[propuckstopper]

Hi everyone. I just wanted to put up a post to hopefully save some of you four-speed guys some time and grief in the future.

Last winter, I had my 1965 GTO 389 engine freshened. I also had the Muncie transmission looked at, because everything was apart anyway. I decided that because the engine and transmission were separated, I might as well go ahead and put in a new clutch.

I ordered a clutch kit locally and bought a new pilot bushing (paid $5.00) through a Pontiac mail order company. The company name is not important, because I am not writing this to trash the company. I am writing this to help you know what to look for in a pilot bushing. It really does matter.

After assembling the engine and transmission and putting a few miles on, I noticed a screeching/squealing noise from the transmission area. This noise would only occur with the clutch pedal pressed to the floor, which means the input shaft is stationary and not turning at engine speed.

I did some Googling about my situation, and found several sites with information about junk pilot bushings. It seems these Chinese made units are magnetic, which means they have a high iron content. It is this iron content that not only makes the squealing noise, but can wipe out your input shaft over time.

I was directed to a company out of New York called Autogear, who specializes in driveline stuff. I spoke to a gentleman by the name of Nathan who indicated that he had several custom Oilite bushings in stock but none for a Pontiac. But he was willing to make one.

I ordered another cheap $5.00 pilot bushing and had it sent directly to Autogear. They have now created a Pontiac bushing that is available in stock. It is true Oilite, not the magnetic junk that I originally bought.

My buddy and I pulled my Muncie yesterday and installed the new Oilite bushing. And sure as hell, the pilot bushing we removed stuck to my magnet like glue. In fact, my buddy shook the hell out of the magnet and could not shake the bushing off of it. It was ridiculous.

Anyway, this is not a commercial for Autogear, nor am I affiliated in any way with them. In fact, I just found another true Oilite bushing available at the McLeod Clutches web site.

The moral to this story: wherever you buy your pilot bushing, BE SURE it is not magnetic. The magnetic ones sell for about $5.00, while the proper Oilite bushings are in the $35 to $40 range. Oilite is oil-impregnated, and that is what saves your input shaft.

Whatever you do, spend the big money for the proper bushing. Saving thirty bucks or so to find out later that you have a steel bushing riding on your input shaft is not a good deal.

[fiedlerh]

You can use a bushing if you want, and some people prefer to, but Pontiac used the 7109 ball bearing in every manual trans V8 application. Trouble is the 7109 bearing is not commonly used in industry anymore, so it is rather expensive. Some people have used the 6202 bearing, but the crank hole may need to be machined a bit deeper.

See: http://www.pontiacpower.org/PontiacCranks.htm

Agree a sintered iron bushing would get noisy once the oil cooks out. At least bronze will remain relatively quiet.

[Kevspontiacs@aol.com]

thanx for the heads up. will be tearin into my 76 today. i'll add that to the checklist
Kevin

[67gtospud]

If it ONLY happens when the clutch is pressed it's most likely the throw out bearing not the pilot bushing

[propuckstopper]

Originally Posted by fiedlerh

You can use a bushing if you want, and some people prefer to, but Pontiac used the 7109 ball bearing in every manual trans V8 application. Trouble is the 7109 bearing is not commonly used in industry anymore, so it is rather expensive. Some people have used the 6202 bearing, but the crank hole may need to be machined a bit deeper.

See: http://www.pontiacpower.org/PontiacCranks.htm

Agree a sintered iron bushing would get noisy once the oil cooks out. At least bronze will remain relatively quiet.

Many people don't recommend a bearing, as they do not tolerate slight misalignment as well as a bronze bushing will. There is also the argument about the "moving parts" in a ball bearing. If one of the moving parts fails, the others quickly follow and you have a mess on your hands.

From the research I have done, I feel better with a bushing than I would with a bearing. Your mileage may vary.

[propuckstopper]

Originally Posted by 67gtospud

If it ONLY happens when the clutch is pressed it's most likely the throw out bearing not the pilot bushing

I agree with what you are saying in principle, and your idea is what is normally the issue. However, in this case, it was a bad pilot bushing without question. The throw out bearing is pristine.

When you step on the clutch, the throw out bearing contacts the "fingers" of the pressure plate. But don't forget that while this is going on, the transmission input shaft ceases to turn. So, now you have a stationary input shaft while the crankshaft remains at engine speed. Because the pilot bushing is "part" of the crankshaft, the pilot bushing is spinning on a stationary input shaft. This is precisely the source of my noise. Steel on steel.

