914/4 steering rack play, Anyone has bushing inner and outer dimensions? Options

[larss]

Found that the rack has a play in its outer right end, about 1/16" sideways and up and down, not in/out, guess the bearing sleeves has to be changed.
What more should be done at the same time?


/Lars S

[914Sixer]

Try and find a good used one. Rebuilt ones are $1600 plus. There is no excuse for this price but I guess they feel like manufacturers can get away with it. Special Kuko bearing pullers are needed to do the job. Rebuilding is covered in the factory manuals, not sure if the Haynes has it.

[larss]

Thanks!
Would a 911 rack from the same time period fit? Guess not since it has Another part no...





/Lars S

[r_towle]

try used first.

The replacement parts are two bushings, two bearings, and two seals.

All can be obtained from places like Eastern Bearings.

If it gets bad the pinion gear needs to be replaced...so then again, you start looking at used racks.

I would look for a used rack first.
Last time I rebuilt one I had to go through two or three racks till I found the pinion gear that worked for the rack.

Nice part is that this part does not rust, so they are out there and plentiful.


Rich

[SirAndy]

Would a 911 rack from the same time period fit?

It should. I have used a 911 unit in my car (with a 911 frontend), but now switched back to a 914 unit.

Also make sure you inspect the rubber coupler between the rack and the shaft going up.

http://www.914world.com/bbs2/index.php?showtopic=205961

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[underdog]

Found that the rack has a play in its outer right end, about 1/16" sideways and up and down, not in/out, guess the bearing sleeves has to be changed.
What more should be done at the same time?


/Lars S

AA sells steering column wheel/ball bearing. They say this corrects up and down movement but does not say anything about side to side movement. Perhaps George will see this and respond.

[SirAndy]

AA sells steering column wheel/ball bearing.

His problem is with the steering rack, not the steering column ...
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[FourBlades]

Just making sure here, but is the play in the rack or in the inner tie rod that screws into the rack?

The rack itself ends with a threaded hole on each side. The stuff screwed into those holes is all replaceable.

I also agree with looking at the rubber coupler under the gas tank that connects the steering rack to the steering shaft. Those can get wallowed out.

If it really is the rack, you can get a good used one from bdstone or other members for reasonable money compared to any other option.

John

[larss]

Thanks everyone for great help!

I have checked, it is the sleeve bushing in the outer end ofhe rack housing , I can see the play between the bushing and the rack itself.

Would it be possible at all to change the bushing with the rack still in the car as a temporary solution (while rebuilding another rack)?


Thanks again!



/Lars S

[porschefile2010]

I had to get my steering rack serviced when I brought the car into the country because there was too much slop in it.
I dropped the whole assembly out and took it to a steering specialist engineer shop and he went over the whole deal. From memory it wasn't an arm and a leg-maybe an arm - sort of $450 or so. See if you can get it rebuilt by a professional shop. If you buy second hand 911 or any other type you won't be sure what you're getting till it's in the car?? Then it's luck.
At least rebuilding you know what you've got.

[larss]

I have managed to get the bushing out of the housing, there is something strange here, the bushing is of bronze/copper with perfect fit on the rod but lined with some tape (IMG:style_emoticons/default/mad.gif) to fit in the housing, of course this does not work!

Should'nt the bushing be of plastic/nylon material?


/Lars S

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.lsmteknik.se-10787-1367568172.1.jpg)

[r_towle]

the bushing is bronze.

You need to pull the rack out of the car, and pull the pinion gear out.
Then pull our the rack (just a rod with teeth.

Then press in the new bushing.

The pinion gear wont let you remove the rack...
Pull the whole steering rack from the car, its simple enough to pull it apart from there.
Whe you look at it you will see its not very complicated.
The lack of teeth at either end of the bar is the stop for the rack...it cant go any further.

Before you go to far, center the rack.
Mark the pinion gear in reference to the body of the rack.
Pull the pinion gear and make sure to flip it 180 degrees when you re-assemble it.
That gets rid of the worn wobbly section when the wheel it straight.
That is what I was chasing...
Its a very slight difference in the lash, but once its all together, I can feel it.


