HYRYSC

Bit of history. I recently upgraded quite a few things with a 4.5" lift, SYE, new custom Adam's driveshafts front and rear, new pinion yokes, 4.88 gears lockers front and rear with a Detroit locker in rear. All of this has been done within the last few months. Gears and lockers were installed by local shop that only does gears, lockers, diffs, trannys etc.

SInce it has been pretty cool the last few days I have taken the jeep to work with the windows down. Never really noticed it before, but there is a noticeable clunk when shifting from park or reverse to drive and from drive to reverse. Is this normal and to be expected with these taller gears and Detroit locker?

andrewmp6

Normally that sound is from u joints but yours are new.But all i can think of is your rear axle angle up a lil for the sye or not ?It could even be the Detroits i have one in a car but the exhaust is so loud if never hear it if it does clunk like that.I would have a friend shift it in to gear with a foot on the brake while you stand next to the jeep and try to pin point where the sound is coming from.

Fred/N0AZZ

I would stop back by the shop that did the work (gears/lockers) for you and ask them about it. Could be several things from nothing to an adjustment of the locker or set the gear to spec if out.

salad

In addition to what's already been mentioned, sloppy engine and transmission mounts will contribute to this.

HYRYSC

Well guess I should have checked the Eaton site first.

Q: When I step on and off the gas pedal, I hear the unit make a "clunking" noise. Why?

A: Because Detroit Lockers have "backlash" or "slack" between the drive and driven teeth and you will hear this in everyday use going through corners and when going from drive mode to coast mode. Also with the vehicle on the ground and the transmission in neutral you will have 1\4 to 1\3rd of a turn of lash in the driveshaft, this is completely normal.

TRCM

All non-selectable lockers are like that......if the backlash or slack as they call it wasn't there, they'd never be able to unlock like they should/do. And they do so a lot more than most people realize.
That's why you hear it during turns, and when getting on & off the gas just like they said.


Checking engine & trans mounts tho is not a bad idea....as they will definitely make the 'clunk' worse.

The sliding joint on the driveshaft can also give you this same sound if there is any kind of wear ridge on it in the splined area. The small sound as it slips over this ridge is amplified by the driveshaft tube to the point you can hear it.

The Dodge in my avatar would do it so bad, you'd have to grease the slip joint every 2-3 weeks to keep it down until I finally got some custom denny's shafts made for it.


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