SAAC Forum

The Cars => 1968 Shelby GT350/500/500KR => Topic started by: Corey Bowcutt on March 06, 2018, 12:52:31 PM

Title: 1968 GT350 Throwout bearing replacement
Post by: Corey Bowcutt on March 06, 2018, 12:52:31 PM
I am considering replacing my throwout bearing when I swap out my transmission.  I am wondering two things.  1) is there a good place to buy a throwout bearing for the GT350?  2) Does anyone have any exploded views or how to documents for replacing the bearing?

Thank you, Corey
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: CharlesTurner on March 06, 2018, 04:41:03 PM
It's typically recommended that all 3 clutch components should be replaced at the same time as they all wear together (clutch disc, pressure plate, release bearing).

Title: Re: 1968 GT350 Throwout bearing replacement
Post by: shelbydoug on March 06, 2018, 04:46:09 PM
I've seen throwout bearings with well over 100,000 miles on them that were still tight and just were "polished" on the contact areas.
They usually cause very little problem.

If you feel the pedal hanging it is not usually that bearing.

I'd wait to do the entire clutch rather then pull the bell apart to change the throwout bearing?
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Bob Gaines on March 06, 2018, 05:09:28 PM
Quote from: shelbydoug on March 06, 2018, 04:46:09 PM
I've seen throwout bearings with well over 100,000 miles on them that were still tight and just were "polished" on the contact areas.
They usually cause very little problem.

If you feel the pedal hanging it is not usually that bearing.

I'd wait to do the entire clutch rather then pull the bell apart to change the throwout bearing?
Unless it starts squealing.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Corey Bowcutt on March 06, 2018, 07:36:38 PM
Bob hit the nail on the head.  I do not know for absolute sure how many miles are on the current set up.  But the PO did the engine and trans overhaul between '95 and 2000 so I have to believe he put in a new clutch at that point.  He barely drove the car.  My guess is the set up has certainly less that 10,000 miles on it and possible less than 5,000.  So I have no reason to believe the clutch or pressure plate are bad.  But the throwout bearing does squeal especially when cold.  So I was just thinking while I swapped transmissions I would swap the bearing ion it was easy.  I have never done it before so not sure exactly what is involved.  But I rebuilt a 66 Mustang when I was 17 years old and knew nothing and that did not stop me.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: KR Convertible on March 06, 2018, 07:55:50 PM
It is easy to change with the trans out.  You can reach in through the bellhousing and change it.  It just clips on the end of the fork.  Some of them have grease fittings to lube them.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: KR Convertible on March 06, 2018, 08:11:47 PM
If it does have a grease fitting, go easy with the grease.  You don't want to contaminate the friction material.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Corey Bowcutt on March 06, 2018, 08:38:55 PM
Thanks KR Convertible, that is what I was hoping.  Any idea where the best place is to get a new bearing?
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: KR500 on March 07, 2018, 08:46:49 AM
Corey
Most auto parts stores have them or can get them easily. Make sure the front transmission bearing retainer is not worn as the release bearing can hang up on it.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: PR on March 07, 2018, 09:27:11 AM
Clutch kit are cheep, while your in there do it all, then you know for sure what you got, you may be surprised how worn it looks, turn the flywheel and replace pilot bearing , ram - McLood makes good stuff , you be glad you did afterwards
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Corey Bowcutt on March 07, 2018, 09:44:31 AM
Is there anything tricky about swapping out the whole assembly and pilot bearing?  Any special tools required? and pictures of this procedure?
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: KR500 on March 07, 2018, 09:59:40 AM
Corey
sent you a PM
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: CharlesTurner on March 07, 2018, 10:34:19 AM
Quote from: Corey Bowcutt on March 07, 2018, 09:44:31 AM
Is there anything tricky about swapping out the whole assembly and pilot bearing?  Any special tools required? and pictures of this procedure?

