Pop on acceleration - been troubleshooting and still no luck

[NitroRC Ed]

First off - yes I've searched quite a bit and have gone through a bit of replace and work on the Explorer in trying to locate this pop issue.

So I've got the pop on acceleration issue not all the time of course and doesn't matter if going straight or on a corner from a stop. If I ease on the gas pedal it will not pop but if I give it a bit more then I can get the pop to happen.

-2 different transfer cases have been used - still pop
-front driveline had a bad U-joint but found a deal on a new one and swapped out - still pop
-replaced both CV axles - still pop
-had alignment done after messing with the Torsion Bars and shops said the front end looks pretty good for 273,x.. miles
-3 different sets of wheels (new and used) have been used over the last 7 years - still pop

Pop seems to happen up front on driver side - not necessarily up around the feet area but maybe it is. What i'm trying to figure out is if there is something in the front hub that could be slipping under heavier than normal acceleration or if it could be something in the transmission?

I'm running out of ideas.

Thanks in advance!

Ed

2000 Ford Explorer 5.0 AWD 273,x.. miles torsion/Warrior shackle lift and 31"

 

[swshawaii]

Slip yoke checked?

Clunks, Slip Joint, & Other Fun Stuff

 

[NitroRC Ed]

Have not checked the one on the rear driveline - didn't think of that one as the sound and feel sure seems to be more up front that behind me.

I can give that a check next though.

 

[swshawaii]

Check both front sway bar end links, especially if original. Amazing how much noise they can cause, even when they appear intact. Also inspect the sway bar frame bushings while you're under there. Won't cause popping, but squeak very loud when dry or worn.

http://www.moogparts.com/pdf/problemsolver/english/MOOG_PS_Bulletin_25471_K7275_En.pdf

Newer design with poly bushings (K700542)
http://fme-cat.com/livedocs/MOOG_PS_Bulletin_213006_Sway_Bar_Link_ENG-R.pdf

 

[NitroRC Ed]

Now that you mention it I think i did already replace the sway bar links with the blue Moog ones - though i should check to make sure they are not loose.

 

[bigred4x4]

Id check the rear leaf springs for damage, ball joints, control arm bushings, and torsion bar wear pads.

Also rear u joints, and front axle bearings for play at CV's and pinion yoke.

 

[Spudhut]

I had an Excursion that did the same thing.

Every time I pulled into my sloped driveway or hit a slight bump on the road, it would pop/bump. I got under it many times. Checked all that you mentioned. I eventually had my son drive up and down with it on the driveway while I laying under it and hunting for that pop sound (had 35's and 6" suspension lift).

The culprit was a large bracket that was welded to the frame that hung down for the sway bar links. It cracked all the way through from the frame. The ONLY way I could see that it was broken was when the suspension flexed and it caused a gap, but the metal was rubbing along the crack and popped in place when returning to its 'normal' position. Welded it up....sound was gone!

 

[Turdle]

Suspect #1 is the cv joint at the transfer case end f the front drive shaft. You mentioned replacing the u joint but I am referring to the other end. This is the number one cause of your issue as described.

#2 is the transmission mount. It may be flexing enough under acceleration to allow the transfer case to make contact with the crossmember skid plate. You might remove the skid plate (13mm bolts) to see if there is any evidence of contact on the top side of it.

 

[NitroRC Ed]

Suspect #1 is the cv joint at the transfer case end f the front drive shaft. You mentioned replacing the u joint but I am referring to the other end. This is the number one cause of your issue as described.

#2 is the transmission mount. It may be flexing enough under acceleration to allow the transfer case to make contact with the crossmember skid plate. You might remove the skid plate (13mm bolts) to see if there is any evidence of contact on the top side of it.

I did replace the front driveline with a new one - found a good deal online at 20% off and free shipping

I'll check the trans mount when i get a chance to climb under again.

The pop sound is ONLY heard under faster than normal acceleration - never when just driving around.

Thanks,
Ed

 

[bigred4x4]

One thing I learned is if it isn't hurting any thing there is no sense in throwing parts at something believe me i was on a quest to make my ex perfect as in no noticeable problems no matter how small and eventually learned it was a huge waste of time and money I'm to the point now with everything I've replaced, rebuilt, or repaired that the little stuff psh I'll deal with it when it breaks then you know exactly what it is,I have popping up front and a clunk upon going into gear and hard throttle from a stop that shouldn't be there with all the parts I've thrown at it. I've just realized that it is a 20+ year old SUV and it is not a brand new vehicle. I'm not trying to be a jerk, I'm just saying I wish I would have realized this sooner because my ex is one thing I've had no problem throwing money at Everytime I suspected an issue, drive it until it breaks then fix what broke, worst case it's a missed day of work and a tow truck bill which is better than countless hours and more money spent than you are willing to admit trying to work out and trouble shoot the little things and fix it before it breaks,I was this person not long ago until I realized it was a battle that is a constant uphill and not worth fighting in the end.......

Again I hope you figure out the issue as this probably seems way out in left field but to many people on here myself included get obsessed with the little things and don't get to fully enjoy there explorer, because they spend more time turning wrenches and visiting auto parts store, and researching, etc.... If it's something you can live with id say drive it until the problem becomes more obvious as far as the cause, if it ends up getting any worse.

 

[NitroRC Ed]

I've been living with it for a while and just take it easy on the gas pedal. I've got a teen that wants to start driving in a year or so and figure this is what shes going to start off with

 

[bigred4x4]

Well my first vehicle was actually an explorer lol not the one I have now but my old one has left me broke down I figure it's something most people will experience sooner or later as long as it's safe I wouldn't worry too much, sounds like something an experienced mechanic would have to look at in person to make the correct diagnosis one time I had this good awful noise when accelerating that I thought my torque converter was going to blow up at any time turned out to just be bad u joints on the rear drive shaft.