8-3/4 gasket

[Glenwood]

Just wondering if you guys use a gasket when installing the pumpkin or just RTV it?

 

[1967coronet440]

Just wondering if you guys use a gasket when installing the pumpkin or just RTV it?

My 8 3/4 had A gasket & rtv I didn't assemble it but ran it for 5 years that way with no problems.

 

[themechanic]

I tried an expensive reusable rubber gasket with no RTV, OEM paper gasket with RTV and still had leaks. My leak was via the studs where they come through the flange; they are knurled and press fit into the flange.

I took Doctor Diff's advice and used Permatex Gear Oil RTV with no leaks:

 

[Glenwood]

Makes you wonder why dr diff sells the gaskets.
I'm about to install the pig and axles now that i have the 3.55s and axle bearings installed. I thought maybe the gasket was needed for general spacing. I thought some metal to metal surfaces might mate better with a gasket rather than just sealant.

 

[dan juhasz]

I tried an expensive reusable rubber gasket with no RTV, OEM paper gasket with RTV and still had leaks. My leak was via the studs where they come through the flange; they are knurled and press fit into the flange.

I took Doctor Diff's advice and used Permatex Gear Oil RTV with no leaks:

View attachment 409309

I've never seen that product. Still learning all these years later.

 

[themechanic]

I also think it may have had something to do with installing the third member with the housing out of the car. I applied the RTV on the housing with the flange facing up then dropped the pumpkin down on top. That way I got an even distribution of pressure on the RTV around the flange.

Dr Diff also suggested using Ford 9 inch rear copper washers to seal the bolt holes. That worked but made it a major PITA to remove the pumpkin when I learned my housing was bent.

 

[Garys1969RR]

I just cleaned the housing and 3rd member mating surfaces real good, then used Permatex ultra oil resistant RTV on there. That has worked great on 2 rear ends with no leaks for several years.

 

[eagleone1983]

I just used a paper gasket, so far my leak is too slow for me to care about. Maybe one drip a week or so. Whenever I need to remove it I'll be using that gear gasket goo. As far as leaks go anyway the rear end is the least of my problems. Transmission leaks way more.

 

[moparnation74]

I use the gasket and coat both sides with Indian head shellac..Never had one leak

 

[Glenwood]

I use the gasket and coat both sides with Indian head shellac..Never had one leak

Never heard of that stuff.

 

[moparnation74]

Never heard of that stuff.

It is older than all of us lol...Made by permatex. You can get it from oreillys, autozone etc...

 

[Glenwood]

It is older than all of us lol...Made by permatex. You can get it from oreillys, autozone etc...

Probably banned here in libtario lol

 

[mr. b]

I used black rtv on mine don't leak a drop indian head is a real mother to get off if you have to get in there again

 

[65-440]

I used the pink reusable from Dr diff, had center out 2 times ... no leaks ...

 

[Bb70charger500]

Gray rtv is best for rears no gaskets ,I assy dump truck rears with gray and car rears its a pain to pull it apart later though

 

[Glenwood]

quite the RTV bouquet! black, gray, blue and I think I have copper RTV in my box too. Makes my head spin lol

 

[1967coronet]

When I switched mine I used the paper gasket with a thin film of black RTV on each side of the paper, no leaks.

 

[Glenwood]

When I switched mine I used the paper gasket with a thin film of black RTV on each side of the paper, no leaks.

What was your reasoning for using a gasket with RTV and not RTV alone?

 

[1967coronet]

Just my old overkill self lol, main reason was I didn't want the fight of getting the old style gasket sealer off if I ever had to change it out again, the rtv you can pretty much rub off the cast with your finger and it helps seal around the studs, the paper...... I just wanted in there to seal , mine had a old paper one to start with when I tore it down.

 

[threewood]

Gray rtv is best for rears no gaskets ,I assy dump truck rears with gray and car rears its a pain to pull it apart later though

Ultra Grey is all I use, anywhere on the motor or rear end. That is all my engine builder on my poly used. It is fantastic on metal to metal. Never had one leak.