Replacing lower steering column - wothwhile, but a bear

[gmushial]

I spent about 6 hours net net yesterday replacing the lower steering column in the Z (this is the collapsible piece that runs from the firewall, down through two u-joints, a flex disk, to the input of the steering rack).

Over the last year I had noticed a less and less precise feel to the steering in the Z, a greater tendency to tramline; and this last summer after going to solid LCABs (even more so than the ///M ones) and still not getting the feel back I wanted, did a piece by piece inspection of the steering system, only to discover that the flex disk was torn and the lower u-joint had a lot more than non-zero play. [rack was solid, rod ends were solid, ball joints had zero play, everything was bolted tight etc]

I had read other's experience with replacing the piece - not pretty - and managed to delay doing such until now, so, not only did I get to fight with it, but got to do so in a freezing garage (not good thinking on my part - should have done it while the weather was still warm, or waited until it warmed up again)... but what I was hoping to be a two hour job, turned into a six hour "flustercluck" [will let others deSpoonerize]... although the outcome and the improvement clearly made doing such worthwhile, during the process I'm not sure I was very convinced of such.

This is clearly one project where those gents with ladyfriends or wives with petite hands, and ones that one can convince them to do the wrench twisting, would be a whole lot easier - the biggest problem is access... the other approach is guess would be to start removing the intake manifold and associated plumbing - probably a job that if one already has such off for other reasons, one might consider doing, so as to not have to fight it otherwise/later.

The job is basically simple: four bolts off, four bolts on and done.

The lower column is held in place by a pair of cross bolts: one attaching it to the splines on the upper steering column coming out of the firewall; and one at the splines on the input to the steering rack.

Access to the bottom cross bolt isn't a problem: it is accessible and comes out easily from under the car. The upper one is quite the opposite: it is only marginally visible, ie, one has to remove it by feel; and the bolt head is only accessible with the steering wheel in a limited range of positions.

The other part of the process is to unbolt the steering rack - two bolts: 15mm hex heads, 16mm nuts - where the heads are trivial to get to, but the nuts one gets to do by feel.

The real problem, at least in my case, and seemingly for most if the YouTube vids are indicative: is the corrosion that forms btwn the splines on the shaft and the splines on the receivers. Some people talk about soaking them the night before, or for a couple nights before. I tried that. They were still locked up tighter than a rat's a$$.

The saving grace that I found was: to tap the blade of a standard screwdriver - as large as possible and with a square shaft - into the clamping slot on the receiver; and then put a wrench on that square shaft and try to torque open said slot, breaking the corrosion free. On the lower one one has access and other than breaking the tip off the largest (3/8" - 1/2"??) Craftsman screwdriver I owned, I was able to get the slot to open [used another HF screwdriver next to the tip still in the slot]... and although the slot closed after torqueing on the screwdriver, the corrosion had been broken/the two surfaces have been separated... afterwards I took a small screwdriver and tapped it into the slot, but coaxial with the shaft, and left it there so that the receiver was being held open while I removed the shaft. [noting that the rack doesn't want its input shaft tapped on in any significant way - so, do it gently; likewise the upper receiver has a shock sensitive airbag tied to it - gently is the word.]

The upper spline was the hour waster. First there is no access for my big paws; and second, even with my longest screwdriver (over a 12") I still couldn't get to the spline from above the clutter.

My second attempt was to grind a "screwdriver tip" out of some steel stock I had around, and tried to use a set of oil filter vice grips tightened all the way down to force it into the slot, while snaking my hand up from below: managed to get the wedge to stay put long enough for me to drive it in with the vice grips... but wasn't able to drive it in far enough - the receiver is aluminum, so the first thing that happens when one drives a tip into the slot is for the aluminum to give... then finally the corrosion breaks - after the corrosion has broken, then any force to split the slot does exactly that.

My third attempt was to use a standard screwdriver socket on a 3/8" ratchet - where the goal was to get the tip of the screwdriver bit into the slot, and then use the leverage of the length of the handle to pry the slot open... which actually worked. But this was at hour four, and after, although not a biggie, the cross brace under the engine was off - that provided a few critical inches of working space. After getting the corrosion (or maybe dissimilar metals welding - the shaft is steel, the receivers aluminum) I was able to tap another small screwdriver into the slot opening it by maybe 20 thou - but again enough so that there was a hint of clearance btwn the two pieces, or at least the clearance was greater or nearly so than the roughness of the surfaces; or at least one was able to with hand/arm force and a lot of pulling and wiggling get the two to move relative to each other.

