super diff drilling a holein it?

Discuss VW transaxles and transmissions. Gearheads wanted!

Moderator: Henryhoehandle

Post Reply
jo at 2000
Posts: 142
Joined: Fri Nov 08, 2002 3:01 am

super diff drilling a holein it?

Post by jo at 2000 » Wed Jan 10, 2007 12:59 pm

I'm installing my first super diff in a 67 ghia trans. I was told that i would have to drill a hole in the diff so it gets proper oilling. Where do you drill the hole and do most of you use a drill press to drill it? Thanks for any info

User avatar
Ephry73
Posts: 3278
Joined: Fri Mar 02, 2001 3:01 am
Contact:

Post by Ephry73 » Wed Jan 10, 2007 1:01 pm

I believe the oiling hole just needs to be expanded. There should be an oiling hole to the side of it.

I will be doing this soon.



E

Bruce2
Posts: 6776
Joined: Sat Oct 13, 2001 3:01 am

Post by Bruce2 » Wed Jan 10, 2007 4:38 pm

I hate having to do that.

Have a look at the casting. Look at the machined part where you put the shafts for the spiders in. Move to the raw casting away from the ring gear mounting surface. There you will see 2 protrusions in the casting, 180º apart. You are supposed to drill oiling holes right beside that wall. Which side? It depends on whether you are rear engine or mid engine, straight axle or reduction boxes. Drill the hole on the side that causes the wall to scoop oil to the inside of the diff, depending on which way the diff is rotating, which depends on which way it is installed (starter side or clutch arm side). Drill it at least ½" in dia, and drill 2 of them, one beside each wall. A hand drill is fine for this.

But you are not done yet. Look to the other side of the machined part for the spider gear shafts. down in the groove of the raw casting between that machined part and the mounting face for the ring gear, you need to drill more holes. Drill 4 holes, 90º apart, ¼" in diameter. This provides oil to the side gear.

After deburring the holes and washing it in solvent, you are now finished modifying that new part.

Having to drill the diffs is one of my pet peeves. Why should I have to modify a brand new part??? My diffs used to come from ERCO, but the last one I got from CIP1.com. Imagine my joy when I pulled out the diff and it was already done! If you get the Bugpack diff, you don't have to modify it. Sorry Eric, you're not getting any more of my superdiff business.

User avatar
Ephry73
Posts: 3278
Joined: Fri Mar 02, 2001 3:01 am
Contact:

Post by Ephry73 » Thu Jan 11, 2007 7:30 am

Bruce,


So you're saying Bugpack already does the drilling for the oiling? That's good to know.

The LSD units we exchanged emails about still sound like the better solution.


E

Casting Timmy
Posts: 89
Joined: Sun Nov 17, 2013 9:42 pm

Re: super diff drilling a holein it?

Post by Casting Timmy » Fri Nov 03, 2017 9:19 am

I'll try and add some photo links to this as well. Bruce posted a factory ZF bulletin of adding oil holes in the side covers to get oil to the fulcrum plates.

It seems like a lot of the super diffs now come with the holes drilled, but some still enlarge these holes even at times to get more oil to the side gears.

I need to do a swing box this winter and am trying to run down the latest mods/ what's best for a super diff especially for a freeway car. So far I plan on opening up the scoops a little more and adding the oiling holes on the side covers to ensure the fulcrum plates get enough oil to them.

Topic on thesamba that drifts into IRS diffs a little as well
https://www.thesamba.com/vw/forum/viewt ... p?t=688423

Another set of pictures I will try and load this weekend is from DB on Facebook, I think he migth be Dangerous on here?? Anyways he opens up a hole in teh top of the side cover and three down below with matching holes/openings in the daisy as well. To ensure the daisy stays correct he put a pin in the side cover for one of the gaps in the daisy. He said this was the mods for a Quaffe and not needed so much on a superdiff.

User avatar
Pablo2
Posts: 369
Joined: Sat Jun 25, 2011 7:37 pm

Re: super diff drilling a holein it?

Post by Pablo2 » Fri Nov 03, 2017 9:54 am

The hole ALWAYS goes on the same side, regardless of how the diff is installed. The only exception would be a counter-clockwise engine conversion (Corvair or Honda?).

There was a good write-up awhile back on Samba, of Ray Vallero's mods to open up the diff oiling to a reasonable size.

A swing axle "super" diff absolutely needs additional oiling.
aka Pablo, gears, Geary
9.36 @ 146 in '86

Casting Timmy
Posts: 89
Joined: Sun Nov 17, 2013 9:42 pm

Re: super diff drilling a holein it?

Post by Casting Timmy » Fri Nov 03, 2017 8:14 pm

Just took notes of Ray Vallero's modifcations:

Enlarged the two holes (drilled at angle)next to scopes to 1" and milled the surface to help scoop oil into center section.
Added 4ea 5/16" holes along center ring between spider gear shafts.
Enlarged or added two 5/8" holes with scoops in front of ring gear mounting surface to add oil to side gear.

Additionally he adds a path for oil to get to the fulcrums around the diff bearings by milling a path up top on the side cover, flong oil gets throw up top and drips down to the fulcrum plates from outside the diff.

User avatar
Clatter
Posts: 1625
Joined: Sun Apr 28, 2002 3:01 am
Location: Santa Cruz

Re: super diff drilling a holein it?

Post by Clatter » Sat Nov 04, 2017 10:40 am

Since it's been mentioned, here's what's left of Ray Vallero's trans build thread:
https://www.thesamba.com/vw/forum/viewt ... ht=vallero

Here's a big fat middle finger FU to photobucket for holding these pics hostage..
"Oh, You don't need to do all that... The valve seats are just going to fall out of it anyway!"
- Doug Ellsworth

Beginners' how-to Type 4 build thread ---> viewtopic.php?f=1&t=145853

Bruce2
Posts: 6776
Joined: Sat Oct 13, 2001 3:01 am

Re: super diff drilling a holein it?

Post by Bruce2 » Sun Nov 05, 2017 3:18 am

Pablo2 wrote:
Fri Nov 03, 2017 9:54 am
The hole ALWAYS goes on the same side, regardless of how the diff is installed. The only exception would be a counter-clockwise engine conversion (Corvair or Honda?).
This needs to be double stressed.
There are many people who think the hole must go on the other side of the paddle for mid-engine, or Bus with reduction boxes. Not so, the hole always goes in the same place.
The drive side of the ring gear teeth is always the drive side.

Way back when people used Corvair engines, they installed reverse rotation cams and a rewired starter to run it the same direction as a VW.

Post Reply