1st time on dyno, driveshaft grenaded, carnage insued (long)
05-07-2006, 09:54 AM
#21
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Originally Posted by agreif
Heard summit makes em for ~20. Funny how I never caught any of the earlier posts about this. Looks like I'll be ordering up a Denny's Driveshaft here soon. I feel my wallet floating away.
05-07-2006, 09:58 AM
#22
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Originally Posted by TouchOfEvil04
Could i run an aluminum drive shaft in my heavy *** truck???or would that be too much to ask of an aluminum shaft?
05-07-2006, 10:00 AM
#23
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Originally Posted by La Riddler
I called Denny's and they recomended a Hd Aluminum DS. Aluminum should feel softer than steel because of the weight diff. I'm getting mine soon....waiting to try it out and see how it feels.
the hd drive shaft works great!!!!!
05-07-2006, 10:37 AM
#24
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I'm not knocking getting a new drive shaft, anything for safety is worth the money, but I think it's the u-joints that slip or fail. I think one or more driveshaft loops ($20 Summit) and some HD u-joints are more important. Most tracks have it as a requirement. See image below.
05-07-2006, 01:18 PM
#25
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I put down over 400 at the wheel on my camaro with a factory alum driveshaft. The steel ones that came on the camaros were terribly balanced but the alum ones were good for us.
Go figure right. If made correctly and balanced either one should work most like alum since it is critical to cut down on rotating mass.
Go figure right. If made correctly and balanced either one should work most like alum since it is critical to cut down on rotating mass.
05-07-2006, 06:09 PM
#27
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Blown, I actually found that link last night. When I go back to get the parts I'm going to measure the thickness and see if it coorelates.
Here are some pics of the damage. I'll get a pic of the parts tomorrow.
Can still see the bolts attaching the extension housing to the trans.
Housing
Pinion Yolk Right side bolt pulled right out.
Dent into the cab, that's carpet that you can see.
Here are some pics of the damage. I'll get a pic of the parts tomorrow.
Can still see the bolts attaching the extension housing to the trans.
Housing
Pinion Yolk Right side bolt pulled right out.
Dent into the cab, that's carpet that you can see.
05-07-2006, 08:04 PM
#28
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Damn dude! That sucks. What's up with all that rust under your truck??
You could really use some new shocks, rust removal, and some black undercoating work!
Jim
You could really use some new shocks, rust removal, and some black undercoating work!
Jim
05-07-2006, 08:28 PM
#29
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Hmm, this topic reminds me of a dyno day not so long ago, in a different vehicle...
What I found in researching the solution to this problem with my Avalanche is, like quicksilverdo said, OEM driveshafts do come poorly balanced from the factory. After talking with Denny's, Inland Empire Driveline, Oceanside Driveline, etc., I found that the best solution for me was to order another OEM driveshaft and have it balanced. They couldn't make me another 5" diameter, 72" long driveshaft better or cheaper than GM. So that is exactly what I did.
I found out that the OEM part is only rated to 105 mpr or so, and I was going 141 on the dyno when the above happened. BlownChevy is right, these driveshafts were not made to go over 105 mph, and as such, they are only tested to that speed. But you can get them to go faster if you balance them correctly.
Even more likely, as exhappen alluded to, you need to ensure your pinion and transmission angles are correct (equal and opposite). If you have messed with your suspension (drop or lift), you have likely changed the angles and need to correct them. If they are out of sync, you will end up with resonance at a certain speed. With my Avalanche, I had some vibration at 70 mph due to a poor pinion angle after a drop, compounded by a poorly balanced OEM driveshaft. Of course, they blasted right through 70 mph on the dyno, right up to the next harmonic, 140 mph (70 x 2). That's when she gave up the ghost.
Moral of the story....if you want to go fast in a vehicle, take the extra time, energy, and money to check your pinion/tranny angles and also to balance your driveshaft before testing on the dyno or elsewhere. Even if you've never touched your suspension, the OEM specs have enough latitude that both measurements can be out of whack from the factory. No biggie up to 105 mph, but if you run it up well past that, all hell can break loose.
Two shops measured my pinion angles for free (took all of 5 minutes) and Oceanside Driveline charged me $15 to balance a new OEM driveshaft. Cheap insurance.
What I found in researching the solution to this problem with my Avalanche is, like quicksilverdo said, OEM driveshafts do come poorly balanced from the factory. After talking with Denny's, Inland Empire Driveline, Oceanside Driveline, etc., I found that the best solution for me was to order another OEM driveshaft and have it balanced. They couldn't make me another 5" diameter, 72" long driveshaft better or cheaper than GM. So that is exactly what I did.
I found out that the OEM part is only rated to 105 mpr or so, and I was going 141 on the dyno when the above happened. BlownChevy is right, these driveshafts were not made to go over 105 mph, and as such, they are only tested to that speed. But you can get them to go faster if you balance them correctly.
Even more likely, as exhappen alluded to, you need to ensure your pinion and transmission angles are correct (equal and opposite). If you have messed with your suspension (drop or lift), you have likely changed the angles and need to correct them. If they are out of sync, you will end up with resonance at a certain speed. With my Avalanche, I had some vibration at 70 mph due to a poor pinion angle after a drop, compounded by a poorly balanced OEM driveshaft. Of course, they blasted right through 70 mph on the dyno, right up to the next harmonic, 140 mph (70 x 2). That's when she gave up the ghost.
Moral of the story....if you want to go fast in a vehicle, take the extra time, energy, and money to check your pinion/tranny angles and also to balance your driveshaft before testing on the dyno or elsewhere. Even if you've never touched your suspension, the OEM specs have enough latitude that both measurements can be out of whack from the factory. No biggie up to 105 mph, but if you run it up well past that, all hell can break loose.
Two shops measured my pinion angles for free (took all of 5 minutes) and Oceanside Driveline charged me $15 to balance a new OEM driveshaft. Cheap insurance.
05-07-2006, 10:28 PM
#30
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good moral, ill probably have to do all that before i lower the truck, good thing i didnt read this a long time ago or else dyno tuning at 130mph would have made me uneasy