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Help. Leak from sump cover on bottom of J-OD

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2wrench

2wrench

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Six bolts hold sump cover on. One appears to be stripped
and not holding, allowing a leak.

This was a unit bought on the internet already rebuilt.

If I remove that bolt, I imagine all tranny fluid will drain??

Do I helicoil? Do I go slightly oversized and tap out?

Also, car is starting and running. I'm thinking to take it
to a shop and have somebody equipped and experienced set
the timing and the carbs to their sweet spot.
 
2W,

It seems that that is a common leak spot on the J unit, even without a stripped thread. You can guess how I know that. To do it correctly, you would have to remove the cover to install the heli coil and that means the fluid would drain out. The filter, or one of them, s behind the plate.

And the fluid is no mystery. It is 30W NON Detergent motor oil per John at Quantum Mechanics.
 
2wrench said:
If I remove that bolt, I imagine all tranny fluid will drain??
Click to expand...

The J-type and A-type O/D's both share oil with the main transmission unit and the oil passage between the two is not at the lowest point in their respective cases. As a result, when you drain the O/D there will be some oil left in the main transmission case. After you repair the stripped bolt, just replace the cover and top off through the transmission fill hole. I've been using Valvolene Racing 20W-50 for a few years and I have had good results.
 
From what I've read and heard ,might as well weld that cover shut to keep it from marken it's spot the rest of it's life.
 
The problem is not with stripped bolt threads; rather, the OD casing.

Okay. So I cannot find a helicoil at any local store to fit the 1/4 by
1/2 inch long fine thread bolt.

Guess I can't see the forest for the trees, here, guys. Tell me what you think I should do. I am looking at these choices:

Wait/find/order the proper size helicoil kit to place/replace original size
1/4 inch fine threaded bolt (not available locally.)

Fill hole with JB Weld, drill and tap to proper 1/4 size for fine threads.
(Concerns: Inability to redrill and tap straight; hole threads need to be
cleaned well to accept/stick with JB Weld (also, after cleaning, oil will
likely seep back down fouling the adhering surface, possibly, which sucks.)

Or, one I hadn't consiered much: Buy a 1/4 inch helicoil repair kit for
a coarse-threaded bolt and go with the one bolt replaced with coarse thread
(only sorta sucks cause it's one weird bolt not to spec, which is a pain
for any other times a mechanic would turn a wrench...(commonly heretofore
referred to as DPO kinda work.)

Lastly, as I remove this sump cover, are there gaskets that "must" be replaced
or is there a chance I can replace the cover with the existing gasket(s)....
and Brosky mentioned a filter behind...."must" this be replaced as well, if
taken apart.
 
Helicoil is coarse thread into the aluminum (for gripping purposes) and the actual bolt is fine-thread. You <span style="text-decoration: underline">can</span> reuse the gasket or cut a new one out of gasket material. It is just a thin piece of paper. I use Hylomar here as it never hardens and seals nicely. And too, the J-type is <span style="font-weight: bold">supposed</span> to leak. Keeps rust off the rear of the car.

Oh, and that filter is cleanable, does not need to be replaced.
 
Permatex Hylomar.


...but hold out and get a HeliCoil or other thread repair solution before you go to reassemble it.

1/4-28 is NOT "unobtanium" for Heli-Coil. Go to NAPA.
 
2W,

Forget the JB Weld idea. It won't work.

Try MSC for heli coil style repair kits. Here's a link for trailing arm repair kits that are 5/16's, but they probably make the 1/4" as well. https://www.6-pack.org/sixpack/phpbb2/viewtopic.php?t=7433

The filter is a mesh screen that can be washed with carb cleaner. Available at Big 3 with gaskets below

There is a gasket readily available from Big 3.

Try Hylomar as the sealer. And copper washers on the bolts.

After all that, you'll only need a small drain pan under the car instead of a big one. Oh, once this stops leaking, the three seals on the shifter rods will start.

You already know that you don't have to ask me how I know all of this so well.
 
