Cracked Flexplate / Loose Flexplate bolts?

[steveC]

The bolts holding the torque converter to the flex plate are a LOT smaller than 14mm. So are the bolts holding the flexplate to the crankshaft.

I think the reference we used here was to the head size, are you referring to the shank? The shanks on the TC/Flexplate bolts are M10x1.5, and should be abount 14mm long (more than this will bottom out, had that problem previously). The heads on the dealer bolts (I used p/n 34202497) are place-bolt style, and require a 15mm socket.

I just replaced some "substitute" bolts I had with the dealer ones a couple of days ago, so was just in there. And the red Loctite was pretty stiff...

 

[roscoecoltraine]

Wait...how does that knock go again?????? J/K Mine is actually doing the same thing, so does anyone know how much the flexplate should flex before I suspect its cracked?

 

[g0dz1ll4]

I've been doing research for the last week or two on this topic, as I was told by two reputable shops that my flexplate was probably cracked (based solely on symptoms - not firsthand observation). I was poking around tonight, trying to locate said cracks and decided to pull my starter just for grins, as I was not finding any cracks. After pulling the starter, I noticed that there was a gap of 3mm or so between my tranny and the engine - it turns out that the two lower engine bolts were not torqued and things were sagging. The noise disappeared after I tightened things up. Just thought I'd post it here for anyone else having a hard time locating the source of strange noises.

 

[cygnus58]

I am about to check out the same suspected problem.
I have an 89 Cherokee 4.0 which has developed a horrific knock- warm, at idle, new oil, pressure at 30 lbs, like something will poke it's ass thru the block at any moment.
I called the local Jeep servicer, and a totally cool Mech told me since it seems to quiet under load, and gets worse when warm, and TOTALLY, intermittently, DISAPPEARS AT TIMES, he has seen alot of flexplates cracked, which sound like an really bad internal problem.
I have read in many threads while searching this mysterious noise that i could get lucky, and just torque the TC bolts. I should be that lucky. Can't wait to crawl under tomorrow, and see if anything is visible.

 

[Townie]

I believe I have the same issue:

http://www.naxja.org/forum/showthread.php?p=243504376#post243504376

How difficult is it to inspect TC bolts? The noise grows louder :bawl:

 

[Yucca-Man]

How difficult is it to inspect TC bolts? The noise grows louder :bawl:

Take the inspection plate off, and you will see one, if not two, Torque Converter bolts. Torque, then rotate the TC to the next bolt. Re-do until all four are correct. Replace inspection plate / cover.

 

[dizzymac]

.....and check plate for cracks.

 

[cygnus58]

Still haven't "properly" checked it out. A guy I work with has a lift in his own garage and we will run it up on wednesday. I did crawl under and remove the access plate. Didn't see anything and didn't really pry too hard on anything. I did wrench the only bolt visisble which wasn't loose but as the TC turned a bit I heard a distinct click. I swear it was the same click I hear about 4-5 times a second at warm idle, only very quiet.

 

[iBarsky]

Had mine replaced on the '96 last year. Didn't have the time to do it myself. Th mechanic said the holes on the fp were "wallowed out". Allowed it to move around way too much.

 

[cygnus58]

Well, there were twoTC bolts loose, but that didn't fix it.
With the engine running, and the Jeep on the lift,
the sound is most definitely coming from the TC/flexplate area.
It goes in next Wednesday for the job...

 

[cygnus58]

Well $745.00 and a week later it is fixed.
It was cracked around the perimeter of the cranks bolts as I have read is usually where it occurs.
Now it purrs like the 19 year old kitten that it was...
(also had some suspension work done)

 

[cygnus58]

http://farm1.static.flickr.com/238/524066199_24f10bc31f_b.jpghttp://farm1.static.flickr.com/238/524066199_24f10bc31f.jpg

 

[lawsoncl]

Ouch!

So that was $45 for the new flexplate and $700 labor to pull the tranny, swap the flexplate and reinstall tranny? That's 10 hours labor at $70/hr. Should have been a two hour job with a quality tranny jack, or maybe three for an amateur like me. I think you might want to shop around for an honest mechanic for your future work.

 

[dizzymac]

Think he had some other work done too, but it still does seem high. I had my flexplate replaced and TC (242) swapped out for $350.

 

[cygnus58]

Work was done at a full service Mopar/Jeep dealership.
$91.00 for plate,
$19.00 for tranny juice,(of course this is high, I suppose I could have supplied my own??)
$28.37 for bushing kit
$90.00 for end link
$63.90 for two front stabilizer sway bar links
$18.00 labor for shift linkage sticking,
$420.00 labor @$60/hr for tranny in/out
The point is, when I was younger, I swapped out clutches, pressure plates,etc. in my own Mopars. ('70 Dart 340 swinger, '68 Coronet 440)
but I am in no position now to do such work myself.
I wish I could get have gotten the work done cheaper...
Did I really get ripped off considering they had me by the balls?
I couldn't "shop around" given I am a single dad, and this is my only ride.
Another more "friendly" garage couldn't get me in until mid-June, and given the increasing noise, it couldn't wait, unless no one would count the cost of a rollback in the total scenario.

 

[cygnus58]

any way you look at it, OUCH applies...
can anyone tell me what the bushing kit was?
part no. 18163...
sounds aftermarket?

 

[dizzymac]

I can see a dealer charging that price, they have a lot of "overhead". Mine was done @ a local shop during his slow season so I got a good deal. I didn't put any pressure on him timewise, had a second vehicle, but did the XJ back in two days.
I guess the main thing is you got your vehicle back, no more noise, and being a single dad you did the right thing and had the suspension fixed so now you have a safe, quiet , XJ .

 

[cygnus58]

My mistake,
the 90 dollar charge on the end links was for the labor not the part.
Seems like a long time to install 2 front stablilizer swaybar links.

 

[cygnus58]

first new full day driving, I decide to try accelerating now that the flexplate has been replaced.
on heavy acceleration around 3000 rpm the tach jumps wildly and engine misses terribly. does not backfire.
Is this a coincidence or can anyone suggest something that would have been done during the trans removal/replacement that would cause this?
It always reliably accelerated to 4000-5000 rpm smoothly before the repair.
please Help!!
'88 cherokee 4.0l
I am an amatuer but am guessing the flywheel position sensor would have been removed for the job. Would a coneection problem allow the engine to run smoothly except upon heavy acceleration?

 

[dizzymac]

Check the CPS. How is the noise issue now that the flexplate has been replaced?