Throw out bearing question

[shadowfax101]

Hello, new to the site, and I have this issue that has been a problem since I bought the car. Its an 81 Vin 06060 and it has a squeaking throw out bearing. When you are not pushing in the clutch it is very noisy and loud squeaking. When the clutch is pressed in even an inch or so the noise stops. My first attempt to fix this was about 3 months ago and I had a new clutch, throw out bearing, fork, master and slave cylinders, and steal line installed. After about 2 weeks the noise came back. I am not sure how to go about fixing this. I am not sure if the shop installed something wrong, that I had the luck of having a bad throw out bearing installed, or if I should look some place else for the problem. Thanks

[Jacko]

I was hoping someone would jump on this question with an answer. The exact thing was happening with 4915's throwout bearing which was the one thing that caused me to send her to DPI. I thought the throwout bearing would be completely at rest with the clutch out ... maybe it isn't disengaging completely. I don't know.:question:

[shadowfax101]

I am glad that I am not the only one with this problem. I do hope someone can share some insight

[David T]

Sounds like an input bearing. I would pull the transmission and open it up. Check all of the bearings on the input shaft and make sure the nuts on the ends are nice and tight. Before even pulling the trans check the oil level. If it is very low put some in and maybe the noise will go away.
David Teitelbaum

[DMC5180]

If it is the TOB the actual P/N is SKF 4040. Only PJ Grady sells them separate from the Clutch kits that I know of, if you do indeed need one. Did you replace the Pilot bearing? The pilot bearing only spins when the clutch pedal is pushed IN, which is opposite what you've described.

[Jacko]

If it is the TOB the actual P/N is SKF 4040. Only PJ Grady sells them separate from the Clutch kits that I know of, if you do indeed need one. Did you replace the Pilot bearing? The pilot bearing only spins when the clutch pedal is pushed IN, which is opposite what you've described.Dennis, do you mean the throwout bearing only spins when the clutch pedal is pushed in? I thought the pilot bearing stayed pretty much static.

[Nicholas R]

Dennis, do you mean the throwout bearing only spins when the clutch pedal is pushed in? I thought the pilot bearing stayed pretty much static.

The pilot bearing never changes or moves. It is inside the crankshaft and only serves as a support for the end of the transmission input shaft. It is not affected by clutch engagement and disengagement.

Also, As far as I know, and in all the times I've changed clutches on DeLoreans and other cars, you want the throwout bearing lightly riding on the fingers of the pressure plate, even when disengaged. This holds the throwout bearing in place. If it isnt against the fingers, the throwout bearing and clutch fork have will vibrate and slide around on the input shaft while the clutch is disengaged.

[Raphael]

I experience the same issue. The fact is the noise isn't related to RPM; it's the same whatever the gear and engine speed. in case you'd ask; YES my TOB is new, the fork pivot is greased and the noise is still there, anf it tends to appear at temperature. and it disappears as soon as I gently press the clutch.
so it's not a bearing ( I had 2 bad TOB in the car's life and it's definitely different noise, that appears when you depress the clutch.)
I suspect the clutch fork to vibrate at rest position and squeak. when I lean over the engine or under the car, it sounds like it comes from the above, from the fork area.
When I keep the fork steady in my hand, the noise stops.
I tried to attach a spring from the engine bay to the top of the fork but it didn't work.
So now I plan to attach some sort of rubber bumper. maybe a piece of hose bent in u-shape. I will let you know

[Bill Robertson's Sock Puppet #1]

Sealed bearings aren't worth 2 cents. You are totally at the mercy of whatever kind of grease, and however little, the nice Chinese people who make them put in. And the rubber seal is not moisture proof (in fact when you regrease them yourself that's how you know they are full -- grease squishes out around the seal).

Buy a needle tip for your grease gun (smallest diameter possible). End of the tip is cut just like a phlebotomist needle. It will pierce the rubber seal, allow you to inject the bearing full of grease of your choice, then reseal the hole when you pull it back out.

[LEVY]

Sealed bearings aren't worth 2 cents. You are totally at the mercy of whatever kind of grease, and however little, the nice Chinese people who make them put in. And the rubber seal is not moisture proof (in fact when you regrease them yourself that's how you know they are full -- grease squishes out around the seal).

Buy a needle tip for your grease gun (smallest diameter possible). End of the tip is cut just like a phlebotomist needle. It will pierce the rubber seal, allow you to inject the bearing full of grease of your choice, then reseal the hole when you pull it back out.

Have you ever done that? As far as I know rubber seals have metal on the back.


LEVY

[Bill Robertson's Sock Puppet #1]

I've done it many times. I knew it would hit something in the middle, but I always assumed that was one of the bearings itself. Go in at the edge of the race. Needle will pop right in.