The only special tool is the clutch disc alignment pin, which usually comes with the clutch kits.  If you're going to swap all the clutch parts, might as well get the flywheel checked out and possibly resurfaced.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: shelbydoug on March 07, 2018, 11:03:05 AM
Quote from: Corey Bowcutt on March 07, 2018, 09:44:31 AM
Is there anything tricky about swapping out the whole assembly and pilot bearing?  Any special tools required? and pictures of this procedure?

Yes. Getting out the pilot bushing requires some alchemy. There is no specific tool for it that I know of although it is POSSIBLE that there was one made and included in the original "Service Dealer's tool kit", although I've never seen one?

I usually wind up using a tap threaded into the bushing and when it gets through will press the thing out of the crankshaft.

I'd stay away from a bearing type replacement. The bronze bushings rarely wear out and certainly are a lot more forgiving then a bearing in there.

The only reason to replace them would be if it obviously had worn oblong and the hole is seriously out of round.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Jim Herrud on March 07, 2018, 11:36:01 AM
With regards to doing clutch work, I was recently educated about the importance of "indexing" the bellhousing to check for proper centerline alignment and promote long bushing life. Some folks experience driveline vibration and occasionally have repeated bushing and clutch failures. One cause is a bellhousing that is not accurately aligned with the flywheel/crankshaft. If the bellhousing is more than approximately 0.005" out of alignment, the out-of-round condition can cause this vibration and lead to premature failure of the bushing and other clutch components. Bellhousing offset pins are available to bring it into proper alignment. MD and other resources have documentation on how to perform the indexing procedure. MD's procedure is located here: http://www.moderndriveline.com/Technical_Bits/proper-bellhousing-alignment-indexing.htm

I did this on my car since it will see extensive driving and rather severe duty. It checked out OK - just inside the acceptable limits.  My standard size magnetic base was too large to fit on the flywheel without interfering with the inside of the bellhousing when I rotated the crankshaft. I purchased a mini-magnetic base for my small dial indicator from Grainger that did the trick.

Shelbydoug mentioned an actual bearing that is now available to replace the pilot bushing. I had also recently discovered this and spoke with MD to get their take on it. They said that so far, the bearings seem to work OK, but at the same time, the bushings work just fine and have less chance of causing a problem. KISS principle.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Corey Bowcutt on March 07, 2018, 11:46:52 AM
This is all great information.  I really appreciate the help.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Cobrask8 on March 07, 2018, 11:52:56 AM
Also a big issue is if the throw out slides smoothly ion the trans snout. Any bumps, ridges, etc will make the clutch work horribly no matter what else you change. This is a very typical problem for late-model Mustang guys with the T-5 aluminum snout. We all change to a steel one.

Use a quality clutch with above average material, and normal pressure plate specs.

Also - all our classic mustang/Shelbys are prone to pedal, linkage, and bushing wear. Check it all out carefully!!!! That alsdo makes clutch operation poor.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: KR Convertible on March 07, 2018, 12:11:52 PM
Corey,

Whichever way you decide to go, just make sure you use quality parts.  For the throw out bearing I would go to Napa if sourcing locally.  Look for a name brand bearing such as National or Timken if you decide to order online.

The pilot bushing can be a problem to remove.  I have never had too much trouble, but have heard some horror stories.  I have a slide-hammer with a bearing hook that I use.

If you want to make the trip, I would be happy to help you do the job.  I have a lift, trans jack and brake lathe if the flywheel needs surfacing.  I am an hour north of Philly.
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Corey Bowcutt on March 07, 2018, 01:32:48 PM
KR Convertible PM sent
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Steve McDonald Formally known as Mcdonas on March 07, 2018, 04:33:57 PM
Corey if you need a pilot bearing puller I got one you can use. Or your can do it the old fashioned way and pack the pilot bearing hole with grease and use the wooden dowl that fits snuggly in the hold and hit it with a hammer.
I think I have an old Ford self training book that shows how to "index" the bell housing to the block
Let me know and I'll dig them out
Title: Re: 1968 GT350 Throwout bearing replacement
Post by: Corey Bowcutt on March 07, 2018, 04:57:49 PM
Steve,  I sent you an email.

Corey