rear axle movement through travel

[MTBLAZER89]

Ok I need somebody elses thought process on this. The rear axle with a shackle flip and its movement as it travels.

As it moves up it also moves rearward and vice versa for droop.

As it moves rearward and upward does the distance increase because it is moving rearward or decrease because it is moving up?

As it droops but also moves forward does the distance decrease because it is moving forward or increase because it is moving down?

I am trying to figure out driveshaft length, and I am probably overthinking this.

 

[mnstrburbon]

Going to be in the same boat so im in need of the same info i think you would just mesure at ride height and go from there. And should be ok correct me if im wrong, whos doing the shaft and are you a 1 or 2 piece now and what are you going to be running

 

[MTBLAZER89]

No I already have the shaft. I bought it used and it fits. I have the perches from DIY4x that allow movement forward or backward nd just trying to figure out the optimum location.

 

[y5mgisi]

what do you mean by distance? are you talking from transfercase output to rear end input? I would say alot of it has to do with how flat your springs are.

 

[454k30]

Stock rear drive shaft with flat stock springs. I never once pulled that driveshaft out of the t-case.

 

[1979jimmy350]

here is the measurmets i use on drive shafts, on the ground measure total length and angle then repeat the measurenents with the suspension maxed, you can also compress the suspension and measure length. By subtracting you can figure out your slip needed. Basically down travel makes the shaft longer up travel makes it shorter. Its a lot less than you would think

for example my 74 blazer has a ORD flip in the rear, and my drive shaft only changes half a inch in lenght between ride height and full suspension down travel

 

[MTBLAZER89]

for example my 74 blazer has a ORD flip in the rear, and my drive shaft only changes half a inch in lenght between ride height and full suspension down travel

Ok well this statement makes me feel better. I really didn't think it was a large number. Plus most of the wheel travel is independent off road unless you are jumping or doing high speed whoops.

I think the shaft is at a good spot right now..maybe a little long, but I did want to move my rear back one inch with the perches, but I was worried that may be to much and pull out at full droop.

 

[tRustyK5]

Yeah, the rear doesn't need a ton of slip...really only the front with the heavy offset of the pumkin that needs a lot of slip. I had 1 1/2" of slip left at static height with soft springs and never came close to compressing all of it. Had about 2 1/2"-3" of outward slip left and never had a problem.

If it was a dune truck that saw lots of airtime it might be different, but for regular driving and trail/rocks/mud it's A-OK.

Rene

 

[MTBLAZER89]

Word :d

 

[chulisohombre]

basically you need to have the slip joint centered.so that the shaft has the same amount of compression and extention and move your axle from there to achive this.only needs a couple of inches either way.

 

[vortec]

when i installed my 4" lift, it only pulled the slip yoke maybe 3/4" farther out.

 

[chulisohombre]

when i installed my 4" lift, it only pulled the slip yoke maybe 3/4" farther out.

alot of times with a 4 inch lift or smaller,you can get away with using the same driveshaft.you just have to watch the extention on dropoffs or if you air your truck out.most people dont do this and it is not an issue.