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Review: Liberty Gear Rx7 transmission

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Old Jan 21, 2020 | 12:30 PM
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Review: Liberty Gear Rx7 transmission

I have now had my Liberty's build transmission installed for a few hundred miles, so figured I would share my thoughts with the forum. I recently destroyed my 3rd gear at Autoclub speedway catalyzing my decision to purse and upgraded transmission.

To start, I sent a low mile 99spec transmission to liberty and had them give it the full treatment except I kept 1st, 2nd and 5th gears synchronized. This means 3rd and 4th are face plated with appropriate sliders/hub, everything is cryo treated, shot peen, certain bearings are upgraded to liberty's desire and of course the strengthened milled main-shaft. I also had them sandblast and clear-coat the housing which looks superb. You can customize the transmission to how you want it, and they are very easy to work with. If you don't want any gears face plated, you can keep them all synchronized which saves you money also.

Given there isn't much information on how the FD trans behaves with face plates, I wasn't sure what I wanted initially; torn between face plating or not. I've seen multiple t56 conversions on youtube which seemed pretty streetable. Like many members on here, my car falls in the middle on the street car - track car spectrum. Its focused on being a track day toy however I still enjoy it on the streets occasionally and as we all know balancing such a car is difficult. Face plating the gears definitely pushes it more to the race car / less streetable end. It is certainly streetable, however it does not behave anything like a synchronized gear. It is pretty noisy (during shifting, no gear wine since the gears themselves are OEM) and can be harsh if you dont learn how to treat the gears. Even when driving it correctly, it is significantly more harsh than stock, no comparison. Face plated gears do need to be "slammed" into gear. It actually takes less force to put in 3rd and 4th vs stock however rushing it into gear makes the shift smoother. Shift too slow, and you will grind it in. Rev matching is KEY and doing things such as dropping it into neutral at hwy speeds letting the revs fall and then shifting it into 4th without rev matching can scare you. Double clutching does make the shifts noiseless and perfectly smooth.

Paul at liberty is great, he is easy to reach... actually I never had a time when he didn't come to the phone to answer any questions. He is very knowledgeable and is familiar with FD transmissions. It took about 3 months to complete my trans, limited by the mainshaft milling. Unfortunately my 2nd gear synchros is faulty and my trans does need to go back to liberty. Despite this, I still recommend them for any of your transmission needs. Per Liberty, face plated gears should last longer than any synchronized gear when it goes to driving a car hard. They are also easy to replace if/when the time comes. You will need to clutch when shifting however you are no doubt shifting MUCH faster. Its a matter of how fast you clutch and shift and honestly, do it fast enough and your sounds like a dogbox/sequential almost. My car is anywhere from 450-500whp right now with a new ACT extreme clutch (non-puck), if I shift fast enough 2nd to 3rd it does actually slip a little.

In conclusion: I still am not sure if I made the right decision face plating my 3rd and 4th gears. My first track day with this trans is coming this Friday so perhaps that will help me decide. Streetability did take a big hit and maybe I would have been perfectly satisfied having a great working OEM transmission that doesn't break at my power levels. Just my opinion

I will upload some videos driving around town and hopefully on track soon

Last edited by ArmenMAxx; Jan 21, 2020 at 12:32 PM.
Old Jan 21, 2020 | 02:36 PM
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Nice. That's great that they can upgrade and work with the stock trans.

Can you give us a ballpark on the price?

Dale
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Old Jan 21, 2020 | 03:44 PM
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Mazda RX7 | Liberty's Gears

I believe mine came out to ~$2,200 shipped
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Old Jan 21, 2020 | 07:39 PM
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I'm glad to hear the positive results!! Mine is in there currently for similar upgrades, minus the face plating.
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Old Jan 21, 2020 | 07:44 PM
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Nice. Thanks for sharing your experience.
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Old Jan 21, 2020 | 08:07 PM
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For all the work they did, that seems like a pretty good price for being upgraded where these tranny's appear to be weakest. Thanks for sharing!
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Old Jan 25, 2020 | 12:01 PM
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Few laps around Buttonwillow. Don't mind the commentary from my buddy who's a factory porsche instructor. The transmission felt great between the face plated 3rd and 4th. Unfortunately my second gear became completely useless which really was only needed for turn 2, 1st gear also began grinding.

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Old Jan 25, 2020 | 12:19 PM
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Originally Posted by ArmenMAxx
Few laps around Buttonwillow. Don't mind the commentary from my buddy who's a factory porsche instructor. The transmission felt great between the face plated 3rd and 4th. Unfortunately my second gear became completely useless which really was only needed for turn 2, 1st gear also began grinding.

https://youtu.be/bwSkQxPskbs
Met you at Buttonwillow yesterday. Lovely FD. I was in the Subie. Thanks for the review!
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Old Jan 26, 2020 | 01:08 PM
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I've upgraded a lot of things without really needing to. I don't track my car that much. If I had them simply upgrade the tranny without going to face-plating any gears, would I notice any better shifting? Any increased longevity?
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Old Jan 26, 2020 | 02:00 PM
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Interesting...so face plating is basically converting to a "dog-ring" type shift system like in race car transmissions. I can't speak to the relative life of synchro v dog, but here is some stuff I know.

