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Discussion Starter #1
If you replace the stock rear control arms with the new extended to center the wheel in the fender well do you have to have the drive shaft extended 3/4" or is their enough length on the yoke to stand the extra distance.

Thanks
 
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Discussion Starter #2
If you go Metco, they are a true 3/4" movement, and I would say yes, it is a good idea to get a new DS...I think, but don't quote me, that some people are running the stock DS with the Metco's. The Hotchkis are closer to a 1/2" movement, and a majority of people using them stay with the stock DS at least for a little while. I am not an expert on this, but I have been doing some research of my own to find out what combination I want.

Aside from that, why the extended? I would go with stock length LCA's...No need to buy a new DS, only have to buy ONE set of arms, and it will allow for better weight dist. when drag racing, if you are into that.

There has been so much talked about stock vs extended, and I am sure that I just started something again!


Troy
 
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Discussion Starter #3
But don't you have to go with the extended control arms to get the wheel centered in the wheel well. I do not like the way it looks now. Thanks for the info.

Jeff
 
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Discussion Starter #4
Yes, you would have to use extended length arms to center the axle, that or move the wheelwells forward...


I ran the Metco extended arms with the stock driveshaft for several years with no problems.

I would install the arms and measure the amount of spline engagement. If you don't feel comfortable with what you've got, then install a longer shaft. (that sounds kind of dirty, don't it?)

It really depends on how much power you're putting through it and if you want to run slicks or sticky tires. If you're looking to go really fast then a longer (and stronger) shaft would be a good idea, along with a driveshaft safety loop.
 
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Discussion Starter #5
Stock driveshaft should be find you just pull the extra slack out of the transmission tailshaft. I just applied the same theory to my silverado when i lifted it, the extra slack needed pulled out of the trans.
 
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Discussion Starter #6
OK, here's the driveshaft issue.

If you do extended arms with the stock driveshaft, yes it pulls the shaft out a bit.

The key here is that it pulls it out far enough to leave LESS than MINIMUM SPEC of driveshaft engagement into the tranny tailshaft. Put another way, the "stock" engagement into the tranny tailshaft leaves less than 3/4" of extra before you are below spec. This is why Hotchkis only went 1/2" back on their extended arms....keeps the driveshaft engagement within spec.

This lack of spline engagement, in turn, leads to premature wear on the tranny tailshaft bushing due to higher side loads.

There is also the increased (albeit still small) likelyhood of twisting either the yoke or the output shaft splines due to this reduced engagement. Something to consider if you're not just "cruisin" in the car.

Personally, if I were to goto 3/4" extended arms (I'm not, but that's been covered before in other threads
) I'd consider the driveshaft to be mandatory.
 
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Discussion Starter #7
Originally posted by Sublvr72:
Stock driveshaft should be find you just pull the extra slack out of the transmission tailshaft. I just applied the same theory to my silverado when i lifted it, the extra slack needed pulled out of the trans.
There is no such thing as extra slack...

This is what happens when people become slackers. :eek:
 
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Discussion Starter #8
With the minimal DS angle on our cars does ride height play into DS engagment much, if so maybe the guys that are going extended are also lowering and that is helping keep it closer to spec. :confused: Makes sense to me anyway people who are worried about the centering thing are likely to want to close the wheel gap on top too.

With our minimal angle though I am not sure rideheight would change the engagment that much, but it is an idea anyway.
 
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Discussion Starter #9
A while back I checked out how much I could compress the suspension before my 4" driveshaft hit the floor pan(hit pinion snubber first). I also checked out the slipyoke engagement into the trans with suspension both fully compressed, and fully uncompressed. I did this with springs removed BTW.. I determined that the difference between fully compressed and uncompressed was about 1/4". So someone lowering a car 1-3" probably won't even see any difference in yoke to spline engagement...

This was back when Ed and I were wondering if we should install larger pinion snubbers to stop the driveshaft from hitting the floorpan.... I ended up leaving mine how it was. Not sure about Ed though.
 
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Discussion Starter #10
I did the extended arms a few years back. I went with the dynotech extended shaft and found a problem with the shaft hitting the floor with 4 people in the car. The reason is that the OEM snubber was now hitting on the yoke rather than the housing. A switch to a energy suspension offset snubber cured the problem. I like the look and glad I did the change.
I have known guys who have used extended arms with the stock shaft with no problems but if your the type who puts a load on the shaft by doing holeshots, I would highly recommend a longer shaft.
 
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Discussion Starter #11
Since my driveshaft was (often) hitting the floorpan, I ended up doing the snubber. It is a larger front snubber from Energy Suspension, and costs around $10 for a pair of them. Solved the issue completely.

That said, it looks like the "will the bigger shaft hit the floorpan" issue depends a lot on what pinion angle your particular car has.....experience has shown this can vary somewhat from GM ;) . The more negative the angle, the less likely to hit the floorpan. Since I have adjustable uppers now (finally!), I plan on checking the pinion angle and adjusting it if necessary to obtain approx -1.5 deg in back (seems a reasonable compromise between launch traction, U-joint life, and floorpan clearance in my case and power point).
 
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