I just got back my rebuilt 4 speed trans from Ed H. and he sent me a new brass pilot bushing to install. My question is my present pilot bushing has a steel flange with a brass insert on the inside. What is this application and should I just take it out and install the brass bushing. Why was it there to begin with? See pics:

 

the pix are a bit fuzzy, but i don't see any wear in the one that is in the end of the crank now. if so, i'd put some moly grease in the hole and keep on using it.
Bill

 

I had a hard time taking the pictures because of the flash would blurr the pictures. When I looked at the brass portion of the inner bushing it was pitted and had deep scratches in it. Bill was this steel flanged bushing just another type of bushing or was it used as to fix a problem? I don't want to remove it and find out that the brass bushing won't work and can't find another one like the steel bushing I have. Richard

 

I don't think you want a steel bushing. You want bronze and that may be what the builder sent you. Also if you don't install the bushing the builder sent you, and you have shifting problems, you may have a problem with the warranty on the trans. Call the builder. He should be able to explain what is best and why.

 

Try the new bushing on your input shaft to see if it fits, hold it to flywheel to check. Never had a prob with them.

 

I did that and it appears to be the same size as the OD of the out steel flange. That is what scares me what is the size of the hole in the crank that accepts the brass bushing. I guess I don't have any chose now but take it out and see what I've got. I did contact the trans builder and he thinks he remembers the old steel flange type back in the day but he can't remember why they were used. He prefers I use the new bushing and I do too. I just hope I am not opening a can of worms.

 

I've never seen a flanged steel pilot bushing with a bronze insert; was never an OEM part.

If you use your camera's "macro" feature (little flower symbol), your close-up shots will be properly focused.

 

Looks like a ford...

 

there was a time that automatic trans cars (maybe it was turboglide...) had a larger hole in the end of the crank (don't know when they stopped the practice..), and special oversize pilot bushings had to be made.

nevertheless, just take the old one out and put the new one in. if the hole in the end of the crank is oversized for whatever reason, just have a new one made, it doesn't have to be a 'sleeved' bronze/brass one; a machine shop can turn you one from a larger bushing or suitable material... no problem...

FWIW, all the bronze bushings i have found lately are slightly magnetic (i'm curious, please hold a magnet to your new one), so i would make sure that you gease the pilot bushing hole before putting the trans in.



Bill

 

You should not use grease on a bronze pilot. The good pilot bushings are made from Oilite which is a porous bronze that is oil impregnated. Using grease will clog the pores. If a magnet sticks to the bushing, you don't have the right type.

 

i tried and tried and tried to find an oilite bushing that was not magnetic and came wrapped in a special wrapping to keep the 'oil' from weeping out. no luck.... even in those that were from reputable vendors and advertised as oilite.

so, i will use the 'magnetic' bronze version and still grease it. the grease will protect/lubricate regardless whether the pores are clogged.

i'm still curious as to whether the bushing supplied to him is magnetic.
Bill

 

I haven't tried the magnet thing yet. But Ed Hartnett who did the trans rebuild said he had the same problem with the magnetic bushings and this caused him some call backs so he said that he found a source that makes them for him that aren't magnetic.

 

If you can find a source for an Oilite (porous) bushing, that would be ideal.

But, let me explain more than a few things that makes this "oil or grease" thing an issue:

The original Oilite bushings were porous bronze (non-magnetic) that were especially impregnated with an oil. And no, just soaking a porous bronze bushing in oil does not work. The impregnation was done under vacuum and heat, so that as they cooled down, the oil would wick and be drawn inward. The pores of the bronze held the oil, and they had to be wrapped in a packaging (plastic, or at least waxed paper) that did not allow the oil to be wicked out (cardboard or regular paper would wick out the oil and the bushing is no longer oil impregnated). As long as the bushing you have is oily and was wrapped in plastic, and was non-magnetic, that is an original style (good) bushing, and should not be greased. Grease has "soaps" (the thickener that make it a grease), and these will block the pores in the porous bushing. A light film of motor oil on the input shaft is all that is needed for these bushings.