With dog rings, the life of the dogs on the rings and the mating dogs on the gears depends almost entirely on shifting technique. Shift slowly like in a synchro trans and you may grind the dogs and destroy them in short order. If you don't match revs properly, similar wear can occur. However, done properly, the dogs can last a long time. There are several sources on how to shift dog-type trannies properly - the Hewland website has a good one. I couldn't link it but I copied and pasted it below:
---------------------------------------------------------------------
For successful gear shifting, remember that it is critical to ensure that all mechanical elements between the drivers hand and the dog faces are in good order and properly set. This includes the gear linkage in the chassis. Successful up-shifting (defined as fast and non dog-damaging) will be achieved by fully moving the dog ring as rapidly as possible from one gear to the next, preferably with the engine's driving load removed until the shift is completed. (The opposite is true of a synchromesh gearbox as used in passenger cars, where slow movement helps). It should be remembered that it is not possible to damage the dogs when fully engaged (in gear). The damage can only take place when initiating contact during a shift (the `danger zone`). Therefore this period must be made as short as possible. If a driver moves the gear lever slowly, or if the linkage is not rigid and effective, dog wear will occur. We always recommend lightweight yet solid rod linkage, as opposed to cables. We list below the different methods of up-shifting that are used in racing most commonly. These are in order of shift method preference. Automated (semi-automated): The movement of the dog ring is powered and the engine is cut / re-instated in a co-ordinated manner. Gear-shifts take milliseconds. This system produces zero dog wear when set up well, and highlights the advantages of minimising gear shift time. Manual with Engine Cut: This system is almost as good as an automated one as long as the driver pulls the lever very quickly. A `cheat` version of this is to shift on the engine rev limiter, which can work well. With this system it is especially important to move the lever as fast as possible. Otherwise the engine will be reinstated during partial dog engagement, causing damage. The damage can usually be felt by the driver. Manual: With no assistance from the engine management, the driver must lift off the throttle sufficiently to allow the dog ring to be pulled out of engagement. He should then stay off the throttle long enough to allow the dog ring to engage with the next gear. In practice, the driver can move the gear lever faster than he can move his foot off and back on to the throttle. Therefore the effective method is to apply load to the gear lever with your hand and then lift the throttle foot off and back on to the pedal as fast as physically possible. In lifting your foot, the loaded gear lever will almost involuntarily flick to the next gear before the foot is re-applied to the throttle. Another method is to load the gear lever with your hand, stay flat on the throttle and dab the clutch to release the dog ring. The overall effect on the gear shift is similar to the above method, but clutch wear may become a big issue. The worst method (most destructive and definitely slowest) is to attempt to change gear in a `passenger car / synchromesh` way, i.e. lifting off the throttle, dipping the clutch, moving the gear lever, letting the clutch up and re-instating the throttle. The method causes unnecessary clutch wear, does absolutely nothing to help come out of gear and usually causes dog wear whilst engaging the next gear. This wear is due to several reasons. Firstly, it is impossible for a driver to co-ordinate the complicated sequence of all five physical movements accurately. Consequently the engagement dogs often find themselves engaging whilst the throttle is applied. The lever is usually pulled more slowly as it was not pre-loaded, lengthening the `danger zone`. Successful down-shifting: Similar rules apply regarding speed of shift, with the unloading of the dogs obviously performed in the opposite manner. Whilst braking, the dogs must be unloaded by either touching the throttle pedal or by dipping the clutch. However, one sharp dab of clutch or throttle is appropriate per shift. Continued pressure on either will cause dog damage for different reasons. `Blipping the throttle` just before engagement is advisable if the rev drops between gears are over 1300 rpm, as this will aid engagement and stabilise the car. For ease of downshifting, make the downshifts as late as possible in your braking zone (i.e. at lower road speed), because the rev drops between each gear are then lower. So many drivers make the mistake of downshifting as soon as they begin braking, causing gearbox wear, engine damage and `disruption` to the driving wheels. For any further advice or questions, please contact our Commercial Team, who will be happy to advise.
----------------------------------------------------

Last edited by DaveW; Jan 26, 2020 at 04:07 PM. Reason: added info
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Old Jan 26, 2020 | 05:48 PM
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You definitely still need to use the clutch while shifting with faceplated gears. I'm not sure is a dogbox is considered "clutchless" or not.

Face Plate/Pro Shift Gear Modifications | Liberty's Gears
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Old Jan 26, 2020 | 05:54 PM
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Originally Posted by fendamonky
You definitely still need to use the clutch while shifting with faceplated gears. I'm not sure is a dogbox is considered "clutchless" or not.

Face Plate/Pro Shift Gear Modifications | Liberty's Gears
A dog box can be shifted w/ or w/o clutch. Both techniques will work. Most shift clutchless. However, for my F2000 formula car's transmission (Staffs) and old type VW CV joints, use of the clutch extends component life (less shock loading). YMMV
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Old Jan 26, 2020 | 06:05 PM
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i have 2 transmissions from liberty and they take a lot of abuse whereas the stock one didnt last at all

one "stock" with just the mainshaft upgraded and one close gear ratio straight cut and synchro-less.
One of the best upgrades to my car to take the abuse. the "stock", well feels stock
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Old Aug 30, 2023 | 01:10 PM
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Bumping this thread. @ArmenMAxx 3 years later were faceplated gears worth it? I just spoke with Liberty Gear and will be having them rebuild a FD box in about a month. Debating if I keep the box stock or make it a bit spicier.
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Old Aug 30, 2023 | 03:41 PM
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I found the faceplated gears too aggressive for street use. Its doable but I wanted a bit more drivability. I ended having liberty build another trans without faceplated gears which has held up well so far.

The faceplated setup was really fun, but personally I would reserve for a track only setup
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Old Aug 30, 2023 | 03:47 PM
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Fantastic, good to know. I'm looking forward to dropping a spare box with them in the near future.
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