RENE'S RAGE

iTrader: (96)

How high do you spin it?

My6speedZ

iTrader: (18)

I asked that earlier, I had a hunch it may have been stressing the pushrods after pump-up. Since he doesn't really know, who knows. But I will say from what I have witnessed LS7's like less preload than more preload at least IMO, what is your take of that.

x2 how are we talking here?


Going back to stock is an option on these heads, but only if the rocker is somehow the culprit.

Did you get these heads new?

Blown06

iTrader: (32)

"I don't remember, but it checked out fine" wouldn't give me a warm fuzzy.

Check that ****.

Jc803

iTrader: (2)

Well its running just fine again. This time I took the head off to ensure I drilled and taped for the timesert at the right angle. Thankfully there was no internal damage. Replaced two push rods even though only one was damaged, two scorpion rocker arms, two bolts, and both ls7 lifters even though both were untouched. And another ls9 head gasket. Sucks that the one I took out was two weeks old.

Everything checked out fine again so I'm thinking the head might just have a soft spot in the aluminum in that area.

Thankfully stick wars was cancelled on the 27th due to weather and rescheduled for later this month. Have an appointment to finally get an alignment Thursday then I'll be track ready and maybe go Friday if the weather allows

BriancWS6

iTrader: (18)

So you've had valve springs break, and pulled the threads out of two rocker arm holes? Man, I'm gonna have to say smthing is going on here. Are you running the AFR 8019 springs on those 225s? Did you check the installed height of the springs? What's your cam specs? What's the preload on those LS7s?

I can help you get to the bottom of this, don't run the car anymore til we get some things figured out. You have been very lucky that these failures haven't caused more damage. The age old saying of doing the same thing over and over yet expecting diff results is the definition of insanity comes to mind here. Trust me, I've been in the LS game 12 years, and have set up multiple valve trains with zero issues. And I've also been a machinist for 17 years.

I've turned my current setup as high as 7300 so far, my previous stock bottom end heads/cam setup to 7100, and a buddy of mines 347 I built for him to 7k, and not just once or twice by any means, and they all take it without a hiccup. Your recent dyno runs at CMS didn't even hit 6k and u were on the rev limiter u said, so ur not even spinning it that high and still having some issues.

Jc803

iTrader: (2)

Yea things have been crazy for a year now. I'm on my phone but I wrote everything down as far as sorting installed height and preload specs. I'll post them and a picture of my cam card when I get home. Only thing I know right now is I'm using PRC 650 springs and that's also what springs broke

I'm now 3 months and 1 week from getting out the army. Plan is to hit 10s just once then put everything on hold till I move back to SC and buy a house, build a shed, and install a lift. Then I'll have somewhere to put all my tools, welders, plasma cutter, and everything else. Then I can have a place to get the boost build going because doing everything in my apartment parking lot is killing me (and the complex supervisors)

But thanks for volunteering to give advise when I rebuild the engine lol

Jc803

iTrader: (2)

Oh yea and as far as the rev limiter on the dyno. You know how you caught my 4,300 lb typo? I think I do that a lot because the day before the dyno I lowered the rev limiter just in case the guys went past my shift light (which I also lowered) but I must have typed in 5,700 or something crazy. Haven't checked it yet

And then when I drove the car to work yesterday I noticed my shift light was coming on super early. Checked it and instead of it being at 6,000 where I had put it for the dyno it was at 4,600.

Maybe I'm going crazy. I don't drink so I'm not changing things while drunk. Maybe one too many 24 hour shifts or my last deployment is catching up to me. I don't know what is it lol. Now I'm double and triple checking everything I do.

But normally no, I take it past 6k rpm. Normally have my light set to 6,200 so by the time I react and shift it's probably around 6,400 rpm. If I go slightly past that, that's when bolts rip out. Thinking about putting the rev limiter from 6,800 down to 6,400 and shift light at 6,100

BriancWS6

iTrader: (18)

Haha man that's crazy!

