Klaus - 2006 Montero Build

pwjazz

Member
So... We put Bilstein 4600 shocks on the front today. They're damping a little better, but Klaus still feels underdamped and bouncy. I'd say he's driveable now, but still not optimal. Need stiffer springs maybe? Or maybe this is just life with a lifted SUV...
 
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pwjazz

Member
Well, that was an expensive way to learn something...

So, looking at the specs from the FSM, as well as from Ironman, I think I finally understand what's going on. Apologies if this is obvious to people who are used to lifted suspensions.

1. The free length of the Ironman spring is basically the same as stock. The lift comes from having a spring rate that's higher than stock. I can't actually see a spec for the stock spring rate, but the Ironman diameter is 19mm vs 16.4mm stock, so it seems like a good guess that they're stiffer. I also found specs for OME's light duty equivalent that show the same free length but a rate of 650 pounds for OME vs 805 pounds for Ironman. I can't imagine that OME's rate would be less than stock, so it seems that the Ironman front springs are just really, really stiff.

2. The springs being stiff makes sense because in addition to the bounce, my hitting speed bumps is actually quite unpleasant/jarring.

3. My guess is that the Ironman Gas charged shocks are just plain underdamped for the Ironman front springs. The shocks that we pulled actually rebound on their own, so they're probably not blown. Also, Ironman USA has just a single SKU for gas-charged struts, not multiple depending on load like OME does. Unless I'm missing something, a single non-adjustable shock can't be valved to match different duty springs, and I'm guessing the shock that they sell is basically valved for the OEM springs.*

4. The Bilstein shock seems a little better but still not great because being a monotube it's probably more resistant to heat, but it's still valved for OEM/light duty springs, not the Ironman springs.

5. The reason that I don't have this problem in the rear is that Ironman achieves lift with springs that are the same diameter as stock but are longer. So the fact that the rear shock is probably valved for OEM duty springs isn't an issue, since the spring rate is likely very similar to the OEM springs.

I need to noodle a bit on what to do next to make sure I don't waste even more money, but the answer probably involves either OME or OEM.

* - As a side note, I'm pretty angry that I asked Ironman why their shocks seemed underdamped and they couldn't just tell me that's because they are underdamped.

EDIT - Prior to putting on the Bilsteins, I just had new tires installed last Friday (slightly upsized to 265/70R17). It occurred to me that those could affect ride quality, so I checked the pressure. Sure enough, the tire shop put 40 PSI in the two driver side tires, and 34 PSI in the two passenger side, when the door sticker calls for 29! Not only were they way overinflated, but they weren't even matched left to right ?‍♂️ Since the new tires are slightly larger than stock they don't even need 29, so I deflated to 28 and wow what a difference. I can still tell that the shocks aren't firm enough for the springs when I do a bounce test, but at least the tires aren't adding to the stress while underway, and Klaus no longer feels unsafe from behind the wheel.
 
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DenTar

New member
This has been all very interesting. Really do appreciate the updates and insights. That tire pressure...:oops:.

I run around 29-30 on the front and 35 on the rear. I run 265/75/16 MT's with stock front suspension and OME medium springs on the rear. Glad to hear the adjusted tire pressure is making things better.
 

DSSA

New member
Alright, ya'll might be convincing me to come around to poly bushings. The thing that kind of scares me off is their reputation for squeaking and the fact that I don't really want to tap for zerk fittings to allow regreasing. Have you had any noise issues with the ones you've used?

I have not, but that said, I've mostly worked on the street driven Mitsubishis (DSMs/Evos) over the last 25+ years. With proper installation, I've yet to hear squeaks even on ones that were installed over 10 years ago (granted, not off-roaded).

That said---they WILL transmit more noise/vibration to the driver than rubber OEM bushings. Take that into account before you start swapping them into your rig.