Getting the rack off is trivial. and having the two ends of the shaft splayed open and slightly/somewhat moving, actually, as I slid the rack forward, the shaft pulled off first the rack end, and then with hand-force I was able to pull it off the upper end.

Putting the new shaft in is about as much "fun" as getting the old one out. Luckily I preloaded both receivers with the small screwdrivers so that there was clearance (or at least not an interference fit btwn the splines and receivers).

Putting the upper half together was the trick/challenge: one can't see the spline one is trying to fit, so one get's to do it entirely by feel. Getting the splines to even mesh is the first trick [for this I tightly wrapped my left forearm with wax paper and literally shoved it btwn the intake manifold and plumbing so that I could work on it from above and not from below - don't think it would be possible from below given the alignment and forces involved], and just by trial and error I got it started; but the real trick is getting the shaft slid on just the right amount so that the cross bolt will fit. The force to slid the receiver onto the spline is on the order of 30 or 40 lbs, and one is basically pushing and wiggling it upward. The first go at it I managed to over shoot and drive the shaft on too far. So all my hard fought effort had to be reversed. Initially I tried to slide it down, trying to get the right position for the cross bolt. Murphy won: one second the shaft wasn't moving, the next it was entirely off. Mumble - though maybe the slide on and then off was beneficial in that the second time getting the splines to mesh was easier - I didn't say easy, but easier. The second go at it I passed the shaft down to my wax papered arm, with the bolt in place; and where once the splines were started, I unthreaded the bold, slid the shaft upward a little bit, and then reinserted the bolt... where the mode was to keep my thumb on the head of the bolt trying to push it into the slot, as I wiggled the shaft upward. This basically worked, in that after pushing it upward some, the bolt slit in a bit - telling me that I was near the slot - and then I wiggled the receiver about until it slid in entirely. Once I got it finger started I left it be. Remember: this is all done out of sight.

At this point one has to attach the lower end - which is visible, but more importantly, one has to align the steering/rack so that the steering wheel is horizontal, when the car is going straight forward. Luckily the steering wheel has the locks when the key is not engaged... so: find the straight ahead position for the steering wheel, and let the lock hold it.

Since the Z was being held in air by large pine rounds under the front jacking spots, the wheels were hanging and easily moved. The procedure was to: get the rack laterally aligned with its mounting bolts; then aim the wheels to straight forward and then as one slides the rack rearward, one slides the shaft onto the rack. This took three tries. The first two the rack was off to the side, so when everything was together, the steering wheel was saying straight ahead, the wheels were turning to the left. If one has gotten this far, then this is a minor problem: just slide the rack forward, disconnecting the sheering column from it; one rotates the input shaft to the rack a spline or two, and reassembles.

Anyway: after getting washed up, I took the Z out onto a) one road that caused the worst tramlining - 99% of it was no longer there, and b) took it to my favorite curvy back road - and it was so wonderful to feel the connectedness btwn the front wheels and the steering wheel again, something that had been fading over the last year.

So: if your Z is tramlining and you've checked and refreshed all the steering parts... you might take a look at the lower steering column.

Was the column at fault: sure... the rubber flex disk was torn at two of the mounting points, providing maybe 5+deg of free rotation; and the lower u-joint had two of the bearing sets sloppier than all get out. With the new column, it drives like a bimmer again. :-) and I'm very glad one only has to do this every 200k miles or so.

Oh: there were several comments on the web about marking the splines so that one can put the new column in the same position - the problem with this is: the upper connection is not visible, so how one would make the marks and after the fact align them I don't know. And getting the upper end of the shaft started is a proposition where one is grateful for it to mate in any position, never mind a specific one... and with the top going on in any position, what good are any marks at the bottom??... though after the fact, it looks like I somehow managed to catch exactly the same spline orientation with the new one that the old one had (pure luck I'd guess).

[kobayashi]

http://www.bimmerforums.com/forum/sh...-favorite-mods

[gmushial]

:-) So it took six years for someone to attempt another one :-) [Ghery's posting is from 2009]

Though I like the idea of the hockey puck and bolting it through, ie, for those with only a torn/worn flex disk, one has enough access from below that one would be able to simply unbolt one and bolt another one in, bypassing the entire dance of removing the shaft - that would have made it a 15 minute job... though the first time one would still have to remove the shaft to carve the old disk out and dimension up the puck to fit (the bimmer disk is 15mm +/-; while a puck is 30mm and there is zero give in the mounting points of the shaft, unless one tries to play game with trying to partially collapse it :-( .

