Broken PAR gear, again....

Ok guys I need a little advice. Last week I broke another PAR gear. I know, I know "impossible" or "was it re-built properly ?" It was built by a pro, and NEVER tracked or launched. Last year I broke a tooth off the ring gear, last week I broke a tooth off 5th gear. WTF ?

My question is really what should I do, what would YOU do ?

I can: Buy a donor tranny (626, probe, mx6) and swap in my LSD OR

I can: Just swap in a open dif tranny from one of those cars and just run it. OR

I can: Buy a new 5th gear custom made to any ratio and cut I want from PAR for $$$. OR

I can: Buy the 3rd and 5th GTX gears from Ken, and buy 1st, 2nd, and 4th from OEM Mazda and swap them in my tranny housing onto my PAR shafts...

I'm at a loss here for what to do. I run 13-15psi daily on a built block, and want to keep the car "fun". SO will I just end up breaking stock trannys if I choose to swap in junkyard trannys ?

Ther other part of this is : My PAR gear ratios are not optimal for a turbo car, they are extra short ratio. Ex: in 5th gear cruising at 70mph, my revs are at 4,000rpm dead even. The car is def fast with these gears BUT, it's all acceleration and no top speed, also not allowing the turbo to spool to it's full potential. My gear set would be sick for a NA track car or even daily (loud though). Bottom line, I need to decide soon because my car has been down for a week already.

Here are MY PAR ratios: 1st: 2.818 2nd: 2.00 3rd: 1.540 4th: 1.227 5th: .960

Here are stock tranny ratios: 1st: 3.307 2nd: 1.842 3rd: 1.313 4th: .970 5th: .755

As you can see, my 1st gear ratio is more desireable than the stocker, but after that it just goes down hill.... I mean s***, look at my 5th compared to a stockers 4th. There almost the same. It's like my car is a 4 speed but with a short 4th. I could use any valuble input from you guys. Mainly, how long do you think a stock tranny ( junkyard or new) will last at 15 psi ? I'm at a loss here. Sucks

BTW: I bought my car with these gears in it, and i think SlowmotionMSP bought the gear set from TRI-Point racing off this forum, not sure though.
 
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Nope, wasn't even shifting into 5th. Just cruising in the bottom gears, then the tooth off of 5th jammed up my ability to shift into 2nd, 4th, reverse. Took it out and 5th was broke. no damage to other gears though. What would you do ???
 
Im really interested as to why the gear broke... Im wondering if the short ratios have anything to do with that... Honestly you shouldn't be breaking PAR gears, because in comparison Mazdaspeed2003.5 has stock gears that are IIRC shoot peened and cryo treated and he is pushing almost 500whp. I hope you figure it out and get the car back up and running.
 
The gears I have are the 1st gen gears that PAR made for tr-point racing...the gears PAR make NOW are much stronger but still, PAR says they should hold the power I make...which i'm unsure of how much i make, lol. Advice people, help lol. WWJD ?
 
I would stop spending massive amounts of cash on those gears if they keep breaking.. but I don't know enough about these transmissions to give you any good advice besides that. I just got my first 5-speed (yellow MP3) about a month ago so I'm not the guy to be listening to about transmissions.. however I do know that those PAR gears are super expensive and supposed to be damn near indestructible. If you broke two already, I would stop buying them..

And Jesus would sell the car and get a Prius lol
 
dude. those gears have a warranty.. i think lifetime.. talk to dino @ speedcircuit

or sam at crossover auto.. both are dealers I THINK!
 
not bashing the PARs here as I have no experience with them....

from what I learned in school, straight cut gears are NEVER as strong as helical cut gears
helical gears are the stock gears (except reverse)

now the reason why many race cars are using straight cut is:
-it's easier/cheaper to machine
-there's less side load therefore if case or bearing weakness is an issue, straight cut gears "solves" the problem
-it does not need to have as much width as helical gears, which means reduced with allows for larger synchro or dog cut assemblies to hold power better
 
not bashing the PARs here as I have no experience with them....

from what I learned in school, straight cut gears are NEVER as strong as helical cut gears
helical gears are the stock gears (except reverse)

now the reason why many race cars are using straight cut is:
-it's easier/cheaper to machine
-there's less side load therefore if case or bearing weakness is an issue, straight cut gears "solves" the problem
-it does not need to have as much width as helical gears, which means reduced with allows for larger synchro or dog cut assemblies to hold power better


All of those things school taught you are correct. You've been paying attention. Tooth profile will determine strength in addition to the "style" of cut. IE: helical or spur. Our stock helical cuts have a puny tooth base/ profile compared to the PAR straights. Also, the PAR's are actually a softer compound designed to withstand impact and abuse, rather than being built for longevity. BUT

On a side note, this thread isn't really meant for pontification about why PAR gears are breaking, but more so for me to get suggestions on what I should do now. I want those of you who have experience breaking trannies, to tell me what you did, and also what kind of power can a stock tranny take. I'm seriously considering buying a junker tranny and swapping it in.

Does anyone know the price of brand new gears from MAZDA ? ?
 
I would stop spending massive amounts of cash on those gears if they keep breaking.. but I don't know enough about these transmissions to give you any good advice besides that. I just got my first 5-speed (yellow MP3) about a month ago so I'm not the guy to be listening to about transmissions.. however I do know that those PAR gears are super expensive and supposed to be damn near indestructible. If you broke two already, I would stop buying them..

And Jesus would sell the car and get a Prius lol


LOL, In all seriousness, I'm not sure why I ever strayed from owning Nissans and Toyotas but, I'm going back to Nissans and never looking back. I <3 sr20det.
 
LOL, In all seriousness, I'm not sure why I ever strayed from owning Nissans and Toyotas but, I'm going back to Nissans and never looking back. I <3 sr20det.

You strayed cuz Mazdas (MSPs in particular) are a blast to drive, and have a whole lot more character to them ;)
 
Subbin' for info on Trannies.
I NEVER use 5th gear due to fear of blowing the tranny
 
I would recommend getting a junker tranny with less than 100k if possible.... Swap the LSD into it and take it from there. Also make sure you check out the 3-4 shift fork, because many people recently have been haveing issues with third gear popping out, and when my tranny was rebuilt my shift fork needed to be replaced as well... AS far as handling power, I and others would probably recommend staying under 300whp on a stock tranny.
 
i thought the limit was 250whp?

There is no set "limit" per say.... But there are multiple people that have been running over 250whp on the stock tranny for some time without breaking major components... But that's not to say that you cant blow a tranny with 200whp.
 
I never hear of anyone else breaking Par gears, I would have to say its your short gear ratio. Those gears should not break so easly. I would Get a new set of Par gears and sell your 1-4th gears. But make sure you get near stock, or longer gear ratio. Because that is way to short for a turbo application. the Tri-Point were not turbo'd cars.
 
i thought the limit was 250whp?

Most trans for our cars est. about 250-300 before they break. All depends on the car. Each MSP is different for some oddreason, some break ALOT more then others. But If I knew someplace around me I would just go get my gears cryo Treated but I have no clue where to look to get that done.
 
when you are running a sticky tires, a monster clutch, solid mounts, a build lsd and msp axles the next weak link is..
 
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