91 Galant VR4

[Pushit2.0]

I am picking up a few parts trannys tomorrow. And I am talking with Jacks trans and he has a few ideas to help make the tranny last a little longer, but in a nut shell he thinks I will always break a tranny, its just how often and having a back up to swap in.

He is not a fan of the dog box, and the $6000+ price tag at Magnus is a lot to take, I can build and fix a lot of trannys before I get close to that mark.

~John

[Mark Leasure]

I am picking up a few parts trannys tomorrow. And I am talking with Jacks trans and he has a few ideas to help make the tranny last a little longer, but in a nut shell he thinks I will always break a tranny, its just how often and having a back up to swap in.

He is not a fan of the dog box, and the $6000+ price tag at Magnus is a lot to take, I can build and fix a lot of trannys before I get close to that mark.

~John

I would be curious to hear what Jack’s recommended?

[95talonracer]

Would going auto work better for you?

[turbotalon1g]

Have you looked into using a cooler I know that a lot of guys have been talking about it and I was looking into it before i sold mine.

Also I have that galant gsx trans if u could use it.

[Matt D.]

Have you thought about cryo treating the gears? You should talk to the guys at Frozen Rotors, they are local.

[Pushit2.0]

Yes jacks said to cryo treat the new gears, sense its a race car it does not see a lot of street miles to get a good number of heat cycles threw the gears.

Jack also said he was working on another gear set with stronger gears, and he has sent out a few sets to people breaking evo 3 stuff, and he told me I would break these new gears also.

Jacks does not like the dog box's on the market due to the straight cut gears. This puts all the stress into the shafts. He would like to see a helical cut dog box.

I think just about everything gear ratio wise is different in the galant GSX, I will look into a tranny cooler, but when it broke there was almost no heat in the tranny, it drove off the trailer, did a burn out and broke at the 30' mark.

I do not want to put an auto in the car, if I wanted to bracket race the car and have almost 0 fun driving it, then auto would be the way to go. But on the street this thing is a blast to drive.

~John

[goodhart]

When I talked to Dogbox racing last year while transmission shopping they said they make a helical cut dog engagement trans. No idea on the price though.

How did those parts trannies look inside? Hopefully there were plenty of good parts.

[Halon]

Helical cut dogbox? I'm not a tranny expert, but I thought "dogbox" trannies meant straight cut dogs (like reverse), not helical...?

[Matt D.]

Helical cut dogbox? I'm not a tranny expert, but I thought "dogbox" trannies meant straight cut dogs (like reverse), not helical...?
Stolen from NASIOC:

What types of engagement are available? This is a common source of confusion when searching for information on transmissions. There are two types of engagement: Synchro and Dog.

Synchro engagement (also known as synchromesh) is what most passenger cars use.

Advantages:
a. Smooth operation on the road
b. No special driving style required

Disadvantages:
a. Synchros and shifting forks can break when abused and shifted aggressively
b. Slower to shift vs. dog engagement

Dog engagement is what most race prepared vehicles use.

Advantages:
a. Engage at any rpm
b. Allows for wider gear design
c. Will flat shift (Flat shifting is a practice where the clutch or gas do not need to be totally lifted in order to shift. Users will slightly lift one or the other to unload the dogs to allow a very fast shift)

Disadvantages:
a. Difficult to drive on the road
b. Recommended only for race use
c. Special care required under normal street use

What is a dog box? A dog box is the term for a transmission utilizing a dog engagement. A dog box can have either helical or spur gears or both.

What is a half dog box? A half dog box utilizes a combination of synchro and dog engagement. It depends on the manufacturer and customer preferences. Generally speaking, the first and second gears are dog engagement and the rest of the gears are synchro engagement. A half dog box can have either helical or spur gears or both.

What is synchronizer (synchro) engagement?
Synchros are synchronizers inside the transmission. These are the actual parts that move when you move your gear shift from side to side and back and forth. Their job is to connect the gears of the transmission to the shafts that they ride on and lock them together. This must be done at a gradual rate or the gears will grind. The synchronizer drives a cone shaped metal piece against the gear and starts the gear spinning. It accelerates it to the speed of the output shaft. When the gear reaches the speed of the output shaft, the synchro meshes completely with both of them and directs drive through its splines from the gear to the output shaft or vice versa.