Apologies as well for not getting those measurements done yet on the Taurus fan install. I measured the space on the Montero, remembered that they come with a shroud themselves, and figured that I'd need to take more time on that venture than I have yet had.
 

pwjazz

Member
Well, Klaus went on his first camping trip this weekend. Nothing fancy, just some car camping at an improved site. There's definitely more space than on my Outback, and I didn't even remove the 3rd row seat to use that spacious cubby under the load floor.

Sadly, Klaus still bounces like a carnival ride and squeaks like a mouse. The kids thought it was fun at first, but it was bad enough that it stopped being fun before we arrived at camp. Tomorrow he's going to a 4 wheel drive specialist in town for a proper diagnosis. I'm very curious what they'll have to say.

20220429_111803.jpeg
 

pwjazz

Member
Some progress this week (I think)

1. The latest mechanic to look at the struts says that they're installed incorrectly and the shocks aren't actually engaging at the beginning of the stroke. Current working hypothesis - the previous shocks were installed incorrectly as well, and on reinstall, despite my handing him the factory service manual, the mechanic simply copied the prior installation and hence the bounce remains. Specifically, I think they may have left off the spacer that goes between the top nut and the thicker part of the shaft, but I'll have to take it apart again to find out. So quite possibly the Ironman shocks were just fine and it was an installation issue. ?‍♂️

2. I seem to be losing coolant somewhere and can't find it by visual inspection. Coolant doesn't look contaminated, and the oil didn't look milky when I last changed. To be sure, I ran a combustion leak test which came up negative, so probably I don't have a head gasket leak(?). For anyone who wants to run this test on the Montero, a couple of tips:

a. Most tutorials recommend siphoning off coolant from the top of the radiator to avoid aspirating it. There's not much room to get a turkey baster in on these radiators, so instead I just drained some fluid from the petcock at the bottom. At first I thought the thing was clogged, but I had to almost completely unscrew the valve before fluid started coming out of the hose.

b. Even after draining a good amount of fluid, I ended up aspirating coolant during the test. It turns out that I was sucking it in from the overflow tank, so I took the dipper hose out of the overflow tank and ran the test again. This time, no coolant aspirated, and fluid stayed blue even after coming up to temperature and testing for a good minute or so.

?‍♂️ is becoming my main emoji. At least I'm learning stuff!
 

SONICMASD

Adventurer
Front Suspension can be challenging on these rigs. 99% of squeak complaints from the front end after strut install is from improperly assembled struts. Check out these videos and feel free to post some photos up and I'll see if I can spot anything:



As for the springs - have you confirmed which model of spring is in the vehicle? Is there a chance Ironman HD coils got installed rather than the Medium Duty ones? In any case, 806lb/in is a really high spring rate and I'm not surprised at the bounce. For reference, the factory coils' spring rate was 580, Lovells Medium Duty is 680, and even Lovells HD springs for rigs with lots of added constant weight on the front end is 820.
 

pwjazz

Member
Front Suspension can be challenging on these rigs. 99% of squeak complaints from the front end after strut install is from improperly assembled struts. Check out these videos and feel free to post some photos up and I'll see if I can spot anything:



As for the springs - have you confirmed which model of spring is in the vehicle? Is there a chance Ironman HD coils got installed rather than the Medium Duty ones? In any case, 806lb/in is a really high spring rate and I'm not surprised at the bounce. For reference, the factory coils' spring rate was 580, Lovells Medium Duty is 680, and even Lovells HD springs for rigs with lots of added constant weight on the front end is 820.

Great video, thanks!

I did confirm that the product code on my springs is the medium duty one.
 

pwjazz

Member
An update on the cooling thing.

A few days ago, I ran a test.

1. With cold engine, fill coolant to fill line
2. Run engine, blast AC to create some load, later blast heat to exercise heater core
3. Turn off engine
4. Check the next morning after engine is cold

In this test, once the engine came up to operating temp, the level in the overflow reservoir rose a bit, which I think(?) is expected since the coolant expands as it warms.

Immediately after turning off the engine, the level in the reservoir stayed the same.

After sitting overnight and cooling down, the coolant level in the reservoir dropped considerably.

I replaced the radiator cap with a new one and repeated the test, problem solved.
 
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pwjazz

Member
feel free to post some photos up and I'll see if I can spot anything

So I think I figured it out. The Bilstein struts ship with a washer that's supposed to sit between the dust boot and the lower bushing. The wide flat part of the lower bushing bears on this washer, and the other side of the bushing bears on the strut mount. When the spring compresses, this forces the shaft of the shock into the body and lets it do its thing.

Unfortunately, my mechanic didn't use this washer (or maybe substituted it for the top washer). On my initial test drive, everything seemed fine because the rubber was doing the work without the washer, and I didn't really hit any bumps or anything. But now, shaft has ridden up into the cavity of the lower bushing. Because of that, now there's a gap between the bushing and strut mount. Now, when the suspension compresses, the shaft rides up an inch or so before the bushing starts to bear on the strut mount and actually compress the shock and/or slide further onto the dust boot. I'm just glad that the shaft didn't ride up enough to puncture my battery tray or airbox!

Tomorrow, I'm pulling the struts. Hopefully the guy used Bilstein's washer as the top washer and I can just move it to where it belongs. Otherwise, I might have to get another pair of washers from Bilstein. If I'm lucky, the bushings aren't torn or cracked, otherwise I'll have to substitute some Chinese-made KYBs that I have on hand.

I'm pissed that I didn't pay more attention while the guy was working on these and instead spent most of my time caulking a shower! :mad:

I'm really curious how this thing will ride with the Bilsteins+Ironman springs once it's actually built correctly.

boot.jpeg

gap.jpeg

washer.jpg
 

pwjazz

Member
Finally! I pulled the struts, took them up to this awesome DIY Shop here in Austin. Using their wall-mounted spring compressor, I rebuilt the shocks properly and now the thing rides like a normal vehicle should. Steering feels normal, ride is smooth but firm, no bounce at all, very nice. I'll have to spend a little more time on the road to see how much I like the Bilstein/Ironman combo, but so far so good.

Looks like I was too quick to blame Ironman - I'm certain their shocks were fine, just installed incorrectly. The 2nd mechanic then repeated the mistakes of the first, but this time with the Bilsteins. I do wish that they'd been able to tell me that the shocks were installed incorrectly based on the photos I sent, but they clearly don't have a lot of experience with the Montero here in the US, so I can't really fault them for it.

This shows the order in which things should be installed, namely washer, bottom bushing, top hat, top bushing/washer/nut (not shown).

good.jpg
 

Michael Brown

You followed me, so now we're both lost
Glad to hear you got the shocks figured out. I have to make time to install my Bilstein and Lovell's at some point this year.

For the coolant, check in the valley between the heads. The back of the water pump housing has an o-ring that is prone to leaking if not replaced during the timing service. Mine wasn't drawing from the tank because it had clogged the hose to the radiator cap. Once I cleared that, it was drinking new coolant every night. It would pool in the valley and run down the back of the engine. You can reach the o-ring by either the front or the top. Front requires timing belt removal, so I took off the intake manifold to get to it. I used the OEM o-ring which is shared with the EVO 4G engines as well.
 

pwjazz

Member
Glad to hear you got the shocks figured out. I have to make time to install my Bilstein and Lovell's at some point this year.

For the coolant, check in the valley between the heads. The back of the water pump housing has an o-ring that is prone to leaking if not replaced during the timing service. Mine wasn't drawing from the tank because it had clogged the hose to the radiator cap. Once I cleared that, it was drinking new coolant every night. It would pool in the valley and run down the back of the engine. You can reach the o-ring by either the front or the top. Front requires timing belt removal, so I took off the intake manifold to get to it. I used the OEM o-ring which is shared with the EVO 4G engines as well.

Were you able to see this, or would it show up on a pressure test?
 

Michael Brown

You followed me, so now we're both lost
I could see the coolant with a flashlight at the right angle. I have an inspection camera which makes it easier to look behind things.
 

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