When you let off the clutch pedal, the input shaft spins in conjunction with the pilot bushing, so my noise would go away.

[PONTIAC DUDE]

What did you use for lube on the bushing?


Using High temp Wheel bearing grease eliminates issues.

Curious......... How can you get screeching if there is grease in the bushing?
The iron percentage content is to keep the bushing from wearing and keep the hole centered.

It's not the Chinese made units as I have pilot bushings in stock that are over 20 years old and have a magnetic content from Pioneer.

[propuckstopper]

Originally Posted by PONTIAC DUDE

What did you use for lube on the bushing?


Using High temp Wheel bearing grease eliminates issues.

Curious......... How can you get screeching if there is grease in the bushing?
The iron percentage content is to keep the bushing from wearing and keep the hole centered.

It's not the Chinese made units as I have pilot bushings in stock that are over 20 years old and have a magnetic content from Pioneer.

Hi there. To be dead honest, I did not use any lube whatsoever on the original Chinese bushing because true Oilite is not supposed to be lubed. As this was my first time ever doing a project like this, I did not realize that this Chinese bushing was not true Oilite, so I installed it lube-free and went to town.

If I had of known about the high iron content in the first place, I would have either (A) lubed it with high temperature wheel bearing grease like you suggest, or (B) thrown it in the garbage and bought a true Oilite bushing.

As it stands at this point, I chose option "B". And I did not put any lube on the bushing once again, because this time it is a true Oilite bushing, complete with vacuum-impregnated lubricant.

I called Beemer Precision, the makers of true Oilite Bronze, and they assured me that if in fact my new bushing is genuine Oilite (which my new bushing definitely is), that no additional lubricant is necessary. As the bushing begins to warm up, it slowly releases its factory-installed lubricant.

I actually purchased an extra true Oilite bushing from Autogear just to have on the shelf. It is amazing to see the "film" of lubricant through the zip-lock bag it is stored in. The bag looks quite cloudy.

Conversely, I kept my original offending Chinese bushing and also put it into a zip-lock bag. There is absolutely no sign of a lubricant whatsoever.

So, as I have now learned, I guess you could get away with some wheel bearing grease on a high-iron (magnetic) bushing, or go the true Oilite route.

Knowing that the true Oilite offering is permanently lubricated and is "softer" on the transmission input shaft, I would definitely stick with the Oilite bushing.

[PONTIAC DUDE]

Having used the std Pilot bushing since the 60's with lube (owned a lot of 4 spd cars and a 68 Z-28) & (As per industry install instructions) and NO issues I wouldn't say Chinese as I don't think they were made back then in China.

All pilot bushing are metallic with ALL manufactures, I.E. Chevy, Ford, Mopar, the list goes on. So don't blame the product, it's knowing what you are supposed to do if you are going to do it yourself. Hope the new pilot bushing has the right hardness to handle the loads of the input shaft.

Millions were and are sold.
As you stated, you didn't lube it.

Question: So if oil weeps out the Oilite brg, when does it reach it's saturation point and no more oil is impregnated in the bushing?

Not doggin ya dude, but having sold and used aftermarket pilot bushings for over 45 years I knew there had to be obvious reason.

Have fun with you ride and hope it works out for ya.

[propuckstopper]

Originally Posted by PONTIAC DUDE

Having used the std Pilot bushing since the 60's with lube (owned a lot of 4 spd cars and a 68 Z-28) & (As per industry install instructions) and NO issues I wouldn't say Chinese as I don't think they were made back then in China.

All pilot bushing are metallic with ALL manufactures, I.E. Chevy, Ford, Mopar, the list goes on. So don't blame the product, it's knowing what you are supposed to do if you are going to do it yourself. Hope the new pilot bushing has the right hardness to handle the loads of the input shaft.

Millions were and are sold.
As you stated, you didn't lube it.

Question: So if oil weeps out the Oilite brg, when does it reach it's saturation point and no more oil is impregnated in the bushing?

Not doggin ya dude, but having sold and used aftermarket pilot bushings for over 45 years I knew there had to be obvious reason.

Have fun with you ride and hope it works out for ya.

No offence taken. I do not think you are doggin' me at all. In hindsight, you are correct in the fact that I should have lubed the magnetic bushing but I did not know that because I assumed it was self-lubricating (Oilite), which of course it wasn't. So, in essence, I feel that my squealing could have been eliminated by applying proper grease to the improper material.

