Loud vibration around 40mph (1 Viewer)

[cruisergear]

This is pretty much exactly what my pinion/t-case angles look like. So I don't see how a DC shaft is a bandaid solution. Seems like the proper solution to me?

By calling it a bandaid solution that implies that there is a greater issue at hand, and the true CURE for the greater issue would be mounting the motor up higher to straighten out the driveline angles. Am I reading into your reply correctly?

Since my 1.4* measurement was not on flat ground we do not know for sure if the motor is mounted too low, BUT, let's assume the motor truly is mounted too low. Let's also assume that the only problem this has caused/will cause is the rear driveshaft isn't at proper operating angles for a standard driveshaft.

If that is the only problem that the low-motor-mounting will ever cause, then a DC shaft would fix the problem.

If all of those assumptions are true, then a DC shaft not a bandaid solution. it's an alternative CURE.

So I guess the real question at this point is: Will low-mounted-motor cause other future problems that are bigger or more costly than a DC shaft? (Keeping in mind the DC shaft was free, so i just need to pay to have it lengthened)

(@Tin basher )

 

[Tin basher]

The reason I mentioned the motor being crooked
Was I moved my small block over a 1/4 inch on the mounts only to pass side to clear a different manifold to steering box and it caused a bad driveshaft vibe
Only change was the exhaust and moving motor
Moved the motor back and no vibe

 

[Tin basher]

@cruisergear I don't like running a dc in a rear shaft
Because I have had problems with the dc joints
In a lot lighter a truck and less power
Toy mini truck running gear in a samurai
More than double the wear items
They last in a front because it's not used all the time
And when you are climbing there is less load on the front
I don't know what your driveshaft shops are like where you are but here re tubing and balancing a driveshaft Is 200 min and about 90 to shorten
With the shims in yours now your angles should be almost the same also I wasn't looking at your angles as being on a level surface your angles where like this \ / by you installing shims your angles are now //

 

[tmxmotorsports]

@Tin basher I installed shims in my 62 not @cruisergear just to clarify.

 

[Tin basher]

This is why I mentioned how the shims are installed these shims where installed by a driveshaft spring shop for the PO yes that's them between the spring and u bolt plate some fine work there lol

Ok old guy not paying attention lol didn't realize two diff guys
Anyways I measured my angles in my 40
Not on flat ground and couple tires half flat
My pinion angle is 2deg \ and tcase is 1deg\
4inch springs and 4 inch over stock shackle
It's got no vibes at any speed with a driveshaft I made with simple tools a pipe cutter a grinder a dial indicator and welder

 

[Str8Razor]

@tmxmotorsport hijacker, his info is spot on... It's somewhere in the variables, Im sure he will find it..

 

[cruisergear]

little update on this. for my vibration we made some drop-down spacers for the t-case. about 1/2" drop. The vibration is virtually gone now! That's a good enough solution to get me by.