Axle Shim Measurement

[spry]

I've been having some driveline vibrations in the QC after the 6-Speed swap, and have been thinking it's my driveline angle. I found a great article on Pirate4x4 (Pirate4x4.Com - Extreme Four Wheel Drive) for measuring angles, and this is what I came up with. I mainly used this picture (before calculating for cruise throttle). http://www.pirate4x4.com/tech/billavista/PR-shaft/worksheet sc.jpg

My QC has a JTSVP 2/5 kit, a t56, a JTSVP billet kicker shock, a single piece driveshaft, and possible Caltracs in the future. Upon measuring angles, I am currently at (in Degrees): Front 4.5 down, Rear 4 Down, Driveshaft 1 Down. Therefore, by my calculations, my angle at rest is .5 Down.

My vibrations seem to happen on the highway, especially when passing other cars. I believe this has something to do with my angle at cruise throttle. According to the article, the angle changes around 2 Degrees when cruising. Therefore, my angle at cruise throttle is 1.5 Degrees up. I could only imagine what the angle is at full throttle at highway speeds.

In order to straighten out the driveline angle at cruise I will be installing a 2 Degree shim. My question is, does it make sense to install a 4 Degree shim to compensate for further axle wrap upon acceleration?

 

[VENOMOUS1 RACING]

I've been having some driveline vibrations in the QC after the 6-Speed swap, and have been thinking it's my driveline angle. I found a great article on Pirate4x4 (Pirate4x4.Com - Extreme Four Wheel Drive) for measuring angles, and this is what I came up with. I mainly used this picture (before calculating for cruise throttle). http://www.pirate4x4.com/tech/billavista/PR-shaft/worksheet sc.jpg

My QC has a JTSVP 2/5 kit, a t56, a JTSVP billet kicker shock, a single piece driveshaft, and possible Caltracs in the future. Upon measuring angles, I am currently at (in Degrees): Front 4.5 down, Rear 4 Down, Driveshaft 1 Down. Therefore, by my calculations, my angle at rest is .5 Down.

My vibrations seem to happen on the highway, especially when passing other cars. I believe this has something to do with my angle at cruise throttle. According to the article, the angle changes around 2 Degrees when cruising. Therefore, my angle at cruise throttle is 1.5 Degrees up. I could only imagine what the angle is at full throttle at highway speeds.

In order to straighten out the driveline angle at cruise I will be installing a 2 Degree shim. My question is, does it make sense to install a 4 Degree shim to compensate for further axle wrap upon acceleration?

Our traction system will fix you spring wrap bud. Definitely get your pinion angle correct and are you sitting on bumpstops in the rear? That makes vibrations too . 2/5 is too low without c notching :burnout:

 

[SRT2SLOW]

I've been having some driveline vibrations in the QC after the 6-Speed swap, and have been thinking it's my driveline angle. I found a great article on Pirate4x4 (Pirate4x4.Com - Extreme Four Wheel Drive) for measuring angles, and this is what I came up with. I mainly used this picture (before calculating for cruise throttle). http://www.pirate4x4.com/tech/billavista/PR-shaft/worksheet sc.jpg

My QC has a JTSVP 2/5 kit, a t56, a JTSVP billet kicker shock, a single piece driveshaft, and possible Caltracs in the future. Upon measuring angles, I am currently at (in Degrees): Front 4.5 down, Rear 4 Down, Driveshaft 1 Down. Therefore, by my calculations, my angle at rest is .5 Down.

My vibrations seem to happen on the highway, especially when passing other cars. I believe this has something to do with my angle at cruise throttle. According to the article, the angle changes around 2 Degrees when cruising. Therefore, my angle at cruise throttle is 1.5 Degrees up. I could only imagine what the angle is at full throttle at highway speeds.

In order to straighten out the driveline angle at cruise I will be installing a 2 Degree shim. My question is, does it make sense to install a 4 Degree shim to compensate for further axle wrap upon acceleration?

I had the same problem as you with the same drop and 1 piece drive shaft. 4 degree with fix it. I have zero vibrations.

 

[spry]

Sweet, thanks guys. I'm going to be picking up some 1/4" plate steel, and will be building c-notches soon. I sit about 1/4"-1/2" higher than the bumpstops. Looks like I'll be going with the 4 degree shims! Scott, I may hit you up once I've got all this other crap done.

 

[bmxam962]

Sweet, thanks guys. I'm going to be picking up some 1/4" plate steel, and will be building c-notches soon. I sit about 1/4"-1/2" higher than the bumpstops. Looks like I'll be going with the 4 degree shims! Scott, I may hit you up once I've got all this other crap done.

Western Chassis 52118 Rear Frame Notching Kit - Speedway Motors, America's Oldest Speed Shop

Save your self some time and buy these there nice. I member is installing these right now.

 

[ViperPete]

Mine only vibrates from 98-103mph. Other than that, no vibrations.

Have shims, but haven't installed.

 

[bmxam962]

Mine only vibrates from 98-103mph. Other than that, no vibrations.

Have shims, but haven't installed.

My truck won't go that fast haha

 

[SRT2SLOW]

Mine only vibrates from 98-103mph. Other than that, no vibrations.

Have shims, but haven't installed.

mine did the same thing until i put the shims in. stop being lazy

 

[bmxam962]

mine did the same thing until i put the shims in. stop being lazy

What are you fools going over a 100 for

 

[Stanimal]

What are you fools going over a 100 for

Because. Racetruck.

 

[bmxam962]

Because. Racetruck.

Agreed that's the sticker you will see on my fuel cell behind my truck lol

 

[spry]

Mine only vibrates from 98-103mph. Other than that, no vibrations.

Have shims, but haven't installed.

Shim it. Mine vibrated at 100 and I blew out the rear output seal on the transmission. Finding that seal sucks.