Transmission - Hurth HBW10 - Sealing Case Question

I have my transmission apart. Upon disassembly there was no seal or sealant between the two halves of the case. it goes against my best judgement to reassemble with out any sealant, but it had none to start, I am leaning toward assembling it the way I found it.

Does anyone have experience with this?

Regards
Greg

I don't have hands on with this particular transmission, but typically you don't see any sealant. The clearances in a transmission can be excruciating, and as such, any sealant risks changing a critical dimension. Remember we're talking a couple thousands of an inch here. So, make sure the mating surfaces are completely clean, and torque it evenly and carefully.

I have never seen an assembly that holds lube oil without a gasket or some form of sealant. Doesn't that trans use ATF? That will run through ANY slight crack like water. There is a sealant used in motorcycles that works very well for this sort of application, metal to metal. Hondabond or Yamabond is a grey, viscous, sticky goop that never completely dries so it keeps sealing. Also squishes out of tight tolerances yet leaves just enough to seal. Use sparingly.

That said, I would find out for sure before I sealed it up with or without sealant. Hansen Marine in Marblehead, MA rebuilt my trans. They can answer the question for you.

RT

Hansen uses a silicone gasket product. Hondabond is great too but as Rob said I'd check with Hansen first..

Hi Y'all
A very acceptable sealing mechanism for machined mating surfaces is to use Indian Head gasket cement on the surfaces (light coat) then carefully lay a silk thread inside all bolt holes . This is used on aircraft engine crankcase halves when assembling. Works on any machined mating surface. The thread acts as a dam and is smashed quite flat when the halves are drawn together. Works on VW aircooled engines as well.

By the way you may use any color silk thread ! Black for engineers , fuscia for interior designers, white for wedding planners, red for .........

sleepingsquirrel said:

Hi Y'all
A very acceptable sealing mechanism for machined mating surfaces is to use Indian Head gasket cement on the surfaces (light coat) then carefully lay a silk thread inside all bolt holes . This is used on aircraft engine crankcase halves when assembling. Works on any machined mating surface. The thread acts as a dam and is smashed quite flat when the halves are drawn together. Works on VW aircooled engines as well.

By the way you may use any color silk thread ! Black for engineers , fuscia for interior designers, white for wedding planners, red for .........

Click to expand...

Is that why every LyCon AC engine I have seen has a puddle of oil under it! Just kiddin', AC engines so seem to leak oil more than maybe old British or HD motorcycles. I have a buddy that works on radial AC engines. He says never mind the leak, its when it stops leaking you have to worry, 'cause its out of oil!

I'll also have a tough time explaining the greasy fingerprints on the wifes sewing kit....

RT

On the old VW air cooled engines we used a product called Gaskasinch It comes in a Small can with a foam ball/brush on the inside of the lid. It is about the consistency of water and does do a good job of sealing machined surfaces without changing tolerances. It is what I would use. (no commercial interest) Edd

OK OK OK - I've been working on vintage Alfa gearboxes, and they just mate the machined surfaces, and they all ooze. Next time, I'll have to try one of these nifty sounding sealants and see if my garage floor looks better.

Well, when you really put some thought into it ,anything that requires constant replenishing of fluids because of a leak, is most likely being better maintained than one that just gets new oil or fluid every 50 hours. Oh, no disposal problems! If a Lycoming engine is getting a quart and a half every hour , that equates to an oil change every four hours. Same for sailboats.