Hi all
Well I am back from my holiday which I was sick for most of it with Dengue fever.
Anyway I went down today to watch my motor on the dyno as they put it back together while I was away. They found no vibrations at all. It did Max torque 410 ftlb @ 3900 rpm and 362hp @ 5150 rpm.
So here I go chasing vibrations again. I am going to check my transmission shaft to crank alignment.
One thing the dyno shop pointed out was the nose of the converter is bottoming out in the back of the crank when bolted up to the flexplate. They recommended spacing the converter back giving a 2mm clearance in this area and maintaining a 5mm pump clearance.
My question is, could this have been causing the vibration if the converter was bottomed out and not able to run true? I have attached a video of the uneven marks worn on the converter throat.
Cheers
http://www.youtube.com/watch?v=kBjnjn_svZ0&feature=youtu.be

 

Hmmm after pondering the question a bit, I dont think that could cause a vibration (bottomed out TQ in the crank) BUT maybe something to check is the run-out of the input shaft, if it has any discernible run-out it could cause the vib and the marks that the seal has left. (Kind of grasping @ straws here, someone else jump in)

 

Try and borrow a converter for testing..

 

so you hit 1 hp per cubic inch with a very mild cam and a smaller style dual plane intake... Nicely done!

3900-5150.. Thats a nice sweet spot and it wont kill parts. Did she hang on after that in the pull or fall off sharp? If she dropped flat or went fat measure your retainer to guide clearance and shim the springs a bit.

I've asked this question a couple times and you didn't reply ( you had a lot on your plate so no biggie but it's important) EXACTLY what front damper and pulley are you using. Post a pick.

That wear isn't correct IMO. She's walking on you.

What is the TC from? And exactly what flex plate are you using. Can you post a pic?

 

Flex plate cracked maybe?

 

Thanks guys
After I find the vibration I might chase a bit more HP. I will post the dyno sheet when they email it to me as I just have a hard copy at the moment. My cam specs show a max range of 5400 rpm from memory.
The front dampener I am using was the one that came with the engine. I am using the magnum serpentine belt set up.
http://i1081.photobucket.com/albums/...0/59581128.jpg
The converter is a 2800 stall dacco. It has 90 degree feet so it bolts up in any position. It is neutrally balanced. You can see in the photo there is a tiny weight to balance the converter.
http://i1081.photobucket.com/albums/j351/maca110/IMAG0588.jpg
http://i1081.photobucket.com/albums/j351/maca110/IMAG0586.jpg
Here is a pic of my flexplate.
http://i1081.photobucket.com/albums/j351/maca110/IMAG0589.jpg
One concern is the bolts for the converter are very small. As you can see in the video with the bolts in there is a lot of movement. I could drill and tap the holes bigger but once the nose of the converter goes into the crank it self-aligns and the bolts just fasten the flexplate. So I don’t think this would be the cause.
http://s1081.photobucket.com/albums/j351/maca110/?action=view&current=VIDEO0070.mp4
The dyno shop pointed out that the converter when fastened is bottoming out in the crank. They suggested there should be a 2mm gap in there. I have enough pump space to allow me to space the converter back if needed. Maybe with the converter too far forward, as revs pic up it cannot self-align and the centrifugal force is trying to pull the converter back. Seems unlikely though.
I think the most likely problem may be the shafts are not aligned. I friend suggested to check it with a dial indicator on the crank as the photo shows below.
http://i1081.photobucket.com/albums/j351/maca110/6rt3dg.jpg
http://i1081.photobucket.com/albums/j351/maca110/vrbnvd.jpg
Does anyone know if the converter is supposed to be hard up in the crank or not.
Cheers maca

 

The flex plate looks like it is for an externally balanced motor. It has weights at the top and one large one at the bottom.



The balancer is a wierd one that also looks like it is a externally balanced one.

 

BINGO. You have a weighted front dampener and flex plate on an internally balanced engine. Originally she was weighted at the front pulley and dampner assembly and flex plate.

You can not separate the pully. They are pressed in and can NOT be separated.

Pull that and take it to the machine shop over there. They can throw it in a lathe and neutral her out. Cheapest way I can see to do it with your shipping costs.

Knock the weights of the flex plate.

Vibration will be gone.

 

I thought 360 magnum motors were externally balanced. When i had mine checked they did not internally balance it. They just checked it. When they did this they took the whole rotating assembly including the dampener and flexplate. When it came back they said it was only very slightly out. Not enough to cause a vibration. That was where they drilled the 2 shallow holes in the weight on the flexplate to get it exact.
So it should be externally balanced still as it was out of the factory.
When it was run on the dyno they ran it with the flexplate.

 

They are. You are correct. In your opening post you mention neutral balance tc. Which we all know doesn't fly with the LA motors in the 360. And some magnums were balance on the TC too. When they went to 46RE tranny from the RH they went to balance on the flex plate.

So your TC is neutral and all should be well.

I have a neutral TC from an 01 RT 5.9 in the shop. If you want to mic some measurements there and PM them, I will get a TC down and measure to compare.