What is dog engagement? Dogs are basically no more than cogs on a slider. The shifter pushes them into a receiver ring which engages the gear it is attached to. There is a separate dog and receiver for each gear in the transmission. On a racing transmission, there is a lot of "slop" (the gaps in the receiver are a lot larger than the teeth on the dog), which makes it easier to move into and out of the gears at higher RPMs without fully engaging the clutch.

Can a dog box be driven on the street? Though generally reserved for race applications, many users drive dog boxes on their daily driven vehicles. To do so, you need to learn proper shifting techniques and rev matching skills to decrease wear on the dog gears. The Shifting FAQ, this article, local personnel, or your transmission professional should be able to provide assistance with proper shifting techniques. This is one decision that should not be made lightly. If there is the slightest doubt in your mind as to your technique or attitude towards a daily driven dog box, you should opt for a synchro engagement transmission. Another thing to keep in mind is that a dog box is definitely not an option for a vehicle that sees occasional use by others such as your spouse, friends, visitors, valet, etc.

[Pushit2.0]

I think the Grinding gears does throw a few people off, the only gears that "move" inside the tranny on a dsm for shifting is reverse, and even then there is a synchro on reverse but it just stops the input shaft to select reverse.

As said above when you shift a synchro tranny the gears are always in mesh and spinning, but you are moving a hub that is on a slider that is attached to the main shaft. The hub applies force to the synchro ring to match the shaft speed to the gear speed to engage that gear. They use what is known as Dogs to apply the force from the hup to the synchro ring and match the speed. The synchros are also known as the breaks in a MT. So when you have a double or triple synchro you are making your "breaking" surface a lot bigger then a single synchro.

http://www.google.com/imgres?imgurl=http://members.cox.net/elans4/gear_sync.jpg&imgrefurl=http://www.8thcivic.com/forums/mechanical-problems-technical-chat/176064-fwd-transmission-how-works-inside.html&usg=__rTPrcRLBsDzVDk8bBLY2TSYH3Fc=&h=419&w=732&sz=26&hl=en&start=189&zoom=1&tbnid=dwo1XpylKUf2tM:&tbnh=93&tbnw=163&ei=u2H1Td2vJOLj0gHr9-jtDA&prev=/search%3Fq%3Dsynchro%2Btranny%26hl%3Den%26biw%3D19 20%26bih%3D975%26tbm%3Disch&itbs=1&iact=rc&dur=372&page=4&ndsp=32&ved=1t:429,r:8,s:189&tx=60&ty=48&biw=1920&bih=975

So on the left they show the neutral position for that gear.

And the middle they show you selecting that gear, so you are moving the slider onto the gear, as you do this it applies force threw the dogs to push the synchro onto the gear and match there speeds.

Then in the last pic it shows the hub fully engaged onto the gear, so the hub is on the out side and the dog is in the middle of the last pick, in the dsm tranny there are 3 of these for each gear. And the dogs have spring clips on both sides to help hold them in place, but I suspect under rpm its centrifugal force that pushes the dogs into the hub, and as you move the hub up or down to select a gear it pushes the dogs in to "grab" and push the synchro into the gear you are selecting.

Goodhart is talking about "Pro shifting" a tranny, that does not solve my problem. My tranny shifts great at 10,000rpm, but the gears are not strong enough to handle the crazy hp my car makes.

Doing a pro shift makes a synchro tranny shift like a dog box, or a motor cycle but the gears are not stronger because they are stock gears cut up in a mill.

http://www.google.com/imgres?imgurl=http://www.dogboxracing.com/gears_op_652x489.jpg&imgrefurl=http://www.dogboxracing.com/Transmissions-DSM-AWD.html&usg=__gqOgnhPhlQXoIUbx92986D1FrUU=&h=489&w=652&sz=61&hl=en&start=0&zoom=1&tbnid=qq66XrGyWnb6NM:&tbnh=139&tbnw=187&ei=t2T1TeCMBanv0gGMsMHsDA&prev=/search%3Fq%3Ddsm%2Bdog%2Bbox%26hl%3Den%26sa%3DX%26 biw%3D1920%26bih%3D975%26tbm%3Disch%26prmd%3Divns&itbs=1&iact=rc&dur=379&page=1&ndsp=63&ved=1t:429,r:18,s:0&tx=100&ty=93&biw=1920&bih=975

Here they show a pro shifted tranny, its stock gears with dog engagement.

http://www.sheptrans.com/dogbox/dsm_awd.htm

This is a true dog box, with dog engagement and straight cut gears.

~John