Project BMP

Page 12


Will it ever end?

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I am now 8 weeks into the build and things are slowing down a bit mainly due to how much each new piece I add interacts with other components. The sway bar mounting is a good example of this.

When I bent up the lower frame last week I had to verify the frame was narrower than the sway bar so the sway bar would have plenty of clearance to swing up and down. Next I had to drill two holes inline with each other through both lower frame rails.  I got the holes pretty well lined up but I still had to use a pair of straps to move the sway bar mounting tube inline with the second hole once it was through the first hole, then I tapped it through the second hole with a hammer. This is the same sway bar I had on Project MP with one difference; I replaced the rod ends that came with the kit with some teflon lined rod ends.  The ones that came with the kit squeaked mercilessly after getting dirty, one of the guys commented my rig sounded like a bird aviary!  I took to spraying some silicone lubricant on the heims before every run but this solution should fix the noise issue permanently.

Another small but time consuming project was the rear bump stop plate. I took a flat plate and bent the sides up to give it some rigidity, added some speed holes, drilled a mounting hole for the bump stop, positioned it and welded it in.  I still think I need to space down the bump stop since they compress a lot.

Another task I needed to complete before starting on the front suspension was figuring out the front driveshaft.  My theory was to use a two piece driveshaft up front which would allow me to run a double triangulated 4 link suspension and eliminate the need for a panhard bar.  The two piece driveshaft allows me to move the point where the driveshaft drops below the belly from right in front of the t-case to right in front of the cross member where the front lower link mounts attach. The parts for the driveshaft would come from a pair of rear 85 Toyota truck drives hafts and a carrier bearing from a 92 extended cab Toyota truck.  

Here's a shot of the adapter I made to allow the tubing from the 85 rear Toyota truck driveshaft to work with the 92 carrier bearing.  Once I tack welded up the carrier bearing mount I positioned it, measured the distance between it and the t-case flange, then cut the rear driveshaft down to fit.  I ran into one small issue, I couldn't get the driveshaft tube to fit over my adapter even though I machined it undersized.  I suspect the driveshaft tubing is not quite round because even after letting the adapter sit in the freezer for a few hours to shrink it the two would not go together.  I eventually took the pieces over to Mark's to use his press to try and press them together.  I made the mistake of not tack welding the adapter to the carrier bearing when I had it all nice and lined up.  Somehow during the course of pressing the driveshaft to the adapter, the adapter got tweaked in relation to the carrier bearing.  So basically it has a wobble to it.  I'll try and figure out some way to get rig of some of the wobble down the road.

Also shown above is the lower link mount plate, the carrier bearing mounts to this.

The rear driveshaft went together a little easier, I had a new flange put on my old CV and then cut the end off.  Next I took the end in to work and used the lathe to turn down the tubing so I could get the splined insert out.  Once the splined insert was free I just turned it down till I matched the ID of the driveshaft tube.  A short time in the freezer and it pressed on nicely.  As you can tell I am going for slight press fit on the drive shaft components since I have no way of fixturing them to get the two ends line up before welding. This is good and bad, good because everything should be positioned good and shouldn't move when welding, bad because if you mess up the press there is usually no good way to get the two parts apart again.

While sorting thru my old links and heim joints I noticed some wear and tear. The weak point on the 3/4" heims I used on my previous suspension seems to be the shank.  Even with only a 1/4" of the threads showing I still managed to bend a few of them.  I am setting up the new links with no threads showing, this means I won't be able to adjust them so I have to get the lengths right up front.

Next up was the upper link mount plate which would also serve as the steering ram mount.  I made a cardboard template first to check the fit and then plasma cut the plate to match.  I had to re-cut a few clearance notches after some more test fitting.  Once the plate was fitted I marked the location of the link mounts and steering ram, the rest of the plate was fair game for weight loss.  I spent almost two hours with the hole saws and half inch drill, the plate is noticeably lighter now.

With the upper link mount plate tacked into place I mocked up my steering ram.  The ram came from Performance Off-Road Systems (POS) (334-567-7229).  It is a 2 1/2" bore double ended cylinder with 8" of stroked but has been de-stroked to 4.25".  I did this so if down the road I ever wanted to upgrade the axles I wouldn't have to buy another ram.  Instead I can just pull this one apart and pull out the internal spacers and have a full 8" of stroke.  Also shown above is the upper link mounts on the axle, I was running out of time and energy for this weekend so that's all the farther I got on the suspension.

For steering linkages I am using an old Kong's Off-Road tie-rod.  I cut the ends to the required length and will use a tie rod end on one side and a 3/4" heim joint on the other.

I really like the fit and finish of the steering ram, my only complaint would be the clevis ends were the wrong size (I ordered 5/8", they were 3/4") and there were no misalignment washer included with the clevises.  Making the misalignment washers wasn't hard, but then again I have access to a lathe.  Without it would have been tougher to make them as they ended up being very thin, just under .125"

It's getting really close now.

Part Numbers

Rock Equipment

27" Sway bar Kit

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