Project BMP

Page 31


1 Year Update

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Now that Project BMP is a year old I figured it was a good time for an update.  Right off the top the chassis is in great shape.  I have a few small dings here and there but no cracks so far.  The only visibly deformed tube is one of the diagonal windshield braces (1.00 x .120 wall) but I can't remember ever hitting it. 

As you can see the aluminum skid plate is holding up well to the abuse.  You may recall the UHMW (plastic) skid plate I initially installed only lasted a few runs before caving in.  I also checked all the links for straightness and so far so good.  The decision to sleeve the lowers and brace them with a rib along the top looks to have been a good one.

The link mount cross members also looked to be in good shape with no visible bowing or cracks.  This was one item that concerned me after seeing all the carnage over MLK weekend but it appears that my bracing method has allowed the .120 wall cross member tubing to take the loads I have placed upon it.  I did discover the bolts that held the transfer case mount to the transfer case had come loose causing the transfer case to weep oil.

My beadlock rings haven't been taking the abuse so well.  This is a picture of one of the front rings off of my Trailready beadlocks.  I had ordered their slim rings because I liked the way they looked but now feel these are too thin.  I was also having problems with constantly loosing retaining bolts and feel the ring was part of the problem since it was distorting so easily. I have since replaced all the supplied nuts with nylock nuts in the hope that if the ring gets tweaked any more the nuts won't be able to back off.  Steel is definitely a better material in this application.

The motor mounts need a re-design.  I should have put the rubber bushing at the motor end of the mount and triangulated the tubing off of the chassis. The existing setup allows a for a lot of movement which has caused the plates at the end of the mounts to start bowing.  Looking at the motor in the engine bay also reveals a slight list to the drive train.

The plate I welded to the lower steering arm has continued to be a problem.  Luckily when the area around the welds lets go, the upper steering arm is beefy enough to take the loads and I have been able to make it back to the trailer.  I also bent the front axle cross member after a good rock hit which caused some of the welds on my ram mounting blocks to break.  I am still working on a re-design for this area.

Update 2-12-06 - I increased the thickness of the cylinder mounting plate and fabricated a plate that ties the upper link mount tube to the cylinder mount plate.  To make the cylinder removable I had to make this assembly bolt on.

On the steering arms I cut the top off of a 4" long piece of rectangular steel tubing and wrapped it around the bottom of the knuckle to create a tight fit.  Next trimmed the leading edge down so I was left with a single flap of steel which was hammered around the front of the knuckle and welded to itself on the other side of the knuckle. Next I welded the steering arm brace to this new lower bucket.  Now the force of the steering should be working the U-shaped brace instead of the welds.   I got this idea after seeing a variation of it used on another club members rig.

The rear mounted winch was a short lived experiment.  When it was working I found is useful to suck down the back end in off camber situations.  Unfortunately the winch motor appears to have burned out after I stalled it once.  I need to confirm this by pulling the unit apart but for now I removed it from the rig.

One thing I have found lacking after a year is power.  To be fair when I built the rig we weren't attempting obstacles with the level of difficulty that the current obstacles have provided, we definitely ratcheted up the difficulty a notch in the last year by driving stuff that in the past we would have winched.  So far power level has been just enough if everything was working 100% and I didn't have too much weight on board but I have noticed rigs with slightly more power having an easier time on some of the vertical obstacles.  So, a new power plant may be on tap if I can locate one for the right price.  The current front runner is a Toyota 2.7l for it's small size and impressive power output but I would also consider a Suzuki 2.0l.

I am still happy with my choice in tires.  The 42" Irok's provide great traction and have proven fairly reliable.  I did slit one a few months back but so far my homegrown patch job has held (I left the tire plugs in and applied a tire patch to the inside of the tire.  The cut was about 3-4" long in the middle of the sidewall.

Project Hellraiser