custom pitman shaft bushings
#1
Melting Slicks
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custom pitman shaft bushings
I want to start a new thread because it seems like there is enough talk lately worthy of its own thread.
Gary, Jim and others have recommended using custom fitted bushings when rebuilding the steering box. I have a few more questions so that I can order raw material and plan the machining.
1- what are the nominal dimensions of the bushings? OD x ID x L
2- what are the typical tolerances seen? ie: is the required ID typically undersize by a few thou?
3- which material is better to machine? 660, 841 bronze or others
4- what is the interference fit to the housing?
:cheers:
Gary, Jim and others have recommended using custom fitted bushings when rebuilding the steering box. I have a few more questions so that I can order raw material and plan the machining.
1- what are the nominal dimensions of the bushings? OD x ID x L
2- what are the typical tolerances seen? ie: is the required ID typically undersize by a few thou?
3- which material is better to machine? 660, 841 bronze or others
4- what is the interference fit to the housing?
:cheers:
#2
Tech Contributor
Re: custom pitman shaft bushings (Turbo-Jet)
Original bushing are :
1.250 OD,
1.125 ID,
1.360 long.
I use 660 bronze now, I can buy it at the local bearing supplier for $18 for 13" cored rod stock,(1.5"OD x 1" ID) I have used oilite bronze also.
I cut a groove in them after final fit for grease to travel. I machine them for .001 fit which will crush down when you install them in the housing. final fit using brake cyliner hone. I go for .001-.002 final fit.
check with corvette steering I was told they sell undersize ID bushings.
Gary
1.250 OD,
1.125 ID,
1.360 long.
I use 660 bronze now, I can buy it at the local bearing supplier for $18 for 13" cored rod stock,(1.5"OD x 1" ID) I have used oilite bronze also.
I cut a groove in them after final fit for grease to travel. I machine them for .001 fit which will crush down when you install them in the housing. final fit using brake cyliner hone. I go for .001-.002 final fit.
check with corvette steering I was told they sell undersize ID bushings.
Gary
#3
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Re: custom pitman shaft bushings (Turbo-Jet)
I have the stock bushing in my hand. It is 1.248 od so 1 1/4 inch stock will work. The id is about 1.125 but this is custom fit to the pitman shaft. The length is 1.360 but I used longer at about 1 1/2 inches.
I picked up 2 peices of bearing bronze in blank form at 1.250 od and used it as is, I bored the id to match the piman shaft after polishing the shaft, I made the id the same as the od of the shaft and left the blank the furll 1 1/2 inches long. I made 2 of them.
Once pressed into the housing the ID shrinks a little because of the press fit so I then honed the id for a slight press fit or no more then .001 max.
I picked up 2 peices of bearing bronze in blank form at 1.250 od and used it as is, I bored the id to match the piman shaft after polishing the shaft, I made the id the same as the od of the shaft and left the blank the furll 1 1/2 inches long. I made 2 of them.
Once pressed into the housing the ID shrinks a little because of the press fit so I then honed the id for a slight press fit or no more then .001 max.
#4
Melting Slicks
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Re: custom pitman shaft bushings (norvalwilhelm)
are you worried about abrasive grit from the hone impregnating the bronze, and then causing scoringof the shaft? probably not an issue as the grit is pretty fine...
McMaster Carr has 1-1/4" x 1" x 1-1/2" long 660 and 841 bronze bushings that I will order and modify. the OD is +.002-3, so I can turn down if needed for proper press fit.
thanks for the help
McMaster Carr has 1-1/4" x 1" x 1-1/2" long 660 and 841 bronze bushings that I will order and modify. the OD is +.002-3, so I can turn down if needed for proper press fit.
thanks for the help
#5
Melting Slicks
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Re: custom pitman shaft bushings (gtr1999)
I cut a groove in them after final fit for grease to travel. I machine them for .001 fit which will crush down when you install them in the housing. final fit using brake cyliner hone. I go for .001-.002 final fit.
check with corvette steering I was told they sell undersize ID bushings.
Gary
check with corvette steering I was told they sell undersize ID bushings.
Gary
#6
Tech Contributor
Re: custom pitman shaft bushings (Turbo-Jet)
I just used a rotary burr in a Dremel tool to add a small groove 180* apart.