Idler and Pitman arm alingment and heights?

**BMWTurbo** · 09-02-2012, 07:01 PM

Hi Guys,

I stumbled accross a thread the other day when investigating bump steer that reference the BMW Serivce Manual for E34 that's talk about setting the height of the Pitman arm up to match that of the ilder arm.

Being that I have to tighten my pitman arm the other month I thought I'd check this out on the weekend.

What I found was what I half expected they were out ot alingment horizontally by about 8-10mm!!!

I found the passenger side was lower than the drivers side. I tried adjusting the pitman arm as low as it would go to match them, but no good. I ended up using the chassis rail as the reference with the underside of the ball joint thread being 85mm on the passenger side and 78mm on the drivers side.

The only way I can see this happening is someone (maybe me, I'm not sure) has bent the idler arm down. I can't see how the pitman arm could be bent up as any force to undo the BJ would be downwards.

I will buy a new idler arm and bush, even though the current one 'feels' okay, something isn't right.

On to the actual question, does anyone have an ACTUAL measurement or reference as to where these should be?

The height of the drag ling plays a massive part of bump steer reduction. The height relative to the control arms determines what the wheels do in bump/compression.

I have found reference to the BMW special tool P/N 32-2-120 as you can see above, but I can't find any information on it's height etc. I'd like to set my car up to try and resolve the bump steer.

Does anyoen have any more information about what this should be set as? Possibly some panel beating notes might have the information I need.

My gut feel is that it should be around 75mm from the underside of the chassis rail to the underside of the tie rod threaded section on the inner BJ of the steering arm, but I would liek to know this before getting too involved in getting mine straight.

Thanks
Ben

**shogun** · 09-02-2012, 08:42 PM

I have never done this. On the E34 forum is a thread about same subject from 2010, but no clear answer here too, I just noticed you also asked there
http://forums.bimmerforums.com/forum....php?t=1537994
I just have asked there if someone has dimension drawings of the tool.

Here are BMW tools, maybe you get a better pic of that
http://www.samstagsales.com/bmwtools.htm
http://www.kochtools.com/index.php?p...&parent=2&pg=1

**BMWTurbo** · 09-02-2012, 09:06 PM

Thanks Errich,
I couldn't find the tool on those pages. I suspect a lot of E32 and E34's will have this problem, and replacing them with new parts re-aligns it. I'd like to know exactly what is out though before throwing new parts at everything.
My Pitman arm from the box feels nice and tight, so don't think it's an issue.

**BMWTurbo** · 09-17-2012, 05:03 AM

I stopped in to my local wreckers today and got a rough measurement from a '92 730 that was there.

From the top face of the crossmember to a line drawn straight through the centreline of the draglink balljoints the measurements was 56mm.

I have not had a chance to measure this on my car yet, but will over the next few days.

**shogun** · 10-23-2012, 12:41 AM

any news on this?
"I just got an email from Aleksey asking me:
Hey buddy, I just wanted to see if you ever replaced pitman arm (drop arm from rack to center tie rod)?

Would you know if adjustment is no longer needed due to modifications? I know pitman arm has to be secured on the rack spindle at specific clearance (per TIS) but once i installed new plastic spindle and new arm there is absolutely no space left for it to travel up or down. I assume its a new design that simply does not require owners to figure out where to clamp it to the rack but wanted to see if you did this job before and what advice do you have. Thanks."

**BMWTurbo** · 10-23-2012, 05:56 AM

Hey Errich,
I haven't progressed any further with this. I don't have enough adjustment in the steering box arm to match the Idler arm. The idler arm didn't feel excessively worn, so I'm not sure what is going on.
I have ordered a new Lemforder idler arm, so when I get that I'll compare to what I have on the car now and see how they match. If they are the same, then either my steering box arm (early <88 model) will be bent or the idler or steering box mounts are bent.

I do remember having a hard time getting the drag link off a few years back and wonder if I've bent either arm in the process even though I was very careful. I'll keep this updated as I go.

**shogun** · 10-25-2012, 05:29 PM

Aleksey asked me to post it here:
quote
So I'm wrapping up the job, it seems like the parts are in fact identical but the plastic spindle on the bottom of the steering arm got degraded over 20 years and became a bit flat thats why there was more clearance. With new spindle and arm once you align the steering rack completely the clearance where steering arm connects to the rack will become greater, here is the thing (what I think) the special tool (in TIS) is not really needed.
Once you connect pitman arm and run center link across them tighten them up, you can measure ends of the center link relative to axel support and make sure they are relative to it on both steering arm and pitman arm. If it's a bit lower/higher on steering arm you move it up/down on rack until it's aligned and then measure clearance making sure it's within the spec (in TIS).

