Everyone has their own voodoo. This is my voodoo. This is what works for me.
Servo Saver Horn & Left Side Steering Crank Slop Fix
Right side = Most of the slop is in the shaft to saver pipe fit.
The servo saver spring helps put pressure on the bearings so the bearing slop is not an issue.
Left side = Most of the slop is in the bearings themselves.
This became clear after I staked the inside of the horn & the shaft with an automatic center punch, installed a .005 shim on top of the lower bearing and reinstalled everything.
Initially, I installed a spring under the horn = that didn't work out.
Next, I upgraded to pricey hybrid ceramic/steel bearings = same slop.
The best option I have come up with to fix the left bell crank slop is to install another servo saver assembly as the left bell crank.
Additionally, I decided to upgrade the non-adjustable Ackerman rod to an adjustable one at the same time.
The oem rod has two right hand threads = a PITA to adjust because I had to keep taking it off, adjust and put back on = I upgraded it using a servo turnbuckle.
One HPI 93317 (servo) Turnbuckle - this will replace the A186 Ackerman rod = the oem Ackerman rod has right hand threads on both sides / using the servo turnbuckle instead allows you to adjust the Ackerman link without removing it.
You'll need to cut the upper deck brace to access the new Ackerman turnbuckle.
One HPI 86195 Ball Studs
One HPI Z125 Ball Cups (and two Zip Lock Bag disks) or RPM 73375 Heavy Duty Ball Ends
One HPI 86190 Servo Saver Shaft
One HPI A181 Servo Pipe
One HPI 85097 Center post/Servo Horn/Steering Crank Set
One HPI A182 Servo Saver With Nut
One HPI B017 Bearings
Plumber's Teflon Tape
Contact Anthony at ICB Hobbies www.icbhobbies.com/
He has a Buy It Now RC 'bone yard' on that left coast auction site & I was able to get the parts quite reasonably priced AND he ships FAST!!!
He lists the parts as HPI RACING SPRINT 2 SPORT FLUX STEERING BELL CRANK & 23 24 25 SERVO SAVER HORNS
Just Google 110861283944 and follow the link.
Plumber's Teflon Tape is nice.
It takes up the shaft slop is self lubricating and a PITA to apply on small parts - but IMO worth the effort.
For the Ackerman link mod
- remove the upper deck & cut out the section shown in the picture - reinstall the deck leaving the two forward most screws out for now.
Right side Servo Saver assembly -
Remove the two forward most upper deck screws - remove and disassemble the servo saver assembly - wrap the lower part of the servo shaft with the plumber's Teflon tape - barber pole style.
Follow the pictures for wrapping & trimming the Teflon tape.
NOTE: If you wrap the tape clockwise make sure when you reinstall the shaft in the servo saver pipe that you 'screw' it in counter-clockwise SLOWLY.
Wrap the shaft, install it in the servo pipe, assemble the shaft in the pipe, the pipe in the horns and trim the Teflon tail. Next install the spacer & E clip.
Then wrap the upper section of the shaft (just a straight away wrap) so that it fits in the upper deck hole with minimal play.
Probably about 5 warps or so.
Place a spacer/shim under the servo saver nut to keep it from backing off when you reinstall – DO NOT over tighten the nut – you need a little give so the servo saver does it’s job – and not burn out your servo.
For the left side cut off the servo arm - you won't need it.
Repeat the right side procedure for the left side and install on chassis.
Reinstall the two forward most upper deck screws.
Trim the excess Teflon tape after the upper deck is refastened.
Now, with everything back on the chassis -
Looking at the new left assembly as it would be mounted to the chassis, use the outside hole on the new assembly for the toe turnbuckle ball stud.
The Ackerman hole for the ball stud remains the same.
Once your Ackerman and toe links are reinstalled place your car on your stand, turn on the TX & the RX - your servo should center.
Adjust the new Ackerman rod FIRST
so that the new left servo assembly is in line with the right servo assembly =
Your right & left Ackerman ball cups should be evenly parallel (same amount protruding) from the upper deck.
Your left side toe will be WAY off.
The right side should not have changed.
Check your camber & toe - readjust as required.
NOTE: I'm told that the Ackerman link is not supposed to be adjustable - Mine is.
A BETTER mod for the left side slop is in post #17