But in the case a disintegrating u-joint, then one is forced to remove the shaft (the u-joints are peened in, like in the driveshaft, and as such generally not serviceable).

Though Ghery's comments about access - I wish, gawd I wish... but at least in the case of a '99 roadie, you have the intake manifold and one hose on one side (the hose moves out of the way when you press on it, so it's not really a problem - the manifold very much doesn't), and you have all the plumbing of the ASC on the other and too little clearance btwn the two for at least my arms to get btwn.

W/re the limited number of bolts/connections one has to break/make - quite true: really just 4: the one at each end of the shaft, and two for the rack... and for me that was part of the "deception" (really more misguessing on my part), ie, with that few bolts, how could it take very long.

What I hadn't appreciated was the corrosion "gluing" the splines in place, and especially the upper spline being hidden behind the power brake booster.

W/re replacing the flex disk with the aluminum: suspect over time and miles on less than perfect roads, one's hands are going to get beat up, ie, every little shock from the rack is going to get transmitted... that's why if one doesn't replace the disk with another OEM-like disk, then the hockey puck makes sense. [though one should note: as delivered by bimmer: the disk is riveted in place (I presume for perceived safety reasons, ie, never able to come off unintentionally) - so if one is going to drill out the rivets, one probably is best advised to lock nut the replacement, and/or, loctite it in place... after all: steering is somewhat important and something one wouldn't like to loose].

But as all our Z's get older and accumulate the miles, I suspect more and more of us are going to have to cross this bridge... though I hope others have a better time of it. Likewise, I suspect I'm going to get to "perfect" my technique in that one of the three Zs locally that I seem to be keeping an eye on, the steering is that same kind of loose that mine was, and suspect if I try to move the shaft around I'm going to find the same shot u-joint or torn disk. [of note: the first lower shaft I got off eBay, arrived with one of the u-joints crunchy as all get-out, and that was from a Z with < 100k mi on it; its replacement, also from a crashed Z with < 100k mi was ok, ie, these things don't last forever.]

All said and done: I'm glad it's done, and I really like the improved/glued-down feel that's back... but the surgery sure wasn't as much fun as doing the VANOS [still my favorite repair on the Z, from the actual doing it to the improvement from the efforts].

[kobayashi]

Though I like the idea of the hockey puck and bolting it through, ie, for those with only a torn/worn flex disk, one has enough access from below that one would be able to simply unbolt one and bolt another one in, bypassing the entire dance of removing the shaft - that would have made it a 15 minute job... though the first time one would still have to remove the shaft to carve the old disk out and dimension up the puck to fit (the bimmer disk is 15mm +/-; while a puck is 30mm and there is zero give in the mounting points of the shaft, unless one tries to play game with trying to partially collapse it :-( .

Odd because Ghery specifically stated that a hockey puck is the exact same width as the stock disk. Did yours not have the raised portions that he described?

The bushing has risen portions where the bolts go through, so it seems thinner. It is actually the same width.

[gmushial]

I think I stand corrected - my bad: (having just retrieved the old shaft from the garbage) yes there are raised areas where the rivets go through (the main body is 15mm)- the space occupied by the bimmer disk is: 22 x 75mm... so a puck is close (1" x 3" or 25.4mm x 76mm).

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A follow up: I just bought one of these http://www.ebay.com/itm/NEW-6-Oz-Bla...3D221285214711 and will try to replace the disk in the old shaft with it... won't be able to use the resulting shaft because of the dead u-joint at one end, but will be able to speak to the process of swapping one disk for another, and the resulting dimensions. [kind of a shame: in my native NH there were pucks in the entry/mud-room, there were pucks in the garage, there were pucks in the kitchen, there were pucks on the bookshelves and window sills of every bedroom, and short of that I could go to any sports shop and buy them off the shelf... here I have to order one :-( ]

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A further follow up: has anyone heard back from Ghery in terms of how long/well the hockey puck has held up? I'm expecting well... but given that not all engineering rubbers are created equal - would be interesting to see what his actual experience has been...

