LOOKING AT DRY FILM LUBE COATINGS FOR TRANSMISSION PARTS

[bob8907]

We have a transmission that simply will not shift under load. We increase the engine output by 300% and this creates binding in the sequential transmission. The thought came to mind to try and reduce friction on all the sliding components in the trans to help shift quality.

I am looking for real (not theoretical) feedback on DFL coatings to see if they are more of a fluke than actually helpful. I have a hard time believing that a moly coating will be much different than oil with moly in it...

Thanks

 

[patprimmer]

Can you reduce the undercut on the dogs.

Regards
Pat
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[ccfowler]

I would look primarily at the detailed mechanics of the problem, but I would also check with several high quality lubricant suppliers. Some really do have proprietary additives that provide superior performance under severe loadings. I would not bother with dry film lubricants in a transmission, they would soon be flushed away by the lube oil.

Valuable advice from a professor many years ago: First, design for graceful failure. Everything we build will eventually fail, so we must strive to avoid injuries or secondary damage when that failure occurs. Only then can practicality and economics be properly considered.

 

[bob8907]

The dogs are straight cut from the OEM. Should not lock together at all. Lots of guys are front cutting them so they "want" to disengage but this is killing shift forks.

 

[patprimmer]

While they may be straight cut, there will be microscopic undercuts from the machining process.

Try polishing in line of draw as the dogs disengage.

Regards
Pat
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[LionelHutz]

I've read/seen some systems having a spring loaded shifter mechanism with one or more microswitches. This allows there to be a contact change when there is pressure on the shifter. The micro switches are then wired to cut some or all of the engine power when they are engaged. When the driver pushes towards the next gear the micro switch change state which cuts power just long enough to change gears.

 

[bob8907]

These gears are truly straight cut from the factory. Many are and then companies offer undercutting for extreme power applications. We are having the opposite problem where th gears will not shift. Not where the gears are popping out.

We actually make an ignition interrupt so I know what you are referring to. Problem is even with it, we have to cut the power way too long to get it to shift. This trans is just NOT smooth at all. We will probably start by removing some of the dogs that are not used and see if it will find a gear easier.

 

[LionelHutz]

I had believed you still had to cut the power to shift one of those...

I wouldn't use complete ignition interruption, but rather just retard the timing for the shift.

 

[patprimmer]

Did you understand what I meant and the implications of draw polishing.

Regards
Pat
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