Fabricating rear shock extenders

I lifted my Japanese Jimny with a set of Old Man Emu shocks and coils. Unfortunately the rear shocks are still rather short; on level ground they are fully extended, so when I take a sharp bump I get the annoying CAPLUNK! from them bottoming out.

I'm making a set of shock extenders with 6mm plate steel. I' thinking about 38mm 1 1/2", which is a tad longer than the commercial ones you see around. Are there any concerns about making them longer than usual?

The length of the shock has two issues to consider:


1) Will the shock be so short that on full compression it will be too short and get fully closed long before the suspension has fully lifted causing it to be crushed as it continues to lift.

2) Will the shock be so long that it allows the spring to dislocate and fall out.


So it has to be long enough to not get crushed and short enough to not allow the spring to dislocate. The people who sell lift kits have this all worked out, so it's better to just get a kit than try to match bits and bobs.

If you want to use rear shock extensions you could consider measuring their extension and buying shocks of the right length - IE: a 3" lift with a 2" shock spacer needs only 1" extended shocks.

This is something I've been considering as I have Rhinoray's extended shock mounts and I'm in the market for a new lift kit as my springs are knackered. Jimnybits does Procomp shocks in all different lengths, have a look at Russ' website to see if it helps you.

Kirkynut

Kirkynut

kirkynut wrote:
...So it has to be long enough to not get crushed and short enough to not allow the spring to dislocate. The people who sell lift kits have this all worked out, so it's better to just get a kit than try to match bits and bobs...

I did go with a lift kit from a vendor, it didn't fit right This is a Japanese Jimny (660cc turbo) and got the 3” OME kit from a vendor in the U.S. The vendor said that this was correct for a Japanese specked Jimny but:

- Front lifted 1 inch shorter than rear
- Rear shocks are overextended: just sitting there the shocks are pretty much bottoming out.
- 1” Spacers are too narrow, they won’t fit over the mounts.

I’m guessing that what I got was for some other form of Jimny but I can make it work.

This is for an expedition-type Jimny. I’m aiming for the ability to reach places, carry a load, and self rescue. As such the variable-rate OME coils are a delight; softer on the top but when you put a load on, they stiffen and give you plenty of stability.

I’ll go ahead and take the back apart to see how much extension I can get away with, then I’ll fabricate the extenders accordingly. I returned the spacers (no point on paying top dollars for a piece I’m supposed to modify anyways) and will be making my own out of high density polyethylene, which will also let me fine tune how much lift I need (the upcoming winch will affect things).

Now that I’m raising the center of gravity (lift plus roof rack that I plan on loading often) I’m wondering if 32mm wheel spacers would make a significant contribution to stability…