440 / 727 engine shake.
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440 / 727 engine shake.
Okay and now for today’s transmission challenge, and this one is driving me up the wall. This will take a while but I will get to the point.
I have a 1973 Chrysler New Yorker ~ a demo derby rescue, the car was way too good to trash. When I bought the car the exhaust system was a ruin and had a blown exhaust manifold gasket. The transmission was a bit hit and miss and the engine needed a good tune up.
So in brief I installed a rebuilt 727 tranny and new torque convertor, hung a compete new exhaust system on the car, fixed the manifold gasket, sorted a few ignition system ills and installed a new 4 barrel carb. The car now runs very well but…
I’ve got an engine vibration, mostly noticeable at low rpm and feels like a dead cylinder though that is not the case. I’ve replaced the whole ignition system end to end. All cylinder compressions are 140psi, all cylinders are firing and the exhaust note is regular with no dead beats audible. Engine is a standard 440 with cast crank.
The only thing I can think of is that the torque converter is the wrong one for this engine, the tc that came out of the car was externally balanced with a single balance weight fitted at the 9 o’clock position – this when viewing the tc from the drive plate side with the drain plug at 12 o’clock.
I need to confirm the position of the balance weights on the new tc but I know they (2 of them) are not at 9 o’clock. I managed to get hold of some 1975 tc data sheets and they list tc #3515282 for the cast crank 440 in 1973, the tc that came out of the car isn’t listed anywhere.
I am not looking forward to pulling that tranny out again, but if I must. Are there any tranny experts out there who can confirm the correct tc for this year 440 please ?
I have a 1973 Chrysler New Yorker ~ a demo derby rescue, the car was way too good to trash. When I bought the car the exhaust system was a ruin and had a blown exhaust manifold gasket. The transmission was a bit hit and miss and the engine needed a good tune up.
So in brief I installed a rebuilt 727 tranny and new torque convertor, hung a compete new exhaust system on the car, fixed the manifold gasket, sorted a few ignition system ills and installed a new 4 barrel carb. The car now runs very well but…
I’ve got an engine vibration, mostly noticeable at low rpm and feels like a dead cylinder though that is not the case. I’ve replaced the whole ignition system end to end. All cylinder compressions are 140psi, all cylinders are firing and the exhaust note is regular with no dead beats audible. Engine is a standard 440 with cast crank.
The only thing I can think of is that the torque converter is the wrong one for this engine, the tc that came out of the car was externally balanced with a single balance weight fitted at the 9 o’clock position – this when viewing the tc from the drive plate side with the drain plug at 12 o’clock.
I need to confirm the position of the balance weights on the new tc but I know they (2 of them) are not at 9 o’clock. I managed to get hold of some 1975 tc data sheets and they list tc #3515282 for the cast crank 440 in 1973, the tc that came out of the car isn’t listed anywhere.
I am not looking forward to pulling that tranny out again, but if I must. Are there any tranny experts out there who can confirm the correct tc for this year 440 please ?
Mopar Lover
Joined: Nov 2007
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I'm not familiar with specific numbers, but here's a few rambling thoughts:
Six pack 440's WERE externally balanced. I'm not sure, but I think 400's are.
The point being, be very suspicious of EVERYTHING until you check it out.
I assume this exhibits the problem in neutral, so that you've eliminated drive shaft vibration?
have you troubleshot the problem with the belt(s) disconnected to eliminate them?
If you get "down to it" I'd suspect anything. has the engine been rebuilt, and is it possible that some odd crank/piston combo has been used?
I'm not familiar with how the converters are balanced, but it seems reasonable to suspect that a weight(s) is / are missing
Six pack 440's WERE externally balanced. I'm not sure, but I think 400's are.
The point being, be very suspicious of EVERYTHING until you check it out.
I assume this exhibits the problem in neutral, so that you've eliminated drive shaft vibration?
have you troubleshot the problem with the belt(s) disconnected to eliminate them?
If you get "down to it" I'd suspect anything. has the engine been rebuilt, and is it possible that some odd crank/piston combo has been used?
I'm not familiar with how the converters are balanced, but it seems reasonable to suspect that a weight(s) is / are missing
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440 / 727 engine shake.
