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Looks like Nissan no longer makes the right hand side steering rack bushing for the 89 Sentra's. I've got what they say will work and it's about 1/2" to big in diameter and the other part that is suppose to work is the wrong shape. Needless to say, I need to make this work somehow. Does anyone have any experience modifying an existing bushing or fabricating new ones that can help. Or do you know of someone who does have the knowledge on how to do such a task?

TIA

You could buy bulk polyurethane bar stock in too large a diameter. Then, drill a center hole in one end and chop it approximately 1/2" larger than the height of the hole in the rack into which it will be placed. Then, cut you piece in half. For each half, using the centering hole as a guide, cut the bushing 1/2" diameter over-sized with a hole saw. This will form the lip. Then, using a hole saw that is the correct diameter for the hole in the rack, on each piece, drill down half the height of the total bushing. You know have two halves of a bushing. All you need to do is source a sleeve of the right internal diameter to run through it, drill the bushing to fit, and fit it to the rack. The clamping force of the mounting bolt will keep each two bushing halves together.

FWIW, I am awaiting shipment of a quick ratio SVT rack to fit to my Focus and I will be doing this myself in the near future. I am going to make the bushings myself (although I will be making them offset and taller to reduce bump steer) so if you want to split some raw materials, let me know. I also have a drill press on which I intend to accomplish this. About all I need are the appropriate hole saws, which I cannot determine without the rack in hand. If you want to pool resources in anyway, let me know.

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Rich
http://www.v8mongrel.com/

About 15 minutes after I posted this I thought of the similar solution. Was going to look into the hard rubber instead of polyurethane because of cost (I've already got the left side and I just need to get the right side) Looks like you've got a little bit of experience with this maybe already, or have really done your homework. If it ends up that it will be cheaper for me to go poly instead of rubber, I may take you up on that offer somehow. I've got some time, and it sounds like you've got a little bit of time, so I'll let you know soon. Thanks for the info too.

I have done this once before and it is not hard. I have never myself nor heard of anyone else successfully manufacturing their own rubber bushing. I hope you are the first, but I have heard that the grain of the rubber makes cutting it accurately, particularly into a circle, all but impossible. That is why all rubber products are molded.

As for time, I am hoping to have the rack in for November Rockingham.

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Rich
http://www.v8mongrel.com/

Ok. After massive consideration on this with my lack of knowledge (and tools nontheless) I would like to take you up on your offer depending on the cost of materials. How much is a block of the polyurethane going to run? If it isn't going to be more than the cost of the car, then I have no problems with it. I will figure out a way to get the original bushing to you and go from there. Thanks.

If this bushing y'all are discussing has a round O.D. and a round I.D. and the two are meant to be concentric, make it on a lathe. Make it out of HDPE (Delrin) or something like that. HDPE is very inexpensive.

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Brad

Brad has a point about using alternate materials. Polyurethane is a bear to machine (cut) unless it is rock hard (like 90 durometer). We used to use it for machine "hard" stops and resorted to dipping the bar stock into liquid nitrogen before turning it in the lathe so that the cuts were smooth. Using a hole saw in polyurethane could be dicey since the urethane tends to grip the cutter. If you have experience doing this I'd be interested in hearing how you got around that problem.
As far as using HDPE (high density polyethylene, not Delrin - which is acetal), it is indeed very cheap, but is more difficult to cut with a hole saw since it tends to be VERY stringy. It will cut OK but will not be pretty and will have a rough surface. Delrin will be much easier to machine, it cuts very smoothly and if you need to "tweak" the diameter, I have been known to run a bolt through the center and smooth the outside diameter using a file while the part spins in the drill press (use good sense if doing this). Delrin is more expensive and is much more rigid, so if you are looking to keep some compliance in the rack to smooth out the road vibration a softer material would be better.
Have you considered molding the bushing in place? If you can support the rack and block leakage paths you could pour in liquid polyurethane and make a custom bushing. The polyurethane comes as a two part material that hardens in hours and is available in varying hardnesses. It can be sourced from mcmaster.com part number 8690K1 or similar. 5 pounds is $55 (it has gone up since I used it last).
Keep us posted on your progress.

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1998 BMW Z3
1987 BMW 325is
2000 BMW
1996 F250 Turbo Diesel

For forming in place or to a mold you could use windshield Urethane. It can take several days to cure solid depending upon the thickness of the final product. It is softer than delrin. If you form it in place with proper priming of the mating surfaces it should be stronger that the old bushings and they lasted 16 years. It is about $15 a tube and if you seal the end of the tip it should not harden for up to 2 weeks.

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George Bright Member # 141
One of the youngest of the old farts.
Yes I voted against you joining the club.

Charlie, I machine quite a lot of poly and delrin. We use 60a and 85a shore hardness stock and have no issues, with the right tools

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91 Jetta GLI STS/DSP 111
85 Porsche 944 ASP 11
http://www.blackforestindustries.com

Adam's right "with the right tools". Delrin is easy to machine with just about anything. I was refering to using a hole saw (not the "right tools") and trying to cut a rubber-like material.

The comment regarding HDPE, LDPE and UHMW materials still stands. Unless very sharp tools are used the friction heat of the cutter causes localized melting and results in a stringy, messy cut.

Did I just hear Adam volunteering to help machine the bushings?
I have a milling machine but not a lathe, and this sounds like a lathe job.

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1998 BMW Z3
1987 BMW 325is
2000 BMW
1996 F250 Turbo Diesel

Charlie, Do you use these guys?

East Coast Plastic & Metal
5885 Shady Grove Circle
Raleigh, NC 27609
(919) 877-8172

Pretty sure I've bought Nylon rod from these folks. Either them or Piedmont Plastics in Raleigh. Whichever I used, they had "drops" available in a big bin at the counter. I think I paid around $10 for a 1-1/2" X 3' bar of Nylon. Most of these types of distributors stock Nylon, Delrin, HDPE, Polyuretnane, Polycarbonate, etc. in sheets and rods.

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Brad

East Coast Plastic and Metal.........No it has been a long time since I bought the raw materials myself. I just discovered that the plastics supplier that I used to use in the downtown area is no longer listed. I know that Piedmont is used by my preferred machine shop. They also get good pricing from a supplier in Greensboro and one in Fla.
I have spoken with East Coast when I was looking for an emergency source for something (I forgot what), and they seemed reasonable to work with.
Drops are the best way to get what you need if it is available when you need it. Often if I need just a small piece of material, I buy from McMaster-Carr because I can get it shipped and I don't spend valuable time trying to save a few $.
Charlie Guthrie

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1998 BMW Z3
1987 BMW 325is
2000 BMW
1996 F250 Turbo Diesel

If we were making a true bushing wherein the unit is to supply some sort of movement capability, I would agree. However, we are talking about making a mount for a steering rack. Lathe level precision is not necessary and doing it on a drill press with a constant centering hole is about all you need in this application.

I will think about Delrin, that might work. Compared to urethane, how well does it absorb vibration?



When my rack arrives, I will let you know so that we can make are that we can use the same base stock. First, if we are going to share, I think we have to decide on a material. Delrin is nice, but I am afraid of the vibration. Urethane I have worked with before, and it is very friendly.

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Rich
http://www.v8mongrel.com/

Rich, whatever you think will work is fine by me. I just need something that will replace the 16 year old bushing that is currently holding the right side of my steering rack.

Have you checked with NAPA? They stock a surprising amount of parts for >50 year old vehicles!
(They stock Kingpins and bushings for my 56 Panel truck for example)

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SPIN or WIN!
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