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Rattling

JNickel101

NAXJA Forum User
Location
Alamogordo, NM
Ok...so I have this annoying rattling sound coming from my jeep....sounds like marbles or a loose bolt rattling around.....I finally got around to laying under it with a rod and trying to pinpoint the sound, and it is the loudest/most noticable from the back of the engine/bell housing of the transmission. I took off the inspection cover and checked the bolts on whatever it is under the cover (flex plate?). I checked everywhere with the rod that I could think of...doesn't appear to be coming from the oil pan, or the timing cover...nor the valve cover. Definitely loudest from the bell housing area.

Any other ideas? Thanks in advance...

J
 
Mine did the same thing. Turned out to be the Catalytic Converter. I am not recommending you do this, since it is illegal, but I solved it by cutting the cat off and running a straight pipe to my flowmaster. To check to see if it's the catalytic converter, get under it and shake the hell out of the cat. I recommend kicking it, since it will be hot.
 
Nope, I know what a cat rattling is....it isn't that. This sounds like there are a handfull of marbles rattling around inside the engine....but the sound pinpoints to the bell housing of the tranny. Took the inspection cover off and started it up, was definitely a bit more noticable....
 
that sounds like a cracked flexplate.
putting the trans in drive to load the engine should quiet or change the rattle if the plate is cracked.

every cracked plate sounds a bit different, mine was worst when cold, and progressively grew worse rattling all the time even coasting in drive.
 
It's possible that one of the flex plate to torque converter bolts came out. I had the exact same problem on a 91 that I had. Take of the panel at the front of the bell housing and take a look inside.
 
do you know how many bolts are supposed to be in there holding the two together?

Thanks guys. How could I tell if the flex plate is damaged/cracked? I had the inspection cover off last night and didn't see anything out of the ordinary - checked all the bolts (that were in there) and they were all tight.
 
4 tc bolts
6 crank to flexplate bolts
mine had no visible sign of cracking, even when a prybar was used
didnt deflect, or make a noise when pried on

3321066599_ba88540cc6_b.jpg



3321066011_e2203f3b31_b.jpg


The crack went around the outer edges of the 6 bolt holes, and the 4 tc bolt holes were wallowed from an earlier loosening incident after an engine swap
the new one is torqued to spec on all fasteners, and for good reason
 
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Awesome, thanks for the pictures. I was really hoping to avoid pulling the transmission, but it looks to be the only way I'll know for sure....
 
let me know if you go ahead with it

pulling the trans is the minor part!

the driveshafts, exhaust, wiring, TC shifter, center console, console shifter and fluid lines, that was the beehatch.

Anyone who says its a weekend job...is real fast and even dirtier.
 
FML...
 
I dropped a manual transmission and did a clutch over a weekend... What does that make me? lol

If the XJ is lifted or you can get it up high enough on jack stands or 4 ramps.. I dont think dropping a transmission is that bad. I would definately recomend a floor jack (more or less a requirement) and a transmission jack adaptor if you dont have it already. I did it w/o one and wished I had it the whole time. haha.

Edit: I still remember the first and 2nd clutches I did... One on an old ford pickup and one on an explorer... Well we had to change/drop the transmission multiple times for the exploder... Once for clutch, once for a blown output shaft... each time with either of those vehicles our jack was a rope around the transmission (up through the hold in the floor) and a small bottle jack towards the rear of the transfer case. God it was alot easier to do it with an actual jack :D
 
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