Aoto Gear sells the good pilot bushings, and they will custom make one any size or length that you want.

 

National Bearings PB-656-HD is a good non magnetic Oilite bearing. It won't appear to have any oil on it unless you heat it up. Then the oil will come out of the pores. I just purchased some on Amazon.https://smile.amazon.com/National-P...B0052XNFR0/ref=sr_1_7?ie=UTF8&qid=1550433118&sr=8-7&keywords=national+pb-656-hd

SKF B656 is magnetic junk.

QuarterMaster 110013 is a good extended length pilot bushing. It too is available on Amazon.Sorry! Something went wrong!

Auto Gear, as stated, has pilot bushings and offers good extended pilot bushings.

You need to take a measurement form the trans face to the start and end of the input shaft pilot extension. Then from the bellhousing face to the flywheel. Determine if there is enough room for the extended bushing to clear the fatter part of the shaft. Leave some room for play forward and back
(maybe 1/8 inch).

It's difficult to say what you will need. It's a YMMV type of thing. Different cases, input shafts, and clearances can all affect the stick out length of your input shaft. So it's best to make the measurement then decide.

You can also "short install" your pilot bushing by 1/8" if this will get you within spec. Just don't hammer it in as far. That's what we did before we found the extended bushings. A back in the day type of fix. I would avoid this now since the extended bushings are available off the shelf.

I like to see full engagement of the shaft...Others may have different thoughts....That's my personal take.

 

Thanks for the responses. Just got back from local auto parts with the National PB- 656-HD bushing. As mentioned I will have to take some measurements to determine if a longer bushing is needed. Not going to install the bushing until after I measure and determine the standard is good. Have to mock it up anyway to do bell housing dial in check. If I determine I need the extended bushing Ill get it.

 

Thanks for the responses. Just got back from local auto parts with the National 656 bushing. As mentioned I will have to take some measurements to determine if a longer bushing is needed. Not going to install the bushing until after I measure and determine the standard is good. Have to mock it up anyway to do bell housing dial in check.

Take a measurement of inside diameter of your installed pilot bushing. Compare it to your average input shaft diameter. You want .002 to .003 clearance here. A stock new shaft is .590 by spec, many bushing tighten up after install. I use a .593 reamer to bring the bushing into spec if needed.

A bushing that is too tight will cause shifting issues. More so when it heats up through use.

 

Al,
Right you are. I once installed a bushing that was .007 larger than the crank bore. Should have known better as it was so difficult to drive into the bore. All it did was compress to the point that the input shaft would not go into the bushing. Then getting that bushing back out was a chore.
Guess I could have reamed it out as you mentioned. Anyway 2-3 thousandths is good as you mentioned.

 

The QuarterMaster 110013 is a 1/4" longer than the stock spec pilot bushings. (forgot to mention)

 

I've always went with .001 per 1 inch diameter for a pressed fit, (bushing into the crank), but that's a steel to steel thing. Not sure for a oilite bushing but IIRC, that's about what the autogear bushing I used turned out to be. Aftermarket cranks NEED to be measured.

 

Jerry.... I agree, Have you ever worked in a Tool & Die Shop. I use your 1 for 1 for press or a sweat fit. Same deal with flywheel ring gears. 1 X 1 = a perfect fit. .001 per inch of Dia. = :thumbsup:
Bob

 

Well after mocking it up to do a bell housing dial in and taking some good measurements for the pilot bushing and input shaft I was able to determine that after adding the block plate the input shaft would only engage the standard length pilot bushing approx 1/4 inch. I happen to be talking to Jody on another matter so I ask what is the minimum the input shaft should engage the bushing. He stated it should be the diameter of the tip of the input shaft. On my trans thats 5/8 inch and I will only be approx 1/4 so I am going to get an extended bushing.

 

Have you found a source for an extended length pilot bushing?

Here's the Auto Gear parts with available dimensions. From what I understand, they can custom make bushings to your preferred size. Looks like you'll need another 1/8" over the commonly available extended bushing to get you 5/8" minimum.

http://www.autogear.net/wp-content/uploads/2015/03/pilot_bushing_chart.pdf

 

Went with this one.

You are being redirected...

 

That's a good piece. Non Magnetic. Quarter Master 110013 Pilot Bushing

 

I got one from Auto Gear a few months ago.

 

Rule of thumb for input shaft to pilot bushing support.

Bare minimal, a pilot tip must be supported lengthwise by its diameter

A GM manual transmission input shaft tip measures .590" so the pilot tip must be supported by .590".

On an average, an extended pilot bushing is about 1/8" longer than stock.