Driveline slip length

[NV_K5]

Hello, I posted a lost driveline link on the garage but now it's getting more unique to Gen I questions. I got my new High Angle driveline and last night during mockup realized after all the modifications (after ordering the DL ) that the slip assembly is overall about 6 inches, installed it has about 1.5" of compression available. Anyone have a recommendation? Is 1.5" compression going to cut it or am I going to push the t-case bearings through the front?

8 inch Skyjacker lift, offroad design shackle flip, DIY4x shackles, no blocks etc. I'd just use the new perches I installed and push the rear back an inch but then I'll be hitting my tank and likely rubbing my tires on fenders.

Old photo - not so good - yes the exhaust was in development and heated up the shackles etc and has been fixed.

 

[NV_K5]

 

[vtblazer]

Having a front drive shaft that is to long can cause problems, I can attest to it.

The P/O was running 1.5"s for compression of the front shaft and this happened to me out wheeling.

Ripped apart the rear case of the th-400.

When I ordered the replacement shaft from High Angle, I had him do a 12" slip joint.
Installed it had about 2.5" + - of compression and it was fine.

Old vs. new:

 

[NV_K5]

Wow that's a drag! fortunately my front driveline is recently rebuilt and has more than enough travel. I may have forgotten to mention it was for a rear driveline... ops.

 

[vtblazer]

just thought it was the front you were talking about.

Oh well, now ya know about the front too.

 

[bp71k5]

I've got about the same amount of compression on my rear shaft. It probably depends on how flexy your suspension is. The rear end moves backward as the suspension compresses so you'll probably be ok.

 

[rcamacho]

You should have functional bump stops set to where your overload leaf engages. Measure distance from t-case to diff with the rear suspension fully compressed and then subtract a bit for safety. That should give you an idea how long the DS needs to be under compression.

 

[4X4HIGH]

Why not make a call to the "expert" and call Jesse and ask him for his opinion on this. As noted already though, the rear diff will move rearward when compressed since the shackles are at the rear of the springs and the shaft is forward of the axle. The front shaft on the other hand when the suspension compresses the axle moves rearward as well but because the shaft is rear facing it will stuff a shaft and start breaking things if there's not enough slip in the shaft.