Bearings

[edward ericson]

Some of you know I screwed up my front wheel bearing lash when I put my new disk brakes on just before heading up to Carlisle. For those who don’t, I offer the following cautionary tale.

First I installed the Empi 4-bolt Karman Ghia-style disks and rotors, with the new spindles. Everything went together fairly smoothly. I installed new wheel bearings and races even though the kit instructions say to pop the old ones out of the old hubs. Too greasy for me. 

I “pressed” the new inner races in by the Muir book, using a big socket as a drift, putting a 2×4 on that and hitting the 2×4 with a small sledge hammer until it would not go any further. I greased the new bearings as they should be. I cursed my stupidity in not getting a box of nitrile gloves. I used a lot of Dawn dish detergent on my hands when I was done. 

Inner and outer races seemed to go in OK. I did this same job on the drums a couple years ago.

I put the disk/hubs on the spindles, packed a ton of grease in there and put the big king nuts on the end. 

These are the split nuts with the 6mm Allen set screw in them to keep them still once they are right. The driver’s side is reverse-threaded to keep the wheel from trying to spin them off. . 

Muir says snug them up good and tight with the wheel spinning, until it stops, then back them off so the wheel turns, snug them up again and then set the torque on them so the big washer under them just moves when you pry it with a big screwdriver. 

At that point the wheel should turn with little or no drag, but if you try to wobble it with your hands at 12 and 6, it won’t. Got both sides like that, tightened the allan bolt and had trouble getting the dust caps to seat. Driver’s side too tight. Passenger too loose. I got the pass side to stay by wrapping some alumatape around the hub before putting the cap on. Driver’s just took a little persuasion.

Test drive. Brakes work great! Drove around, did about 30 miles, parked the car.

next day I try the 6-12 wheel shake test. Uh oh. Driver’s side is a little loose.

I jack up the front end and re-set the lash. Same procedure. It comes tight and so I drive the long way to Carlisle with the caravan. 

The trip is uneventful, in terms of wheel-related concerns. (Engine quits randomly for like 1 second on the highway, three times…wha??)

Everything seems Jake until the Auto-X. I do the 6-12 test on the show field and–DAMN!–Loose again. WTF?

So we tighten them again, hurriedly, before hitting the track. 

I believe this was a mistake. Never hurry repairs before a race. Right? 

But I looked at the bearings, looked for any grindings, saw none and they tightened up OK.

So I flogged her around the track a few times. Wow, that’s a lot of brake fade! I thought these disks were supposed to NOT fade like drums. And also, WTF? The fade comes in like the second lap, in the middle slalom. Then she’s good for the far right turn, then no good again on the next turn before the start-finish. Weird.

And so you know: Loose again. Tested them after the laps. They are way more loose than I’d ever felt them. My brakes were not fading; my rotors were wobbling a quarter inch side-to-side, pushing the calipers apart.

Now I figure I need new bearings for sure. I buy new bearings but, again, on the field, messing around in the grease, these bearings don’t seem beat to death. Again we tighten them up.

Next day, running home in the rain, they feel fine. I shake the tires when I get home and there’s just a little play. Maybe more than is right, but not by much, if any.

Yesterday i get up early for Cars & Coffee. Chilly morning. I break out the Snoopy hat, gloves and goggles. Psyched.

Roll out the driveway, down the street. I hear this weird groan-squeak coming from the front. Sounds like front-right. Matches speed. Turn around and park it.

So today I’m back into it. With the front end on jack stands the freeplay at 6-12 is basically gone. The passenger side has a little drag, but it feels almost like a bit of disk brake drag. Ok so I take the dang wheels apart again. Grease looks good. No shavings to speak of. The bearings feel ok. 

Finally I do the thing you are supposed to do every time you take the bearings out for any reason. I clean. Here is the outer right side. Keep in mind: it is the left side (driver’s) that takes the brunt of the pressure on the auto-x.

That, my friends, is not a round thing. Amazingly, the bugger still spins pretty smooth in my hands. But I suspect I have found my squeak-groan. 

I quit for late lunch/early dinner. After this I will remove all of the others and put the new ones in with new grease. 

Somehow, I hope I have learned something.

edsnova2015-05-24 16:15:04

[edward ericson]

And. Update. 