[kobayashi]

Ghery didn't use the hockey puck but he should have. The solid metal bushing is known to cause problems.

[robb1887]

Just ordered a hockey puck from prime while all my engine compartment is torn open. Thanks for the info!

[gmushial]

Ghery didn't use the hockey puck but he should have. The solid metal bushing is known to cause problems.

I guess I misread his posting: seemed like he went with the puck... will have to reread. And, what problems with the metal? To the driver's hands? Or, to the rack? Or?

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Just ordered a hockey puck from prime while all my engine compartment is torn open. Thanks for the info!

Clearly first check it and see if there is any play, in either of the u-joints, or in the disk - if so, then replace/rebuilt it now... with an engine out this should be a 15 minutes, half-hour job (depending on how corroded the splines are)... but with access this should really be about as difficult as changing the oil + filter. On mine the rivets had elongated an opposing pair of holes in the disk, allowing rotational play, and probably the tramlining. If your u-joints are ok, then just replace the rubber and be done with it - either with a puck: which I suspect should give a more ///M type of feel to the steering (more solid, yet slightly forgiving - kind of like the LCABs non-///M with the cutouts vs the old ///M solid rubber ones)... or, you'll have to check the dimensions, but I have seen lower steering column bimmer part-numbered rubber disks - for similar era 3 series... and as I said, you'll have to check dimension, but suspect bimmer didn't build each and every model with uniquely dimensioned parts [doesn't make inventory sense]. But if you're going to unrivet the shaft anyway, bolting in a replacement makes sense.

Just a heads up: the part number for the lower half of the column is 32311092644, and when one does a reverse search on REALoem, these columns are unique to our Z's - the same part number is used on all the Z's - 1.9's thru S54 ///M's... and not making any predictions, but I think I'd be concerned about them NLA'ing it on us, ie, there're a whole lot fewer Z's on the road than 3's etc, ie, if one doesn feel like rebuilding their current column, and thinks there's a chance they're going to need one, and has an extra $250 around: one might grab one while they're still available. [The other thought on these getting NLA'd is: they used to list for $140, like the ones for the 3 series - now they're $250ish.]

Other note: it looks like the flex disc from the E46 might be the same dimensions - though how it's connected up is entirely different, but one might be able to cannibalize a Z oem like disk from there. ... if someone tries they might post what they encounter. Part number is 32301094703.

[kobayashi]

I guess I misread his posting: seemed like he went with the puck... will have to reread. And, what problems with the metal? To the driver's hands? Or, to the rack? Or?

Some steering rack failures if used on non-E30s. Vorshlag also sells their replacement steering shafts which are two-piece, internally-collapsing: http://www.vorshlag.com/product_info...6a2a6ef52f6f5c

[gmushial]

Some steering rack failures if used on non-E30s. Vorshlag also sells their replacement steering shafts which are two-piece, internally-collapsing: http://www.vorshlag.com/product_info...6a2a6ef52f6f5c

Good find... though if the bimmer one is available, one is still $100 ahead... but with theirs you can see the added clearance needed for the driverside exhaust manifold w/ a LSx transplant.

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Just a heads up: on eBay currently, there are a half-dozen lower steering columns (part #32311092644)... used + new. Since I suspect I'm going to be doing this on another Z I snagged one for $35 shipped... we'll see if it's any good when it gets here. But at least for the present, if $250 is a bit steep, eBay might be a source (though as usual used parts are hit and miss :-( ) - do a search on "BMW 32311092644" and include the description in the search (not just titles).

[robb1887]

From reading Ghery's thread the metal one cause a little extra vibration back through the steering wheel but not unbearable. The larger reasoning I believe was that it cause premature/accelerated issues in the steering rack and is why a few companies stopped manufacturing the full metal ones.

[Ghery]

Ghery didn't use the hockey puck but he should have. The solid metal bushing is known to cause problems.

I made a couple of urethane replacements, the production run never turned into reality. Have had it on with my quick ratio rack and have had no issues.

[BimmerBreaker]

I'm thinking I really need to do this soon. My steering wheel has a decent amount of play.

[gmushial]

I'm thinking I really need to do this soon. My steering wheel has a decent amount of play.