Your gonna be leaving a lot of mph and et on the table if you have the limiter that low and shift that early. Smthing is wrong like I said which is why the failures keep occurring.

Once u get the info I asked we can begin to track it all down and you should be able to spin it as high as needed for the setup without **** hitting the fan.

You can PM if you prefer instead of cluttering up the thread. Up to u

Jc803

iTrader: (2)

Well my question now is, can I change the t56 output shaft by taking the tail housing off, or does the trans have to be pulled out and taken apart.

Went to the track to see what all these new parts would do, launched off the 2 step at 4,500 rpm, then snap. I made it about a foot. Thankfully I have a safety loop. But I can't even be mad because it's a stock output shaft. I'll have to find something better.

I think soon I'm going to invest into a truck and trailer because these tow bills are kicking my ***

Blown06

iTrader: (32)

No **** on the tow bills. Hopefully your car is just going through a phase. Where you snapping any pics of the wife at the track lol. If so and as much as we all enjoy seeing those types of pics, I believe she would not be allowed to be photo'd anywhere near the car again. lol

Jc803

iTrader: (2)

Ha no, I made sure all the cameras were put away and made her bundle up and cover her face. Those two guys that I've been wanting to run were both there. I lined up with the supercharged SRT8 then that happed on my first attempted pass. I think he was praying to the car gods and he got his wish.

I pulled the driveshaft out an hour ago at 3am. Heres a pic. And the output shaft isnt looking much better and now I'm thinking the tail shaft might be messed up too. Couldnt get good pics of those in the dark but I will later.

Also, the tow truck guy bent the hell out of my bumper and took some paint off. My amazing paint job is quickly going to s***. At this point, depending on the condition of the tail shaft and input shaft, I might just put everything down and take a step back until I move. Then I can have the time and space to get everything right and go with a 4L80E swap. I'm just about done with this whole 10 second NA t56 goal.



This lip is supposed to be flat and level. Now its almost touching the damn ground

a98ws6

iTrader: (48)

That bumper! God damn ! Hope he is going to pay to fix it? I hear you on those tow bills. I found a guy I like to tow my car and make to ask for him by name. He is super careful and professional and I only use him so things like your bumper dont happen to mine...

BriancWS6

iTrader: (18)

Looks like that cast slip yoke on the drive shaft is to blame.

Jc803

iTrader: (2)

Yea. I've always seen and heard of peoples drive shafts twisting but haven't heard anything about yokes breaking or I would have swapped it out with something better a long time ago.

Well the update is I took the exhaust, torque arm and all that off, got the tail housing bolts out, then it started to rain and called it quits. Once again I'm doing all this in my apartment parking lot with the car maybe a foot off the ground.

From the looks of it I can save the output shaft. Need a new bushing though. My question is I don't know if this yoke is stock, if its a 1310, 1330, or 1350 u joint, and I'm looking online for a cheap or stock yoke just to get this running, but they have all kinds of different lengths and diameters. Can anyone help so I can get one ordered?

Reason I'm doing everything stock is because I'm officially done with this t56 crap and have decided on a Th400. Also because I need to sell my daily Camry soon for the move, already have a civic in south Carolina. But I need to drive the ws6 for about a month until I actually move.

Jc803

iTrader: (2)

Well I did my homework. Its a 27 spline, that was easy. Did the measurements and confirmed its a 1350 series and not the stock size 3R. Also found out the seal diameter is 1.503". Now my only question is what length I need. The rest of the yoke is still wrapped around the output shaft so I'm hoping I can get it off without damaging the splines, then maybe I can hold it to the yoke to find out the length that it used to be.

But as far as length, the two lengths I'm seeing are 6.94" or 5.47". My gut is telling me its the 6.94" because of the ones I'm seeing in that length its telling me it will fit a 4L60E. And in some threads I read people are saying that the driveshafts are interchangeable from T-56 and 4L60E. Any ideas will help because I could order this that much faster instead of waiting for me to get the tail housing off the trans and pull the broke piece off.