Thanks 440, this a std 440 with cast crank, the engine is original and has the correct stamping.
From what I've managed to dig up, all 440 forged crank engines use an unweighted torque convertor, all cast crank use a balanced version.
This vibration occurs when parked so my newly rebuilt drive shaft isn't putting me shame.
I disconnected all belts, no change. Replaced motor mounts ~ ghastly job ~ and tranny mount, no change. Replaced the whole ignition system, compression tested (more fun), nothing.
Both the old and new tcs are Mopar items, the weights are between .5" and 1" in length thin steel plate (1/16th) and are welded to the outer case of the tc.
I have 3 remaining strategies for this:
Confirm the correct tc, infuriatingly the Mopar tech doc I have published in 75 does not list the tc that came out of the car with weights in that position, there are 4 tc options listed depending on year.
Negate the balance weights on the new tc by gluing the same size weights to the tc face and depending on the outcome, adding another weight at the originals 9 o'clock position, this might give me some pointers.
Unmount the new exhuast system from its hangers and prop it on wooden blocks to eliminate any engine bending stresses from the equation. I have a Mopar tech doc that describes this as a potential problem for cars of that era.
If these all come up with squat, I need to look into the harmonic balancer, though it looks in good shape. Last candidate is valve gear, 140 compression alround doesn't mean each cylinder is getting fed and exhausted properly, a slightly worn cam lobe, bent rod or lazy lifter could be play a part here.
Sheeshhhh......I hate this job.
From what I've managed to dig up, all 440 forged crank engines use an unweighted torque convertor, all cast crank use a balanced version.
This vibration occurs when parked so my newly rebuilt drive shaft isn't putting me shame.
I disconnected all belts, no change. Replaced motor mounts ~ ghastly job ~ and tranny mount, no change. Replaced the whole ignition system, compression tested (more fun), nothing.
Both the old and new tcs are Mopar items, the weights are between .5" and 1" in length thin steel plate (1/16th) and are welded to the outer case of the tc.
I have 3 remaining strategies for this:
Confirm the correct tc, infuriatingly the Mopar tech doc I have published in 75 does not list the tc that came out of the car with weights in that position, there are 4 tc options listed depending on year.
Negate the balance weights on the new tc by gluing the same size weights to the tc face and depending on the outcome, adding another weight at the originals 9 o'clock position, this might give me some pointers.
Unmount the new exhuast system from its hangers and prop it on wooden blocks to eliminate any engine bending stresses from the equation. I have a Mopar tech doc that describes this as a potential problem for cars of that era.
If these all come up with squat, I need to look into the harmonic balancer, though it looks in good shape. Last candidate is valve gear, 140 compression alround doesn't mean each cylinder is getting fed and exhausted properly, a slightly worn cam lobe, bent rod or lazy lifter could be play a part here.
Sheeshhhh......I hate this job.
Mopar Lover
Joined: Nov 2007
Posts: 2,424
Likes: 248
A quick and dirty way to eliminate the engine is to do this:
make sure it is tuned good, running smooth, warmed up good and adjust idle for good smooth idle. If you are running "lots" of advance, temporarily run advance back to no more than 5 or 8 BTC, and set idle for a good smooth idle, maybe 700 or so.
Now, take a test tach that you can REALLY READ with a wide scale, and do a "cylinder balance." simply use a wire to ground each plug at the distributor tower. One way to do this is simply pull the dist. boots, and use a probe between the wire and tower, or (pre) loosen the wires so you can pull one at a time. GROUND the tower as you pull the wire to prevent cross-fireing.
This should show up imbalance.
It might also pay you, before doing radical surgery, to find someone who has a good leak down tester. You can make them, but getting the proper orifice is questionable.
Just Google home made, "leak down tester"
Personally, I would concentrate either on incorrect engine internal parts or the torque converter.
It certainly is possible that exhaust could cause this, especially in these cases where these cars are old and parts have been modified/ changed, etc over the years. If you are using non-standard hangers in the exhaust, I'd take a good look at them.
make sure it is tuned good, running smooth, warmed up good and adjust idle for good smooth idle. If you are running "lots" of advance, temporarily run advance back to no more than 5 or 8 BTC, and set idle for a good smooth idle, maybe 700 or so.
