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bigmal

Chasing a Vibration - Flex Plate?

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I don't recall the history of your engine mal, is it stock or rebuilt, did you ever have a flex plate for it?

On mine, even with the 28oz imbalance, a weight was added to balance. So a stock FP may or may not work. 

If your motor is stock, I'd just bolt up a stock FP.

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1 hour ago, RPM said:

I don't recall the history of your engine mal, is it stock or rebuilt, did you ever have a flex plate for it?

On mine, even with the 28oz imbalance, a weight was added to balance. So a stock FP may or may not work. 

If your motor is stock, I'd just bolt up a stock FP.

I don't know anything about it other than a 351 4V Cleveland with electronic ignition (unknown type), 600 Holley and Edelbrock Performer. Seems reasonably tight and no smoke. It does have a strange lumpy idle that appears like it may have a cam but I'm not sure.

I'm pretty sure I will change the cam so I know what I have. I have a reconditioned set of 2V head to put on and an Edelbrock Performer manifold. The flex plate on it is the one it came with. I recall it was marked with felt pen '351 Windsor' so it has been changed at some point. I have no history on the car at all so I have to work it out as I go. At least if I rebuild the engine and get it balanced I will know exactly what I have.

Still a little nervous that the vibration may end up being the torque convertor but have been told that they don't get out of balance. I have no idea how they work or if they could get a build up of sediment etc. Any thoughts?

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10 hours ago, DocWok said:

Seems like you've already made up your mind, but if it were me and the motor runs ok, I'd just buy a 28oz flex plate and try it.

It's a lot of extra work to get a engine balanced when it may not be necessary.

That's what I would do as well.  If replacing the flex plate doesn't work,  you are only out a Saturday of your time it took to change it.  If the current flex plate came from a wrecking yard there's a chance it's the wrong one.  Plus after you open the motor it could snowball and you'll be into it for a few thousand dollars or so. 

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2 minutes ago, 1969_Mach1 said:

That's what I would do as well.  If replacing the flex plate doesn't work,  you are only out a Saturday of your time it took to change it.  If the current flex plate came from a wrecking yard there's a chance it's the wrong one.  Plus after you open the motor it could snowball and you'll be into it for a few thousand dollars or so. 

I hear you. I just don't want to do it twice. The vibration is bad enough I don't enjoy driving it as much as I should. As I will have the motor and transmission out I will probably make my final decision once the heads are off. Also a good opportunity to fix some oil leaks.

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I would've removed the torque converter and start it to eliminate the TC. I understand the work involved as I've R&I'd the trans over 10 times chasing my issue. 

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3 minutes ago, RPM said:

I would've removed the torque converter and start it to eliminate the TC. I understand the work involved as I've R&I'd the trans over 10 times chasing my issue. 

Unfortunately, I have a different firewall as part of the RHD conversion and there is no access to the bell housing bolts. I have to take the engine/tranny out together. I have some other tidying up to do while it's out so not a big deal.......... this time.

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1 hour ago, bigmal said:

Still a little nervous that the vibration may end up being the torque convertor but have been told that they don't get out of balance. I have no idea how they work or if they could get a build up of sediment etc. Any thoughts?

not enough sediment to cause your excessive vibration. in the us, you can also get a torque converter balanced.

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3 minutes ago, barnett468 said:

a clevo...oh please let us make it haul ass for you.

I wish I had a decent budget. Unfortunately it will be a very limited build. Springing for a cam will be a stretch.

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Well, engine out and this is the plate. Tomorrow (yesterday for you guys) I will strip the engine and take the lot for balancing. Fingers crossed he will say it was way out. I don't see any  point in replacing the flex plate at this point as it will get balance with the crank. Unless you guys suggest otherwise????????

IMG-0486.JPG

IMG-0485.JPG

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For the relatively low price of flex plates, I'd get a new one and make certain it is correct for your motor before balancing.  Just think of the problems that can occur if the flex plate later needs to be replaced.

I know the machine shop should catch it if you have the wrong combination of parts.  But if they don't and try to balance the assembly you bring, you can yell and scream and blame them all you want.  But, bottom line, the damage will be done and a small mess made worse.  One that you will likely have to straighten out.

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Thought I’d give an update on the progress. Been a little slow due work and family but back into it during my 6 weeks of Christmas holidays.....and yes I’m bragging.

the balancer said while there was some minor balancing needed he didn’t think it would cause noticeable vibration so hoping the rebuild will happen to jag a fix. I spoke to my transmission guy and the torque converter overhaul shop and they were confident that it wouldn’t be the TC. They showed me how to flush it and there was no metal so looks like it’s not that.

Have retained the Crane cam, fitted overhauled 2V 58cc heads and Edelbrock Performer manifold. Decided do go rebore to .020. New pistons, rings, bearing, lifters, valve springs and some other bibs and bobs. Compression is 10.1:1. Hoping to see some improvement off the mark With the changes . 

Started assembly but now sitting on a plane to Cairns for a week hunting snakes with my young bloke so a weeks delay on finishing.

If I still have a vibration it looks like the transmission which is on its way out but fingers crossed I have jagged it withe the engine build.

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On ‎6‎/‎23‎/‎2018 at 9:55 PM, RPM said:

Hey Mal, I've chased a cyclical vibration since I got mine running over a year ago. I changed a bunch of parts including, wheels & tires, rear pumpkin, drive shaft, trans mount, all 4 rotors, and wheel bearings. My vibration only occurred when power was put thru the trans to the rear.  I read were a guy had removed his OE trans dampner and thought I'd locate one to replace the one "somebody" tossed out during teardown. I solved the vibration by reinstalling the trans vibration dampner.

