MGB throw out bearing going bad

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marankie
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MGB throw out bearing going bad

Post by marankie »

My MGB-GT clutch throw out bearing is going bad. It makes noise when the clutch pedal is depressed and there is a smell. I suspect that the upgrade aftermarket roller type throw out bearing that i got from Moss is starting to seize. Bummer, as I installed it only about 4 years ago when I rebuilt the car. What are the experience based comments about the roller bearing as apposed to the the factory carbon type throw out bearing.
To replace the throw out bearing, which is quicker....remove the motor or remove the gearbox?
I'm getting a bit older. If I wanted a commercial repair tech to do this work, what shops would be recommended? I live in Agoura Hills which is in the Thousand Oaks area.
Your inputs are welcome.
Martin Jansen
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Steve Simmons
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Re: MGB throw out bearing going bad

Post by Steve Simmons »

Hi Martin, I don't have any personal experience with roller bearings but I've done a lot of research on them. The problem is that the MGB fork travels in an arc, which puts a side load on the roller and it isn't designed for that. And while there have been a lot of failures, a lot of people have had good luck with them as well. Seems to be luck of the draw, or maybe something about driving style. My choice is a good quality carbon bearing, which seem to last just about as long as the clutch. Getting a good one is sometimes the hard part, but the Moss unit in my car has done well so far. Just inspected it a while back after 10K miles and it looked new, so I put it back in.

Unfortunately there is no way to pull the gearbox with the engine in place without cutting the rear cross member. It's tight, but you can pull the engine without the gearbox. So unless the gearbox mounts or seals need to be replaced, that's the easiest way to go. And while it's apart, may as well get the clutch rebuilt (unless it's low mileage of course).

There's a shop in Thousand Oaks but they were really snobby when I tried to get work on on an MGA a few years ago. Dave Wellwood is in Ventura. In the west valley are Darrin's MG Service (Darrin Sher) in Chatsworth, Checkered Flag (Joe Siam) in Chatsworth, and Kavanagh Motors (Declan Kavanaugh) in Tarzana I believe.
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tannyo
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Re: MGB throw out bearing going bad

Post by tannyo »

There's also British Car Service (Russ Thompson) in Northridge, CA at 818-256-0693

You might consider using a TR7 clutch instead of the stock MGB clutch if you replace it.

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marankie
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Re: MGB throw out bearing going bad

Post by marankie »

Thanks Steve for You comprehensive reply. Very helpful. Thanks to you too Tanny. You know as yone get s older, the urge and energy to work under the car for big projects lessens considerably.
BR
Martin
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Re: MGB throw out bearing going bad

Post by VWNate1 »

I hear you martin ! I'm old and crippled and i trust no one to do things properly but it's getting hard, very hard indeed .

Anyways , is there no source for ball bearing typ throw out bearings ? those are what I always prefer a they don't seem to care about the side loading issues .
-Nate
marankie
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Re: MGB throw out bearing going bad

Post by marankie »

It took a Week the jobs done. It was hard and took about 10 hours spread over 4 days worked on. I was lucky. I had help from ex Brits Colin and Ian, both who spent their professional life as tech reps for Bentley, and both own a 72/74 MGB.
The first day I unbolted most stuf. Then Coolin and Ian came with a Harbour freight engine hoist, and after a couple of hours the engine was out, the gearbox being left in. Then a couple hours cleaning up, replacing the freeze plug in the block which had become dislodged, and replacing the pressure plate, clutch plate and throw out bearing. After the weekend Colin and Ian are back and we spend a couple of hours fighting the lump to get it back in and on the spline. Colin and Ian on top adjusting and pushing, me underneath pushing and shoving and rotating the drive shaft to get the spline to engage. finally it had enough. But there are 8 bolts holding the bell housing to the engine, with almost inaccessible nuts, the exhaust manifold, had to thread the studs back into the head ( were previously removed to allow engine to be pulled) reinstall steering rack, reinstall, radiator starter motor etc etc, most of which was nuts and bolts which are hard to get to. But finally success, we are back on the road. British labour must have been very cheap at the time of build to accommodate all of the fussy build time hours to put the car together.
By the way, i had previously had trouble with the freeze plug at the end of the block becoming dislodged, and requiring a flat bed tow back to my house from Ventura. I was able to pry it back, and fabricate a fill piece between the back engine plate and the block to prevent the freeze plug from popping out again. It had been previously JB "welded" in place. With the engine already out for the clutch, obviously install new freeze plug. Moss offered two , one made of steel ( as I had previously installed, and one made of brass. The brass one measured out to be .020" larger that the steel one. So I installed the brass one first, then JB weld epoxy, then the steel one as a filler, and the the fabricated steel fill piece on top of that. Let's see: that's belt, suspenders, Velcro (JB) and a door stop holding in the "bloody plug" ( British speak).
I love my little MBG-GT, but it is a "pain in the ***" (American speak) to work on. Martin
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Steve Simmons
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Re: MGB throw out bearing going bad

Post by Steve Simmons »

Shouldn't have needed to remove the steering rack, but I'm glad the job is done.

On my MG TC there is an oil galley plug at the rear, covered by the bell housing. They are known to leak so I installed a steel one with sleeve retainer, then a brass one on top of that! Belt and suspenders are good peace of mind. :)
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