2G DIY Trans Rebuild : Dogbox

[Mham2k]

I spent time understanding how to build my own engine and it is still running strong 2 years later with 30 lbs of boost running through it. First time building one.

My trans is down 2 synchros and I think it may be time to buy another trans and rebuild it in anticipation of my current one dying. There don't seem to be as many people willing to build there own trans, is there a reason why?

My initial thought is to buy a ppg dog gear set and a rebuild kit and get to it, being careful and learning along the way as I did with the engine.

Is it much harder?
Why don't as many people build trans as there engines, or is it something not talked about as much?

Thoughts?

 

[bastarddsm]

You don't need a rebuild kit to build a ppg. You need 4 seals, and a few bearings. Ppg requires machining the cases, and paying a lot of attention to the shift mechanism, to make sure it gets full shifts. You'll need a spare case to cut a viewing window in so that you can check easily.

 

[Mham2k]

You don't need a rebuild kit to build a ppg. You need 4 seals, and a few bearings. Ppg requires machining the cases, and paying a lot of attention to the shift mechanism, to make sure it gets full shifts. You'll need a spare case to cut a viewing window in so that you can check easily.

Any good guides out there on rebuilding with a ppg?

 

[dwb]

IMO, a (stock) trans rebuild is easier than an engine rebuild.

 

[CrackedDSM]

Stupid question, but I don't care, how much torque can a dogbox hold longevity wise? If that's worded stupidly, I'm asking at what torque level will a ppg/dogbox basically last forever aside from general maintenance? Because I'm heavily considering one, because I don't want to deal with popping stock boxes at 300-350+wtq.

 

[Mham2k]

Stupid question, but I don't care, how much torque can a dogbox hold longevity wise? If that's worded stupidly, I'm asking at what torque level will a ppg/dogbox basically last forever aside from general maintenance? Because I'm heavily considering one, because I don't want to deal with popping stock boxes at 300-350+wtq.

I hear that they last if you shift well, rev match, ect.

 

[97egl]

Stupid question, but I don't care, how much torque can a dogbox hold longevity wise? If that's worded stupidly, I'm asking at what torque level will a ppg/dogbox basically last forever aside from general maintenance? Because I'm heavily considering one, because I don't want to deal with popping stock boxes at 300-350+wtq.

I beleive at any power level dogboxes require more maintenance than a regular transmission. Had a buddy who was sending his out almost every couple years to have adjustments made/clearances check and stuff. I don't really know exactly what was all done to it when it was sent out. I'm sure someone will chime in with more info that knows way more than I do, but I wouldn't put a dogbox in anything except a mostly strip or race only vehicle. Even if you don't mind pulling it to make adjustments they also are very noisy.

 

[CrackedDSM]

I don't mind the gear whine, and I've driven a friend's dog box equipped 1G so I know that you have to basically rape them into gear. I didn't mind it as much as I thought I would. I hated the lack of A/C and P/S more than the dog box honestly. But pulling the trans to often make adjustments has me a little nervous in the same vein as having to pull the pan and check your Al Rods. Bummer. I really want something with 350+ wtq that I don't have to worry about an exploded transmission on every launch.

 

[ist dwa]

A stock trans can handle 350ftlbs of torque easily.

Dogboxes require machining the dogs. Every shift is literally wearing them out. They can be machined about twice then they have to be replaced.

 

[jdxnc]

I know that you have to basically rape them into gear.

Completely untrue, they shift very nicely with 2 fingers if everything; shift rails/cables/clutch are all adjusted well.

People asked me how it was so I just threw together a little video driving around town. The most difficult part is down shifts, basically need to rev match.

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[CrackedDSM]

A stock trans can handle 350ftlbs of torque easily.

I’ve heard that but then seen people grenading their trans at around that wtq more than once. I’m overly cautious, but pays to be prepared.

Completely untrue, they shift very nicely with 2 fingers if everything; shift rails/cables/clutch are all adjusted well.

People asked me how it was so I just threw together a little video driving around town. The most difficult part is down shifts, basically need to rev match.

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Good stuff, thank you. My quote was an attempted joke, and also a partial quote from a guy named Taboo from DSMTalk back a billion years ago.


I mainly meant that it has to be shifted with purpose. If I tried to lazy shift it or second guess any shifts we would all have a bad time.

 

[ist dwa]

I’m overly cautious, but pays to be prepared.

Well I hope your "prepared" to pay 10,000$ for a dogbox setup. 2k$ for the twin disc and then you have to buy evo disc, plus about 8k$ for a box itself.

 

[diambo4life]

A stock trans can handle 350ftlbs of torque easily.

Dogboxes require machining the dogs. Every shift is literally wearing them out. They can be machined about twice then they have to be replaced.

Damn. They are not cheap. Too bad stock manual transmission numbers are finite. Time to start adapting non Mitsubishi transmissions into our cars. We are the only platform who doesn't do this for whatever reason. The Honda boys have been very creative in the past 10-15 years with these AWD stuff...remember, they don't run autos.

 

[llxkevinxll]

A stock trans can handle 350ftlbs of torque easily.

Dogboxes require machining the dogs. Every shift is literally wearing them out. They can be machined about twice then they have to be replaced.

For what it's worth my car was tuned by Ricky at Rix Racing to keep torque at or below 400 ft lbs. As he indicated that was the limit, and below that issues should be rare given maintence and driving care. I also bumped into Tim from TMZ this past summer at a show and he said the same thing. I have not put a million miles on my car but I've had the same unknown mileage unopened trans in the car my entire ownership, 12 years or so. And making that 400 ft lbs peak for the past 4 years. I change the fluid basically yearly and I avoid wild launches for the most part, but have done lots of autox runs with the car passing through peak torque repeatedly in 2nd with a car that weighs 3037 lbs without me. I have had 3 engines in my car, against my preference, but the same trans. If dsms have glass drivetrains, I haven't seen it personally.