1110246872_c4vibrationdampner.jpg.dcc60f4dd9d4e4e8f08097181d26b950.jpg

The vibration returned a couple of weeks later. It is rpm sensitive, and occurs more frequently with 3.25 gears than 2.50 gears. 

 

Mustang Steve has replaced everything but the car body trying to chase his vibration. All of the vibration threads I've followed have a lowered stance, and/or a T5 swap involved. I believe the vibrations are due to drive line angles, until proven otherwise. I have not found the answer...yet.

 

Best of luck buddy.

I to have a Cyclical Vibration on my 69, Car has a 4R70W Swap and is Lowered  with 4.5 leaf mid eye springs in the rear and cut coils in the front.

I used Joe Persads trans swap bracket, trans has been gone through 2 times just to check for issues, brand new high speed balanced driveshaft, which I had checked locally after purchase and was found to be dead on, New rear Axle housing with new Axles, bearings Etc... chunk was rebuilt by me and then checked later on by local board member who builds rear ends for a living, and also swapped my 3.50s for 3.73's, have checked and changed the pinion angles MULTIPLE times from Plus to minus and nothing seems to make it get any better or worse LOL.

So now I have decided that the car is probably a bit to low because I drag Power steering brackets, mufflers, headers, etc... So I am going to install the Air Ride Air over Leaf bags and instead of having to remove a leaf like they say I will just use the bags to lift the car to the desired ride height in the back, there by smoothing out the ride and giving me some ground clearance, and as a Side benefit I am HOPING that as it nears a closer to stock ride height maybe the vibration I have will go away, and if it does then I will be able to say that with 100% certainty the vibration was due to ride height and drive line angle... I will also of course be installing bags on the front, but right now for $279.00 the air over leaf set up will allow me to not only get the ride height up like I want but will also allow me the chance to see if that is whats causing my vibrations. 

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 Just for info, my vibration is back, or never left. Imho, I believe it comes from lowering the car. I can't recall a vibration thread coming from a Mustang at stock height. But, I've been wrong before. 

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3 hours ago, MikeStang said:

I to have a Cyclical Vibration on my 69, Car has a 4R70W Swap and is Lowered  with 4.5 leaf mid eye springs in the rear and cut coils in the front.

I used Joe Persads trans swap bracket, trans has been gone through 2 times just to check for issues, brand new high speed balanced driveshaft, which I had checked locally after purchase and was found to be dead on, New rear Axle housing with new Axles, bearings Etc... chunk was rebuilt by me and then checked later on by local board member who builds rear ends for a living, and also swapped my 3.50s for 3.73's, have checked and changed the pinion angles MULTIPLE times from Plus to minus and nothing seems to make it get any better or worse LOL.

So now I have decided that the car is probably a bit to low because I drag Power steering brackets, mufflers, headers, etc... So I am going to install the Air Ride Air over Leaf bags and instead of having to remove a leaf like they say I will just use the bags to lift the car to the desired ride height in the back, there by smoothing out the ride and giving me some ground clearance, and as a Side benefit I am HOPING that as it nears a closer to stock ride height maybe the vibration I have will go away, and if it does then I will be able to say that with 100% certainty the vibration was due to ride height and drive line angle... I will also of course be installing bags on the front, but right now for $279.00 the air over leaf set up will allow me to not only get the ride height up like I want but will also allow me the chance to see if that is whats causing my vibrations. 

If you are standing still and leave the trans in park then hold the engine at around 2500 rpm, does it still have the vibration?

 

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4 hours ago, RPM said:

 Just for info, my vibration is back, or never left. Imho, I believe it comes from lowering the car. I can't recall a vibration thread coming from a Mustang at stock height. But, I've been wrong before. 

You might be on to something there.  But how much is your car lowered?  Mine is lowered 1-1/4" to 1-1/2" with 5 leaf mid-eye rear springs and 600 lb./in. front coils from Mustangs Plus.  It doesn't have any vibration issues.  But I am still using the top loader 4sp trans.  Back in 1980's my older brothers 69 Mach 1 was also lowered about 1-1/2" and it had no vibration issues.  But again that car still had the original FMX trans.  Is it maybe a combination of a lowered car and a trans swap to a later model overdrive trans that is longer than original?  Just guessing, I don't know.  I honestly never had to chase those types of issues.

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Thanks for the suggestions. I have stock rear springs although probably sagged. Front has 1" lowered springs. As the vibration is/was at 1600 rpm +/- 100 and also vibrates in neutral I am not thinking it will be related to lowering. I have finished the rebuild and will have it running in the morning as soon as I get a new oil pressure sender as I damaged it tuning it in.

Fingers crossed I will be posting a very excited 'vibration is gone' post. But I'm not confident.

And Barnett, yes I did have it balanced a second time after the rebore. Thanks.

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On 12/28/2018 at 6:57 PM, barnett468 said:

If you are standing still and leave the trans in park then hold the engine at around 2500 rpm, does it still have the vibration?

 

Nope... My vibration is not engine or trans related.... I can hold any RPM in neutral and its smooth... my engine is also Zero balanced so it's not a balancer or plate issue and vibration was there b4 and after I had motor freshened up.

In case anyone wondered what 4.5 Leaf Mid eyes with 275/40/18 looks like in terms of ride height..here it is

 

20181218_194518.jpg

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Mike, do you know your best friends 69 crank and pinion angles, or can you get them? Looking at the pic of your 69, ours sit the same. However, my exhaust doesn't scrape speed bumps or driveways. 

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