Editing this for the 3rd time. I've read that you want about 1" of extra play in the driveshaft at ride height. Now is that 1" from the inside of the yoke hitting the very end of the output shaft / outside of the yoke hitting the trans tail shaft, or is that 1" from the end of the yoke bottoming out on something on the inside of the trans. Reason I ask is because if they mean 1" from hitting the outside of the transmission or bottoming out on the output shaft then I could just order the longer yoke because the length of my driveshaft isnt changing so it will still be 1" away. But if there is something on the inside of the trans for it to hit then the length will be critical.

Jc803

iTrader: (2)

Well guys I'm a little upset with PST right now. I've been loosing sleep trying to figure this slip yoke thing out taking measurements and racking my brain. Well under some dirt and trans fluid I found the part number CAM798.

I search online for that part number hoping to find a new one to get the length off of it. Cant find it anywhere. But what I do find is countless threads of other guys with driveshafts from PST rated over 1000hp with the same slip yoke exploding just like mine. In one thread a guy even said he found out it was a cheap Chinese knock off.

So it blows my mind how PST can sell 1000hp driveshafts but they cant even handle 500hp because of the knock off slip yoke they put on some of them. And now my output shaft is probably damaged beyond repair, the bushing is done for, and the bushing took out some aluminum on the tail housing. All of which I'm going to have to pay for out of my own pocket.

I'll keep using this driveshaft until I switch to a TH400, but after this I'll never buy from PST again


EDIT: Still looking for this yoke everywhere. But while searching I came across this on brutespeed.com. Glad to know someone else acknowledges this s*** yoke breaks with under 500hp
"I ship out these driveshafts with the stronger Cryo Treated Forged Yoke for no extra charge, this is an upgrade from the standard yoke but I now automatically include it. This driveshaft comes with a much better yoke than the driveshafts that are often found with a chinese made yoke that have a pn# CAM798 on them. The CAM798 yokes are known to break on cars with less than 500 hp."

Blown06

iTrader: (32)

When you install the driveshaft into the transmission, push it all the way in until it seats. The 1" you refer do is the distance it should pull out to engage the u-joint in the yoke on the rearend.

Jc803

iTrader: (2)

Edit: Just deleted this whole message because I don't need to know anything about the length anymore. Brute speed replied and although they didn't tell me the length, they confirmed that their forged yoke is the same length as the CAM798 yoke. Still waiting to hear from PST if they are going to do the right thing and replace their junk at no charge, if not then I'll get the forged yoke from brute speed

BriancWS6

iTrader: (18)

My PST that I purchased in 08 also had the cam 798 slip yoke. While I had the car down building the new setup is when people started having the issues like u did. So before I put the car back together I got a forged unit from PST. I agree it's shitty to sell a 1000 hp shaft with a slip yoke that won't hold near that power.

Don't give up on the 10 sec slip with the 6 speed. You can get there. When u get aggravated just take a step back for a few days or weeks. Finding the weak links along the way is part of the game. When u reach ur goal, the feeling is just awesome!!

Then u wanna go even faster! Haha

Jc803

iTrader: (2)

Damn, wish I would have caught it before like you did. Quick question. Was the PST CAM798 yoke and the PST forged yoke the same length? Of everyone I emailed asking about it the only one to respond was Brute Speed and they say they are the same length. Just want to double check with you. Because if PST doesnt respond by tomorrow I'm just going to go ahead and order it through Brute Speed since they helped me so they have my business.

Heres the link to the only one they sell for F bodies. Hopefully its the same one you have.
http://shop.brutespeed.com/PST-3-3-2...-3-2755UG2.htm

And yea its going to be a while till I have the money for a full auto build so I'll keep trying for 10s with the T56. Its just scary because everything is breaking all the sudden so it makes me think twice. I already know the next time I go back to the track that very first pass I'm going to have my eyes closed praying and waiting for a snap