 

[bastarddsm]

If you break a dsm awd at 350ft*lbs, you are gonna break a dogbox too. From what I've seen leasurely driving is almost no wear on the dogs. I bought mine in 2019, and it's got a bunch of street miles on it. The back sides of the dogs are mint still. Upshifts can be almost silent if you do it right. It's the WOT power shifts that are hard on the dogs. Mines probably got 1 more season on it and it will need a 1/2 slider and a 2nd gear. 3rd's showing some wear too but not as bad as second.

Having had a liberty faceplated set too, I think those dogs last better, but hard to know for sure.

The dogbox is hard on the oil, seems to break it down way faster than stock trans. Does get a lot of crap in it. I use lucas 85-140 and change it pretty often.

Some of yall are crazy on what you think the stuff costs. Dogbox kit was right around 5500 last I was quoted. 10k should be getting you one that's pretty well optioned (front lsd, 4 spider, my billet shift fork and rail ends). Don't need a 2k twin disc either. use a 6 speed miata disc.... I've been 9's on an act miata puck disc and an XTD pressure plate. It's not hard guys.


Lastly, everyone wants racecar shit till you have racecar shit. I love the dogbox at the track, but it f***in sucks to street drive. I'm putting the syncro trans back in for this year. Car is just as quick anyway.

 

[bastarddsm]

Damn. They are not cheap. Too bad stock manual transmission numbers are finite. Time to start adapting non Mitsubishi transmissions into our cars. We are the only platform who doesn't do this for whatever reason. The Honda boys have been very creative in the past 10-15 years with these AWD stuff...remember, they don't run autos.

There's a reasonable cost gearset availible was $2500 a couple years ago. Noone wants to shell out the cash to try though. I was gonna do it, but with allready having a dogbox and more cores than I have time to use, I haven't.

 

[CrackedDSM]

Good stuff man, lots of stuff to chew on. Appreciate the experience/first hand info too. Gonna start making some adjustments to the plan and see how long the current trans lives when pushed. Really don’t want to go auto as I already have something auto and awd. Definitely don’t want a race car or race car shit. Just something basically bulletproof. Don’t think that’s gonna happen but hey.

 

[diambo4life]

Or keep your DSM at stock power level haha....

 

[diambo4life]

If you break a dsm awd at 350ft*lbs, you are gonna break a dogbox too. From what I've seen leasurely driving is almost no wear on the dogs. I bought mine in 2019, and it's got a bunch of street miles on it. The back sides of the dogs are mint still. Upshifts can be almost silent if you do it right. It's the WOT power shifts that are hard on the dogs. Mines probably got 1 more season on it and it will need a 1/2 slider and a 2nd gear. 3rd's showing some wear too but not as bad as second.

Having had a liberty faceplated set too, I think those dogs last better, but hard to know for sure.

The dogbox is hard on the oil, seems to break it down way faster than stock trans. Does get a lot of crap in it. I use lucas 85-140 and change it pretty often.

Some of yall are crazy on what you think the stuff costs. Dogbox kit was right around 5500 last I was quoted. 10k should be getting you one that's pretty well optioned (front lsd, 4 spider, my billet shift fork and rail ends). Don't need a 2k twin disc either. use a 6 speed miata disc.... I've been 9's on an act miata puck disc and an XTD pressure plate. It's not hard guys.


Lastly, everyone wants racecar shit till you have racecar shit. I love the dogbox at the track, but it f***in sucks to street drive. I'm putting the syncro trans back in for this year. Car is just as quick anyway.

I like experimening shit but I have definitely not heard of the Miata disc before. Good to know!

 

[CrackedDSM]

Or keep your DSM at stock power level haha....

I’m admittedly tempted. But man I need something in my fleet faster than 12’s.

 

[er82]

There's a reasonable cost gearset availible was $2500 a couple years ago. Noone wants to shell out the cash to try though. I was gonna do it, but with allready having a dogbox and more cores than I have time to use, I haven't.

If you break a dsm awd at 350ft*lbs, you are gonna break a dogbox too. From what I've seen leasurely driving is almost no wear on the dogs. I bought mine in 2019, and it's got a bunch of street miles on it. The back sides of the dogs are mint still. Upshifts can be almost silent if you do it right. It's the WOT power shifts that are hard on the dogs. Mines probably got 1 more season on it and it will need a 1/2 slider and a 2nd gear. 3rd's showing some wear too but not as bad as second.

Having had a liberty faceplated set too, I think those dogs last better, but hard to know for sure.

The dogbox is hard on the oil, seems to break it down way faster than stock trans. Does get a lot of crap in it. I use lucas 85-140 and change it pretty often.

Some of yall are crazy on what you think the stuff costs. Dogbox kit was right around 5500 last I was quoted. 10k should be getting you one that's pretty well optioned (front lsd, 4 spider, my billet shift fork and rail ends). Don't need a 2k twin disc either. use a 6 speed miata disc.... I've been 9's on an act miata puck disc and an XTD pressure plate. It's not hard guys.


Lastly, everyone wants racecar shit till you have racecar shit. I love the dogbox at the track, but it f***in sucks to street drive. I'm putting the syncro trans back in for this year. Car is just as quick anyway.

What’s the benefit of a miata clutch? Wouldn’t an evo clutch work if staying single disc?