ShopTalk Forums | Aircooled VW Tech & Restoration Help

Shad, I have the same system on the Blue Bug....It works well, and I felt the same about instructions..

I will keep a check on the rotors out back, but I made my own axle nuts, and torqued them to 500 Lb/ft!!!!! I doubt they will come loose.

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Jake Raby
Raby's Aircooled Technology
www.aircooledtechnology.com

I thought you were gonna say that the sytem is trash. Phew!!! I just got my 5 lug Porsche pattern kit about 2 days ago. Everything looks nice but the only thing I fear is the availability of replacement parts. What if a rotor strips out far from home?????


I think their other system uses a 914 rotor which would be better but its $499 instead of $359. I'll be installing it in two weeks since I will going to the VW show in Vegas on Oct.7 I'll be sure to check the torque on the rotor after I drive it. Thanks for the advice.

P.S. Word of caution when ordering from CB. They shipped me the rear 5 lug brake kit and only one 5 lug front rotor when I had clearly asked for two. Well, hell if I ask for two rear brakes wth the Porsche pattern the you'd think I'd also need a pair for the front right? They didn't think so and didn't even offer to pay for the shipping.

Patrick

When ordering from CB, ask for Baya...

She is the most helpful person there, and has never, I mean never goofed my order up..It may have been the fault of the shipping dept..

Baya was the one that took my order, and despite all efforts to have her at least take care of the shipping on the rotor she didn't budge. She was very nice though. I think she took $5 off. Whoopee!!! They didn't have another one in stock so I had to wait 3 days. No overnight or 2 day delivery to take care of the problem either. This isn't the frst time I've had problems with mail order from them. I guess I just have bad luck.

Patrick

Hello-

As for replacement parts, don't worry. Rotors are only $45 a piece to replace. Cheap as hell, huh? The only downside is that they are only 8mm thick, so turning is out of the question - replace every time.

Jake - check your torque again! I'd bet that they're no longer at 500 ft-lb... I went from about 225 ft-lb to less than zero...

BTW, I've been driving around tonight, and the groaning is gone. So, the bearings weren't that badly damaged. They just didn't like to be loaded lopsided, that's all...

Take care,
Shad

Hello-

This is NOT a solicitation, I promise. It is VERY IMPORTANT that ALL who are considering this kit or already have it MUST READ this post.

A few months ago, I purchased CB Performance's Rotohub rear disc kit for my '71 Ghia. It's a well-designed kit and includes all the gaskets and seals and everything, and the pads are semi-metallic. The caliper is a 34mm 1-piston floating dual-action (i.e. cable for e-brake, too) unit. The rotor is integral with the hub (hence the name Rotohub) like a Ghia front, but unlike the rears of a T3 or 914. I measured it with a drum, and it also does not change the rear offset. The performance of the kit kicks ass, and no more rear drum adjustment! It should be noted that the rest of my brake system is more or less stock - stock 19mm dual-circuit ATE master cylinder, stock 40mm dual-piston fixed calipers in front, ATE blue racing fluid, etc.

However, the kit is underdocumented and, I believe, caused by undertesting. The instructions for installation of the disc are good, but they do not mention how to load the calipers with the pads (which, for a guy like me who never experimented much with American iron with floating calipers, required some thinking...).

And, most importantly, they do NOT mention that the rotors are NOT AGED. This causes a MAJOR SAFETY ISSUE. After about 3000 miles of driving, I noticed that it sounded like one of my rear wheel bearings (left I think) started groaning. Uh-oh... it's dying. In a unrelated story, I recently purchased some pretty synthetic tranny oil to replace my conventional oil I used for break in (about 7000 miles ago...). I put the hypoid oil in this morning. With the left-rear wheel off the car, I noticed a big problem - the left-rear axle nut was COMPLETELY LOOSE, as in not even finger tight. Holy ^%$%&!!!. The cotter pin held, so I know that the nut didn't back off much. But, the rotor did shrink. After this discovery, I checked the right side, too. It was still tight (and the cotter pin was still in there), but it did need a good bit more to get back to the correct torque. I haven't driven the car much since this time, so I don't know if my wheel bearing was indeed munched or just not properly engaged thanks to being so damned loose...

End result: I'm calling CB in the morning to warn them about this safety issue. They DO need a break-in period - I'd say to loosen the nuts and re-torque every 500 miles for the first 3000 miles or so (maybe that's a bit much... but I'm conservative . I think I'll ask for a couple new rear wheel bearings, too...

Take care,
Shad

Did you check out the spacer sleeve that goes on the stub axle? I have heard of them crushing under the torque on the assembly. You can get hardened sleeves from Weddle Machine to prevent this.

Thomas

Hello-

The spacer sleeve... you mean the stock one about ~1/2" deep? I didn't check, but I seriously doubt it. I don't see why it would have... it's probably decades old and has been through many drum changes in the past. And, if so, that doesn't explain the simultaneous failure of both at the same time, using nothing more than the stock torque specs just like before.

