Treb
Treb Reader
10/18/13 5:46 a.m.

Audi A4, 1998. There is a bushing in the shifter linkage that is made of rubber; when it disintegrates, the shifter becomes sloppy and eventually it becomes difficult to get into reverse. Or fifth. Or first or second.

And unfortunately, that drop-off from "vague and sloppy" to "2-speed" happens pretty quickly.

So: I need to be able to fab a bushing, but I need a suitable piece of raw stock. I need to do it pretty much right now. Waiting for a part to arrive would be a major inconvenience, especially as reverse on my DD is rapidly becoming impossible. This needs to happen this weekend.

There will be two bolts at 90 degrees to each other, offset slightly. The overall size is probably about 1.5"x1.5"x1.5".

Link to commercial version

Material? Could be anything. The aftermarket one above is steel (though that would be less convenient to make); the audi one is rubber. In-between materials like aluminum, plastic/nylon, or even wood are possible.

I think the piece is slightly too big to be made from a hockey puck, lacrosse ball, etc. Installation -- from under the car -- is inconvenient enough that I'd rather not do it twice. (which makes wood less attractive).

I am leaning toward the welded steel tubes design -- because really, even my welds are as strong as a piece of rubber. (Maybe typing this post has been enough to make me think that through/convince myself.)

But if anyone else has a better idea, I am happy to hear about it. Or, for that matter, design considerations for the steel version.

Okay, hit me with some ideas. Thanks, all.

Matt

revhard
revhard New Reader
10/18/13 7:17 a.m.

What does the oem piece look like?

When i made shifter bushings for my sentra, i used delrin/acetel. easy to turn and wear resistant. grainger and mcmaster have it and if you dig around, a plastics supplier should have it

JeremyB
JeremyB New Reader
10/18/13 7:25 a.m.

You could weld one up as you say, but then use use some bronze to act as a sleeve to keep it working smoothly. I did this on a BMW shifter linkage and it worked great. It really helps to take the slop out of the rubber bushing design.

914Driver
914Driver MegaDork
10/18/13 7:37 a.m.

If steel was the answer, why didn't Audi do it?

I would duplicate the original in some kind of poly, tougher than rubber but dampens vibration as steel won't.

How often is this item replaced?

Dan

4cylndrfury
4cylndrfury MegaDork
10/18/13 7:43 a.m.

can you rig up a simple mold from cardboard tubes - roll up some cereal box cardstock into tubes, cut out the notch where they would meet, glue together with hot glue gun, and fill it with window weld from the auto parts store? let the stuff set up overnight, then soak it in water to dissolve the cardboard. May require some drill press action to get the bores straight.

Steel honestly would probably be easiest if you have access to a welder. Finding appropriately sized stock may be the issue here...

Treb
Treb Reader
10/18/13 8:43 a.m.

Responses to some questions:

OEM part looks like this: link to ad featuring pic of OEM and steel versions

The oem part on my car is ~16 years and ~200K miles old.

I think the point about vibration is correct -- that's one reason (another being expense) that Audi used rubber.

But I like shifters that have a good, direct feel -- even when they're attached, with not an ounce of rubber, to a motor that wants to shake your fillings out (which this isn't.)

I've been thinking about the bronze bushing, and I think that sort of combination is how I will go.

Thanks to all for the ideas so far. Still kicking it around... may go hardware shopping at lunch and see what sort of bronze bushing options I have.

Dr. Hess
Dr. Hess MegaDork
10/18/13 8:56 a.m.

Burn out the rubber from the original piece, turn a replacement bushing from Delrin stock bought from McMaster-Carr, push in the original piece, done.

Curmudgeon
Curmudgeon MegaDork
10/18/13 10:22 a.m.

I made a shifter bushing for the 'Yota trans in my J-H out of bronze Oilite. It's tight, like rifle bolt tight, and was not hard to make in a lathe.

Driven5
Driven5 Reader
10/18/13 11:00 a.m.

