perhaps a dumb lift/vibration question...

[dman1982]

got a 84 k10, did a LS swap to it, running the 4l60 trans with a 208 case, running 4.56 gears with 35's, and a 4 inch lift, i went through the forum so i may not have to bug anyone, but i was talking to a buddy of mine cause i get a vibration at higher speeds right around 70-75 and even more when i let off the throttle, he was telling me i may need a longer drive shaft, right now its a aluminum one out of a camaro/trans am, much light than the stock one, but the same length as the original one....just looking for the cheapest way to fix the issue, was thinking there might be a driveshaft from another pickup with the same u-joints just longer...

[Zoomad75]

So if I'm reading your post right you reused the driveshaft from a Camaro and it actually fit? That's pretty crazy if it did. Still, if it did fit aluminum isn't a bad thing and the type of material shouldn't make a difference. Shoot the new trucks are running them, yet they are usually 5" diameter but they work.

You really need to check some basics. First what axles are you running? What did you do for the rear lift? Blocks, springs or shackle flip? Have you checked your driveline angles?

A great app for checking your driveline angles can be had for free on apple or google play. Get the Tremec Toolbox app. It will walk you through the process of checking the driveline angles and uses your phone's accelerometers to give you an angle reading. It's pretty slick and helpful. Just make sure you have it sitting on level ground on its wheels when you measure it.

Getting back to the Camaro Driveshaft, how much slip yoke is exposed on the t-case. You really want it in the middle of the length at ride height so that you have room to allow the driveshaft to slip in under compresson and not bottom out our pull out under droop and not fall out. Depending on how it's situated will direct you on if the shaft is too short or too long.

[dman1982]

Originally Posted by Zoomad75

So if I'm reading your post right you reused the driveshaft from a Camaro and it actually fit? That's pretty crazy if it did. Still, if it did fit aluminum isn't a bad thing and the type of material shouldn't make a difference. Shoot the new trucks are running them, yet they are usually 5" diameter but they work.

You really need to check some basics. First what axles are you running? What did you do for the rear lift? Blocks, springs or shackle flip? Have you checked your driveline angles?

A great app for checking your driveline angles can be had for free on apple or google play. Get the Tremec Toolbox app. It will walk you through the process of checking the driveline angles and uses your phone's accelerometers to give you an angle reading. It's pretty slick and helpful. Just make sure you have it sitting on level ground on its wheels when you measure it.

Getting back to the Camaro Driveshaft, how much slip yoke is exposed on the t-case. You really want it in the middle of the length at ride height so that you have room to allow the driveshaft to slip in under compresson and not bottom out our pull out under droop and not fall out. Depending on how it's situated will direct you on if the shaft is too short or too long.

thanks for the reply, I'm running the stock 10 bolt with springs, just measured it there is 3 3/4 of slip yoke exposed, i downloaded the app but level ground is a issue right at the moment

[brad_man_72]

As long as the trans yoke goes completely through the tailshaft bushing it shouldn't cause a vibration right away (it will ruin the bushing pretty quick).
Why was the camaro scrapped? Was the camaro ever lifted with a forklift? Have any parts of the camaro driveshaft been replaced since it was balanced?
Ditch the aluminum shaft if its not a show truck. Not as strong and more expensive to work on (having retubed longer).
Yeah new trucks use a 5" aluminum driveshaft. They are about paper thin and hitting a cat can ruin one. 5" steel driveshaft parts aren't made... the diameter is required for the length.

[Keith Seymore]

Originally Posted by dman1982

thanks for the reply, I'm running the stock 10 bolt with springs, just measured it there is 3 3/4 of slip yoke exposed, i downloaded the app but level ground is a issue right at the moment

Level ground does not matter.

You are looking at the relationship between the various components in order to determine the u joint working angle; those remain the same regardless of the orientation of the frame (as long as the suspension is compressed).

http://67-72chevytrucks.com/vboard/s...d.php?t=522180

K

[jjzepplin]

Are you sure the truck did not vibrate prior to the swap? My high speed vibration was from sloppy joints on the front diff. When I was an alignment tech we would always check steering components for tightness and go to the tires next. A high speed balance will reveal most issues. I run a double cardan joint on my front and rear shafts just compensate a bit for the 4"lift. Got my shaft from Tom Woods so I am pretty sure it's good.

[dman1982]

Originally Posted by Keith Seymore

Level ground does not matter.

You are looking at the relationship between the various components in order to determine the u joint working angle; those remain the same regardless of the orientation of the frame (as long as the suspension is compressed).

http://67-72chevytrucks.com/vboard/s...d.php?t=522180

K

The level ground was in reference to getting the angles off the driveline, there is a cell phone app that you can download but need to be on level ground for it to work correctly

As far as the camaro driveshaft the guy swapped out trannys so he needed to switch driveshaft

It didn't vibrate before the lift or after, once I did the swap us when it started to vibrate

[Keith Seymore]

Originally Posted by dman1982

there is a cell phone app that you can download but need to be on level ground for it to work correctly

That's unfortunate.

Level ground is not required when you do it "old school".



K

[dman1982]

Originally Posted by Keith Seymore

That's unfortunate.

Level ground is not required when you do it "old school".



K

Lol...I know...I litterially laughed out loud, but your a 100% right like always

[jeffahart]

[QUOTE=It didn't vibrate before the lift or after, once I did the swap us when it started to vibrate[/QUOTE]

Check the pinion angles as first step in process of elimination. Plus, I don't just be grabbing any driveshaft and stick it in. That shaft is suspect to me also.

Pinon Angles

['63GENIII]

The 3-3/4" of exposed slip yoke is a little concerning. How long is the slip yoke overall? My DS builder has always told me to "bottom out" the yoke and then pull it back 1-1/2" for compression. As far as the level ground issue, get a decent protractor from the hardware store and check the angles relative to each other. I did mine on a hella (old school word) steep driveway with good results. When I say steep its around 25 degrees.
I would really be more concerned with the engagement of that slip yoke though. It sounds like its riding on the last 1/3 or less of the yoke / output shaft.