lockers and LSDs

[fusername]

what about drilling out the rivits and replacing the clutch material?

cluch and brake linings

[Pablo]

Drill out what rivets ? I'm afraid brake pad material (however fastened) wouldn't cut it as an LSD friction material.

Over the past 5-6 years, a number of Chinese LSDs have made their way into the marketplace. The first of these had notched or acid-etched plain steel plates, which did a poor job of providing friction. Then came bonded carbon discs, similar to the cheap discs found in Porsche "street" LSDs. Also attempted were brass coated friction discs. These various cheap friction discs fail in short order, or fail to perform even when brand new.

In my opinion, the only worthwhile friction disc is of the plasma-sprayed variety, where a plain steel plate is bombarded with metal particles at extreme velocity. These particles become so embeded in the steel that they become part of the plate ... not something that comes unglued, unbonded, sloughs off, or wears out in short order. Friction discs are probably the most critical component of an LSD to manufacture properly, and the required outsourcing of the plasma bombarding treatment adds a huge expense to the manufacture of an LSD.

JMHO

[Sneaks]

What is the truth on the AW code for Thing trannies? I read on another site:

"Every Type 1 IRS LSD I have found inside a gearbox came from a 'box with code AW. That is the code for a Type 181 with a ZF LSD. AV is the code for a Thing trans with an open diff."

Whoever wrote that is a pretty smart guy.

Must come with the name, that guy is named Bruce too.

[Bruce2]

I admitedly had the swingaxle (not IRS) VW ZF on my mind when stating that virtually all friction discs are worn out. (I don't think I've ever seen a serviceable disc in a used swingaxle ZF.)

That's a fair statement. The vast majority of the bi-metalic swing axle discs I have seen were junk. Of those, the main cause was improper assembly by the dummy that went inside the last time.
The last version of swing axle ZF used the same technology discs that the IRS diff did. These diffs survive much better.

[fusername]

could this be an attempt at a lsd?

I was at the 914 World transmission clinic this weekend in Sonoma. When I pulled my differential, the leaders were completely baffled by the modification that had been done to it. This is a 902/01 transmission from my 912.

Ideas?

[Tom Notch]

Looks to be a Grade 8 bolt threaded through the diff and the bolt then pressing against the spider gears and held by a jam nut. By cranking down on the bolt applying more pressure to the gears *may* do something, but as the parts wear............

[fusername]

I was thinking the same thing. And I have no idea how the spiders would feel about being loaded like that. Unless there was a matching dimple drilled into the backside of the spider to make it a full lock, or a crazy strong spring wound up to in there to compensate for wear. unlikely, as I imagine a significant amount of force is needed to keep the spin in check.

[fusername]

also as far as cutting corners, I understand there is something in the diff or whatnot you can shim to increase preload, causing a better limit on freewheeling, but at the cost of increased wear. My question is increased wear on what? and more details on this process would be cool. Because if it is something simple enough to do and replacement parts can be had, it would work for me.

[xgrove]

I simply don't understand why they'd make this a locked differential. It's a 912, meant for excellent cornering not dragster style runs. And seriously, it's a 1.7 liter. I'm going to pull it and plug the hole unless somebody tells me otherwise.

RG

[ntsqd]

also as far as cutting corners, I understand there is something in the diff or whatnot you can shim to increase preload, causing a better limit on freewheeling, but at the cost of increased wear. My question is increased wear on what? and more details on this process would be cool. Because if it is something simple enough to do and replacement parts can be had, it would work for me.

I'll speculate, based on a sample of one, that adding another shim to a pass car diff will cause a part to spectacularly fail. Ask me how I know.....

[petew]

ok, "how do you know?"

[ntsqd]

I threw the parts out.

[petew]

what sort of answer is that? you could at tell us WHAT failed and how [pete excited by the thought of someone elses broken metal]

[ntsqd]

My memory is dim, this was about 20 years ago. What I recall is that there is a spacer that fits between the side gears made of rolled and then hardened thick flat stock, which is then ground to size on the ends. It necessarily has hole in to for the crosspin & what-not. Bolting the diff case together with one extra shim in there worked. Right up until I had the buggy 90% reassembled. Then something in the t/a went BANG!!!.


I got to take it all apart again and then find another such piece as that spacer cracked under the pressure and imploded.

[fusername]

does anyone have pictures of how the syncro locker works? either of the locker installed in the case, the selecter pieces, the differences between cases, anything? I just found myself a locker and am probably gonna buy it and put it up on the shelf for later tomfoolery. Need to see how its supposed to work, as it doesn't come with a case or the vac pod. I will try and rig up either a cable pull or just leave it on at all times and discover a locker is wayyyyy too harsh for such a butt heavy car. My understanding is it spins open say when taking a corner, but when one wheel starts spinning faster than the other it turns into a fully locked axle?

be nice I am new here, and spool only tells me how it senses to lock, not how hard.