Needle tips make great Christmas presents BTW. I gave one to my friend just yesterday.

You can also use them to regrease tie rod ends through the boot.

[SS Spoiler]

You can also grease ball joints that don't have zerk fittings

[David T]

Over-grease the throw-out bearing and when it gets hot you will throw grease all over the clutch. Not a "Good Thing". In my experience sealed bearings last a long time (as long as they are not cheap Chinese ones) and they do not get wet. If the car was ever flooded the bearings soon go bad (the grease gets washed out when water gets in). Typically the clutch disc will wear out before the throwout bearing or pilot bearing goes bad.
David Teitelbaum

[Bill Robertson's Sock Puppet #1]

The throw out bearing isn't going to throw grease all over anything. What usually contaminates a clutch disc is oil from a bad rear engine seal.

[DMCMW Dave]

The throw out bearing isn't going to throw grease all over anything. What usually contaminates a clutch disc is oil from a bad rear engine seal.

How does the oil from the rear main get through the flywheel?

[Delorean Industries]

The throw out bearing isn't going to throw grease all over anything. What usually contaminates a clutch disc is oil from a bad rear engine seal.

Does not work like that. Yes oil can get into the base of the bellhousing but it can not contaminate the clutch. I have replaced plenty of clutches and it has never been a contamination issue from a leaking rear main.

[Bill Robertson's Sock Puppet #1]

Grease sure isn't coming out of the throwout bearing. Traditional wheel bearings hang on to their grease just fine, and they don't even have the benefit of a rubber seal.

Anyone care to comment on the unusual location of a leaking DeLorean slave cylinder?

[David T]

A leaking slave cylinder is certainly messy bit doesn't seem to be a problem contaminating the clutch. Probably because you can't drive very long once it starts leaking! It never pays to try to stretch the life of a throwout bearing or pilot bearing. Too much work to change it. Best advice is whenever you are in there working on the clutch you just replace the bearings and the disc if it is worn. What seems to be almost as common as a worn disc is a sticking problem with the splines or the pressure plate because the car sat for too long a time and got rusted into place. Mileage is not the only thing that can cause a clutch (or the bearings) to require replacement. A leaky rear main seal is also very messy but it doesn't get on the clutch disc.
David Teitelbaum

[Bill Robertson's Sock Puppet #1]

Original poster reports problems three months after initial installation. That hardly qualifies as "stretching the life of a throwout bearing or pilot bearing."

[DMC5180]

I helped a friend replace his clutch during a club tech session at Dave Swingle's house (pre DMCMW). His clutch disc was completely WET with oily contamination and Disc friction Dust material. Initially we thought the wetness was due to a leaking Slave cylinder, however the Smell indicated it was Gear OIL. This Wet condition really messed up the Pressure plate and Fly Wheel surfaces with deep grooves. All we could really figure was that the INPUT SHAFT SEAL was seeping Gear gear oil from the transmssion. This oil runs forward along the inside of the TUBE the Input shaft goes through. the Tube terminates is INSIDE the Clutch Pressure plate. Any gear oil dripping off the tube end will land inside the CLUTCH.

In addition to the clutch replacement that day, the transmission was opened up. All seals were replaced, 2nd gear roll pin up graded and coupler other none typical issues were addressed. It's doing just fine 7-8 years later.

[David T]

That can also happen if the transaxle is overfilled and/or filled with the wrong oil. A leaking trans input seal is the most common cause for fluid contamination of the clutch. Doesn't seem to be very common on Deloreans though. As for referring to the OP, I was only saying that if you overgrease a bearing it can come out and contaminate the clutch disc. For a bearing to die "young" the usual culprits are:
Dirt
improper installation (hammering, using the wrong tools, forcing, etc)
wrong bearing
bad bearing (could also be the bearing was never greased when assembled)
too much grease (if overgreased it will churn and heat up and run out or maybe you overgreased with the wrong stuff)

On autopsy you can usually figure it out. Especially if you were the one who assembled it. You know how you treated the bearings during assembly. Not usually a good idea to grease a sealed bearing. I do use the needle tips to lube sealed tie rod ends and ball joints. I don't puncture the seals, I try to get the tip under the edge and into the inner area of the joint. The lubricant in a sealed bearing is supposed to last the life of the bearing. If the lube is not there or not enough you are probably using the bearing improperly or past it's intended lifespan. The lubricant is selected based on the bearings specs for temperature, speed, loading, etc. There is a science to all of this and if the bearing is not lasting there is always a reason. You just have to figure it out.
David Teitelbaum

[Ron]

What usually contaminates a clutch disc is oil from a bad rear engine seal.


How does the oil from the rear main get through the flywheel?

Mr. B?

(You can do it, if you try...)