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Please try this with your XJ and tell me results?

Even with the trans and/or tcase in neutral there's still enough "drag" throughout the system though fluid and friction of other parts to cause things to turn when no resistance is applied to them.

Agreed. The way a torque converter works, it is always applying some load to to the input shaft even in neutral. I've had cars at work I've left running in neutral that will actually forcefully creep forward. What you saw with the output shaft spinning I would say is completely normal.
 
It's getting confusing with you running two threads on this. Yes, it is perfectly normal for the transmission output to freewheel a little bit in neutral when nothing is holding it.

Yeah...I'm trying to stick to this newer thread...I just needed to respond to dsbhealer over there cuz he had suggested the front diff test over there.
 
you are almost on to something here.
"My feeling that an un-braked input shaft in Neutral could cause the problem is based upon the momentum of the spinning input shaft in Neutral vs. no momentum of stationary input shaft in Reverse or Drive. Not saying it's necessarily the problem or that such a braking mechanism even exists...only saying that it fits the symptoms because pausing in Neutral is what causes the clunk/lurch to occur."
To make 1st gear forward clutch and low reverse clutches are applied.
To make reverse, direct clutch and low reverse are applied.
In neutral none of those are applied. forward and direct are driving clutches, low reverse is a holding clutch. IF the driving clutch comes on before the holding clutch, you get a harsh apply.
now when you pause in neutral you give the low reverse time to fully release . so you get to drive and the forward clutch comes on 1st, you get a bunch of trans parts spinning and then the low reverse clutch comes on and stops them from spinning CLUNK . Going the other way into reverse the direct and the low reverse timing is a better. So don't pause in neutral.
 
you are almost on to something here.
"My feeling that an un-braked input shaft in Neutral could cause the problem is based upon the momentum of the spinning input shaft in Neutral vs. no momentum of stationary input shaft in Reverse or Drive. Not saying it's necessarily the problem or that such a braking mechanism even exists...only saying that it fits the symptoms because pausing in Neutral is what causes the clunk/lurch to occur."
To make 1st gear forward clutch and low reverse clutches are applied.
To make reverse, direct clutch and low reverse are applied.
In neutral none of those are applied. forward and direct are driving clutches, low reverse is a holding clutch. IF the driving clutch comes on before the holding clutch, you get a harsh apply.
now when you pause in neutral you give the low reverse time to fully release . so you get to drive and the forward clutch comes on 1st, you get a bunch of trans parts spinning and then the low reverse clutch comes on and stops them from spinning CLUNK . Going the other way into reverse the direct and the low reverse timing is a better. So don't pause in neutral.

I'm not understanding how the clunk/lurch would occur, due to the above, with the transmission output shaft held stationary by the vehicle. Wouldn't that prevent the transmission parts (other than the input shaft) from spinning?
 
I'm not understanding how the clunk/lurch would occur, due to the above, with the transmission output shaft held stationary by the vehicle. Wouldn't that prevent the transmission parts (other than the input shaft) from spinning?

Did some more thinking...are you saying that when the forward clutch engages, it merely connects the input shaft to the guts of the transmission, and those guts ("spinning parts") are not connected to the output shaft until the low/reverse clutch is engaged?
If so, then I think you may have found my problem.
Unplugging the TCU doesn't help...any idea what might cause the forward clutch to (prematurely) engage before the low/reverse clutch?
Any idea how my transmission rebuilder (and also a 2nd transmission shop) could have missed this?
 
Been studying my AW4 manuals...the DIAGNOSIS CHART shows many possible reasons for "HARSH ENGAGEMENT FROM NEUTRAL TO DRIVE OR REVERSE", but if I eliminate the ones that involve driveshafts, differentials, etc. and the more obvious ones that have been checked by multiple mechanics (such as motor mounts, which I will recheck), this is what is left:

Band Misadjusted - Adjust rear band.

Valve Body Check Balls Missing - Inspect valve body for proper check ball installation.

Clutch, band or planetary component Damaged - Remove, disassemble and repair
transmission as necessary.

Converter Clutch Faulty - Replace converter and flush cooler and line before installing new converter.

When the transmission/torque converter were rebuilt (in an attempt to solve the "clunk/lurch after pausing in Neutral" problem), the first thing that the shop owner mechanic tried was to swap in what he called a shift kit, and that didn't solve the problem.

If my transmission had entered the shop with a check ball missing, would the shift kit installation necessarily solve that problem, or does the shift kit just use my existing valve body, such that the always-missing check ball could have been overlooked when the shift kit was installed? In other words, could the mechanic have just assumed that the check balls were all present without looking it up, and then tried out the shift kit with the that check ball missing?

And if that check ball was missing, would my transmission be able to function perfectly in every other way (as it always has), or would there be other noticeable problems besides just my "clunk/lurch after pausing in Neutral" problem?