 

Thanks PK1
I really need to know when the torque converter is bolted to the flexplate should there be a gap in the back of the crank or is it ok to bottom out in there. I phoned 2 transmission shops and one said yes and one said no.
I measured from the face of the crank where the flexplate sits against to the bottom of the whole in the crank.
Then i measured the converter with the flexplate attached. I measured from the face of the flexplate where it bolts to the crank to the top of the nose of the converter.
The converter measurement was 1mm longer which means it is bottoming out by 1mm. So if i need a 2mm gap in there i will have to space the converter back by 3mm
If you have a complete crank-converter-flexplate there that you could measure from that would be greatly appreciated.
cheers Maca

 

If the front dampener & flex plate were both balanced with the motor They should be fine. That still doesn't solve your problem The converter snout should NOT bottom in the crank even .010- .020 clearance should be enough. I don't even know if it would fit? Could it have an LA 360 crank ? Maybe a missing factory spacer ?
Going back and reading You mentioned the Tq bolts were smaller than the holes? Everyone is just throwing out ideas

 

This first sentence still confuses me.

"This is my externally balanced 360 magnum. Neutrally balanced converter."

 

All 360 were external balance.

The magnums started with weights on the TC but went to a flex plate / reluctor wheel weighted setup when the 46RE tranny replaced the 46RH. So those set ups take a neutral TC ( like a 318 / 5.2 motor).

BM made a flex plate specifically for the 727 / mag conversion but it was for strength and is discontinued.

MACA,

measure those bolts / threads and hub OD and send the info and I will pull one from the shop and make sure they are same. Not sure it will help but at least we can eliminate parts issues.

 

My understanding from this thread is Maca has a vibration and couldnt fix it no matter what he did. Spent money on new trans/TQ combo and still had vibration. Now with all the pushrod issues etc out of the way, run up on dyno with HIS flexplate/balancer etc he has no vibration. That being said i would have someone spin up the TQ to make for SURE its neutral balance. I am thinking (not a good thing sometime lol) that he stated that his flex plate WILL bolt to TQ in ANY position (the 90 degrees thing). Is it POSSIBLE that the TQ is NOT Neutral (as we CAN see a small weight) and that the positioning of the TQ/Flex is "off"? Bolt it together has vibration, un bolt TQ rotate 90 try again etc until the proper position is reached?(Maca did you TRY this?) Just tossing it out, as I HAVE worked in trans shops as an R&R guy and some vehicles the TQ would only bolt onto flex plate in a certain position.IF he has BIGGER holes than bolt size that would be a reason that the flex will bolt in any position. I would try and check the TQ to make SURE the mounting holes are symmetrical as he is thinking, or if asymmetrical but the bigger holes 'let' it work. Now I am not for sure if you would get a vibration from a 'bottomed-out' TQ but I would try and space it back for sure. (1 flat washer per bolt between the TQ and Flex would be more than enough - just my quick and dirty way I would do it )

Maca how big of a vibration were you getting? a big one, small one, does it get worse as RPM increases, or stay the same? All kind of important in the way I am thinking. (there i go again lol)

Oh and another thought on the pic of TQ is that it being bottomed out, IF it wasnt totally SQUARE in the crank, it would leave the tail-tell sign on the pump drive collar.

 

Maybe, doubtful, but maybe, but who knows? But see my quick and dirty fix above...

 

That is a good idea. Once its back together if the vibration is still there i will try the flexplate/torque converter in different spots to see what the vibration does. I am taking the converter to a converter shop tomorrow to show them the marks on the snout and see what they say.
cheers

 

Hey guys
I should have the motor back together and running this weekend. I will let you know how i go.
If anyone knows a bit about transmissions please have a look at my post.
cheers
https://moparforums.com/forums/f62/p...843/#post88998

 

For jeeps try 1993-1995 5.2L Grand Cherokee. My book shows a 46RH gasket available for these.

 

did you try summit racing for that M-1
those plugs are oily wats up with that your engine burning oil
i use champions my new motor 318 comp cams edelbrock intake air gap i just fix a oil burning situation that arised about 800 miles i check the valve seals and 2 failed on the exhuast side of the head 6-8 go figure the head shop said it happens i found a torn boot and the other had scratches at the lip maybe he doesnt like mopars
but my plugs were soo even mmt fouling it looked painted i never had such a clean even set of plugs

 

summit racing has a nice selection
Mopar Performance Single Plane Intake Manifolds
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$237.95 - $364.95

 

Hi all
I am putting the motor back in today after having the motor dyno done and I had my converter balanced again. Fingers crossed please

 

Well the motor is back in and I tested it.
The vibration remains.
I feel like I am fighting the alien ship from the movie Independence Day. They nuke the ship and when the smoke clears the soldier say The Target Remains.
At least the motor is running allot better and actually sounds like it has a cam now.
I am out of ideas so I am going to just live with it.
Thanks For all the help and advice.
Cheers maca

I am running it at The Mopar drags this weekend so what ever is vibrating might just fall off.

 

When you get bored try another flex plate. Also make sure your driveshaft is balanced.

 

hey guys
i need to change my lifters in the magnum. Can i get them out by just removing the manifold or do the heads have to come off too.
cheers

 

Manifold off, heads stay on.