft supports on...the end of the shaft towards the front of the motor broke off...this happened at the end of a run at the track...luckily I didn't bend a pushrod...since then I have replaced the shafts with solid billet ones...ain't going to happen again...still wondering why the shaft broke with the supports on...I was using stock shafts which do suck...nothing less than heavy duty shafts for me from now on...

 

[Race Jace]

Originally posted by Pat Adkins
Do they come with a longer bolt?

no they are designed to use the stock bolts. the stock bolts with the supports still have over 2 x the dia of the bolt in thread engagement.

msdgn your shafts had to have been previously fatigued if they broke with the braces on. We had a guy brake a shaft at the track and none of us had an extra shaft. We gave him a set of the braces and he put them on the broken shaft. With the brace actually holding the shaft together, It got him home from the track without the end of the shaft poping off again, We couldn't believe it.

 

[S10xGN]

I'm running Jason's braces and T/A's HD moly shafts - have not had any trouble yet. Been on the rev limiter a coupla times, too!

 

[laz]

Jerry odds are you have to much preload. I have broken a few stock and even a few melling shafts . The best fix is roller rockers new push rods and valve cover spacers for the stock covers. I have gone thru this, a few bucks now over lots more later . Laz

 

[TurboT231]

Broken Shafts

Faster, check your valve spring's, I had a customer's car doing the same thing, it had the wrong spring's, not enough pressure. They would only break at WOT.

 

[turbofrank]

Who sells the solid billet shaft?

 

[MSDGN]

I got mine several years ago from a guy named John Martin...not sure if he's still doing them...here's a pic of the shafts:

http://members.aol.com/gngod/Page2.html

 

[Nick Micale]

Originally posted by turbofrank
Who sells the solid billet shaft?

The HD shafts from TA Performance are not solid, but much thicker than stock, and have close tolerance bolt holes to minimize stress there.

 

[TurboBob]

Originally posted by turbofrank
Who sells the solid billet shaft?

I got mine at the GS Nats a year or 2 before the RJC braces became available. I don't remember who made them.

B

 

[fasterfaster]

test

test

 

[fasterfaster]

Turbo Bob I am interested i need spares how much$
jerry

 

[TurboBob]

200.00 for the whole thing (rockers, shafts)

The rocker retainers are small brass billet pieces, not the nylon buttons. A real high-class outfit.

B