Now, take a test tach that you can REALLY READ with a wide scale, and do a "cylinder balance." simply use a wire to ground each plug at the distributor tower. One way to do this is simply pull the dist. boots, and use a probe between the wire and tower, or (pre) loosen the wires so you can pull one at a time. GROUND the tower as you pull the wire to prevent cross-fireing.
This should show up imbalance.
It might also pay you, before doing radical surgery, to find someone who has a good leak down tester. You can make them, but getting the proper orifice is questionable.
Just Google home made, "leak down tester"
Personally, I would concentrate either on incorrect engine internal parts or the torque converter.
It certainly is possible that exhaust could cause this, especially in these cases where these cars are old and parts have been modified/ changed, etc over the years. If you are using non-standard hangers in the exhaust, I'd take a good look at them.
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Thanks, well you're certainly going all the places I've been, I balance tested with a digital tach before I changed the engine mounts, all cylinders show the same rev drop 
.
Now someone did email me a photograph this morning of the TC that is listed for the cast crank 440 engine, it's one of the TCs I have Mopar tech drawings & specs for and clearly shows balance weights welded to the front face of the TC. Neither the old or new TC has those weights.
I believe the weights on these TCs are the TC balance weight not engine balance weights, the pictures I got this morning also have a TC balance weight in addition to the engine balance weight, so now it's starting to make a little sense.
So....the bottom line is that this is a cop motor and the NYPD used to cruise around in sky blue sun roof New Yorkers in 73 or more likely, both TCs are wrong. The one and only owner died shortly after I bought the car so no recouse to information there.
My next plan is to make up a pair of the correct balance weights and Gorilla glue them to the TC in the correct position next weekend. They should hold on long enough for me to determine if this is the problem. If that is it, I'll weld them on with a heat sink.
If anyone wants a copy of the drawings and specs for these TCs drop me a line and I'll post it somewhere.
.Now someone did email me a photograph this morning of the TC that is listed for the cast crank 440 engine, it's one of the TCs I have Mopar tech drawings & specs for and clearly shows balance weights welded to the front face of the TC. Neither the old or new TC has those weights.
I believe the weights on these TCs are the TC balance weight not engine balance weights, the pictures I got this morning also have a TC balance weight in addition to the engine balance weight, so now it's starting to make a little sense.
So....the bottom line is that this is a cop motor and the NYPD used to cruise around in sky blue sun roof New Yorkers in 73 or more likely, both TCs are wrong. The one and only owner died shortly after I bought the car so no recouse to information there.
My next plan is to make up a pair of the correct balance weights and Gorilla glue them to the TC in the correct position next weekend. They should hold on long enough for me to determine if this is the problem. If that is it, I'll weld them on with a heat sink.
If anyone wants a copy of the drawings and specs for these TCs drop me a line and I'll post it somewhere.
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Mopar Torque Convertor Specs.
Sorry guys, been busy dropping the rear end out of my Jaguar...more fun than any single person should have in a lifetime. If you ever have to do that job let me know, if nothing else I can give you a good list of unique expletives and at which point to use them.
I have the Mopar TC specs, these are a set of Mopar engineering diagrams with the balance weight dimensions and their location on the TC face. They were given to me by an ex Mopar engineer I came across by accident. I'll scan them tomorrow and post them here.
And I still haven't found the cause of this vibration, I'll be installing new tranny cooling lines tomorrow and will investigate further.
I have the Mopar TC specs, these are a set of Mopar engineering diagrams with the balance weight dimensions and their location on the TC face. They were given to me by an ex Mopar engineer I came across by accident. I'll scan them tomorrow and post them here.
And I still haven't found the cause of this vibration, I'll be installing new tranny cooling lines tomorrow and will investigate further.
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440/727 engine shake
year one shows 3 different size weights welded on either side of the torque drain plug. I have 2 sizes. One size was 1/4''. I once seen a set of these weights on e-bay for $55. I paid around $200 for a cast 440 harmonic balancer. Another idea is a cracked or warped flexplate.
