This weekends goal was to get the rear suspension
fabricated. I had gone round and round trying to come up with an easy to
fabricate link mount that I could setup the tabs on the bench to accurately set
the angles. This is what I came up with.
This is the upper link mount for the rear axle.
The first step was to plasma cut the rough shape, next I used a hole saw to
drill two openings above the heim joints. The last step was to draw in the
desired link angle and cut from the hole to the end of the part. The next
two pictures show the bench assembly of the lower link mount, same concept as
the plate above just different angle and heim spacing.
Here's the lower link mount assembly for the
frame. I tack welded it to a scrap piece of tube to grind the tabs to fit.
Once they fit I lined them up with the cutout and tacked them to the plate.
Repeat for the second side, then remove it from the scrap tubing and position it
on the frame. The logic for the openings above the heim joints was this: the
plate is designed to mount on top of the cross member so it won't effect belly
clearance. The cross member is 1.62" thick. The link tabs that will
weld to the plate are 1.5 wide by .25" thick so they won't hang down below the
cross member. So far so good, now the heim joint is about 1.75" in
diameter, this means it will hang down below the cross member if I centered the
mounting hole in the link tab. Instead, the link tab mounting hole is
slightly offset, this moves the heim joint up above the bottom plane of the
cross member but requires a clearance hole in the mounting plate.
We used some homemade plumbobs to position the
rear axle housing and make sure it was square to the frame. We also had to
position the front axle housing to verify the wheelbase. This is the most
tedious aspect installing the suspension but you can't overlook it, measure once
and then measure again just to be sure. We spent a lot of time lining things up
and verifying before welding it on. Another thing to keep in mind is that
you really need all the link tabs and brackets done to start positioning
components. Pretty much everything needs to be mocked up so having one or
two tabs not done means you can't properly position everything.
My friend Scott had come over to lend a hand, he
was working on bending the tubes we needed for the rear axle bridge and I was
working on tacking in the link mounts. While we worked a nasty dust storm
blew thru the area. The wind was blowing buggy parts all over the garage
so we called it a day.
It was really rainy on Sunday, must be a late
monsoon. The rain poured down hard enough at times I had to close the
I gusseted the link mount tower on the rear axle
housing and mounted the airshocks. The lower links are angled 20 degrees
and are 33" long, the uppers are also 33" long and are angled 15" from the
centerline of the chassis, both sets are made from 1.50 x .25 wall DOM and have
threaded tube inserts installed at each end. The airshocks are made by Fox and have 16" of
travel. I plan on adding a stiffening rib along the top side of the lower
links just like my last rig (1 x .38 material). This modification allowed
me to run smaller links which held up well to a year and a half of use.
The old links will be cut down and used for the front suspension. I was going to
go with smaller diameter upper links but couldn't find a suitable material for
them when I bought my steel.
Update 11-12-04 - I have decided to sleeve the
lower links with some 1.75 x .120 DOM tubing. I made this decision after
discovering my old lower links had bowed slightly inward, possibly a result of
previous rolls? Sleeving a link is not as strong as having a link with a
heavy wall thickness but at this point it will have to do.
Since the Toyota axle housings are not made from
very thick material it is a good idea to spread the loads out as much as
possible. As you can see, the gussets on the link tower are welded to the rear
housing at several points and then terminate at a tube that we wrapped around
the rear housing. I also plan on fabricating a plate that will weld to the upper
link mount and extend down to the top of the housing.
Here's a picture of the lower link mounts on the
frame. I am trying a new type of heim joint this time around. They
are made by FK, #KMX12-10, they are a 3-piece, design made from alloy steel,
heat-treated, and have a nylon race instead of a teflon race. They are rated for
just over a 23k lb static radial load which is considerably more than the 16k lb
rating of the Aurora rod ends I used previously. Best of all the are a
little cheaper and look nicer (chrome plated). Time will tell if they work
The last thing I wanted to get done on Sunday was
to re-mount the radiator. I had to remove the original mounts due to an
error in my measurements, I designed the front end around an axle that was 4"
wider, so I wasn't going to have enough clearance between the airshock and the
framerail on full droop.
The solution was to remove the radiator mounts
and narrow the frame in front of the engine mounts. I actually got the
frame mods done on Friday night so I just needed to re-mount the new
radiator. This time I angled the radiator back a bit to ensure the
bottom was above the frame rails and the top was below the cross bar for
protection. This change also allows me to move the winch back another
Frame Works Racing
#KMX12-10 - 5/8 x 3/4-16 Rh Heim Joint
#15589 3/4-16 Threaded Tube Insert (for 1" ID
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