Paulyy

So after doing it twice. I am now doing it the 3rd time (3rd times the charm hey?)
Everyone knows what a crappy job is doing the TT bearings. So i'm here to help with my mistakes. (we all make them, so it's ok if you make one)

And boy are there lessons learnt.

BTW this is not a DIY, this is me giving some advice.


First you need to remove the bearings out of the TT
Use clarks garage method. works fine. no problems there. Click here for link


Second is to inspect your bearings.
the rubbers on the outer housing should be fine. The rubber in the inner bearing is the one to look at. You want it to be intact. But lets face it, it probably wont. Some may have fallen apart a little. If theres a pit missing from it, it's fine. If half of it is gone. throw it away.
The next bit is to check if it's shiny or not. meaning if the shaft has spun on the rubber and is now not able to hold onto the shaft.
A way to check that is to slide the bearing onto the shaft. If it's grips and hard to get on and off. It's good to go back on.
If it's very easy to slide on and off. no force required. Then it's junk. Throw it in the bin and don't think about trying to use it.


Taking apart the bearing from the housing
It doesn't take a rocket scientist to figure this out. The top rubber comes off.
The housing will most likely be 2 half riveted together.
Some are pressed in (easier i suppose)
Drill the rivets out and it'll split apart.


Removing the rubber coated steel sleeve from the bearing
The inner bearing is 30mm ID. So if you can find something that's 29mm to use to tap it out with a hammer. that'll be the easy way. If you can't remove them, take it to a machine shop and ask them to remove them for you.
Only remove if you plan on reusing them
You may be able to use a little pin punch and tap it out slowly.


Replacement bearings
I suppose these are just bearings. There are some requirements though.
The bearing size is 6006. Needs to have a metal shield on both sides.
Clarks garage specifies *** 6006 2Z (*** is the brand name and it's a common bearing)
They'll work or ask your bearing shop for something better if you wish so.

Bearing sleeves - most important info here
If you're reusing the old sleeves. press them into the bearing and be done with it.
If not - Find some good condition used ones!

Do not use Derlin Plastic
Clarks garage recommends Derlin plastic, but i don't.
This actually a poor fix. The plastic will wear out if the bearings are miss aligned a hair out.
once the plastic is warn, you'll get vibrations around 3k rpm at load and all your hard work is out the window.
The plastic can actually wear out the shaft a little also.
This is exactly what happened to me.
We took the plastic to a plastic engineers shop and he recommended something else. (don't remember the name) but it was a little softer so to speak. But it's hard as it's plastic, not rubber.
This time, we had 2 bearings out of align. this time the plastic gripped into the shaft and pulled itself out of the bearing.
So if you do use this plastic, the bearings need to be 100% straight inside the TT or expect them to wear quick. - But i do not recommend. So do your self a favour and find good used sleeves.

Installing the bearings and shaft back into the tube
Use Clarks garage method here. works well.
We did something else with the bearings and machined up a plastic bar with the OD same as the ID of the TT to get them 100% flush inside.
But when putting the shaft back in place, they will move a little.
You've been warned again if you use plastic


Now if you dont want to mess around with the bearings and just want a replacement unit. You have the 944 super bearings to use. Expensive, but worth it.
http://www.blackseard.com/site/index.php?option=com_content&view=article&id=6:944-super-bearings&catid=1roducts&Itemid=9

I hope i've helped.

Paulyy

Saving this space for when we've finished our bearings we're making.

Yes we're making our own carriers and sleeves.

No they're not for production.

jmj951

Thank you! I will be rebuilding my torque tube this year (or sending it off for a rebuild) and had never heard of the Black Sea bearings. After reading the details on their site, I'm just hoping that the shaft is reusable.

Paulyy

They dont really advertise much, there was a thread about it i think in too
Shaft is reusable. don't worry about that!

V2Rocket

Pauly,
I have done a few tubes with the threaded rod method but am considering modifying an air-over-oil hydraulic press for the next one...should go a lot faster and quieter!

I'll share when the time comes, and I intend on the super bearings.

Voith

Plastic/rubber shielded bearings are better but they weren't better in the 80s thats why they used 2Z but it is perfectly fine to use 2RS1 nowdays.

6006 standard tolerance is absolutely not the right kind of bearing and if you used it that is your problem right there, not delrin sleeves. Bearing MUST be C4 tolerance group.

I have sold more than 10 sets of SKF 6006 2RS1 C4 bearings together with delrin inserts and nobody had a problem so far.

Eric_Oz_S2

Pauly

Nice write up.

As a point of reference I'll tell you about my experience. I rebuilt my torque tube probably 5 or 6 years ago. I used acetate plastic sleeves to the spec in Clarks Garage. I reused the outer rubber bearing cases and used c4 clearance zz shielded bearings. Bearings were offset about 50mm from original position so they were on unworn sections of the shaft. New bearing units were pulled in with a threaded rod and the shaft pushed through the bearings (pinned with 3 screws each) with a jack.

The car has been well and truly flogged on the track since then, probably around 40-50 track days - no problems. And that is with a torque tube with the split that are supposed to be un-rebuildable.

Ifly951

I say Super Bearings from Constantine. I am waiting them now, and will begin reassembly this weekend.

I know it's alot, but I do not plan to do it again. And they have some added benefits.