═══════════Frequently Asked Question═══════════

Author: IGSW
Source: www.drive2.ru/l/288230376151824439/
Foundation: topic

I will tell my story about coilovers. Those who don't know, these are basically the same as struts but with more progressive x-coil characteristics and height adjustment capabilities, rebound/tune adjustments, camber, caster.
It was time for me to get such things too. Due to a lack of actual examples on the Yak with reasonable pricing, I decided to try making them myself since it's not complicated structurally, the important thing is knowing certain basic parameters to start from

First, the metal parts needed:
TRD Cartridges — 48511-TA001
TEIN Springs — L120-GCC
Height adjustment bolt set
Cusco Strut Mounts + washers
The struts themselves with bolts

I couldn't find exact numbers from the recipe for 71 anywhere, but I found it on Haciroku) …calculated…
In addition to this, I made several of my own measurements to clarify the picture completely...

Length of stock strut in compressed state with lowered car — 530mm

Clearance 120mm. from ground to jack recess

We will remember these numbers and move forward...

Remove struts, disassemble...

Measure cartridges...

When selecting cartridges I used the catalog www.trd-parts.ru/list_shock-cartridge.html
Here you can find all necessary parameters to understand how much the strut needs to be shortened for a specific cartridge or if it should just have an insert installed
The new TRD is 20mm shorter than stock. In my case, I decided to shorten the strut for the short cartridge by these same 20mm.

Cut off cups, measure length of strut — 420mm in stock

Measure a segment at the old cup location 20mm or better 19mm so that the bolt can be tightened several turns more

Trim out a piece

Inserting old cartridges as alignment guides, spot-weld both parts of the strut and try inserting new cartridges

If everything is straight and it screws in without skewing, weld permanently and clean up

As a result, we have a shortened blank 400mm long
With struts clear, let's set them aside for now and measure the remaining metal pieces

Spring length 200mm. Stiffness 12kg. It’s clear that with such stiffness the suspension travel (springs) will be no more than 20-25-30mm, this point is also to be considered

The length of this piece is 110mm, diameter 50.8mm.(Toyota)
Excluding flanges and bolts, adjustment length is approximately 70mm.

Temporarily assemble the construction...

Now I will draw numbers that I arrived at by handling and adjusting the struts in person

The length of the strut with a cut piece of 400mm + the length of the rod 120mm + the height (thickness) of the top mount approximately 30mm = 550mm, which is already higher than our stock lowered setting by 20mm.
plus we need to consider that the spring will sag under the weight of the car by 15-20mm, resulting in a total length of about 530mm as on the stock lowered setup.
This is at the maximum raised position, i.e., it can still be lowered approximately by 70mm to get 460mm on the strut and 5cm of clearance
Such numbers satisfy me perfectly well, so we measure down from the bottom of the strut 230mm and weld...

Among several options for securing the threaded sleeve, I chose the most reliable. Weld both top and bottom. Use semi-automatic welding with gas, don't forget to protect the threads

Carefully clean up the welds so that the nuts can be properly tightened. Again, don't forget to wrap something around the threads

Now we need to paint everything

great respect to the owner of the paint, without him nowhere 8))

The album won't allow more than 20 photos, so I'll post the result of this venture in part two)