What are my flexplate bolts hitting?

U8MYDZT

U8MYDZT

Wrong guy to follow
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I have been trying to narrow down a slight bottom end knock and decided to check out my flexplate bolts to make sure I wasnt chasing something simple before pulling the pan and inspecting the rod bearings. When I went to check the bolts they were all tight but 2 of the 4 showed signs of hitting something. (See pictures) one bolt even had a sizable shaving stuck to it (pictured as well) I don't see anything on the inspection cover and there is no noticable end play in the crank. What the heck could these things be hitting?
 
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The correct flex plate bolts have a special low profile head on them so they won't run into the torque converter. If yours were replaced with standard bolts that's a problem. I can't tell if the one in your photo has the correct low-profile bolt head or not.
 
Jerry Bransford said:
The correct flex plate bolts have a special low profile head on them so they won't run into the torque converter. If yours were replaced with standard bolts that's a problem. I can't tell if the one in your photo has the correct low-profile bolt head or not.
Click to expand...
Thanks for the response Jerry.
The bolts are indeed low profile. Well they were until hitting something and gathering extra metal on top... lol
 
Perhaps the torque converter wasn't pushed on all the way and twist-locked into place when someone had the transmission off?
 
Jerry Bransford said:
Perhaps the torque converter wasn't pushed on all the way and twist-locked into place when someone had the transmission off?
Click to expand...
I suppose. I have had the Jeep for about 1 month now and it runs and drive really good. Just have this pesky bottom end sound.
If I remember correctly, on a Chevy when the TC isn't fully seated it pretty well locks the engine and makes a terrible noise if started. How can I determine this on the Jeep. (Without pulling the trans)
 
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Think missing transmission bolts could be a problem.....
1571260147157.png
There are a couple bolts missing from the top of the transmission housing. Any chance you know the bolt sizes?
 
I had this problem but it only happened when I was off roading in the sand and the Trans overheated which caused the flex plate to warp enough for the bolts to hit the inspection cover. I installed a trans cooler, deep pan, and gauge to monitor the temp and it has never happened since. The earlier years the trans would get starved of fluid on steep hill climbs and most recommend putting a deep pan and extended pickup tube on the 32RH. So I think it was overheating because of being in the sand on a 90 degree day for hours doing steep hill climbs with 3.07 gears but I didn't have a gauge at the time to tell.
 
Well the one of the missing trans bolts has a broken bolt stuck in the hole and one of my flexplate bolts pulled the treads out of the TC before it got to torque spec. With this and a bottom end knock I my be pulling the whole damn engine and trans out to give it a once over...

Edit: Got lucky and was able to use a 8x1mm bottom tap to fix the stripped torque converter bolt.
 
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Yeah, so I really F-ed up. My bottom end knock is gone, but....
The 8x1mm bolt I used was just a little longer than the original and it was enough to bend the torque converter housing and destroy the torque converter and possibly the transmission.
When I first started the Jeep after installing the new bolt it made a funny sound like something was rubbing, then quickly went away. I figured it was just a fluke and drove it about 15 miles to a store then back home. Drove perfectly to the store without any funny sounds or feeling. Then on the way home (about 5 miles from my house) the Jeep began smelling like burning transmission fluid and was shifting funny, then just stopped moving all together. Now when I put it in reverse it makes a terrible sound and jerks as it moves. Going forward basically doesn't work at all. I am guessing I bent the torque converter housing in enough to damage it with the longer flexplate bolt (bolt was only about 1/8" longer than the original). So disappointed in myself............ 😢
 
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Well tomorrow is the big day... I will be pulling out my torque converter and swapping in a new one. The only TC I could find was from a company called Pro-King, it is the exact same one every auto parts store has and I am hoping it's correct. Here is the description: Torque Converter: 131 Tooth Wide Ring Gear; Contains Stator Bearing; Codes: 878, 879, 957, 875, 514, INK-131; Lock Up; 11 Inch Diameter; 23 Splines; 1.810 Inch Pilot; Slotted Hub; 4 Lug Mount; 10 Inch Bolt Circle; High Stall: 1690.
Does this look right for a 97 4.0? Also I have read you can get to the TC without removing the transmission completely, anyone tried this and know if it works?
 
Went thru a similar situation on my son's old XJ as there were quite a few that experienced this with torque converter bolts on the XJ's. We pulled his auto and found the main dust cover (the one you have to pull the trans to remove) was nicked by one of the bolts and basically destroyed. Sourced a new plate, bought a new converter and OEM bolts and it was good until he sold it last year.
 