If you are unable to align them that A) center link is relative to axel support on both arm sides AND steering arm is within clearance specifications (0.5mm I think) then you might have A) frame damage C) component damage if you are reusing old arms or center link.

You can post that, I don't have an account there. Thanks again.

Aleksey
unquote

**BMWTurbo** · 10-25-2012, 08:59 PM

Does Aleskey know what the 'TIS' spec for the height is? That was my whole reason for starthing this thread

That measurement will clearify identify where my discrepency is.

**shogun** · 10-25-2012, 10:18 PM

I gave him the link to this thread, I just post for him here, as he is not registered. So he knows the whole thread and can read it.

**BMWTurbo** · 11-03-2012, 07:02 PM

I took some measurements yesterday when I had the car jacked to replace the CA's.

I levelled the car so the sbframe was the same height from the ground and took measurements.

Both struts hang at the same height, but the LHS was lower at the idler arm which made the inner pick up on the drag link lower also.

I did visually put the Lemforder arm beside the one int he car but didn't notice any obvious difference, but I doubt I'd notice 5mm holding it up anyways.

Once I get a new BJ seperator I'll drop the idler and replace it. I'm hoping it's just a fraction bent down and I can move the pitman back up towards the steering box a bit once I insall it.

**shogun** · 01-22-2013, 06:23 AM

any update on this? Just out of curiousity.

**BMWTurbo** · 01-23-2013, 11:05 PM

Originally Posted by shogun

any update on this? Just out of curiousity.

Not yet. I actually changed out the thrust arms for the Lemforders last night and fitted new eurothanes bushes. The arms from FCP felt a little loose and the previous eurothane bushes had 'ovalled' a bit in the bush centre.

I had another look at the idler arm when under it and checked it again, it fells nice and tight under there.

When I get some more time I'll drop the Drag Link out and double check the BJ's in it and change the idler.

I am trying to find the source of the steering shake when I go over bumps. The whole front of the car suspension has been replaced, aside from the struts and strut tops. These are the last on my list.

I also have some AKG 1inch thick roll centre/bump steer blocks that I will fit to try and reduce this even more.

**shogun** · 03-13-2013, 09:54 AM

I found a German DIY instruction to do this measurement with a simple self levelling laser from the next hardware store, run this thru google translate and hopefully the translation is understandable:

Mittlere Spurstange richtig einstellen. Dieser Tip gilt gleichermassen für E23, E32, E38
hier mal die Beschreibung wie die mittlere Spurstange sauber eingestellt wird. Vielen ist das nicht bekannt und bei Falscheinstellung resultiert ein nervoeser Geradeauslauf bei Unebenheiten, da sich die Vorspur der Raeder beim Einfedern unterschiedlich aendert.
Warum ist das so?
Die mittlere Spurstange liegt waagerecht und die aeusseren Spurstangen knicken davon im Winkel nach unten ab. Beim Einfedern verlaengert sich dadurch scheinbar die aeussere Spurstange.
Anders gesagt: Ausgefedert ist das Mass (Distanz) zwischen den aeusseren Spurstangenkoepfen kleiner als eingefedert. Das macht gar nichts, da die Federbeine schraeg stehen und durch die Anordnung der Querlenker und Druckstreben das restliche Fahrwerk sich gleich verhaelt.
Oder anders gesagt. In dem Weg, in dem sich die Spur scheinbar beim Einfedern aendert, aendert sich die Spurweite des gesamten Fahrwerks. Damit bleibt die Vorspur beim einfedern neutral.
Wenn jetzt die mittlere Spurstange so eingebaut wird, dass sie schräg steht, passiert Folgendes:
Rechte und linke Spurstangen haben einen unterschiedlichen Winkel. Beim Einfedern ist also die scheinbare Laengenaenderung unterschiedlich und damit die Vorspur jedes Rades unterschiedlich.
Das fuehrt zu sehr nervoesem Geradeauslauf bei Unebenheiten.
Wie wird nun gemessen?
BMW verwendet dazu ein Messwerkzeug, was in die Aufnahme des unteren Querlenkers geschraubt wird. Weil die meisten von Euch das Messwerkzeug nicht haben werden, habe ich mir etwas anderes ueberlegt.
Man nimmt einen selbstnivelierendes Lasermessgeraet aus dem Baumarkt.
Dann stellt man das Auto auf die Hebebuehne und stellt die Hebebuehnenaufnahmen so ein, dass das Auto absolut waagerecht steht. (Mit dem Laser messen)
Dazu als Bezugspunkte die vorderen Aufnahmen der Querlenker am Achstraeger verwenden.
Dann stellt ihr Euch den Laser auf einem Stativ - zur Not auf einer Leiter- so ein, dass er gerade so unter der Querlenkeraufnahme durchstrahlt. Ihr koennt dann mit dem Messschieber an der mittleren Spurstange messen.
ACHTUNG: Laserstrahlen koennten den Augen schaden, alo niemals direkt in den Laser schauen und noch besser Laserschutzbrille tragen.
Toleranz ist 1,2 mm
Wie stellt man ein?
Der Lenkstockhebel, also der Hebel der Lenkgetriebe und mittlere Spurstange verbindet, sitzt verschiebbar auf dem Zapfen des Lenkgetriebes. Man loest die Klemmschraube und verschiebt nach oben oder unten bis es passt und zieht die Schraube wieder fest.
Achtung danach unbedingt komplett von rechts nach links durchlenken und schauen das alles freigaengig ist und nichts klemmt.
-------------------------------------------------------------
Adjusting the middle tie rod correctly. This tip applies equally to E23, E32, E38

