1955 Willys strange noise

[BlaZeus]

This is my 1955 Jeep Willys I got a couple months ago. Its got a 4.3L Chevy carb'd V6 with a th350 trans and a twin sticked np205 transfer case. Ever since I got it and even before that Its had the weirdest clunking noise at random times. This particular moment was when the rear wheels were off the ground, put in drive, accelerated to shift through all the gears and then put on the brakes. Immediately after the wheels stop this clunk happens. Cant really tell where its coming from but it sounds like the trans. Stumped as to what this could be....and ideas? Thanks!

 

[PWagon]

The video you posted is not viewable. It's set to private, and no one can view it. Can you make it public?

 

[Justin V]

Is this your first 350 trans?. With no video, I am not sure what clunk, but my old th350 would make a noticeable sound (wouldn't call it a clunk though) as it dropped back into 1st while decelerating, such as rolling up to a red light.

 

[diesel4me]

Might be the driveshaft splines --I've had some with wear that would not let the yoke slip on the splines freely,and when you let off the brake after a stop,it would suddenly slide back in the yoke with a "whump" you could feel through the floor..

I'd check the engine and transmission mounts as well..

 

[PWagon]

I've experienced a similar issue, and it turned out to be worn out u-joints. Have you checked yours?

 

[BlaZeus]

The video you posted is not viewable. It's set to private, and no one can view it. Can you make it public?

Is this your first 350 trans?. With no video, I am not sure what clunk, but my old th350 would make a noticeable sound (wouldn't call it a clunk though) as it dropped back into 1st while decelerating, such as rolling up to a red light.

Might be the driveshaft splines --I've had some with wear that would not let the yoke slip on the splines freely,and when you let off the brake after a stop,it would suddenly slide back in the yoke with a "whump" you could feel through the floor..

I'd check the engine and transmission mounts as well..

already checked and tightened trans mounts.
fixed the vid...sorry about that.

 

[diesel4me]

Loose torque converter bolts maybe ?..or a cracked flex plate..

 

[Justin V]

Loose torque converter bolts maybe ?..or a cracked flex plate..

X2.

Also, that is definitely not the sound that I was referring to in my early post.

 

[Kay86K5]

X2.

X3 to check. What makes me think it's this is the fact that the clunking sounds seems to mimic the sound of the exhaust (at least from what I can tell in the video)

 

[BlaZeus]

Loose torque converter bolts maybe ?..or a cracked flex plate..

X2.

Also, that is definitely not the sound that I was referring to in my early post.

X3 to check. What makes me think it's this is the fact that the clunking sounds seems to mimic the sound of the exhaust (at least from what I can tell in the video)

Thanks for the help!
I've checked out the flex plate before as that's where I kinda thought the sound was coming from and there's no bell housing but didn't really notice anything...I will look again today though. I will also be sure to tighten up the torque converter bolts. I'm guessing there's a torque spec for them?

 

[diesel4me]

Cracks can be hard to see in a flex plate with it installed and the tranny in place sometimes--usually they'll crack around the bolt holes..

I'd guess about 35 ft/lbs is about right for the converter to flex plate bolts..

You may be able to get that noise to happen,by holding the engine speed at a fast idle,and turn the key off,and just before it stops completely,turn it back on again--if you hear that clunking then its almost a sure bet its the flex plate or converter bolts doing it..

 

[Justin V]

Another thought has crossed my mind, and I hope this is not the problem.

I have seen about 3 or 4 4.3's with broken cranks. Only one quit running.

 

[BlaZeus]

Another thought has crossed my mind, and I hope this is not the problem.

I have seen about 3 or 4 4.3's with broken cranks. Only one quit running.

CRAP. Yeah I tightened up all the flex plate to torque converter bolts, the torque converter to trans bolts and it still knocks. I listened closely and it sounds like it's coming from inside the torque converter???

 

[Kay86K5]

CRAP. Yeah I tightened up all the flex plate to torque converter bolts, the torque converter to trans bolts and it still knocks. I listened closely and it sounds like it's coming from inside the torque converter???

Flex plate bolts that attach to the crank....obviously the only way to check those is to remove trans. My brothers flex plate broke right there on his 6.0/4l80e combo...it happens

 

[diesel4me]

If the flex plate has cracks, the tightness of the bolts may not matter,the two now separate pieces of the plate slap against each other--..
It also could be the internals of the converter,or perhaps the front pump,but you'd likely notice other issues with shifting ,slippage,etc too,if that were the case--the crankshaft is a long shot, but nothing is impossible..

I have seen the converter "snout" fail to seat properly in the hole in the crankshaft too,and that will make the converter want to wobble and stress things,make noises,and eventually hog out the front pump seal and or the pump itself..often "forcing" a tranny in place using the bolts in the bellhousing to draw it onto the engine results in misalignment and can cause these issues too..

If the engine came from a vehicle with a manual transmission,the pilot bearing had to be removed in order for the converter snout to seat right--sometimes someone tries cheating and just pounds the bearing or bushing in till it bottoms out in the crank,instead of removing it-and that doesn't leave enough room for the converter to seat properly..

Another thing--the other end of the converter that slides into the tranny's front pump has two "slots" cut into it,which engage lugs on the pump and drives it,if those became worn or sloppy,that can lead to noises and eventual pump failure..

Here is a photo to show why the bolts being tight may not stop the noises--

 

[BlaZeus]

Another thought has crossed my mind, and I hope this is not the problem.

I have seen about 3 or 4 4.3's with broken cranks. Only one quit running.

Flex plate bolts that attach to the crank....obviously the only way to check those is to remove trans. My brothers flex plate broke right there on his 6.0/4l80e combo...it happens

If the flex plate has cracks, the tightness of the bolts may not matter,the two now separate pieces of the plate slap against each other--..
It also could be the internals of the converter,or perhaps the front pump,but you'd likely notice other issues with shifting ,slippage,etc too,if that were the case--the crankshaft is a long shot, but nothing is impossible..

I have seen the converter "snout" fail to seat properly in the hole in the crankshaft too,and that will make the converter want to wobble and stress things,make noises,and eventually hog out the front pump seal and or the pump itself..often "forcing" a tranny in place using the bolts in the bellhousing to draw it onto the engine results in misalignment and can cause these issues too..

If the engine came from a vehicle with a manual transmission,the pilot bearing had to be removed in order for the converter snout to seat right--sometimes someone tries cheating and just pounds the bearing or bushing in till it bottoms out in the crank,instead of removing it-and that doesn't leave enough room for the converter to seat properly..

Another thing--the other end of the converter that slides into the tranny's front pump has two "slots" cut into it,which engage lugs on the pump and drives it,if those became worn or sloppy,that can lead to noises and eventual pump failure..

Here is a photo to show why the bolts being tight may not stop the noises--View attachment 212010

I think I may found the problem...took the bolts that connect the flex plate to the torque converter out and am seeing that the holes look to be pretty ovaled out.

 

[Justin V]

Pull all of those torque converter bolt out, push the converter back (should move about a 1/4" back) and see if that flexplate has slop at the crank. Loose bolts there or broken flexplate should be evident

 

[BlaZeus]

Pull all of those torque converter bolt out, push the converter back (should move about a 1/4" back) and see if that flexplate has slop at the crank. Loose bolts there or broken flexplate should be evident

That's exactly what I did. I started it up and the flex plate was wobbling quite a bit. Will try and post up a video soon.