U8MYDZT said:
Yeah, so I really F-ed up. My bottom end knock is gone, but....
The 8x1mm bolt I used was just a little longer than the original and it was enough to bend the torque converter housing and destroy the torque converter and possibly the transmission.
When I first started the Jeep after installing the new bolt it made a funny sound like something was rubbing, then quickly went away. I figured it was just a fluke and drove it about 15 miles to a store then back home. Drove perfectly to the store without any funny sounds or feeling. Then on the way home (about 5 miles from my house) the Jeep began smelling like burning transmission fluid and was shifting funny, then just stopped moving all together. Now when I put it in reverse it makes a terrible sound and jerks as it moves. Going forward basically doesn't work at all. I am guessing I bent the torque converter housing in enough to damage it with the longer flexplate bolt (bolt was only about 1/8" longer than the original). So disappointed in myself............ 😢
Click to expand...
ive been having an annoying tick related to flex plate bolts as well, its only an annoyance at this point and i can see the aluminum build up on the bolt heads (very slight on all 4). was about to pull the trans 2 weeks ago to try to figure out the issue but for fear of something like this i decided not to... glad i waited actually...

post lots of pictures and good luck!
 
Jerry Bransford said:
The correct flex plate bolts have a special low profile head on them so they won't run into the torque converter. If yours were replaced with standard bolts that's a problem. I can't tell if the one in your photo has the correct low-profile bolt head or not.
Click to expand...
Not sure how the head of those bolts would be hitting the torque converter??? Isn't the bolt pictured one of the bolts securing the flex plate to the torque converter??
 
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reddvltj said:
Not sure how the head of those bolts would be hitting the torque converter??? Isn't the bolt pictured one of the bolts securing the flex plate to the torque converter??
Click to expand...
correct.

torque converter is behind the flex plate deeper in the bell housing

they rub on the inspection plate or bell housing front cover near the top of the motor or something else in front of the flex plate...
 
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Bigmac said:
correct.

torque converter is behind the flex plate deeper in the bell housing

they rub on the inspection plate or bell housing front cover near the top of the motor or something else in front of the flex plate...
Click to expand...
I knew something didn't sound right there... The only bolt heads the TC would be able to come into contact with would be the flex plate to crank bolts... that would create a completely different problem...
 
reddvltj said:
I knew something didn't sound right there... The only bolt heads the TC would be able to come into contact with would be the flex plate to crank bolts... that would create a completely different problem...
Click to expand...
That's what I was thinking of. It was 13-14 years ago I installed my 32RH.
 
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Got the trans pan off and found a bunch of chit had clogged the filter to the point it had started to collapse, starving the trans of oil and stopped the Jeep from moving. Not exactly sure what the crap was. There were no metal flakes in the fluid or filter, just what appeared to be rubber or friction material, the fluid was clean and still nice and red.
I had a hell of a time finding a torque converer for my 97 32RH. The first one I got from O'Reilly's was incorrect ( Pro-King CR63 ) because it had the ring gear intergraded into it and mine has the ring gear on the flexplate. After a lot of research I ended up with one that is listed for a 42RH with a high stall ( Pro-King CR69 ). The CR69 has a 2400-2600 stall and an Offset bolt pattern. The offset bolt pattern wasn't that big of a deal, it just offsets one flexplate bolt and the original hole is easily elongated to accommodate. I did find one torque converter that would have worked without the modification to the flexplate (Pro-King CR90) but it had a lower stall rating of 2000-2200. I just figured I might as well upgrade if I am in there.
And I found the source to my bottom end noise and what my flexplate bolts were hitting. It was the upper dust cover. It was badly bent and had a huge gouge in it. Not sure how this happened, but at least it's fixed now.
I will have the transmission back in tomorrow and update on how things are going.
Here are some pics.
(Too deep!!)
20191019_150542.jpg

(Gouged dust cover)
20191020_125918.jpg

20191020_125923.jpg

(Fixed dust cover)
20191020_172112.jpg

(Pro-King Torque Converter catalog listing)
Screenshot_20191019-153118_Drive.jpg
 
U8MYDZT said:
Got the trans pan off and found a bunch of chit had clogged the filter to the point it had started to collapse, starving the trans of oil and stopped the Jeep from moving. Not exactly sure what the crap was. There were no metal flakes in the fluid or filter, just what appeared to be rubber or friction material, the fluid was clean and still nice and red.
I had a hell of a time finding a torque converer for my 97 32RH. The first one I got from O'Reilly's was incorrect ( Pro-King CR63 ) because it had the ring gear intergraded into it and mine has the ring gear on the flexplate. After a lot of research I ended up with one that is listed for a 42RH with a high stall ( Pro-King CR69 ). The CR69 has a 2400-2600 stall and an Offset bolt pattern. The offset bolt pattern wasn't that big of a deal, it just offsets one flexplate bolt and the original hole is easily elongated to accommodate. I did find one torque converter that would have worked without the modification to the flexplate (Pro-King CR90) but it had a lower stall rating of 2000-2200. I just figured I might as well upgrade if I am in there.
And I found the source to my bottom end noise and what my flexplate bolts were hitting. It was the upper dust cover. It was badly bent and had a huge gouge in it. Not sure how this happened, but at least it's fixed now.
I will have the transmission back in tomorrow and update on how things are going.
Here are some pics.
(Too deep!!)
View attachment 120938
(Gouged dust cover)
View attachment 120939
View attachment 120940
(Fixed dust cover)
View attachment 120941
(Pro-King Torque Converter catalog listing)
View attachment 120942
Click to expand...
thanks for the pics. now i know what mine looks like without having to pull it 😏
 
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