"Big Foot 43"

 

or

 

Wheel exchange incl. tire exchange

 

Important notice: The following explanations only show my trial for an emergency with no external help. What I have done can cause serious damage and cause danger! I rufe ANY liability in case someone wants to test it as well and damages anything or even worse causes injuries for himself or other people!

 

While preparing Big Foot fort he paint-job I took off as well the wheels, because I wanted to paint the bodies of axle as well. Furthermore the rims had only a priming, but I had on the other hand still another set of rims, which were already in silver – exactly as I wanted the first ones to be finally.

Therefore I had decided to dismantle the wheels and change the tyres, so that I could paint the rims better. At the same time I wanted to practice the wheel change and to find which extra tools I still need for that job in the tubeless wheels, in order to be able to do this also a case of emergency and being alone.

First job was to dismantle the wheels where my son helped me but even with the help-tool (pls. refer as we well to here) and extension on the wheel cross he lacked some kilograms to loosen some of the nuts, which I had tightened before 2 years with 650Nm - some stuck extremely.
 

Dismanteling:
For absolute beginners: Loosen the nuts whilst the wheel is on the ground and brake applied and wheels are secured. Once the nuts have been loosened by half a turn, lift up the wheel with the jack and loosen them all completely. Take off the wheel, this can be tricky but if you use the wheel cross with two entensions under the wheel and lift it up on the other two you can pul on the top of the wheel and bit by bit pull it off.

 

 

After the wheels were dismantled, the tyres had to get off. So the valves were removed and with the hydro-jack the tyres were pushed off the rims by using the truck frame as the counter force.

 

 

 After I had dreadfully struggled myself with the first wheel, I had bought the installing paste (kind of soap), which you can get for little money e.g. in 10 kg of buckets at any the good truck and/or car parts dealer. Here you see my son well lubricating full of enthusiasm the wheel rims and the bulges of the tires.

 

 

Here the tools, two "small" assembly levers with 65 cm, lying on the wheel and - bought because of despair (see above.) – this nice lever with more than 1 meter length.

 

 

While you squeeze down the tyre on one side so that it nests into the recess you push the lever between rim and tyre and lift the bulge over the rim.

 

 

Now you put the second lever into the created gap.

 

 

At both ends of the long lever are two round bars welded. Either you can put this part on the inner edge of the rim and lift the bulge further over the rim ...

 

 

... or you puts it on the short assembly levers. I prefer the last option, because it does not scratch the paint of the rim.

 

 

So, that’s it, nevertheless I must say after 4 wheels that the now following part is harder.

 

I

I set the wheel upright for the second part and pushed the rim through. It is important always to have the part of the rim with the recess near the bulge which you want to dismantle!
Now push in the assembly lever and lift again.

 

 

Now you can use two additional short assembly levers. On one side they have a kind of "hook” which fits perfectly over the wheel run flange. The use of a hammer – should have at least 2 kg – makes life easier. Hammering on the side of the assembly levers plus lifting them from time to time helps a lot.

 

 

Sooner or later the rim will fall out of the tyre.

 

 

Put the  tires on the rims, in my case onto those already painted in silver. Again it is very  important that tyre and rim are well in-soaped in the crucial places. The part of the rim with recess upward and then lay the tyre onto it.

 

 

Use the assembly lever to lift the tyre bit by bit piece over the wheel run flange.

 

 

You feel like the King!

 

 

However still the last part is missing. Oh, behind me is the pack of the trim-powder, you put it including bag into the wheel, whilst driving the bag opens and the powder distributes itself at those places, where normally trim-leads would have been attached. Truck wheels are balanced normally always on their one and not on the axle. So I hope that by using the trim powder (name should be something like “Equal-XXXX” in English, just in case you want to ask you supplier for it) it is as if the wheels were balanced "on the axle".