My personal opinion still remains: for those of you out there that have the experience to know that these magnetic bushings need lubrication, I guess they will work. But I believe there is a better way (the true Oilite bushing).

Just so you know where some of my research comes from, I have supplied a few links:

http://forums.corvetteforum.com/c1-a...-question.html

http://www.camaros.net/forums/archiv.../t-150426.html

http://www.chevelles.com/forums/arch.../t-357685.html

I just don't want to see anyone in the situation I found myself in, but at least this thread will help people realize there are actually two very different types of bushings available:

1: Iron-containing magnetic bushings that must be lubricated.
2: True Oilite bushings that are plug and play.

[RamAirIV28]

Originally Posted by fiedlerh

Pontiac used the 7109 ball bearing in every manual trans V8 application.
.

they did not. do a search.

[propuckstopper]

Originally Posted by RamAirIV28

they did not. do a search.

That is what I thought, and every old "NOS" GM pilot bushing I have ever seen "appears" to be genuine Oilite Bronze. I say appears because I have never actually had one in my hand.

Give me a few minutes, and I will be back. I am going to take a picture of the junk steel bushing I took out of my car side by side with a true Oilite bronze bushing (my spare).

I think you will be able to see stark colour differences...but you be the judge in a moment or so.

[propuckstopper]

Originally Posted by propuckstopper

That is what I thought, and every old "NOS" GM pilot bushing I have ever seen "appears" to be genuine Oilite Bronze. I say appears because I have never actually had one in my hand.

Give me a few minutes, and I will be back. I am going to take a picture of the junk steel bushing I took out of my car side by side with a true Oilite bronze bushing (my spare).

I think you will be able to see stark colour differences...but you be the judge in a moment or so.

OK. I have snapped a total of five pictures, and would like to take a moment to explain each.

Photo one shows a picture of a genuine Muncie transmission input shaft. A transmission guy gave this to me to use to install the new pilot bushing as well as to use this as a clutch disc installation tool. If this input shaft looks a little weird to you, it is. A machinist friend of mine cut the gear off at the end of the shaft for me. He made it easier for me to use as the aforementioned clutch disc installation tool. This genuine Muncie input shaft fit much better than the cheap plastic installation tool supplied with the clutch kit, enabling the transmission to slide in much smoother. Note the diameter of the shaft. The Chinese magnetic pilot bushing is on the bottom, and the new Autogear Oilite pilot bushing is on the top. The Chinese bushing had been used for about 1000 squealing miles before I took it out. It was cleaned up with brake clean before this photo.

Photo two shows the magnetic Chinese bushing taken out of the car. Note the .6035 measurement. I do not know what diameter this bushing left China with, but it is a lot bigger diameter now than the genuine Muncie input shaft would like to see. However, as PONTIAC DUDE suggests, I obviously should have lubricated this bushing. The extra big diameter was probably caused by lack of lubrication, hence the squealing.

Photo three is pretty straightforward. This picture shows a new Autogear Oilite bushing. It is virgin. Note the measurement of .591.

Photo four shows the Autogear Oilite bushing on top, and the Chinese magnetic bushing on the bottom. Again, the Chinese bushing has been well cleaned. Just showing this picture for comparative purposes, but note the Chinese effort looks far from bronze.

Photo five supports all the information from the links I supplied above in an earlier post. I put the bushings side-by-side on the counter, then "snuck-up" to them with a magnet. I don't need to tell you which one stuck and which one is laying on the counter.

At the end of the day, I fully realize that PONTIAC DUDE is correct in saying that I should have lubricated the magnetic bushing. It certainly would have eliminated the squeal and excessive wear. Yet, all my research pointed to not having to lubricate the bushing, because I believed it to be self-lubricating. It wasn't, as the calipers show. I also believe this: PONTIAC DUDE has been lubricating pilot bushings for over 40 years. Somewhere, in the span of 40 years until now, the composition (metallurgy) of these bushings has gradually changed. Forty years ago, I believe they were genuine Oilite and that fact that PONTIAC DUDE added extra lubrication really did no harm. As the metallurgy changed, PONTIAC DUDE continued his method of lubricating them and had no problems because the more modern bushing actually requires lubricant. If I am correct, PONTIAC DUDE may have spared tons of more modern pilot bushings because of his original methods, and there is certainly nothing wrong with that!

I would absolutely love to get my hands on a genuine NOS GM pilot bushing just to see what material they were made of back then. I would bet the farm that they were Oilite or a derivative of the same.

