Shim Torque Converter?

EngineerDoug

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Hello all,

Got an easy question for you. I am about to bolt my torque converter to flex plate (727 trans), and observe the gap between the flex plate and converter is 0.245". My understanding is this is a bit too much? I've read the max gap should be 0.187", and that I should use some grade 8 washers between the flex plate and the converter. That would bring the gap to about 0.170" or so. It will reduce the thread engagement of the 7/16 ARP fasteners, however, but there is no way around that.

Does this all sound OK, or am I missing any considerations?

Thanks!
 

pnora

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Sounds Ok to me. You do not want to put shims between the converter lug and flex plate. As long as the converter pulls up to the flex plate bolt it down.
 

Don Frelier

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I'm no expert but it would seem to me that an extra 1/16th inch of engagement is next to nothing?
I'd bolt it up and drive it.
 

747mopar

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I've never heard of shimming a torque converter but I know all the ones I've installed had a decent bit of play.
 

steve340

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I have shimmed plenty of Chev converters. I set them to about 1/8 th of an inch.
Torque converters get shorter each time they are opened up and you have to compensate for this in some way.
I use hardened automotive washers between the converter and the flex plate.
I would use slightly longer grade 8 fasteners and trim them equally or use grub screws as studs. What ever you use it must all be of the same weight at each mounting point.
I think a quarter inch would be too much.
 

beanhead

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I must be missing something here...
If you think the gap between the two is too large now(.245) shimming between them will push them even farther apart...
Let the converter pull against the plate until it stops, and it's home...
The only way you could get them closer together would be to machine down the mounting lugs... although I have no idea why you would want to do that, unless you're afraid the converter isn't engaging the pump enough? I doubt that's an issue.
 

beanhead

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You are shimming the converter back in to the transmission.
Right, I understood what you were saying about converters being a little too short, but he was saying that he felt he has too large of a gap between them and he thought the gap should be made smaller..
 

69 GeeTeeX

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What torque converter and flex plate are you using? I'm assuming both are aftermarket with the larger 7/16" ARP bolts? Does the converter slide forward all the way against the flex plate like it's supposed too or is the converter hub bottoming out in the back of the crankshaft leaving a gap between the flex plate and converter bolt lug?
 

Fran Blacker

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If you do shim it I'd use hardened washers! Never measured depth of pump slots they must be more than 1/4".
 

Lefty71

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You are shimming the converter back in to the transmission.

Exactly, or to put it another way, "you are keeping the flats on the converter drive slot well aligned with the flats on the oil pump gear lugs". Winded, I know, but I think there could be a possibility of the 45 degree nubs on the end of the converter drive pushing hard on the oil pump lugs which could break them, or cause premature wear on the pump housing if the converter is too far out of the trans. I, personally have never heard of an issue tho, like, its only another 1/8".
 

steve340

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Lefty71 is right if you shim too far back you will bind everything up and that is no good.
I forgot this before in earlier post the converter should have 1/8 movement back after shims are installed.
I don't care whether it is a Chev, Ford or a Mopar pull that converter too far forward and see what happens.
 

Lefty71

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Got an easy question for you. I am about to bolt my torque converter to flex plate (727 trans), and observe the gap between the flex plate and converter is 0.245". My understanding is this is a bit too much? I've read the max gap should be 0.187", and that I should use some grade 8 washers between the flex plate and the converter. That would bring the gap to about 0.170" or so. It will reduce the thread engagement of the 7/16 ARP fasteners, however, but there is no way around that.

Like many answers i'd say "it depends". If you are doing a stock type rebuild on a street only car, then I'd not worry about the shims. If you are doing a car where it's higher power and will see some abuse, then your best bet may be to pick up an SFI approved flex plate. That unit does'nt cost too much at all for neutral balance applications, and the flexplate is a much nicer, slightly thicker unit, which will probably put you right back in the sweet spot with the engagement. Also, keep in mind, if a car is going to see some abuse with a cheapie converter that may balloon, the that clearance will be eat up quickly, and may be a completely different measurement the next time you tear it down!!

HTH, Lefty71
 

Nevada dan

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If you think you need to shim a torque converter you’re overlooking the real problem causing it and your going to have a failure
 

Curiousyellow71

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On a mopar your messing w the ring gear depth for the starter engagement. I can't think of any case on a mopar to shim it unless something is totally custom.
 

66Satellite47

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Do you have a problem with the converter hub not sliding into the crank all the way? I have had to sand the paint off the converter hub to get it slide into the crank properly. Just a thought. I've had many converters and many flex plates, never used any washers.
 

440Coronet500

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I've never shimmied the flex plate torque converter bolted joint on any Mopar. Never removed one that had shims either. Pull the torque converter tight against the flex plate and bolt it together! 440'
 

pnora

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Do not shim it there is absolutely no reason to do so. I have never used shims or ever saw shims. Working in a dealership I have seen thousands. Plus if it was a recognized repair shims form Mopar would be available. Shoving washers between the converter lug and flex plate is a hack job. I don't care how you view it.
 

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