Here is a description of how to adjust the middle tie rod properly. Many people are not aware of this, and incorrect adjustment results in nervous straight-line running on bumps, because the toe-in of the wheels changes differently when the suspension is compressed.
Why is this so?
The center tie rod is horizontal and the outer tie rods bend downward at an angle. During compression, the outer tie rod seems to lengthen.
In other words, the distance between the outer tie rod ends is smaller when the suspension is released than when it is compressed. This does not matter at all, because the suspension struts are slanted and because of the arrangement of the control arms and compression struts the rest of the chassis behaves the same.
Or in other words. In the way, in which the track changes apparently with the compression, the track width of the entire chassis changes. Thus the toe-in remains neutral during compression.
If the center tie rod is now installed so that it is at an angle, the following happens:
Right and left track rods have a different angle. So when the suspension compresses, the apparent change in length is different and therefore the toe-in of each wheel is different.
This leads to very nervous straight-line running on bumps.
So how is it measured?
BMW uses a measuring tool, which is screwed into the lower wishbone. Because most of you will not have the measuring tool, I thought of something else.
You take a self leveling laser gauge from the hardware store.
Then you put the car on the lift and adjust the lift mounts so that the car is absolutely level. (Measure with the laser)
To do this, use the front mounts of the control arms on the axle carrier as reference points.
Then set up the laser on a tripod - if necessary on a ladder - so that it shines just under the wishbone mount. You can then measure with the caliper at the middle track rod.
ATTENTION: Laser beams can damage your eyes, so never look directly into the laser and even better wear laser safety goggles.
Tolerance is 1,2 mm
How to adjust?
The steering column lever, i.e. the lever that connects the steering gear and the middle tie rod, sits on the pin of the steering gear and can be moved. Loosen the clamping screw and move up or down until it fits and tighten the screw again.
Attention, then steer completely from right to left and see that everything is free and nothing is stuck.
Translated with www.DeepL.com/Translator (free version)

**BMWTurbo** · 03-13-2013, 05:49 PM

Thanks Erich... I have translated and will try and decipher

"To set the track rod system (centre drag link angle) correctly. This tip applies to all E23, E32, E38

Once you have a wheel alignment completed and the steering tie rod is adjusted correctly. Many will be unaware that any horizontal missalignment in the drag link can resulti in bumps being felt through the steering wheel due to the fact that the toe of the wheels changes during compression of the suspension.

Why is that?

The centre drag link should be horizontal and the outer tie rods bend down from this point and then angle down to the bottom steering plate at the lower end of the Mcpherson strut. During compression the tie rod moves on an arc which changes the relative length of the tie rod to the UCA and this changes toe.

In other words, the measure is Out ret (distance) between the outer Spurstangenkoepfen smaller than compressed. This is nothing, because the struts are hatch and by the arrangement of the control arm and the rest of the undercarriage struts are equal behaves. (not sure on this paragraph)

Or in other words - the way in which the track seemingly MODIFIES during compression will change the gauge of the entire chassis. Thus, the toe remains neutral during compression.

If now the average tie rod is mounted so that it is inclined, the following happens:

Right and left tie rods have a different angle. During compression, the apparent change of length varies and thus the toe-in of each wheel vary.

This leads to very nervous tracking on uneven surfaces.

And how will this be measured?

BMW used a measuring tool, which is screwed into the receptacle of the lower wishbone. Because most of you will not have the measuring tool, There are some other methods through which this can be measured and set.

Take one self levelling laser gauge from a hardware store.
Then, leave your car on the lifting platform and use a jack so that the car is perfectly horizontal. (Measured with the laser)
These photographs as reference points, the front of the wishbone on subframe use.

7410774.jpg

Then set up the laser on a tripod - it may be necessary to use a wire to be able to align the laser with each side of the vehicle to set it up correctly. You can then measure with the callipers/steel ruler the distance from the laser level to the tie rod.