If you think you can source material and have the time/ability to complete making it faster than you would receive it if ordered immediately, I would want to replicate it in the easiest suitable material. More or less copying the JHM part would be a reasonable choice. As might rebushing the stock part with another material.

But typically for a car that can't afford the down time, I would try to get something on order immediately. Fast Enough Performance is listed as a JHM dealer in Lexington...Might want to give them a try and see if they can get one in your hands even more quickly. Is there any possibility that by calling around to local dealerships or parts stores that they might carry a stock replacement, or being able to get one by tomorrow? It sounds like at this point late stage, the need for a quickly installed solution pretty much trumps all other considerations.

aussiesmg
aussiesmg MegaDork
10/18/13 11:03 a.m.
Dr. Hess wrote: Burn out the rubber from the original piece, turn a replacement bushing from Delrin stock bought from McMaster-Carr, push in the original piece, done.

absolutely this

RealMiniDriver
RealMiniDriver UltraDork
10/18/13 12:43 p.m.

In reply to Dr Hess and aussiesmg:

Have you looked at the part in the link above? It doesn't look like a simple burn and push solution.

EDIT: Maybe with two pieces, it would work.

turboswede
turboswede UltimaDork
10/18/13 12:50 p.m.

Probably simpler to hit the local hardware store and find a piece of aluminum approximately the right size. Cut the aluminum to the proper size (looks to be roughly rectangular in shape) and then drill a couple of holes. If you need to clearance the sides to allow for movement, a simple cut off wheel or die grinder can do that, especially since it is aluminum.

If you could find a piece of plastic, that might be an option as well. Both are equally easy to work and cheap.

The only draw back is that it will eventually wear out, but by then you should be able to acquire a better replacement (either NOS or aftermarket)

Treb
Treb Reader
10/28/13 11:02 a.m.

So my car, an early 98, has a different shifter rod -- one that matches to early 97s, I think. The 97-98 model year change does not seem to have been smooth. Lots of odd things about 97.5 cars.

http://www.audiworld.com/tech/eng90.shtml

Simpler to rebuild, at any rate. Thanks, all.

GameboyRMH
GameboyRMH MegaDork
10/28/13 11:03 a.m.

Someone on here once said that if you retrofit skateboard bearings in place of the bushings, you'll get long-lasting buttery-smooth and firm shifting action.

44Dwarf
44Dwarf SuperDork
10/28/13 11:15 a.m.

Burn out the rubber and replace with Bronze bushings from the hardware store.

Leafy
Leafy New Reader
10/28/13 11:56 a.m.

For $90 bucks for the replacement part. I would probably just order it from that shop local to you. Getting the correct sized bits ASAP to weld yourself up one is going to approach that kind of money unless you have a good local metal supplier that will cut you 1 foot sections or happens to have the correct metal drops kicking around. And then the hour or two its going to take you to make this... it makes sense to just buy this one.

This part to machine would require a mill and too big of a chunk of billet than what you would find at the hardware store. You aint doing this on a lathe either.

captdownshift
captdownshift New Reader
10/28/13 12:10 p.m.

http://www.usrallyteam.com/index.php?main_page=contact_us

I'd contact Scott at USRT, he'll put something together

curtis73
curtis73 UltraDork
10/28/13 12:15 p.m.

E30s have the same issue. The rubber wears out and its super sloppy.

Replacement pieces are usually delrin. If you want some cheap delrin stock, buy a bunch of those cheap white plastic cutting boards. A little heat and you can fab mostly anything.

Giant Purple Snorklewacker
Giant Purple Snorklewacker MegaDork
10/28/13 1:09 p.m.

Go with steel tubing if you don't have a lathe or a TIG (you also said you were in too much of a hurry to wait for shipping so I'll assume tomorrow is too long). Local big box will have some 3' lengths of steel tube in a few thicknesses for $9+/- $1 but probably not the same ID/OD as the pic so ... proper ID matching the bolts is the critical interface.

If you can weld w/o blobbing the inside of one tube it's a pretty easy part to make.

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