I'd give the lower end of the shaft a good shaking around and see how loose it is - if there is no play, then I wouldn't go to the bother... but if you have one of those "oh excrement" moments when you give it a shake (and it does shake - either the u-joint is sloppy, or the robber is torn), and you're sure that it isn't the input to the rack that's moving... as much as replacing it was a PITA, it's proved to be one of the better upgrades I've made to the Z - the connectedness to the road feel is a delight... also appreciate the lack of tramlining.

[robb1887]

I made a couple of urethane replacements, the production run never turned into reality. Have had it on with my quick ratio rack and have had no issues.

Have any left over?

[Ghery]

Have any left over?

There is one buried somewhere, no idea where though

[BimmerBreaker]

Any chance of making a small run of them? I'd be in for 2 maybe 3

[robb1887]

Any chance of making a small run of them? I'd be in for 2 maybe 3

This... but I'd only want one. I'm having doubts of this "hockey puck mod"

[Vintage42]

... spent about 6 hours net net yesterday replacing the lower steering column in the Z (this is the collapsible piece that runs from the firewall, down through two u-joints, a flex disk, to the input of the steering rack)... the biggest problem is access... the other approach is guess would be to start removing the intake manifold and associated plumbing...

Access seems better on the 1.9. The steering column is exposed from the firewall to the rack.

[BimmerBreaker]

This... but I'd only want one. I'm having doubts of this "hockey puck mod"

Me too. If Ghery doesn't make a small run of them (I don't really expect him to... and you've got dibs on the one if he finds it) I might see about getting a local metal fab shop to just make me a solid mount type unit. Might transmit some NVH through the steering wheel but would better than the loose boaty steering I have on the roadster atm. Its pretty much the last mechanical thing I need to fix on that car.

[gmushial]

Access seems better on the 1.9. The steering column is exposed from the firewall to the rack.

Wow... I'm envious, big time.

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Me too. If Ghery doesn't make a small run of them (I don't really expect him to... and you've got dibs on the one if he finds it) I might see about getting a local metal fab shop to just make me a solid mount type unit. Might transmit some NVH through the steering wheel but would better than the loose boaty steering I have on the roadster atm. Its pretty much the last mechanical thing I need to fix on that car.

Breaker - you might see if in fact there aren't poly flex disks, just for another steering column to be had (I'm sure I've seen such)... and just because they're for a 325 or whatever, if the dimensions are correct, that might give you an easy answer.

Why a concern about the puck though? Wrong type of rubber given the environment it'd have to live in? Or something else? That's my only concern - but on the positive side: it would be twice the thickness of rubber vs the oem disk - so could be a nice compromise btwn still being resilient but being less pliable than the oem one - might be a happy pt btwn the oem one and poly.

[robb1887]

After looking into it a bit more the durometer isn't as high as I thought it felt to be. Typical durometer measurements seem to be in the 80's which isn't horrible. It felt higher than than in hand.

[gmushial]

I'm not sure we have a lot of choices... one can pay $250ish for an official bimmer one (as long as they are available): suspect they're on the soft end of the spectrum, but probably at least not torn or with blown out u-joints.. there is the AKG poly disc - suspect that's fine for racing, but probably jarring for touring http://www.pelicanparts.com/catalog/...SUSSTR_pg4.htm and they only solve the blown rubber problem (not the blown u-joint situation). If one can find a lower shaft with good u-joints, then maybe the VW van coupler might be a possible - but don't know about the dimension... so that's a big if. Otherwise, it seems to be the puck... or the bucks.

[BimmerBreaker]

I just went out and gave mine a wiggle, there is definitely some play in mine, but the disc seems intact and there is a slight clunking noise coming from the upper portion. I'm going to fiddle with it this weekend I assume something in the joint gave up?

[gmushial]

Sounds like dead/dying u-joint disease... that's what prompted me to swap the old one out... only to find once it was out that the rubber on two of the rubber arms had given up. ... but I don't know if it's a question of age (the rubber simply degrades with time/smog) or miles (only so many cycles and bumps for a service life) that kills these, but as our Z's get older, I suspect a bunch of people will be needing to replace them [hope there are replacements to be had]. ... The u-joints going away is the problem that I see as the larger more difficult one to (re)solve. I suspect the flex disk we'll be able to come up with something: un-rivet the old one and bolt something new in its place... but the u-joints aren't serviceable - so when bimmer's supply of new ones is gone (with the price almost doubling just for ours, suspect that's not far down the road), and all the usable ones have been scavenged from the junk yards: then we're going to be having a crisis as a community.