While you are there, you can check and replace the rubber spacer that is under the tank, it comes with the rack when you remove it.

You need to remove the u-joint inside the car...
Then remove the tank.
Pull off the two bolts that hold the shaft inline to the body...you will see what I mean.

Then remove the two tie rods...and the two bolts that hold the rack.

The rack will then come out with a bit of a fight...but it does fit.

The bushings at both ends should have a seal (seperate piece) and the pinion gear has two bearings.

There seems to be two models.
One model the lower pinion bearing is in the bottom of a hole, but can be removed with a seal puller you make custom for this...just get under the bearing and pull it out a bit at a time.

The oldr models have a cap on the bottom side, two bolts and you can remove the bearing...much easier
The top bearing on on the top of the pinion gear, you will find it easy enough.

I replaced both bushings and both bearings.
Its just worth the extra 20 dollars to do it all at once, the parts are cheap.

For the bushing, I do not believe you can buy an off the shelf item from a bearing supplier, but you can get ones that is close enough with extra material, (so a smaller inside diameter, and a larger outside diameter)

Then get it machined to the exact specs of your rack housing and your bar...that is what I did.

Should be no tape there, that is most likely your problem.

I cant remember what the seal looks like, o-ring or flat ring..
It should be available at the porsche dealer.

rich

[r_towle]

Maybe someone with access to the PET could post an exploded diagram for you with part numbers.
Never know, but Porsche may have all the parts....
I made all mine.

New materials available since the car was created.
Poly Bronze tephlon impregnated is what I used.
Hold lube better, and works fine on a mill.

The item in there now is just bronze with no tephlon.

Rich

[larss]

Many thanks Rich, this made things clear!
I have the old type with two bolts and a cap. I have the PET so parts can be sourced.

The strange thing with the bushings is that they fit perectely on the rack but are to small for the housing but nothing seems to be missing compared to PET.
The bushing is almost like a piece of thin bronze tube but a bit thicker at one end...?


/Lars S

[r_towle]

Many thanks Rich, this made things clear!
I have the old type with two bolts and a cap. I have the PET so parts can be sourced.

The strange thing with the bushings is that they fit perectely on the rack but are to small for the housing but nothing seems to be missing compared to PET.
The bushing is almost like a piece of thin bronze tube but a bit thicker at one end...?


/Lars S

I dont recall honestly.
I took my own measurements and had mine made up custom.
I bought bushings that had enough material to start with, just needed to hone them out for the inside dimension and turned on a lathe for the outside dimension.

It worked out fraily easily.

rich

[larss]

Took a closer look at the bushing today, removed the tape around it.
Its a bronze bushing and there seems to have been a plastic layer outside it, a layer that now is mostly gone.

Does this look as having been an original bushing?

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.lsmteknik.se-10787-1367757318.1.jpg)

[r_towle]

Forgot about this thread.
From what I remember, there may be a piece of plastic on the outside of the bushing and we figured at that time that the cast rack was not the same on each end, nor the same over a whole run of racks, so the solution may have been to use a plastic shim.

I found bronze bushings that were to large, milled them to fit.
Make custom parts, make them fit perfectly, done.

Use tephlon impregnated bronze bushings, camfer both inside edges to ensure the rack does not start digging them up.

I believe the bushing is held in there with a c clip, so you need to pull out the rack, clean it up and measure up for the bushings.

You need to get the two bushings made, and search for the bearings at a supplier.
You can get all of the parts from a good industrial bearing shop, or a good machine shop can find them for you.

It's worth the effort...it will be super tight.

Rich

[larss]

Thanks again Rich for this wery useful information!


/Lars S

[larss]

By the way, does anyone happens to have the precise dimensions for the bronze sleeve bushings at the end of each side of the steering rack?


/Lars S

[toolguy]

here is the only shot I have of the bushings when I pulled my rack apart. . not just a sleeve, they are in some kind of molded holder on the outside