So I got the new bearing set installed last night. Things went together about as smoothly as could be expected. 

Because I’m a real thinker, I swapped the rotor hubs side to side. I did this because the dust cap on the driver’s side was WAY tight, while on the passenger side it was WAY loose. Flipped side to side, I figured, the caps should fit just about right. And I was right.

But when I got the driver’s side back together I could not get a good end play. The wheel kept locking up before the big nut was even close to tight. 

So this a.m. I pulled the wheel, and the caliper, then put the wheel back on to set the lash. 

SMOOVE! Took two minutes to get the bearings dialed in nice.

Then I pulled the wheel again, put the caliper back on, and put the wheel back on. And now it is frozen.

STUCK CALIPER! DAMMIT! 😡

Just for larfs I test drove around the block, with the idea that maybe it would unstick itself.

Nothing doing. 

Now, remember: before I started this procedure, the “draggy” side was the passenger side. The driver’s side spun free and easy. But now, with the former passenger disk now on the driver’s side, the thing is almost locked up. Pass side is just about perfect–just the slightest little touch of the pads on the rotor. 

So I ask all of you: 1. Any theories?

2. Has anyone ever fixed a sticky EMPI Karmann Ghia-style caliper? This one is brand new, as are the pads. Any parts I could lube or fiddle with short of a caliper rebuild?

Cuz I really don’t feel like doing a caliper rebuild.

edsnova2015-05-25 17:08:27

[Royal]

Ed, I had to rebuild my new calipers when I put on discs.   I don’t think their QC is very good. 

[edward ericson]

So continuing my scientific method, after looking at the stuck caliper a minute, I had the idea to shim it.

I took the washers from under the bolts that hold the caliper to the mounting pointon the brake backer, and I put those washers between the caliper and said mounting point.

The wheel spun freely now. So I test-drove it to see how it would do. Pedal was still good. Stopped straight. Seemed OK. Bashed the breaks around the block, pulled into the garage, and jacked her up to find the wheel still spun freely. It was just about perfect. Maybe a touch hotter on the driver’s side than the passenger’s. 

Still. 

That seemed like a bloody idiot “fix.” So I re-mounted the caliper the right way, with the idea that maybe the piston could somehow find its full travel. Nope.

Looked up how to service these. Need an air compressor with a rubberized fitting, which I have none of. Looks like a joy.

How’d you do it, Roy?

[Royal]

Ed, I read somewhere that you had to shim the calipers to get the best fit.  So, I installed and shimmed  mine with washers under the caliper as you did (temporarily).  No problems yet in 2 yrs and 2500 miles. 

As for my caliper rebuild: I am a great one for spending 2 days fiddling around with something just so I don’t have to buy a $3.98 special tool that would have allowed me to do the job in five minutes.  In other words, I think that you could do it with good light and a bit of patience (and no special tool).

My kit came from CIP1.

[edward ericson]

Thanks, Roy. I will examine caliper shimming.

UPDATE: Well tickle my ass and call me Nancy. Page 2 of these instructions did not come in the box I bought–nor the shims. Page 1? That is exactly what I have. 

Looks like I will be in business again sooner than I imagined.

Update to the update: The dang shims are what I took to be the washers. I had the thing fixed this afternoon and did not realize it, second-guessing my theory.

edsnova2015-05-25 20:06:40

[Paul Mossberg]

Congratulations Nancy! Glad you and Ed figured it out.

For the record…I am pretty damn sure no one here is going to be tickling your ass. Just sayin’! ❗

Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster

If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

[edward ericson]

Paul…how long we been friends? I can’t believe you’d be so cold like that. And speaking for all the other guys too. How do YOU KNOW no one wants to tickle me keister? 

[billnparts]

How ’bout we dip you in sh*t and call you Stinky instead?

Bill Ascheman
Fiberfab Ford
Modified 5.0, 5sp., 4:11
Autocross & Hillclimb
"Drive Happy"

[edward ericson]

If that’s what you’re into, I guess I’ll try it.

[Paul Mossberg]

Now, now, Ed. You’re the writer, and yet you mis-quote my words?

 

I said I was pretty sure. I never said I “knew.”

 

There. I feel better now.

Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster

If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

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