Some time long ago, they found that adding "some" iron (which is magnetic) to the mixture of bronze, would make a harder bushing, which would last longer, but "might" damage the trans input shaft once the lube was "gone". These bushings were still oil impregnated, and still had to be wrapped in plastic. They were still porous and still a type of Oilite bushing, and were a relatively "good" bushing (not ideal). Again, grease should not be used.

Note that the higher the magnetic attraction, the higher the iron content, and the harder the material (and potential for damaging the trans input shaft).

But, these porous bronze or mixture of bronze and iron bushings have lately been replaced with a non-oily and higher content iron (more magnetic) bushing, and they are just stuck in a cardboard box or wrapped in paper. Because they contain little or no oil, these must be greased. I recommend a high moly content grease. Left over cam (flat tappet) assembly lube would be ideal.

In other words, if the bushing you are going to use is oily (and packaged properly to prevent the wicking out of the oil), then no grease should be used (just a light film of motor oil is fine).

However, if there is no oil to begin with, then best add a good moly grease, and I would pack a small amount of extra grease in the depression in front of the bushing (but don't pack it completely full, since the grease may try to force the bushing back out - in other words, leave a little air pocket).

The best insurance for your pilot bushing, is to not "use it" often. The bushing / trans input shaft only sees a rotational differential when the clutch pedal is depressed, and the shifter is in gear (and the engine is rotating at a different speed than what that gear is transmitting to the drivetrain). Sitting at a stop light in gear with the clutch depressed is not doing the pilot bushing any good.

Further info as to how an Oilite (porous oil "saturated") bushing works, is that the oil would migrate to the rotational surface due to heat, and the more heat, the higher the flow of oil. Once the bushing cooled back down, the oil would be drawn back into the porous bushing.

Obviously a non-oily bushing relies only on the surface grease film, which is not as sustaining as is the oil from a porous bushing.

Hope this helps,
Plasticman

 

The Federal Mogul pilot bushing, # PB-656-HD, is a genuine non magnetic oilite bushing and no longer comes wrapped in protective paper. None of them do. I'm guessing that modern technology has improved these bushings. They won't 'wick out' until they are heated up.

 

Bill, for what it's worth the bushing that Frankie and I both bought as an option for the clutch cross shaft push rod

http://surfrainbow.com/Load_Product....oductCode=5822

appears to be oilite and is not magnetic, I just checked. I didn't look to see if they sold bushings in the proper size for a pilot, but it's worth a look.

 

I bought some Dorman pilot bushings fairly recently, and they ARE slightly magnetic. I heated one of them on the stove and oil oozed out.

It is very difficult to find a pure bronze oilite bushing. I can't see the advantage to having one without ferrous content, anyway, as long is the bushing is oil impregnated. There is one company that makes them, but the name escapes me.

Almost always, the auto trans cars had cranks machined the same way as manual trans cars, but there WAS a brief period when the rear of the crank was machined differently between the two. Dorman has a listing of all of their GM bushings, and the one for auto trans is slightly smaller in outside diameter because the hole in the crank is smaller. Don't remember the dimensions offhand, but THIS is the most common, standard ID and standard OD bushing used for Chevrolet V8 engines:

http//www.dormanproducts.com/p-11019-690-014.aspx

If there are advantage/disadvantages to a non-ferrous pilot bushing, I would like for someone to point them out to me.

DO NOT use grease on an oilite bushing. This will clog the pores. Use a light coat of motor oil when first installed.

 

Today I removed the old bushing using the pump in grease pressure method. I am sold two taps and the old bushing was out. It is a regular size bushing except it is steel. The center looks like at one time it had brass inside but it is long gone. I used a magnet on the old bushing and when I got within 3 inches it jumped to the magnet. I did the same thing on the new bushing nothing. I ran the magnet all over the new bushing no metal.