 

 

The only thing left is getting the tyre again onto the rim, which is not so easy without a hose. Professionals have kind of large sealing clip (would waste too much place in a camper van) but I am still aware of two additional tricks:

 

The bicycle hose trick:
I put the rim on a chunk, so that the tyre seals itself by the pure weight pushing onto the lower side of the rim. Unfortunately there will always remain a gap on the upper side and normally the compressor never has the capacity to press the tyre by a sudden blow of air and to seal it again the upper part of the rim - even if you leaves the valve out! The solution is using bicycle hose (22" in my case) inflated softly with air and putting it into the gap. Now you pressurize the wheel, whereby the bicycle hose is getting squeezed in. But because everything is well greased you can pull it out easily even up to 1 bar. A short video shows the procedure, just click here (size 4,10 MB, simply go with the mouse over the link, click right "Save in directory" and then start the video from your own hard disk): VIDEO

 

The fire trick:
Brake cleaner burns marvelously! Spray a lot into wheel and then lighten it, it makes "fump" and the tyre is pushed onto the rim by the sudden increase of air internally. Note: I tried it 4 times, until I had sprayed a sufficient quantity of brake cleaner. Use a lot – for my feeling a lot at least. However for this job you should leave the valve in, because otherwise the incineration gases escape immediately and the tyre slides down – off the wheel run flange because of the soap used previously to mount everything easily. In addition you should start immediately with pressurizing the wheel. The incineration gases are cooling quickly by the cold mass of steel and rubber, the pressure decreases and again the tyre slides off the rim! What you don’t see here: After it had finally worked after the fourth attempt I had exactly the problem which I had warned you about at the very end before. So I used again to the bicycle hose trick! OK, who wants to have a look how I using the fire trick, click here (size 1,08 MB, simply go with the mouse over the link, click right "Save in directory" and then start the video from your own hard disk):  VIDEO

 

The hammer-trick:
Smash with a big hammer onto the tread section whilst you are already pressurising the wheel. The smash will create for a short moment a higher pressure, which will seal the tyre against the rim. NOTE: To support the pressurising leave out the valve! And keep the wheel upright.
This worked nearly without any problems after the wheel stood nearly upright for several days and the rim mounted half-way and pushing one side away from the other (reason for that was that I had to wait for the delivery of a new valve). This seemed to have widened the inner part of the tire.

 

The lashing strap-trick
Sling a sufficient solid lashing strap (best a ratchet type) around the tire and the squeezing of the tire should push the shoulders of the tyre to the side of the rim.
Not yet tested, hint from Pirx.

 

Due to input of my friend Stefan Sigl the installing soap can have disadvantages: Driving in deep sand with low tyre pressue the installing soap can cause slip between rim and tyre. As a result sand can get in and so the sealing will no longer be 100% ...
As a result you need to take of the tyre and clean it and the rim.
Due to my experience the installation soap is a MUST, so it would be best to clean everything BEFORE pressurizing. If then the trick with the bicyle hose will work or it will get stuck between rim and tyre I cannot say at the moment.

 

Final mounting of the wheels:
I have got middel-centric rims, fixed by flat collar nuts. As a result it is not that easy to assure that the rims are really absolutely centric. The trick is not to fix the nuts immediately 100% after you have lifted the wheel onto the wheel studs (pls. refer as well to dismateling above, you can use the wheel cross as well for this job and even turn the wheel if necessary, especially for the rear axle where the brake my be applied) but to do it in a "cross mode". AND once you have finished the first turn with a very low torque go for second complete turn with medium torque and than the final and last one. This assure normally, that the wheel is really located centric.
The fixing of the wheels in normal "cross mode" applies for all wheel, even if they are not middel-centirc.
The torque: You need anyhow a longer lever to achieve the required torque. So why not make a marker in relation to you weight and the required torque onto it? E. g. you need Newtonmeter = 600 Nm, your weight  = 90 kg x 9,81 m/s² (gerundet 10), as a result he marker should be at 600 / 900 = 0,66m. So if you press with your 90 kg at round about 66 cm in such a way that your feet nearly lift off you have applied 600 Nm onto the nuts.

 

The data on the rims are as follows:
22,5x1175 IS 135
D/DOT GERMANY
160L
DAF 1247502
27798   (next line):9
857PCP

 

respectively.
Lemmerz
012102
₁
⁷⁸      and behind: /4   
11,75x22,5

 

Due to my measurements the rims in- /offset (depending which way round you mount them) is 135 mm respectively –150 mm. 

The method to determin the rims in-/offset (ET) requires two measurements and a short calculation.
Put the rim flat on an even surface. if you leave the tyre on it may slightly influence the result.
First you measure the distance from the surface to the contact face of the rim (the one showing to the surface). This shall  be "A". Now you turn the rim and measure as before. The result shall be "B".
The calculation is ET = (B - A) / 2
The algebraic sign is depending how the rim is mounted: It is positiv if the the wheel is going inside the chassis, it is negative if the wheel is gettting out of the chassis.