Torque convert wear

what causes this kind of wear on the converter? The flex plate was tight and the converter bolts were tight.
I can feel about .010 on one side and nothing on the other.

Trans not exactly centered behind engine....you need to check and adjust bellhousing alignment.

how much damage to the transmission internals would this cause? I have a spare case, just need to know if I should get another front pump?
BTW, your right, the alinement hole on the trans are not good.
thanks.

It could be a lame build on converter. If trans was not exactly centered, why would it wear just one side of conv. snout?

well I have a new Dynamic TC. But I'm sure I will need to replace the case.

Wear on one side of the impeller is due to "flagpole" - the impeller is not perfectly perpendicular to the converter' lug plane.

A trans that does not share the same centerline as that of the crank would cause wear all the way around the impeller.

The other possibility - when the converter was installed the pilot was not buried in to the crank pocket when tightening the converter bolts.

I decided to rebuild the transmission. Is this converter fixable?

A good converter shop would have no problem doing that - it would have to be cut at the large closure weld - then the impeller hub would have to removed at the weld and a new one installed then the impeller assembly welded back on to the front cover assembly. Local shops here get about $100 - $125 for all that.

What city are you in ?

Make sure the dowels are in the back of the engine

Yes, make sure both dowels are there - but that won't cause this type of wear.

It will cause wear all the way around the impeller. And in extreme cases break the flex plate and/or spin the pump bushing.

Common on new built vehicles - production from our assembly plants, and in service after a tech r & r''s the trans and misses the fact that one or both dowels fell out of the block.

I'm south of Battle Creek.
I noticed one of the holes in the transmission case looked somewhat not so round, like the alinement pin had been forced.
Both pins are in the block.

Sending you a PM -

Also, the hub could be out-of-round.

How do you check block to trans alignment ?

On an auto trans - the same way as you are supposed to on a manual trans bellhousing. A little harder to get in there but take your empty trans case and bolt it to the engine.

Take a magnetic dial indicator assembly and attach it to the cramkshaft.

The indicator proble should touch the OD of the pump bore - that checks bore runout.
The indicator probe should then touch the gasket face of the pump bore - that's face runout.

Spin the crank to get TIR ( total indicator runout ).

Look in a service manual for the procedure - and I think it was also called out in the old Direct Connection manuals.

As long as you have two good dowels in the engine and the trans case bores for those dowels are round and not egg-shaped you are normally good. I can't recall ever having a need to install offset dowels like we did on manual transmissions. The flexplate is more forgiving than the flywheel. Plus the converter internals are forgiving too.

When you add pump bushing to converter clearances, internal converter clearances and the flexplate flexibility that provides more flexibility than the manual trans stack up.

I've got a fresh assembled auto trans, and I don't see how I could get access to do that. I put in 2 new dowels in the block sense they were gone when I got block back from the shop. I trial fitted the trans to the block to check the starter fit, and the dowels were very tight. I'm calling it good

Another observation is that once the trans is bolted in place you should be able to pull the converter in to the back of the crank without much effort. Some rotating clockwise and back while pulling g it forward should enable you to get the drive lugs close to the flexplate. Install your first bolt finger tight then rotate and install the next on and in until they are all installed.

Don't install the first bolt and go to torque - install the next three.

Before installing the trans converter assembly lightly coat the crank pocket where the converter pilots - this also allows the converter to slide in to place without much effort.

Don't forget to take the flexplate and lay it on the converter to make sure you have the offset lug located - then put a paint mark there - this way you install the bolts the first time and they all line up.

I use to use some bright paint to mark one ear on the flex plate and on the converter before taking them apart
I never greased the hubs but that is a good idea

What color is the bushing that conveter rides on, inside right behind the seal. If it is bronze color it will wear the converter hub if it has been replaced. Should have a babbit bushing. Silver color.

Why would a bronze bushing wear the converter ?

Ding ding ding
You nailed it

So what some of you are saying is bronze bushings wear out converters.

So the millions of Chrysler transmissions using bronze bushings have worn out impeller hubs.

Really?

We replace less than 1% of the impeller hubs in the Mopar Reman program - the rest get roller burnished and fall within print specifications.

No arguement that Babbitt bushings are more forgiving on crank journals and converter impeller hubs - but to make a statement that using a bronze bushing is going to wear out your converter is a gross mis-statement.

When the hub is replaced, the new hub is not hardened, and the original hubs were. Aftermarket converters rarely have hardened hubs and usually are sold with a babbit bushing in the box, some people don't think the babbit bushing is necessary and therefore ruin the hub on the torque converter.

A crankshaft is not hardened after grinding and bearing material doesn't cause the journals to wear.

Dirt, poor journal finish, poor conn. rod big end geometry, wears the bearings and journals.

A properly built converter with impeller hub runout within specifications that has been properly installed in the vehicle won't wear the impeller either.

Again, if the impeller is worn on one side that's because of excessive runout or a mis-installed converter.

The Babbitt bushing will wear faster in this circumstance because it has less durability - it's softer.

There are only a few suppliers that make impeller hubs, all those that I have seen by the way are hardened Sonnax, Tri-Components, and a few others.

If the convertor hub is worn on one side it is likely that the hub / snout is not on centre to the convertor. If the hub is worn all the way around then there is an alignment problem between the crank centreline and the trans centreline and it needs to be addressed.

Your first statement is incorrect - your second statement is correct.

Think of it this way - a piece in the lathe being cut - if it is crooked, as you come in with your tool what happens ?

You cut only a portion of the part.

If it is perpendicular to the drive head you cut all the way around.

The crank is the drive head, the converter is the part being turned and the bushing is equivalent to the cutter.

If you place a perfectly round part in a lathe chuck that is perfectly perpendicular but isn't dialed in (IOW, the part is in an elliptical orbit), the tool will only cut part way around as it is fed into the spinning part.

Same with the converter hub, if it isn't centered in the bowl or if the bowl wasn't perfectly centered when welded to the cover, the hub will travel in an elliptical orbit and cause the high part of the hub to wear more than the low part.

Also an out-of-round hub will show more wear on the high side.

Any misalignment of the trans, either lateral or angular, would cause even wear on a perfectly round hub.

Thanks john, I didn't think it was that hard to work out !