Disconnecting the frontend

[Typhoon #2131]

How much ET. do you gain from disconnecting the front diff.? If you take the front drive line out is that you have to do? I was thinking of taking the front drive line out so I could dyno it but was afraid there might be more to it then that and didn't want to screw something up.

 

[dutchty]

Re: Disconnecting the frontend

How much ET. do you gain from disconnecting the front diff.? If you take the front drive line out is that you have to do? I was thinking of taking the front drive line out so I could dyno it but was afraid there might be more to it then that and didn't want to screw something up.

complete frontline out??
cant be done or you have to delete the front spindles and replace them by 2wd front pindels.
You will get issieus with the 4WD drive spindle bearings if you just pull the diff and halfshafts.

only removing the front drive shaft from the BW to the front diff is no problem but still you get drag from the front diff.

Dont know the gain though. I reccon that stock 4WD is better in the wet for traction. but with when its dry with some real drags on 2wd should be faster.

 

['JustDreamin']

Re: Disconnecting the frontend

Here's the problem, Chief....

The transfer case in these trucks is not a conventional part time 4wd box, and isn't designed to run without a front driveline. Sure, it can be run that way, but if it's run that way for long, sooner or later the viscous coupling in the transfer case will be toast. Two possible failure modes for the VC, either it'll lock up completely, which will probably be driveable, as long as you don't hook the front driveline back up, or it'll overheat and puke all the fluid out (or rupture the case, etc) and you won't have any drive at all (no power to rear wheels).

Now, if you're going to go to all the effort to pull the front diff & halfshafts, come up with some way to keep the front hubs together (either the wheel halfshaft stub or a big bolt), rip out the tcase and put a 2wd trans in it, it "should" be faster if set up properly on a prepared surface (ie racetrack) running DR's or slicks, because of reduced parasitic losses (that'd be due to lower rotating inertia and 150+ lbs out of the truck). But don't expect it to have better street manners, especially in the wet.

Don't know if that helps any, but....

'JustDreamin'

 

[Typhoon #2131]

Re: Disconnecting the frontend

Well I was hoping I could just take that front driveline out that goes from the front diff. to the transfer case like on old 4x4 trucks when you break a u-joint. I just thought pulling a couple bolts would be a quick way I could get it on a dyno and get it tuned since we dont have a all wheel drive dyno here in Oregon that I can find........ Thanks for the help and info guy's

 

[MRKING]

Re: Disconnecting the frontend

If you need to pull the front propshaft (technical term) to dyno your truck , that wont be a problem. Some have driven on the streets like that without issue , others with issue .If this is merely for a dyno session only and you will reinstall it , you should be fine .