I have complete AW4 manuals, including valve body check ball locations and also color hydraulic flow diagrams, so eventually perhaps I can figure it out, but if anyone out there already knows these answers...please let me know.
 
And is the converter entirely ruled out?
 
And is the converter entirely ruled out?




He posted earlier (not sure which thread) that the transmission and t/c had been professionally rebuilt and replaced. It's not a common failure mode, but if the clutch inside the t/c is damaged and binding up when it's not supposed to, you'd see heavy engine loading when put into gear. If the transmission guy actually rebuilt the trans and at least inspected the t/c, that should have been obvious (and probably self destructed sometime since he originally poted this a year ago).





He also said those same pros ruled out the easy stuff like motor mounts, high idle speed, throttle body cable, which in my mind are still prime suspects. (How about some pics, btw?) If the mounts have never been replaced they're probably bad and the exhaust pipe is banging against something.



He has also apparently eliminated the rear diff, as the symptom persisted with the rear drive shaft removed and the xfer case in 4-high.



I kinda wish he lived out this way, as I'd love to have a look at this in person.
 
He posted earlier (not sure which thread) that the transmission and t/c had been professionally rebuilt and replaced. It's not a common failure mode, but if the clutch inside the t/c is damaged and binding up when it's not supposed to, you'd see heavy engine loading when put into gear. If the transmission guy actually rebuilt the trans and at least inspected the t/c, that should have been obvious (and probably self destructed sometime since he originally poted this a year ago).
He also said those same pros ruled out the easy stuff like motor mounts, high idle speed, throttle body cable, which in my mind are still prime suspects. (How about some pics, btw?) If the mounts have never been replaced they're probably bad and the exhaust pipe is banging against something.
He has also apparently eliminated the rear diff, as the symptom persisted with the rear drive shaft removed and the xfer case in 4-high.
I kinda wish he lived out this way, as I'd love to have a look at this in person.

I have to periodically remind readers that as long as I do not pause in Neutral, the problem doesn't occur. If it also shifted harshly into Drive without pausing in Neutral then that would greatly expand the possibilities for the problem source.
I've never driven an AW4 before, but to me it performs flawlessly in every way (including lock-up and kick-down functions of the torque converter) as long as I don't pause in Neutral. Shifts are all harsh compared to my Buick, but I'm told that this is normal...that the AW4 is just a relatively harsh shifting transmission. Additionally, all the pros that have driven it agree that it is normal in every way except for this one single problem.
I'm going to post videos of the engine and mounts, and it would be great if the mounts were the problem, but since they've been looked at by numerous mechanics, whereas the transmission was only looked at by one mechanic (the rebuilding mechanic), I'm figuring the odds of something being overlooked in the transmission are higher than bad motor mounts being missed by the bunch of mechanics. But then that's coming from someone who is just now starting to learn about the AW4...for all I know there may be no possible way that the AW4 could ONLY exhibit the very limited problem that I am experiencing. Hoping to hear from an AW4 expert...otherwise, I'll be doing a lot of studying for a while.
 
Honestly.
my jeep has always clunked into drive. figured its a normal AW4 thing.
Its considerably worse on hills.
Been that way for 13 years.
I have never even considered it not normal.
 
Somehow his XJ is special. My current XJ fleet is comprised of 3: 1998 with 284,000 miles, 1998 with 165,000 miles, and 2000 with 126,000 miles. All three clunk now and then, same as the other 5 XJ's I have previously owned.

Been that way for 16 years. I have never even considered it not normal.
 
Somehow his XJ is special. My current XJ fleet is comprised of 3: 1998 with 284,000 miles, 1998 with 165,000 miles, and 2000 with 126,000 miles. All three clunk now and then, same as the other 5 XJ's I have previously owned.
Been that way for 16 years. I have never even considered it not normal.

Tim...you've been very helpful to me in the past (cruise control, etc.) and you always made sure that you understood the problem before commenting, so I just don't understand why you and others keep insisting that you have experienced my XJ's problem while simultaneously describing a totally different problem. I get that all XJ's clunk. That doesn't mean that ALL clunks are benign and normal.
If you and others can't explain why mine only clunks when standing still and after a pause in Neutral, or at least demonstrate that MANY XJ's only clunk when standing still and after a pause in Neutral, then how can you declare it normal?

I removed the drive shaft. and hopefully that will prevent people here from continuing to insist it's the rear end, at least.

I've asked before and I'm asking again...no, begging...for anyone who thinks my XJ's problem is normal to PLEASE move on to another thread and leave me alone. PLEASE!
 
Post video of your noise/clunk from inside and outside the vehicle,i cant remeber if you've done this already.

I still think you're hyper analyzing this problem and there's actually no problem other than this vehicle was designed well before stringent NVH standards of today's cars.

Ill go do your shifting test in a little bit.


