Skullface
New Member
- Messages
- 14
On here i have heard of shift kits and read a description of fitting a washer under the accumulator spring. Another method i have found from a Volvo site was to fit a bar insert inside the spring, barely a 1/4" shorter than the spring itself.
Both methods reduce the time it takes the accululator to fill with fluid but I 'think' would alter the feel of the shift in different ways.
Shimming would quicken up the response and shorten overall shift time.
the bar insert method doesnt stiffen the spring, but causes a dead holt on the piston as it bottoms on the bar. I suspect this would start the shift in a gentle manner (like stock) then suddenly move to a snappy shift part way through.
I wondered if those with a better working knowledge of the shift within our Auto's could see a benefit to combining the methods. I can only imagine that the unshimmed spring is easier on the valve body and clutches movement, to start with, then the dead holt on the spacer would cause full pressure to come in right away onto the plates reducing slip and wear. Tuning the length of the bar would give more or less time to the damped portion of the shift, and shimming the spring would alter the speed of the action during the damped portion. Hell.. it could provide more tuning if a 2nd stiff spring were inserted under the bar, so a soft (stock spring) could be left on the outer, then a bar resting barely shorter than the free piston, with a spring behind that bar to soften the impact and 2nd stage actuation slightly... might give a double cluthing effect to reduce impact on the trans on a hard shift, while still reducing shift time and having a smoother start to it all...
Hell this could all be irrelevant, and or useless to most situations on here, but if anyone else could muse over this to give me an idea if my understanding of the shift theory is correct??
Both methods reduce the time it takes the accululator to fill with fluid but I 'think' would alter the feel of the shift in different ways.
Shimming would quicken up the response and shorten overall shift time.
the bar insert method doesnt stiffen the spring, but causes a dead holt on the piston as it bottoms on the bar. I suspect this would start the shift in a gentle manner (like stock) then suddenly move to a snappy shift part way through.
I wondered if those with a better working knowledge of the shift within our Auto's could see a benefit to combining the methods. I can only imagine that the unshimmed spring is easier on the valve body and clutches movement, to start with, then the dead holt on the spacer would cause full pressure to come in right away onto the plates reducing slip and wear. Tuning the length of the bar would give more or less time to the damped portion of the shift, and shimming the spring would alter the speed of the action during the damped portion. Hell.. it could provide more tuning if a 2nd stiff spring were inserted under the bar, so a soft (stock spring) could be left on the outer, then a bar resting barely shorter than the free piston, with a spring behind that bar to soften the impact and 2nd stage actuation slightly... might give a double cluthing effect to reduce impact on the trans on a hard shift, while still reducing shift time and having a smoother start to it all...
Hell this could all be irrelevant, and or useless to most situations on here, but if anyone else could muse over this to give me an idea if my understanding of the shift theory is correct??
