Superdiff problem

Getbackontrack · Post by **Getbackontrack** » Sat Jan 10, 2009 7:49 am

Hi. I took my swingaxel gearbox apart and found that on of the 3 pipes holding the spider gear axels in place had broken. I was able to take out the two short axels that holds in place two of the spider gears (I run a superdiff with four spider gears) and they spin nicely on the axels. Now I have the long axels with the last two spidergears sitting in the diff. The thing is it seems that atleast on of the spidergears has seized on the axel, and I cant punch out the axel. My question is, has anybody had similar problems like this? How do I get the axel out? And is it possible to buy a new axel to replace the one that obviously must be brooken?

Any input will be apreciated.

Thanks in advance.. Jakob

dangerous · Post by **dangerous** » Sat Jan 10, 2009 4:35 pm

Hi Jakob,
I see this problem quite often,
and in most cases the shaft has to be drilled out with carbide or cobalt drills before pressing out.
I did save one recently by just pressing the shaft out,
but this is not the norm and can ruin the main housing(cast iron),
if it is not supported properly.

Most often cause is one wheel burnouts, and lack of lubrication.
Check first that the oil holes are ample(or even there at all)
and don't be afraid to add more.

I have recently also been using a teflon/moly coating on the shafts and spiders,
and giving the spiders an extra thou of clearance before the coating.

Looks OK so far.

Shafts are around used, and weddle may stock some,
but I just use VW ones,
and cut them to length and
re-drill them for the roll-pin ("3 pipes")size that your diff uses.

I use tungsten drill first,
and then a 1/8 drill after getting through the hard layer.
Larger pin diffs may be able to use the original VW roll pin holes.

I think the VW shaft has better hat treatment,
but gotta have the oil in there
and it is hard to get as much oil in there as a stock housing can
with the two extra spiders and shafts filling the void in the body.

Getbackontrack · Post by **Getbackontrack** » Sun Jan 11, 2009 4:04 am

Thanks for your post Dangerous.

I will try to drill out the axel, just to be sure not to break anything.

When I look down into the housing I can see that the surface up to where the spidergear runs is a little marked, like one of the spidergears has run hard up against the housing. it is not very deep or anything, just tiny little scratches all way around. Does that meen my houseing is junk?

Jakob

Bruce2 · Post by **Bruce2** » Sun Jan 11, 2009 9:44 am

Post pics.

Getbackontrack · Post by **Getbackontrack** » Sun Jan 11, 2009 11:13 am

I will post some pics soon..

Getbackontrack · Post by **Getbackontrack** » Mon Jan 12, 2009 7:40 am

Got the last axel holding the last 2 spidergear pressed out today, 10 ton was what it took to press them out. But I broke the thing in the middle that holds the two axels inside the diff, Anyone know if its possible to buy that part alone? I found a new axel and two fine spidergears in an old IRS diff I had laying around, assume I can use them in my swing diff, right? They look just the same.

Jakob

Bruce2 · Post by **Bruce2** » Mon Jan 12, 2009 10:55 pm

Check the tooth count of the spiders. 10 and 11 exist.

Getbackontrack · Post by **Getbackontrack** » Tue Jan 13, 2009 6:39 am

Hey Bruce, jep I know about the two sizes, actually I was thinkin about upgrading for 10 touth, but is it worth it in my aplication? Im running a 2387 with around 210 horsepower.. Mostly street driven and no slicks.

Jakob

Bruce2 · Post by **Bruce2** » Tue Jan 13, 2009 8:40 pm

You will probably be fine with the 11/17 gears without slicks. However, if you decide to replace your diff, get one for 10/15 gears since it's easy for you to get the 15 tooth side gears.
If you can't find a vendor who sells a diff specifically for 10/15 gears, try ERCO.