How does the 4A work?

[Jdyount]

Any resolution on this? Are you still getting chatter and vibration? I ask because I’m now getting it as well in Sport. Interestingly this also occurred only post-lift for me too- BUT - I used perch collars so there was no alteration to suspension geometry as had been discussed in this thread.

I thought perhaps it was the 37s input on because it wasn’t doing this after the lift only after the tires did I notice it. Are you running larger tires?

Very interested to know the current statues of your

You have a WT, the stock SAS tires are 55 lbs. each (super light for a tire that's 34.4" diameter). Depending on what 37s you went with, there is likely a huge difference in rotating mass. My 37" Trail Grapplers weigh 89 lbs. each. You're gonna get some big changes in feel.

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[NJNMDoc]

You have a WT, the stock SAS tires are 55 lbs. each (super light for a tire that's 34.4" diameter). Depending on what 37s you went with, there is likely a huge difference in rotating mass. My 37" Trail Grapplers weigh 89 lbs. each. You're gonna get some big changes in feel.

Agreed… I went with Falken ATW3s in 37/12.5/17. They only weight 74 lbs each. So not as dramatic as your TGs for sure but I certainly expect some alteration. That said I could honestly careless as long as I’m not fucking up the drive train by failing to address a significant problem or one in the making. Other than this singular issue (and a mild hit to MOG of course) I would do the perch collars on 37s 10/10 times over again.

 

[broncobase1]

From how I’ve understood it, 4A primes the transfer case to be ready at a given moment to engage the front driveline. Essentially the transfer case is engaged vs being just passive in 2H.

This would explain what you might be feeling.

I'm pretty sure 4A is not all or nothing. It can control how much torque is sent to the front and provides differential action so its not a solid connection like straight 4H. Its not simply switching between 2H and 4H.

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