Project Hellraiser 3

Page 32


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After the last run I noticed my transmission wasn't working so well in reverse. I didn't find any chunks of clutch material in the pan so I decided to try adjusting the reverse band.  There are two different reverse band adjustment procedures for the TF904 and I am starting to suspect mine was setup to the wrong one.  One version has you tightening the band to a specific torque, then backing off 7 turns, while the other setup requires 4 turns.  My particular band tensioner was about 6 turns looser than what it should have been.

The last run also convinced me I needed to move the radiator up so it would not blow hot air on the fuel cell. While some of my customers have gotten away with running a 4 cylinder radiator down low I just could not keep the rear tubing from creating a hot zone around the cell with all the heat coming off my 26 x 19 dual pass radiator. I had designed the chassis with this possibility in mind so I just needed new mounting brackets.  I opted for adjustability so I came up with a cradle that is spaced off of 4 tabs.  I can adjust the height of the radiator by changing the spacer lengths.

The upper hold down was made from two pieces of sheet metal, this front piece has two bends in it while the piece forming the back section has a single 90 degree bend and is welded to the front piece.

Here is the painted up bracket with both front and rear tabs braced.

I really need to learn to weld aluminum.  The lower cradle would be nearly half the weight if I had made it from aluminum.  I tried to put ample lightening holes to cut the weight as much as possible.

After applying so rubber strips to the lower cradle and upper hold down I bolted everything back together.  I left a few inches of clearance between the roof and radiator to allow for chassis movement in a roll.

My transmission cooler also needed to be relocated to avoid blowing hot air in the vicinity of the fuel cell. The simplest solution was a pair of tabs that bolted to the original mounting points,  The lower end of the bas were bent at a 30 degree angle to direct the air up and away from the cell. 

This change has left a large open area behind the rear seat which I intended to wall off and use for storage.

The storage cubby behind the rear seat ended up being formed from 3 pieces of aluminum which were then riveted together to form an 8 inch deep rectangular pocket. It should come in handy this winter for jacket/headset storage once we reach the trail.

Something I meant to do but never got around to was to box in the front upper link mounts on the chassis side. the passenger side mount was actually bent inward so it took a while to get it straightened out not to mention the 5/8 bolt was bent in the middle. I think the tabs may have been bent when I slammed the front end back down after doing a massive wheelie  at the Hammers.  I know for sure the front shock mount was bent on the passenger side after that little incident.  

On the test run the new radiator position worked much better once I got the system burped of air bubbles. For most of the crawling and fire road driving the temps stayed at 160-180F with only one fan on. Previously the single fan could hold it around 200F while crawling but I needed the second fan on if I was doing any sort of speeds on road. The fuel pump stayed totally silent the whole trip and the fuel cell stayed around the ambient air temperature.