better superdiff

[PEPPE]

hallo
which are the better superdiff? a friend demolished one of the standard ones used on a rancho prostreet transaxle.

[Pablo2]

If it's swingaxle, step up to what's virtually indestructible: http://images.thesamba.com/vw/gallery/pix/355208.jpg

[Henryhoehandle]

Better have a big wallet, lol

[Bruce2]

ERCO may still have 4 spider gear superdiffs machined for the stronger 10/15 gears. If your friend had a diff with 11/17 gears, the change may do the job.

[PEPPE]

original ZF lsd does any better? i believe not so much since it uses standard planetary gears. i believe that the bruce way is the easier one. the billet one would be too much considering the "cheapness" of the parts inside the rancho trans. p.s. bruce, this was the trans with hand regrind tooths we spoke some time ago.

[Pablo2]

I guess it depends on what "demolished" means. The stronger side gears & spiders won't improve lubrication. I've always felt that just two 10-tooth spiders (along with 15-tooth side gears) in a stock diff machined for dual circlips is a FAR better solution than those "super diffs" in any application except perhaps drag racing. One of the 4 spiders always seems to be unloaded anyhow, and once the effect of low oil circulation kicks in, it's a downward spiral.

ZF side gear on the left, GT side gear on the right
http://images.thesamba.com/vw/gallery/pix/1221085.jpg

[Ol'fogasaurus]

Pablo2 wrote "... I've always felt that just two 10-tooth spiders (along with 15-tooth side gears) in a stock diff machined for dual circlips is a FAR better solution than those "super diffs" in any application except perhaps drag racing..."

Is this also true for those of us who off-road and use turning brakes a lot? If so it sure would make transaxles a lot cheaper. Now if the reverse gear problems could be fixed...

Lee

[Pablo2]

Offroad racing in NZ is specifically where I've seen this combo proven.

As for reverse, being absolutely certain reverse is fully engaged is the key. "Rocking" between reverse and 1st is when reverse is often damaged (from partial engagement). The Hurst shifter allows more positive shifting between reverse & 1st.

[Ol'fogasaurus]

Thanks Pablo2.

Being on the turning brake handle, even with steering tires, while on the sand gets kind of scary especially when you see someone having been just towed back with spider or reverse problems. Using the turning brakes to cause the open diff to act as a locked rear end also a bit daunting when it comes to wearing things out. The guys with a single handle turning brakes can go from locking one side to locking the other side as quick as the arm can move back and forth and a lot of people do do that (some of them now need glasses). Double handle turning brakes are a bit slower to make the change.

The reverse thing, going from 1st to R trying to get out of sitting on the pan in sand and throwing in the turning brakes also it disconcerting.

Also a lot of people forget to let up on the gas when jumping and land with the engine maxed out too. Gotta be some good shocking going on there too; Huckfest at Pismo in October being an example. http://www.bing.com/videos/search?q=huc ... A96A18D2D7

If you are sure about this then I am grateful for the info.

Lee

[Pablo2]

Offroading with a 113 swingaxle in this day & age can only be considered "budget racing" .. not nearly as reliable as a Type II with 091 4-spider chromoly diff. So, what I'm "sure about" is that a stock 113 swingaxle diff, machined for dual circlips, with 15/10 will be stronger (and lubrication will be FAR superior) in street or off-road than 17/11 in a POS "super diff" .. even though it has 4 spiders. (The class I've seen this tested in is stock engine class.)

But .. I'm also sure that anything will break eventually .. especially if driven without any regard for the limitations of budget components.

[Ol'fogasaurus]

"...But .. I'm also sure that anything will break eventually .. especially if driven without any regard for the limitations of budget components."

No argument and I am not trying to start an arguement either. I drive mild on both the road and on the sand. Currently am running an 091 but I also ran a stock sedan transaxle for several years. We also have two swing axle transaxles in our group.

Drag racing (I have done a bit of it) is hard on the diff among other parts but so can off-roading and that is what and why I am questioning/trying to get answers. One of my friends in CA just got his swing axle rebuilt and re-geared and now I understand he is getting a bit gay with his sand rail (including flying it occasionally).

Bruce2 was not impressed with the machining of a Superdiff which is a fairly standard thing to do during re-gearing of both bus and sedan boxes around here. I am trying to find out if something is more reliable than some think the superdiff is; plus the advantages and disadvantages of any changes.

With steering tires I don't use the turning brakes as much as I did but they still get leaned on at times. One of the guys who used to ride in our group had troubles turning to the left sharply so he lifted the front wheels with the turning brake on which I am sure you can figure out what that did.

Anyway, I'm not questioning/challenging as much as trying to get educated on your opinion.

Lee

[woodsbuggy1]

I am not sure if ERCO has fixed the improperly machined superdiffs that they were selling a year ago but German superdiffs are hard to beat if you are running a bus transaxle.
Good Luck
Kenric

[Ol'fogasaurus]

Thank you Kenric! Not going there quite yet. Still trying to get enough information to make a worth while decision.

Lee

[woodsbuggy1]

Lee,
If you are not having problems with the stock German diff, then I would not worry about it. A German superdiff is around $300 these days, It is a must for the riding that I do but we are mean to things at times. I think that German or Weddle should be the only superdiffs that would considered an upgrade to a factory 2 spider diff. The ERCO units that I have seen were very poor quality and resulted in several broken trannsaxles.
Take Care
Kenric

[Ol'fogasaurus]

The 091 I am using in my buggy was a recent rebuild when I got it (I got it from the rebuilder directly as he was junking out a bus two ladies owned that got T-boned). It works great it is just that the gearing is slightly off for my combination.



The other 091 I have is an unknown that I have sitting behind a Cologne V-6 (2.8 Ford that I beefed up a bit but it was build for bottom end torque) and it is really the one I am thinking about.

I got started paying attention to anything with super diff beomg discussed after a comment about the run out on the super diff that Bruce2 made a couple of years ago. What was said in this string is something I had never heard said before and a lot of ground was covered so I was trying to find out where and if there were any limits other then drag racing.

What you said it something else that I was not aware of which, tied with what Bruce2 said clears things up quite a bit. German or Weddle... It was not clear to me that the term "superdiff" was not a generic description but an an ERCO specific product.

Thanks to all of you for the additional information, clarification and patience.

Lee