Re-installing a HM with torus cover?

[spitfire_er]

I'm getting ready to put my 55 HM back on my engine and had a question. I bought a gasket set for the torus cover and it also came with the crank shaft gasket.

I have been reading around and I read somewhere that a few guys recommended putting a thread sealer on the crank to try and avoid leaks. They also said not to use anything like RTV, but there is a special sealant you can use for this type of application.

Does anyone have any experience or suggestions for putting this thing back together. I'm not sure if I should use extra sealant or not and if so which one to use.

thanks in advance.

[1project2many]

The service manual distinctly indicates potential for leaking around the crank to flywheel seal, the flywheel bolts, and also around the cover bolts. Pipe thread sealer is a reasonable choice for the bolts. If the parts are fairly rigid and flat you could use anaerobic sealant aka gasket eliminator. It only cures when no oxygen is present so if the parts don't bolt snugly together, don't try it. As far as a sealant on the crank itself where the seal contacts, I'm not sure of anything appropriate.

Good luck.

[mr48chev]

Several sources that I dug up say NO SHELLAC on the gaskets suggesting using vasoline to hold them in place.

There are some good thread sealants out there that you just paint on the threads of the bolts going through the crankshaft that should work but not leave residue that would get in the trans.

[OrrieG]

I am feeling really uneducated here. What is the HM and torus cover??? I must know them by a more shade tree name...like torque converter or ??? Google is no help, just shows up a bunch of physics diagrams...

[Russell Ashley]

The Motors Auto Repair manual isn't too specific as to what to use on the flywheel bolts:

"Leakage between the flywheel and crankshaft can be corrected by using new flywheel bolts and sealing compound. If this does not stop the leak the threaded portion of the screws should be tinned."
"Leakage between the flywheel and torus cover can be corrected by installing a new gasket which has been coated with rubber cement. Make sure the gasket is not wrinkled and fits properly, and tighten the cap screws evenly to 30 to 35 pounds feet.

I think if it were me I'd use Permatex "Super 300" sealer on the gaskets and bolt threads. It comes in a bottle with a brush to apply it, and is made for situations like this.
http://www.permatex.com/products/pro...sealant-detail

You definitely don't want to have to remove that tranny later.

[spitfire_er]

thanks guys, this sets my in the right direction. I think I'll get some of that permatex stuff and seal it all up. I guess better to be safe than sorry, and I'm guessing in this case, the least amount possible to seal it up would be best too!

[Russell Ashley]

Originally Posted by OrrieG

I am feeling really uneducated here. What is the HM and torus cover??? I must know them by a more shade tree name...like torque converter or ??? Google is no help, just shows up a bunch of physics diagrams...

Orrie, HM = hydramatic. The The torus cover and flywheel seal together to contain the fluid around the drive and driven vanes. They called the vanes torus's. I'm not sure when they changed to a sealed torque converter but apparently this style was used at least through 1959.

[OrrieG]

Ok, all makes sense. I've never had a hydro apart sounds like it could be problematic to seal up.

[dicer]

Its not a torque converter, its a flluid coupling. There are and have been bolt together torque converters, and are much better than a weld together one, as it can be disassembled and cleaned in the field.
http://www.racingconverters.com/ncrc...ng-converters/
And sorry they didn't introduce the worlds first bolt together TC as all old PG trans's had bolt together TC's, as well as allisons and other old automatic trans vehicles of the 50's. The thing that makes a fluid coupling different from a torque converter is a stator, and that is what helps do the torque converting. The fluid coupling does not have a stator.

[Russell Ashley]

Originally Posted by dicer

Its not a torque converter, its a flluid coupling. There are and have been bolt together torque converters, and are much better than a weld together one, as it can be disassembled and cleaned in the field.
http://www.racingconverters.com/ncrc...ng-converters/
And sorry they didn't introduce the worlds first bolt together TC as all old PG trans's had bolt together TC's, as well as allisons and other old automatic trans vehicles of the 50's. The thing that makes a fluid coupling different from a torque converter is a stator, and that is what helps do the torque converting. The fluid coupling does not have a stator.

Dicer, my answer applied the topic being discussed in the thread, a GMC truck. I didn't say it was a torque converter, I said I didn't know exactly when they switched to a sealed torque converter.

[1project2many]

Spitfire_er, you might also take a sharp, flat file and carefully slide it around the torus cover gasket surface to ensure there are no serious distortions around the bolt holes. If that gasket ever developed a leak in the past it might have been addressed by an overeager mechanic who tried overtorquing the bolts to stop the leak.

Dicer, my answer applied the topic being discussed in the thread, a GMC truck. I didn't say it was a torque converter, I said I didn't know exactly when they switched to a sealed torque converter.

Orrie said he was feeling uneducated and asked if he would know the part as a torque converter. I think Dicer's answer is appropriate to that question. I was going to provide roughly the same information and point out that a primary feature of the torque converter is the ability to multiply torque. The HM's torus cannot do this and is not, therefore, a torque converter. Though not said directly, Dicer included that information also:

The thing that makes a fluid coupling different from a torque converter is a stator, and that is what helps do the torque converting. The fluid coupling does not have a stator.

[spitfire_er]

i ordered up some permatex super 300, should arrive tomorrow. hope that works.
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