Mrpatel
512Dart
What are your thoughts on checking runout and what would be considered acceptable?
Torque converter runout
- Thread starter Mrpatel
- Start date
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Duane
Well-Known Member
What is your concern here. I would think if you are locating the converter the same way as a manufacturer does it should be very close runout, say within a couple thou. Not sure that a three jaw chuck is that accurate, and I cannot tell from your pic if you have the snout end in a centre or not.
famous bob
mopar misfit
Not sure , but back in the day, I had a drivetrain out of a 68 hemi roadrunner. The convertor was no problem till I started using b-m j convertors, we had 2 of them w/ excessive run out, they would knock the seal and front pump bushing. B-M did repace them tho.
Don`t take much.
Duane
Well-Known Member
I have a new x block being mated to a newer 904 torque flite.
Because this trans has never been mated to this block, I indicated the pump bore of the trans off of the crank flange with stock dowels
In the block. The runout was .015 thou. Yes 15 thousands.
How many people check this. I used offset dowels from Mopar and got it down to .001. I have seen many people chase leaky seals,worn pump bushings, vibrations and even broken converter snouts, and when you ask them they have never checked trans alignment.
This trans and motor misalignment was the worst I have seen.
Problem is you have to have a gutted empty trans case t bolt on and check.
famous bob
mopar misfit
One reason I usually try to buy an engine w/ trans still attached , to rebuild, never had a problem except w/ the b-m convertors!
Duane
Well-Known Member
Agreed, but if you do not know the history, you gotta check.
transman
Well-Known Member
In any converter shop I've been in, converters being welded together and having the runout check are always mounted on a thick steel backing plate. This guaranteed they were square in the lathe. They are bolted to this plate via the mounting nuts or studs on the converter.
Run out is very limited.
You live in Ontario, I'd phone Pat at SMR transmissions, he's in Bradford, and the number there is 888-846-6603, and see what he allows for maximum runout on the converters they build. The shop I worked at is closed now, so I can't call them to give you their specs
Run out is very limited.
You live in Ontario, I'd phone Pat at SMR transmissions, he's in Bradford, and the number there is 888-846-6603, and see what he allows for maximum runout on the converters they build. The shop I worked at is closed now, so I can't call them to give you their specs
transman
Well-Known Member
This is NOT the way a manufacturer either welds a converter together or checks for hub runout. See my additional post.
transman
Well-Known Member
If you go to www.tcsproducts.com and check the shop tour button, and scroll through the photos, you can see the plate I've mentioned previously. A converter is mounted on the plate and is being welded together.
there is no way to grab that torque to get a accurate reading without using an index plate indexed to the lathe and then to the torque . maybe im not seeing the whole picture .
Mrpatel
512Dart
Thanks for the post guys. I am not performing the runout check, someone else is. This is how he checks for runout. I have access to a lathe a will look at the mounting plate idea. Here are a couple of other photos. I do not know enough about this process and how critical it is or isn’t, hence the post. He squares off at the mounting tabs and goes from there.
Duane
Well-Known Member
I agree with what you are saying, but you should be able to duplicate
A runout check. I would think as long as you used a dial indicater
And spend the time to get it concentric.
You could indicate off the flex plate mounting pads for squareness
And his lathe picture is showing to be clamped on the pilot of the converter. These are the same surfaces that locate the converter on the flex plate. Then the snout should run pretty accurate.
A dedicated converter manufacturer would have dedicated fixtures and jigs to do this in the essence of time but you should be able to duplicate that at home in a lathe.
Having said that there is also a reason there is a flex plate.
In compensates for some amount of inaccuracy within reason.
But no flex plate is gonna compensate for excessive inaccuracies in manufacturing. That's what he is checking.
Mrpatel
512Dart
Thanks for the input. That is exactly where I am at. Right now it is running out at .013” right out of the box. I am going to have someone else check it for a sanity check. I spoke to the manufacturer and they said it would be fine as is,
d55dave
Well-Known Member
I think the run out is a great idea. Perhaps a better way to mount the converter would be to cut the back off an old crank and use it with a flex plate, chucked up on the rear main?
I have often thought of this. I had a customer once bring me an unknown "performance " converter to put in his car. It looked like someone welded it together at home. It went together without issue and properly engaged the pump and input, but after a few days of driving it broke both drive lugs off the pump. I figure it had snout runout issues.
I have often thought of this. I had a customer once bring me an unknown "performance " converter to put in his car. It looked like someone welded it together at home. It went together without issue and properly engaged the pump and input, but after a few days of driving it broke both drive lugs off the pump. I figure it had snout runout issues.
Mrpatel
512Dart
Rechecked it today on a rotary table. .006” TIR (.007” on the motor side and .001” on the hub side) the tabs are from .000” to .020”
Duane
Well-Known Member
Since you have it setup on a rotary table, why not requalify the mounting pads with a light cut on the mill.
Mrpatel
512Dart
Next plan, pads are painted, so I will probably take a skim off on the lathe. I will remove the paint first. Not sure how much the flexplate is intended to absorb
If that comes in at .006 from one end to the other your good to go it aint getting any better than that .
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