6 inch Tuff Country on CUCV Blazer / Driveline issues

[Klink K5]

Hello all,

Its been a minute since I've been on here but working on a 1986 blazer with 6 inch Tuff Country spring lift on all 4 corners .................... and have rear driveline issues.

No transfer case drop, rear pinion angle up but going down the road under acceleration, have vibration coming from the rear end / drive shaft

4:10 swap on both axles, rer is assembled right, just wondering what you have all done to make a smooth reliable truck with that size of lift.

I'm not opposed to spending $$$ in the drive shafts

 

[sweetk30]

you NEED a c/v shaft in the rear with 6" lift on a blazer . some need one starting at 3" lift but 4" up just do it and be done with it .

you will need to point the pinion at the t-case output but down 1-2* to allow for axle wrap when driving .

do NOT drop the t-case yes it helps rear but kills front angles .

 

[Klink K5]

you NEED a c/v shaft in the rear with 6" lift on a blazer . some need one starting at 3" lift but 4" up just do it and be done with it .

you will need to point the pinion at the t-case output but down 1-2* to allow for axle wrap when driving .

do NOT drop the t-case yes it helps rear but kills front angles .

What do you recommend for a pinion angle ?

 

[83ChevyK5Blazer]

Def need a cv shaft, you will need to use an angle finder and measure your angles, with a cv the pinion should be pointed at the output of the tcase.

 

[sweetk30]

What do you recommend for a pinion angle ?

line 2 tells you how to do it in my post . . and i did it on a blazer with 4.56 5" lift with stick shift and 80mph+ she was nice on 37" tires with a c/v shaft .

 

[Klink K5]

Output shaft at 4 degrees, current angle of DRIVESHAFT with slip yoke WITH CV shat to yoke to diff ...............25 degrees, pinion angle at 10 degrees

Measured all on flat floor with magnetic degree angle gauge. I'm curious if I have too much pinion angle

Taking drivelines in for assessment to driveshaft shop / front needs longer slip & spline anyway

 

[Wes Harden]

With CV at t case you want the rear pinion and driveshaft almost straight, 1-2° down on the pinion. Under load pinion will rote up ideally to 0°.

 

[sweetk30]

With CV at t case you want the rear pinion and driveshaft almost straight, 1-2° down on the pinion. Under load pinion will rote up ideally to 0°.

Thats what i said but guess he needs to hear it multiple times

 

[Klink K5]

Def need a cv shaft, you will need to use an angle finder and measure your angles, with a cv the pinion should be pointed at the output of the tcase.

So the same degrees as the transferase output shaft angle the pinion should be the same in degrees? It this correct?

So if I have stock position of the transferase at 4 degrees angle, pinion should be at 4 degrees as well?

I'm reading....................... and double checking the questions to the answers / Thanks

 

[Klink K5]

you will need to point the pinion at the t-case output but down 1-2* to allow for axle wrap when driving

GOT IT / Copied & pasted................... read it Line 2

 

[Blue85]

If you're sticking with the single-joint at the transfer case, the T-case and pinion are supposed to be parallel, so your pinion needs to be at 4 degrees. (in practice, not quite, as mentioned above). You will have to live with some vibration and U-joints will probably wear more quickly.

Output shaft at 4 degrees, current angle of DRIVESHAFT with slip yoke WITH CV shat to yoke to diff ...............25 degrees, pinion angle at 10 degrees

Taking drivelines in for assessment to driveshaft shop / front needs longer slip & spline anyway

If you have a C/V you need to adjust the pinion to take almost all of the angle out of the pinion U-joint, as previously mentioned. Either way, what you have now is not going to work. Is this the slip spline in the T-case output that has a C/V joint connected to it or have you done a fixed yoke conversion? The T-case slip may experience some binding with a 6" lift on a shaft this short because the slip is not in-line with the driveline. A fixed output makes the driveshaft longer and moves slip into the driveshaft where it doesn't get that side-load binding.