Take care,
Shad

Shad...good info...a related question. How is the quality on the CB performance rear caliper bracket castings? Could they survive a little "shaving" on the thickness of the area under the outer bearing cover?. Reason for the question, my 412 uses the same outer bearing cover as a type one, but has a much different axle design...that uses the same rear drum as type 3. This will at first appearances allow me to use 914 rear disc hubs...bolting right up, and the CB caliper bracket bolting right up. The only real difference is that the gap between the outer bearing cover, and the flange face of the axle carrier....where the caliper bracket will be sandwiched...is about .045 thinner than it is on a bug. My choices are to machine a bit off the face of the bearing cover...or off the face of the caliper bracket. Ray

I was referring to the longer one that goes in the middle of the 2 bearing races on the stub axle. It was just a sugestion as I have never heard of a disk shrinking before.

Thomas

Shad... Good post, that can really save some people's cars for sure...

In relation to the shipping and customer service at VW companys...

I have talked to Baya many times at CB, and she is awesome. I have had nothing but good service from them...

FAT Performance... I ordered solid rocker spacers, hardened rocker studs, and a shim pack from them. They asked about my 2270 and the guy instantly said "You know Jake Raby?". Heheheh...

Anyways, they send out my stuff and everything was great... Until I looked at my credit card bill... FAT billed me $934.35 formy $52 order. Whoops. A call back and they took care of everything, no questions asked, and were very apologetic.

Moral of the story, customer service is not only getting it right the first time, but how well you fix your mistakes.

Later,
Tom http://www.qtm.net/~persoj

Hey everybody- ....(hey Dr. Nick!)

Ray - I think you might be okay. The bracket is made of cast aluminum and, IIRC, is around ~1/4" (plus or minus 1/8"... rough measurement, eh?) thick. If you want a better measurement, I can try to look tonight. The 914 hub and rotor idea is similar to CB's more expensive kits. I know that they use 914 rotors, but I *think* that the hubs are different, but similar...

Thomas - I'm not at home right now, but I need to go look at a parts diagram to see what you're talking about... all I removed to make the thing work was the bearing cover and all the goodies inside. The stub axle, CV, etc. were untouched. But, it's important to note that if this is the case, they both failed simultaneously, which doesn't make much sense. Cast iron DOES age. Good, GERMAN drums often come with a bluish anti-corrosion spray on them, indicating heat treatment to eradicate this problem. It's also the same reason why buying a 20 year old lathe or mill and having it rebuilt results in a cheaper machine that holds the tolerances better over time... the aging is already done. If CB sells new rotors for $45 a piece for a highly custom item, they can't be that expensive to make... good German drums, a production item, are often more expensive.

Marco - Most definately welcome. Glad to hear you got it fixed and nothing too serious happened to you! This is SCARY stuff and is a serious safety issue. I'm calling CB right now... I have a bit of free time...

I have access to some materials around here... gimme a couple days. I'll try to find the proper procedure for heat treating cast iron. I don't know many specifics about these processes for cast iron. If it's similar to what it is for some aluminums, then it can be done by you and I in our own kitchen oven...

Take care,
Shad

Here's the specs for the thickness in the picture to the right ---------->

I can only imagine the number of people calling CB saying that their rear rotors have stripped out. Hey for $45, you can't expect much. Most of the stuff says IND.BRAS on it, which means it was made in South America. I've gone throuh a few drums in the past that were made down south. It actually felt as if they were made of hardened cardboard. I hope I don't have that problem with these rotors.

Patrick

OH MY GOD! THEM F^£KING NUT'S
(Hi, I've just put a close box in my bug(63).
It has a 3.88 r&p 3.30/2.21/1.48/1.04 all Erco gears, the gear box is compleatly solid mount and the frame horns tied into the car.
the rear tires are 205/55/16 Yocohamas 24.8in in total hight.
Im using KYB GR-2 shocks and the car is standerd hight the suspention is quite soft at the back, as i have a heavy 2.1 waterboxer , It has about 150bhp at the rear wheels
The problem I have is rear of the car judders when I lanch(5000rpm) from stand still(like wheel hops) and then spins the the wheels as I get moving!
how can I stop this Juddering?)

I posted this on the drag racing forum couple of days ago but i forgot to say I'm using CB discs on the rear!

Guess what happend! thats right, the nuts have worked they way loose from 300flb to 0flb in only 100 miles!
Now its all making sense...

Thanks Shad.

Shad...4speed..Thank you for your replies, they helped. Looks like I may have to take just a hair off the bearing cover also. This rear axle, if you are not familiar with it, uses a forged stub axle, with the type 3 ish looking rotor hat...one piece. The inner end is splined to mate up with the outer cv joint hub which contains a bearing race. This is all machined from one piece of forged steel, and has been heat treated at the outer flange area. It runs in 2 large tapered roller bearings with a hardened spacer. The whole deal is sandwiched together by a long 19mm bolt with locking tabs. Very nice rear axle. The 914 rotor bolts up with about 5 minutes of clearancing to the center hole...about .020 difference, depending on the year of rear end. I'll let you know how it works. Ray