Torque Converter bolt tech

[Crosley.In.AZ]

The bolts that hold the converter to the flex plate.

These bolts must be long enough to fully engage the converter mounting pad BUT not too long so they hit the converter shell.

It a bolt dents the converter shell of a lock up style converter.... this will cause the converter clutch to fail because of the 'high spot' in the area where the converter clutch material applies.

The friction material will slide over the high area inside the converter and damage it.  Soon the converter clutch piston will be metal to metal like worn out brakes.

This applies to a majority of torque converters used in rear wheel drive vehicles, most FWD cars too.

[Fat Cat]

Tony is it possible for you to get us pictures of what the inside of that convertor looks like in that area. I understand all of what you posted here but would sort of like to see the internals that get damaged and maybe a picture of one that is damaged.

[Dave]

The bolts that hold the converter to the flex plate.

These bolts must be long enough to fully engage the converter mounting pad BUT not too long so they hit the converter shell.

It a bolt dents the converter shell of a lock up style converter.... this will cause the converter clutch to fail because of the 'high spot' in the area where the converter clutch material applies.

The friction material will slide over the high area inside the converter and damage it.  Soon the converter clutch piston will be metal to metal like worn out brakes.

This applies to a majority of torque converters used in rear wheel drive vehicles, most FWD cars too.

Im having a heck of a time finding flexplate to converter bolts and nuts for a chevrolet 350 turbo. Do you have any numbers? All i can seem to find is the flexplate to crankshaft bolts?
Dave

[GPster]

You put this in the wrong topic. It should be under the Tech Week Forum. Now I have to pull the inspection cover off the turbo 350 in the Jeepster and hope that I didn't create a problem using the stock bolts off the V8 flexplate to hold the torque converter on the V6 flexplate. Which brings about another question. I have seen occasions where the bolts on high speed (11,000 RPM ?) rotating assemblies are only used one time and then disgarded in favor of new bolts on re-assembly. Is this something that should be done here? GPster      P.S. Maybe we should have a Tech Question of the Week.

[34ford]

Dave,

I was having trouble finding them for my 700r4. No place in the parts magazines or at the part houses. Finally thought the tranny shop that built my tranny should have them. Sure enough, the right ones for .50 each. The ones for the 700r4 are metric too.

So having said that call one of the local tranny shops.

bob

[Dave]

Ill try that.. I dont need em right now and i need nuts also. I just like to have all my ducks in a row when i go to puttin the finish on a car  Ive got the engine and tranny in the frame now and ill prolly leave it together and on my rolling cart while i finish and paint the frame to get ready to assemble .. Ill stop by a trans shop here next time i get down town and ask..
Dave

[Crosley.In.AZ]

Dave,

I was having trouble finding them for my 700r4. No place in the parts magazines or at the part houses. Finally thought the tranny shop that built my tranny should have them. Sure enough, the right ones for .50 each. The ones for the 700r4 are metric too.

So having said that call one of the local tranny shops.

bob

the whole 700r4 tranny is metric bolts and threads

[Crosley.In.AZ]

The bolts that hold the converter to the flex plate.

These bolts must be long enough to fully engage the converter mounting pad BUT not too long so they hit the converter shell.

It a bolt dents the converter shell of a lock up style converter.... this will cause the converter clutch to fail because of the 'high spot' in the area where the converter clutch material applies.

The friction material will slide over the high area inside the converter and damage it.  Soon the converter clutch piston will be metal to metal like worn out brakes.

This applies to a majority of torque converters used in rear wheel drive vehicles, most FWD cars too.

Im having a heck of a time finding flexplate to converter bolts and nuts for a chevrolet 350 turbo. Do you have any numbers? All i can seem to find is the flexplate to crankshaft bolts?
Dave

buy any short 3/8 fine thread bolt and nut.. grade 8 if you can find them or grade 5 .... use lock tite on the threads

[EMSjunkie]

i need nuts  

         

Vance

[1FATGMC]

Dave,

I was having trouble finding them for my 700r4. No place in the parts magazines or at the part houses. Finally thought the tranny shop that built my tranny should have them. Sure enough, the right ones for .50 each. The ones for the 700r4 are metric too.

So having said that call one of the local tranny shops.

bob

the whole 700r4 tranny is metric bolts and threads

How about the rear mount holes.  The one I'm putting in now seems to use SAE bolts in it.  It looks like there might be two threads in the hole.  A larger one and then deeper in the hole the threads that are smaller and  seem to be SAE.  At least I can screw a bolt in a long ways by hand.

What do you think??

Thanks,

Sum

[Crosley.In.AZ]

Dave,

I was having trouble finding them for my 700r4. No place in the parts magazines or at the part houses. Finally thought the tranny shop that built my tranny should have them. Sure enough, the right ones for .50 each. The ones for the 700r4 are metric too.

So having said that call one of the local tranny shops.

bob

the whole 700r4 tranny is metric bolts and threads

How about the rear mount holes.  The one I'm putting in now seems to use SAE bolts in it.  It looks like there might be two threads in the hole.  A larger one and then deeper in the hole the threads that are smaller and  seem to be SAE.  At least I can screw a bolt in a long ways by hand.

What do you think??

Thanks,

Sum

the 700 tranny is fully metric threads and bolts.

A 10mm x 1.5 is near a 3/8 bolt , yet not correct.

I've never seen a multi threaded hole on a 700 tranny OE from  GM

technically, all of the trans measurements are in metric. Friction thickness, steels , alll diameters , gaps , end play , shims.

[1FATGMC]

Dave,

I was having trouble finding them for my 700r4. No place in the parts magazines or at the part houses. Finally thought the tranny shop that built my tranny should have them. Sure enough, the right ones for .50 each. The ones for the 700r4 are metric too.

So having said that call one of the local tranny shops.

bob

the whole 700r4 tranny is metric bolts and threads

How about the rear mount holes.  The one I'm putting in now seems to use SAE bolts in it.  It looks like there might be two threads in the hole.  A larger one and then deeper in the hole the threads that are smaller and  seem to be SAE.  At least I can screw a bolt in a long ways by hand.

What do you think??

Thanks,

Sum

the 700 tranny is fully metric threads and bolts.

A 10mm x 1.5 is near a 3/8 bolt , yet not correct.

I've never seen a multi threaded hole on a 700 tranny OE from  GM

technically, all of the trans measurements are in metric. Friction thickness, steels , alll diameters , gaps , end play , shims.

Thanks, it was a 3/8 that threaded into the hole.  I'll go get metric tomorrow and try them.

Sum

[C9]

Im having a heck of a time finding flexplate to converter bolts and nuts for a chevrolet 350 turbo. Do you have any numbers? All i can seem to find is the flexplate to crankshaft bolts?
Dave

ARP Fasteners.

Catalog:  http://www.arp-bolts.com/Catalog/Catalog.html

Torque Converter Bolts:  http://www.arp-bolts.com/Catalog/Catalog.html

They offer a well written catalog full of interesting tech.
Free . . . don't get much better than that....

[1FATGMC]

A 10mm x 1.5 is near a 3/8 bolt , yet not correct.

Tony you were right as usual   .  I got the metric 10 X 1.5 and they fit.  It is amazing how the 3/8 will thread in, but I see they are smaller in diameter by a little.

Thanks,

Sum