NOTE:- (I’m not certain the above. I will have to check my car, but I would assume that the level will need to be set up on a plane axial with the a line drawn through the UCA and LCA bushes. And that ideally the drag link should be set up close to on this access to reduce bump steer)

CAUTION: Laser beams are harmful to the eyes, also never look directly into the laser and seeing the laser mark is even easier using laser goggles.

Tolerance is 1.2 mm.

What does a mean?

The pitman arm, that is on the steering box output is adjustable up and down once the locking nut has been loosened. You can adjust the pitman arm to the correct level to match the idler arm as close as possible which should make the LH and RH tie rods the same angle. This will mean both wheels change by the same amount of toe for compression.

Once complete turn the wheel gently through full lock to ensure that nothing binds or hits.

**shogun** · 03-13-2013, 06:10 PM

The photos are missing in that post, use the BMW instructions with their special tool as reference.

**BMWTurbo** · 03-13-2013, 07:48 PM

Originally Posted by shogun

The photos are missing in that post, use the BMW instructions with their special tool as reference.

Gotcha... Updated to suit. I'll be removing the steering box and probably drop out the crossmember over the next few weeks so might be able to make a jig up to measure this. The biggest problem is I don't know if anything is bent on my car nor the actaull measurement still, so that makes it tricky.

**shogun** · 10-16-2013, 08:21 PM

Can you give us an update on this, please?

**Tron5** · 10-17-2013, 05:59 AM

I made this adjustment a few years ago on an E34, but the directions are the same for an E32 because they use the same front subframe.

The tool for the job is 322 120 (BMW no.: 83 30 0 492 029)
But BMW has a different number for the tool now:
322 140 (BMW no.: 83 30 0 492 036)

Pictures can be found here and even ordered online:
http://www.ecstuning.com/Search/Site...8465/ES198465/

I didn´t want to spend that kind of money on the tool, but I improvised and used a 90° steel angle tool and a caliper and measured at the side where the pitman arm with the bushing is on the right side of the car, as seen from the rear.
I used the steel angle tool to extend the bottom of the subframe so that I could measure from the bottom of the subframe to the center tie rod.
I used this measurement to set the left side of the center tie rod at the same height.
I followed the instructions from BMW, just without the tool.

I cant remember the exact value of the measurement, but I remember being within 1mm of tolerance.
Whether or not this made a difference in bump steer I don´t know because I replaced every component of the steering: Outer tie rods, center tie rods and pitman arm with the bushing.

**Beesley** · 03-28-2014, 01:37 PM

I'm experiencing bump steer all of the sudden. I replaced the whole front suspension about 4000 miles ago and had it aligned when I was done. Everything was fine. Now, I have bump steer and an odd thumping noise coming from the front.

Does it sound like it's time for me to replace the strut inserts? Or could it just be the bump stops? And if so, does the upper strut mount need replaced also? The noise only really happens on small bumps at any speed. Any ideas or recommendations fellas? Thanks IA

**shogun** · 03-28-2014, 06:54 PM

Or the stabilizer links? http://www.bmwe34.net/E34main/Mainte.../sway_link.htm
In case they were cheap ones, they could be broken again. Some years back I bought a cheap set, the plastic cover behind the ball joint broke quickly and all grease there disappeared, noise started....

**Beesley** · 03-28-2014, 06:59 PM

Ok I'll check those out. I have the spare stock ones just in case. When i go around a turn that has bumps, it's pretty scary.

The only time I let my wife drive it, she skid on ice going about 2MPH and hit a curb with the wheels turned. She took it to a shop without me knowing because it shook really bad around 60MPH. All the shop did was put on wheel weights. That seems like a bandaid to me. I have a feeling something is really wrong.

**Beesley** · 03-30-2014, 08:16 PM

I'm leaning towards struts and springs. I can't push down on the front of the car. It's rock solid. No movement whatsoever. The strut covers have also rotted away. Not sure if springs are shot, but they are 25 years old and it was stored 7 months out of every year.

So at the very least I will replace the struts, bump stops, and strut covers. Should I replace the rubber spring pads and shock mounts also?

**shogun** · 03-31-2014, 02:35 AM

Spring pads I have still the original, you have to check them. Same with shock mounts, maybe they were replaced already once? So better check.

she skid on ice going about 2MPH and hit a curb with the wheels turned

That might be the problem, maybe something is bent

All the shop did was put on wheel weights

like band aids, maybe the real problem is still there.

**shogun** · 03-29-2017, 10:00 AM

**shogun** · 01-09-2018, 06:32 AM

Did someone meanwhile make such a tool DIY based on the dimensions I posted above?
We use the laser method as I described above in German and translated by BMWTurbo

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Idler and Pitman arm alignment and heights?

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