Im starting a fresh thread since the last thread got of topic with the title

This is my truck im talking about:


Things i have changed from stock that could affect driveshaft angles, engine 5.3 to 6.0, transsmission 4l60e to 4l80e, 10 bolt rear end to 14 bolt, lowered 2/4, overload spring removed, but still stock engine mounts
Drove the truck for years with that combination without ever checking pinion angle and it would drive great and would not vibrate

Now im looking for more traccion and i checked pinion angle:
Pinion angle pointing up 5 degrees
transmission shaft pointing down 6 degrees

I see people recomending from 2 to 4 degrees facing down for the pinion angle for traccion since i have caltrack style traccion bars so i installed 8 degree shims wish got me to 2.5 facing down (i know 8 degrees shims is a bit much and i plan on rewelding the axle mounts later for a cleaner setup)



Now to the transsmission part, as i understand if the pinion angle is facing down 2.5 degrees now i want the transsmission shaft 2.5 degrees facing up to elimante vibrations, is that correct? well i dont know how to do that, i lifted it 2 1/4" already just to take messurments and i still end up having 4 degree facing down angle


Now my questions are:
-is it normal to have the transsmission facing that much down to start with?
-i havnt driven it because of the weather right now but wont it vibrate like crazy now?
-did the 6.0 come with different motor mounts and now the engine sits higher then normal??

Thank you for your help

 

You need to measure the working angles of the u-joints, pinion angle is not measured in relation to the ground. Trans to driveshaft and driveshaft to pinion.

 

Need to correct that U bolt too.

If your just driving around. Not being all that aggressive. That 4" shim will be ok. Most people with anymore than a 2" shim will remove the perches and rotate the housing and weld on new perches, especially if your doing any kind of racing.

 

You havent done anything really to change the stock trans angle...you should not need to change it

 

Well i had a chance to drive the truck and to my surprise i didnt feel any vibration, only was able to take it to 100mph but felt good so far
So whats up with the saying u want pinion angle and trans shaft angle partallel? Cuz thats not how my angles are right now at all

Im going to the last track day this year in 2 weeks, theres no way i can change the weldings before that so how should my traccion be better:
Keep the 8 degree shim in there or go back to the way it was?

 

One thing I did when using shims is to drill the locating hole if the shim doesn't have one and then weld a piece of small bar stock onto the end of the spring pack bolt to ensure that it is engaging the spring perch and doesn't slip. Helps a lot if there is a chance of the axle slipping under the shim.

 

The shims had a hole

You think it will be fine this way?

 

Only if the pin (leaf spring bolt) is long enough to go thru the shim and into the spring perch a decent amount. That's why I welded a little extra length on the end of it. Everything located better and stayed put. I did slip the axle once before I did this little mod, no more issues after that.

 

Is this what you mean? The spacer is bolted together with the springs

 

sounds to me like youre not doing it correctly. this link might help.

Pinion Angle - Wolfe Race Craft