Ok guys... I got the car out of the driveway for a moment today. Backed it out, turned the wheel and roll till it was straight and then hit the gas. Holly crap I almost ended up in the back seat... the motor shot to 6500rpm instantly and then I hear thump, thump, thump, thump, thump, thump!!!!! For a sec i almost thought I broke the rear I giggled like the day I first bought my car. The pure adranelin rush from the insane G forces actually scared me.

Drove it back up in the garage and found the driveshaft balance weight was welded onto the LS1 shaft in the same spot that the Spohn front DS loop is. Every time the shaft spins the weight scrapes the loop.

Anyone else got a stock LS1 shaft laying around they can go look at? I want to know how far back the front balance weight is from the front of the tube. Just wondering if they are all in teh same place or not.

I was planning on upgrading to a Spohn or Denny's shaft but not yet. I havent built the 12 bolt yet and I wanted to do them later at the same time. I know the LS1 shaft is far from strong enough but I should be able to dyno it like this. I may be forced to buy a new DS now if I cant find one that has the weight welded further back.

I didnt measure mine yet but the weight on the shaft is in the exact worst place possible and is in perfect alignment with the Spohn front loop 2 inches in either direction... would have been fine.

 

Yea I actually got one sittin in my shed off an 01 SS..Might even put it on tommrow since im off from work

i'll look at it tommrow for u and measure what I have

 

I wouldn't bother buying a whole new shaft. Just take it to a machine shop that balances shafts, have them grind down the weight, and rebalance the shaft. Would be a lot cheaper. It cost me $40 to get my shaft rebalanced.

 

If it were me I would wait on the driveshaft, but it is also dangerous to be running an LS1 drivehaft with the power your are making. I dynoed my car with an LS1 DS on the Power Tour and in put 389 to the wheels. When I returned home I found that the DS was twisted and I was lucky to not have broken it.

At the same time when I installed Penz's Moser 12 bolt I had to have the DS shortened about 1.5 inches. I know that not everyone has to do this and it is supposed to work with the stock shaft, but in his case with an adjustable torque arm, panhard bar, and lca's it would not fit. I would try and wait until you put the 12 bolt in and try to take it easy on it until you get it in just in case your DS needs shortened, this could save you when you do get a dennys since you dont want to buy one and then have to send it out to be shortened.

 

Adjustable torque arm? I A$$ume it's hitting on the bottom of the loop, I had problems with the mount and the 4" intermidiate pipe making contact when the engine torqued over. I had enough clearance top side that I just made a 1/4 plate to shim the mounts down to get the clearance I needed. Then just reset the pinion angle.

Cheap fix, get a few washers and longer mouning bolts until you get your new DS.

BTW, if you have the arm with the double DS loops be very careful of the diameter of the drive shaft. The rear mount made contact with my lingenfelter DS. Think it was 3.5".

JB

 

That is exactly why I wanted to just use the LS1 shaft for the time being. I have run into several people who have had to shorten their DS for a 12 bolt. I dont want to buy 2... but if I put it all in now its a crap shoot as to wether or not I'll have the right gears. I might end up buying gears 2 times.

I might go this route for a temp repair. The LS1 shaft will never hold up with the motor so I have to get a new shaft anyway.


John, yeah its an adjustable Spohn TA. And not its rubbing on the top right so lowering the mounts is not an option for now. I either have to move the weights, buy a new DS, or find someone whos LS1 shaft has the weights welded in a different spot and trade.

And yes it has front and rear loops. The front is the one that is close. The rear loop has plenty of room. I could fit a 4.5" shaft in there if I wanted to
I'll take a few pics tonight.

 

Hope this is what you were looking for...

http://s22.photobucket.com/albums/b3...4z/Driveshaft/

 

project, PM me if you still need someone to take a look at the shaft. I would assume that you just want to know its location on the driveshaft, wouldnt matter if it was on an LS1 car of LT1 car right?

I can snap a cell phone pic for you ASAP and text it your way if that would help.

 

Thats exactly what I am looking for!!!! Thanks!!!

My LS1 shaft has the balance weight welded in a different spot. Its much further forward. In this pic you can see how much clearance I have to the top of the loop because the loop has a ton of clearance at the bottom.



You can see where the weight just scraped off the powdercoat from the loop.



And here you can clearly see the front of the weight is less than 2 inches from the front of the shaft where as your shaft it is clearly almost 4 inches.



I need to find a new shaft or trade with someone. Intrested? I dont want to cause a problem for someone else at the same time.

It might be worth it to spens the $40 (assuming thats what it would cost) to have this one rebalanced with teh weight further back.

 

Yo B, There is a place on river rd. in Camden called Shcimp's. Dude they do awesome driveshaft work. I had my drive shaft (lingenfelter DS John's old one) fixed and rebalanced there. They are pretty reasonable on price aswell. My uncle now uses them on a weekly bases for his shop. Might want to check it out. John

 

Anything wrong with your shaft now, I mean is there any chance of it being weakened from being behind a motor that has that much power?

If not, I might be willing to swap to help a fellow CZ28'er.

 

I cant answer that because its a conflict of intrest

But seriously I dont think so. Its only been behind the new motor for a quick 150 foot rive down my street. It did take a lot of abuse with the old motor but it was a cam only motor.

 

ya i know what you mean. I dont think I would have any problems with it behind a relatively stock motor. if you still need one let me know, we can set something up for a swap if you want.

 

yeah if anything this driveshaft is proven to be strong. Yes I do still need one. I still havent found another. I have to make a phone call to one more friend that I think might have one laying around his shop. I'll PM you once I fine out.