[fiedlerh]

they did not. do a search.

Please enlighten me. If I get a chance I'll look in my parts books over the next few days.

[GTO Dan]

FWIW...Pontiac used a bearing from the factory in the (70,71,72) A-Bodies that I've owned.

I have run a stick in all my Pontiacs for over 30 years for thousands of miles. One street combo at over 600 hp/TQ in a 3600 lb GTO power shifted on drag radials. Never a failure from the bearing. Currently run over 800 hp in my GTO running a Timken bearing (none better). When people tell you not to run the bearing because they will fail, ask them if they also swap out their wheel bearings for a bushing.

The tolerances need to be tight and when the bellhousing is properly indexed to the block the trans will go on and off smoothly and the parts will last.

Order the Timken 7109 clutch pilot bearing from Summit Racing for $24.97, check the bellhousing alignment, check to see the inputshaft spins true and be done with it.

Good luck.

[RamAirIV28]

Originally Posted by fiedlerh

Please enlighten me. If I get a chance I'll look in my parts books over the next few days.

Do.......A.......Search......

[geeteeohguy]

Have always used bearings, not bushings. For the past 35 years and a ton of miles, never a single problem. If the trans/bellhousing does not line up properly, it needs to be fixed. JMHO. Use a bearing and be done with it, as stated previously.

[propuckstopper]

Originally Posted by GTO Dan

FWIW...Pontiac used a bearing from the factory in the (70,71,72) A-Bodies that I've owned.

When people tell you not to run the bearing because they will fail, ask them if they also swap out their wheel bearings for a bushing.

Good luck.

With all due respect, I am not too sure about this particular analogy. You are talking about a wheel bearing that bears the constant weight of the car while simultaneously being subject to braking and cornering forces. They also have to contend with heat from the brakes.

A pilot bearing/bushing does not even come close to that type of environment. As stated earlier in this thread, the pilot bearing/bushing only comes into play when the clutch pedal is stepped on. It really only supports the input shaft, not the weight of an entire vehicle. In my opinion, the pilot bearing/bushing has a very "part-time job" compared to a wheel bearing.

Perhaps I should have gone with a roller bearing as both my 1965 and 1968 Pontiac Service Manuals definitely discuss a bearing, and I just noticed this fact last night. My bad. However, I just heard (and read) about so many horror stories with a bearing, that I decided to go the Oilite bushing route.

Had I gone with a bearing, I definitely agree that Timken is about as good as it gets. In other applications, mostly powersports, NTN is another great choice.

I will certainly be honest and post in the future should I have a problem with the Oilite bushing. I feel forums like this only benefit from honest feedback, and I have certainly gained a ton of knowledge on this board. Thanks for that.

[GTO Dan]

Originally Posted by propuckstopper

With all due respect, I am not too sure about this particular analogy. You are talking about a wheel bearing that bears the constant weight of the car while simultaneously being subject to braking and cornering forces. They also have to contend with heat from the brakes.

A pilot bearing/bushing does not even come close to that type of environment. As stated earlier in this thread, the pilot bearing/bushing only comes into play when the clutch pedal is stepped on. It really only supports the input shaft, not the weight of an entire vehicle. In my opinion, the pilot bearing/bushing has a very "part-time job" compared to a wheel bearing.

Perhaps I should have gone with a roller bearing as both my 1965 and 1968 Pontiac Service Manuals definitely discuss a bearing, and I just noticed this fact last night. My bad. However, I just heard (and read) about so many horror stories with a bearing, that I decided to go the Oilite bushing route.

Had I gone with a bearing, I definitely agree that Timken is about as good as it gets. In other applications, mostly powersports, NTN is another great choice.

I will certainly be honest and post in the future should I have a problem with the Oilite bushing. I feel forums like this only benefit from honest feedback, and I have certainly gained a ton of knowledge on this board. Thanks for that.

Exactly...so why the concern that a pilot bearing will fail.

Regardless, to each his own. Good luck and have fun banging the gears. It is always good to hear of someone running a three pedal car.

Dan

[fiedlerh]

Do.......A.......Search......

I did an internet search and did not find a list of Pontiac V8 engines that used a pilot bushing from the factory. Sure people make them and sell them and some people prefer them over a bearing, but AFAIK the factory put 7109 bearings in them.

Here is an excerpt from the 1974 parts book that only shows a pilot bearing for V8s: