XL. Replacing Żuk’s rear leaf springs

Żuk’s suspension is independent on the front with helical springs (to each wheel an independent arm) and beam axle based on the rear with leaf springs.

Normally you would evaluate whether leaf springs requires to be changed by comparison to their original characteristics:

table-rear_leaf_spring

In my case, I decided to change rear springs not because it looked absolutely necessary but because, since the floor is removed, I have currently best access possible.

leaf-yes-no-maybe

So here’s how the springs are mounted:

p244-schemaAR

Needlessly to say, you’ll need a good 22 wrench. To remove the rusted bolts, it is worth having an impact wrench – I am using a cheap Silverline 593128 400-Watt electric wrench and it worked fine.

↦ Notice the Kierunek jazdy

One thing is important to notice: the leaf spring have a direction;  it is easy to identify by counting the number of leaves within the rebound clips, pióron ze skuwką,  only 3 at the front one, 4 at the rear:

It is worth putting a temporary mark on the front or rear of the new ones to avoid any mistake in this regard. I did put a bit of painting tape on the front:

IMG_20171223_123151.jpg

 

Replacement parts oddities

Here is the list of parts from the catalog:

ressortAR-CATALOG.png

I changed all of them – but the spring leaf was already mounted (catalog parts 14/15/16/17/18 already tied by 9 and 15). All the parts are readily available on allegro or Moto-Trans, etc, it is quite a no brainer in theory.

Except there are said new type of mounting an old type. There are almost the same. Almost.

For instance, for catalog part 4, the spring shackles, płytka wieszak resora, despite the fact I specifically ordered new type version, on item pages featuring a picture of the appropriate new type along with its description, I received, three times, from different sellers, the old type – black version as shown there. I actually never manage to get the proper one -bichromat version as shown there- delivered over the internet, I found them in a small shop in Wrocław, ul. Tarnogajska 5/9.

IMG_20170829_203143.jpg

Are they not compatible? Looks like it but, no, they are not: there is a milimeter more on the new type separating the center of the two holes. As result, the relevant part 1, wieszak resora new type, will never fit. Am I having a laugh? See for yourself:

I have a collection of useless black płytka now (the part being cheap, I did not bother returning them).

Another matter of concerns are the rubber bushing (catalog part 2, tulejka gumowa). You can either use two full rubber bushing per bolt (original type, so 2×6 in total) or bushings in one part with a metal frame in the middle (alternative type said “PRZYCZEP RYDWAN” on webshops for instance, so 6 in total):

Why bothering, you’d ask? Well, putting the bushing within the spring is quite a job, if you ask me.

There is a dedicated tool to put the bushings in. But, in our case, the difficulty to insert the original type bushings arises not when you put the bushings within the leaf spring frame but only when you insert the bolt (on already installed bushing within the leaf spring frame): which mean the difficulty appears only when you are already in place, on the vehicule. So the said dedicated tool is no help, then. With the alternative type, the difficulty exists only to insert the bushing within the leaf spring frame, which you can do confortably wherever in your workshop, probably with the dedicated tool. I used original type bushings but I think, next time, I’ll go for the alternative type. More on this topic below.

 

Umounting the old spring

Let’s state the obvious: make sure the vehicule won’t move; springs will be changed one by one.

First thing to remove are the U-bolts, strzemię resoru (catalog part 12), holding the rear bridge. The nuts where completely welded to the bolt, in the end, I resorted to the angle grinder.

Once removed, you can lift a bit the spring with a jack so it separates nicely from the brigde:IMG_20170830_092423.jpg

Next step is to lift the chassis so it no longer weight on the leaf spring. There as several possible placements for the jack: as long as it stable and not in the way when it comes to manipulate the removed spring leaf, it is fine. Here, you can see the jack behind the bridge.

IMG_20170829_203649.jpg

Until the spring leaf is disconnected, the chassis should be overly high, just high enough so there is no tension on the spring leaf bolts.

Then I removed all the bolts/nuts attaching the spring leaf ot the chassis. Some went away with no problem, some required to be cut.

IMG_20170830_084156.jpg

The front bolt, sworzeń resoru (catalog part 19), cut, would not go, completely melted by rust with the spring hanger. Impact wrench was not enough, neither was the heavy hammer. I only managed to push it out (and it’ll be the same for the other spring) with a system of nuts on rod:

IMG_20170830_105113.jpg

Good but not so good: before letting go, it bent slightly the hanger. I put it back in place but it seemed still a bit bent. The fact replacement for the hanger can be easily be acquired makes me think that could be common issue.

WSPORNIK-RESORU-PRZEDNI-wspaw-do-ramy-ZUK.1710.JPGNonetheless, had I noticed this problem earlier, I would have put some holders to avoid bending the hanger in first place.

 

Mounting the new spring

First, check if the hangers are in proper shape. If they are bent, that could be a problem to insert the new bolts.

You could also make sure the spring is properly prepared. There are conflicting theories on the internetabout how they should be prepared. Some claims no grease should be put in better the leaves because, mixed with sand and dust, that would end up producing an abrasive pasted destroying the leaves. Others claims not putting any grease would make the suspension squeaky. I have no opinion but note that both the Żuk Budowa Eksploatacja Naprawa and the Żuk Autoryzowana Instrukcja Napraw consistenly mention graphite grease applied to the leaf springs.

IMG_20171228_105226.jpg

Next issue is the one suggested in earlier: inserting properly the bushings in the spring leaf frame. You will prepare everything: clean the frame, put the bushings in the cold so gum retracts, make the leaft spring frame hot so metal expand, properly clean the rubber bushings with solvant/benzine just before inserting them. This will be make them slide into the frame with no problem. But the extra width of the bushing could still be a problem. It was for me, it could not get around it. I could apply the extra pressure required so it fit more or less. But then, passing the bolt withing was completely impossible. After hours of multiples tests, I decided to simply insert a wooden rod within some bushings and cut them cleanly to they are a bit thiner.

The result was instant, it was then possible to fit everything with no fuss. I am bit puzzled by this result and, frankly, have my reservations about the possible consequences of such a hacky approach. There is less rubber so it is likely that the bushing will degrade faster. Nonetheless, I’ll document myself about the alternative bushings (described earlier) and, if a replacement is need, I’m enclined to use these instead.

The general idea is to first connect the leaf by the shackles, on the back, since they allow movement.

Once the rear connected (but the bolt still loose), then, you present the front of the spring leaf to the front hanger.  Not that, in this case, for the spring leaf to go within the hanger, you cannot fits the two bushings beforehands, only the one on the side of inside the vehicule. It would be otherwise too large. When the spring leaf properly aligned, you lower the whole chassis (playing with the jack) so it goes in and properly aligns the spring leaf with the hanger.

IMG_20171226_132142.jpg

Once at proper height, you are able to add the missing bushing and the bolt. Then, once the nut in place, you finish lowering the vehicule to the ground, off the jack. Only then you can tighten the nuts with no risk of tearing the new bushings.

Finally, you can install the new U-bolts and their fixation plate.

And that’s almost it. You just need to make sure the spring leaf rubber bumpers (part 5 of first schema, odbój resoru) are there and properly attached. In my case, I had to replace both. The bolts were even missing on one side so I had to put new ones in place (it just require bolts, nuts and spacers).

IMG_20171226_124118.jpg

 

The new leaf spring is now in place:

IMG_20171226_132110.jpg

It does not seems much but the issue with the bushings took me a while to handle – even though I am only half satisfied with the hacky solution I resorted to.

tulejka gumowa = rubber bushing (set A x2 = 65 zł x2)

pióron ze skuwką = rebound clips

płytka wieszak resora = spring shackles strut (set A x2)

wieszak resora = spring shackles (set A x2)

strzemię resoru = u-bolt (21 zł x4)

nakładka resoru = plate to attach the u-bolt (40 zł x2)

sworzeń resoru =  spring bolt (set A x2)

odbój resoru = spring leaf rubber bumpers (10 zł x2)

ucho resoru przedniego = front hanger

resory nowego typu =  spring new type (150 zł x2)

+ kosztuje = 614 zł = 147 € ; Żukventure cost so far = 1982 + 147  = 2129   €

 

 

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