Sent from my SM-G892A using Tapatalk
 
Post video of your noise/clunk from inside and outside the vehicle,i cant remeber if you've done this already.

I still think you're hyper analyzing this problem and there's actually no problem other than this vehicle was designed well before stringent NVH standards of today's cars.

Ill go do your shifting test in a little bit.

Sent from my SM-G892A using Tapatalk

If you went to buy an XJ tomorrow, and you mentioned to the seller that the XJ clunk/lurched rather violently whenever you paused in Neutral before shifting into Drive (but not when you shift quickly from Reverse to Drive), and his answer was just "then don't do that", would you still pay the same price for that XJ as for one that didn't have that unexplained "quirk"?
That is one reason that I need to diagnose this problem...any buyer who has ever driven an XJ would either immediately walk away from this one or would require at least a $1000 discount on the price...if they are smart.
If the clunk/lurch did NOT disappear without a pause in Neutral, in other words if it clunk/lurched no matter how you shifted into Drive, then, if I were unscrupulous, I could just tell a novice buyer that "all XJ's do that" (violent clunk/lurch when shifted into Drive) and a novice buyer might believe it...but I guarantee that anyone with XJ experience would say "no they don't". How do I know this?...because my XJ exhibits normal shifts into Drive as long as I don't pause in Neutral...so I KNOW how an XJ is supposed to shift into Drive...I KNOW what normal is. And the violent shifts into Drive on my XJ after pausing in Neutral aren't even in the same ballpark as the smooth shifts without pausing in Neutral.
If you don't believe me , why don't you believe the professionals that all agree that this is not normal. Two of them were Jeep dealership technicians during the XJ's most popular years...are all these mechanics just insane?
Why do I have to keep explaining this?
If you believe that it is normal, just move on to the next thread...why are you wasting your time (and mine) in this thread. Go help someone who you feel has a real problem...please!
 
All 3 auto XJs ive owned have exhibited some kind of clunk/lurch when shifting into drive. If i test drove yours and i felt it was normal in comparison to my previous experience i wouldnt think anything about it.

Youve been chasing your tail on this issue for what a year or 2? If your intention is really to sell it why expend all this time/effort/stress for a little extra money?

Im on my way out to the garage now ill shoot some.video of the test you want done.

Sent from my SM-G892A using Tapatalk
 
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Here ya go. I think its opposite of yours. even though i got less noise on the N to D shift the noise was reduced the lurch still felt the same. But that will be subjective to whos in the seat.

Also i rebuilt the tcase about a month ago and it had a horribly loose chain. I dont remeber any excessive noise but i also could have just been ignoring it because it was so loose it was jumping the spockets inside the case. And before i had it it waw a garage kept street jeep. Very little if any off pavement work. Still had a stretched chain.

http://youtu.be/PNGhN05is_w

Sent from my SM-G892A using Tapatalk
 
Here ya go. I think its opposite of yours. even though i got less noise on the N to D shift the noise was reduced the lurch still felt the same. But that will be subjective to whos in the seat.

Also i rebuilt the tcase about a month ago and it had a horribly loose chain. I dont remeber any excessive noise but i also could have just been ignoring it because it was so loose it was jumping the spockets inside the case. And before i had it it waw a garage kept street jeep. Very little if any off pavement work. Still had a stretched chain.

http://youtu.be/PNGhN05is_w

Sent from my SM-G892A using Tapatalk

Thank you. Mine always consistently shifts just as smoothly as yours, as long as I don't pause in Neutral. This is what I predicted, but your video confirms it.
Yes, I could just take a big hit on my selling price, but if it's something (missing check ball in transmission?) that I can fix economically, I'd rather do that. I don't mind investing the time.
If readers of this thread had just done my test (or not), which is all I requested (see thread title) instead of arguing with me about its need, this whole thread would have been only a fraction of a page long.
Thanks again for doing the test.
Now I'll get a bunch of posts questioning its need, again, undoubtedly...but now that my question has been answered, I won't need to try to discourage them, anymore. Thanks again.
 
if it's something (missing check ball in transmission?) that I can fix economically, I'd rather do that. I don't mind investing the time.


A missing check ball, even though the symptoms didn't change after a transmission rebuilt, including replacing the valve body? You seem intent on finding some very rare failure mode of the AW4 that no-one here has seen.



If you're still convinced it's inside the transmission or the torque converter, go pickup a used AW4 and t/c and swap them in. They can be had used for under $200. Do you have the means to do a transmission swap?


Personally, I'd start with looking at the easy things that have already been suggested. Get underneath and try to locate the noise. Is the exhaust hitting something? Is your idle rpm too high. Adjust the trans cable instead of quoting mechanics who were obviously wrong. Motor and transmission mounts if original are probably shot. They're relatively cheap and easier than pulling the transmission. Rent or buy a gauge and check the transmission hydraulic pressures per troubleshooting guide in the fsm you have.
 
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