:lol:
 
IMO, order the right heli-coil kit from someplace like MMC . You'll pay a little extra, but they'll have it there quick (generally leaves their warehouse the same day; and you can request same-day delivery if you want). With MMC, if you order it on-line tonight, it should go out by 10 AM Monday.

No way is JB Weld strong enough to hold those threads (I don't care what it says on the package).

"Heli-Coil" is a brand name (the ones MMC sells are Recoil brand as I recall). There is a special tap (in the kit) that cuts threads the right pitch (28 tpi in your case) but enough larger that the hole is the right size after the helical insert is screwed into place.

There are other types of inserts that work as Bill describes; but my preference is for the helical inserts first. If by some chance they get damaged or stripped (which has never happened to me), then the hole is still small enough to use the (larger) solid inserts.

I would certainly want to have a new gasket on hand, even though I have managed to reuse them a few times. I like Hylomar as a sealant (and my J-types don't "mark their spot"). Also make sure the bolts are not bottoming in the hole and have the proper lockwashers on them.

The "filters" (there are two of them, although you have to remove another plug to get at the second one) are just metal screens, so normally they are reusable.

Oh yeah, also check both the housing and the plate for flatness. I had to dress both of them with a fine machinist's file to get them flat. And if someone has been over-torquing to try to stop a leak (which IMO would be the explanation for the stripped threads), the plate may be distorted beyond redemption.
 
More on Heli-coils : There is an odd size drill bit required, but sometimes not included in the kit. My 1/4-28 kit says 17/64. The stripped part of the hole will already be almost that diameter, so it will help you guide the drill straight. In fact, in aluminum you can frequently get away with not drilling at all, and letting the tap ream away any excess metal.

For a blind hole, be sure the insert does not reach all the way to the bottom, as the tap will not fully cut the last thread or two. If you screw the insert into that area, the result will be a hole that is too small and possibly binds on the bolt. For 1/2" deep threads, I would either use a 3/8" long insert, or only thread in about 3/8" of it and cut the remainder off with a Dremel and abrasive cutoff blade. Don't forget to break off the tang and fish it out.

I also recommend washing the tapped hole with solvent, and then using a drop of Loctite on the insert. Otherwise, they can sometimes back out with the bolt. Being somewhat paranoid about that, I also make sure to use anti-seize on the bolts (which IMO is good practice for any bolt into aluminum).
 
All good advice Randall. I hope to remember all of it.
 
I'd like to get some Hylomar. Hafta order. Does Payen make a gasket for that sump? Great quality, could be the ticket.
 
Not that I'm aware of. The gaskets from Moss and TRF are fine. Randall does have a good point about lapping the surface of the cover until flat and smooth prior to installing a new gasket.
 
sail said:
i'm watching you 2w. i have a new zealand od on my workbench.
Click to expand...

Cool. Once I get the leak dealt with, I'll need help getting all the electrical
stuff hooked up. Again, floating in unchartered territory hooking up stuff
that was never there to begin with.
 
Electrical on a J is pretty easy; at least compared to an A-type.
 
So I dropped the sump cover on the J overdrive unit. Sorry for the
quality of the pics, again. I think my camera is starting to go south...

Anyway, here is a picture I took with the plate removed. Interesting to
note that when I put another screw into the screw hole I thought was bad,
it seems to screw right down all the way. Seems to be like the others
that were good. Possible conclusion for me is that the threads in the
OD are actaully fine:

P1010028-17.jpg


This is a poor picture of the corner of the gasket from whence the leak
has occurred. The corner is defnitely torn. Doesn't look like any
sealant was used:

P1010049-13.jpg


Further, I tried to screw the screw that was pulled from that leaking corner
back into its hole. It seemed to lock up before going all the way down. I
did not "push" the issue.

Possible conclusion? Maybe I'll be good with just a new gasket; Hylomar;
new bolt because the one at the leak felt poor.

What's the feedback/thoughts?

PS: Got the right Helicoil kit: 1/4 by 28 TPI. May not need it, though.
That thread hole seemed cool with a different bolt threaded into it.
 
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