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i have never ran into a TQ "weight" problem. ive never bothered with making sure the TQ is in time with the flexplate/crank. 68/70-71/and the 6pak do have different rods in pin height. but as far as i know the six-pack is the only fat rod. when a flexplate cracks it "usually" cracks in the web. i wont argue with your cuz, they are a very strong tranny when cared for. they do make stronger aftermarket flexplates
Last edited by 66sportfury; Feb 4, 2009 at 09:32 PM.
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From: Edmonds, WA
I know this is an old post ...However...
The easy way to resolve that issue, or at least nail it down, had nothing to do with the engine and how it was running. It was all about the Torque converter. He stated in the first post that he had changed the TC. In his second post I think it was, he stated that it didn't match the original, therefore it was NOT going to be balanced the same as it was before. It didn't matter if it was externally or internally balanced, it was now OFF
Here's what I would have done. Since there is no alignment hole to match up to on the flex plate, I would have removed the inspection cover, removed all four of the TC bolts and taken a pen and marked the converter with an arrow to show which way I was going to turn it, and marked the flex plate & converter with a mark to show the original location. Then I would have rotated the converter only (Not letting the flex plate rotate...only the converter) in the direction of the arrow by 90 degrees so the next bolt hole came in to view and lined it up and bolted it to the flex plate with just 2 bolts 180 degrees apart (reduces the work and keep the bolts balanced as well.)
Repeating as necessary until the correct balance position is found. It was VERY possible that he had installed the new TC out of position for THAT new TC. Since it didn't match, it may have needed to be in a different position either 90, 180, or 270 degrees off from the where it was.
That's what I would have done is his position. if NO good balance spot was found, then he needed a different TC.
I'm currently in the process of doing a complete and total tear down and rebuild of a 78 440. It current;y has a cast crank, but I will probably changing that to a Forged and have it all internally balanced utilizing the Professional Products (brand name) Harmonic dampener which comes with weights of you need them, or you run it without weights for internally balanced. At the Machine shop, I'm going to have the entire rotating assembly, Crank, dampener, flex plate and TC balanced with the dummy weights for the rods, pistons, pins and rings on the crank as well. This will be a good true balance. This wasn't an option for this guy. Sadly, he never posted what his final resolution was.
Mopars Live...
Richard
Here's what I would have done. Since there is no alignment hole to match up to on the flex plate, I would have removed the inspection cover, removed all four of the TC bolts and taken a pen and marked the converter with an arrow to show which way I was going to turn it, and marked the flex plate & converter with a mark to show the original location. Then I would have rotated the converter only (Not letting the flex plate rotate...only the converter) in the direction of the arrow by 90 degrees so the next bolt hole came in to view and lined it up and bolted it to the flex plate with just 2 bolts 180 degrees apart (reduces the work and keep the bolts balanced as well.)
Repeating as necessary until the correct balance position is found. It was VERY possible that he had installed the new TC out of position for THAT new TC. Since it didn't match, it may have needed to be in a different position either 90, 180, or 270 degrees off from the where it was.
That's what I would have done is his position. if NO good balance spot was found, then he needed a different TC.
I'm currently in the process of doing a complete and total tear down and rebuild of a 78 440. It current;y has a cast crank, but I will probably changing that to a Forged and have it all internally balanced utilizing the Professional Products (brand name) Harmonic dampener which comes with weights of you need them, or you run it without weights for internally balanced. At the Machine shop, I'm going to have the entire rotating assembly, Crank, dampener, flex plate and TC balanced with the dummy weights for the rods, pistons, pins and rings on the crank as well. This will be a good true balance. This wasn't an option for this guy. Sadly, he never posted what his final resolution was.
Mopars Live...
Richard
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440 / 727 engine shake
I think the 4 t/c bolts are offset; only bolts on one way.seen the dude computer balancing a motor. that probably costs a pretty penny. These cars are real precision machines. Flexplates supposedly give them more power; I would bet the flexplate is what shakes when the car is started. Three possibilities for the shake in my car. wrong flexplate, wrong t/c weights or a steel crank. A challenge to fix without spending a barrel of money.
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