Look what arrived today... No more 4th gear issues!

[cdrazic93]

One must be skillfully rev matching to keep the gears from chattering too much. Much better for clutchless shifting

What kind of fluid would you use with a dog box rather than a helical box? Or does it matter as long as your using an upgraded fluid from factory?

[Koa]

Originally Posted by Chad_W

I thought straight cut and synchromesh were exclusive, how does that work?

not mutually exclusive

Originally Posted by cdrazic93

One must be skillfully rev matching to keep the gears from chattering too much. Much better for clutchless shifting

What kind of fluid would you use with a dog box rather than a helical box? Or does it matter as long as your using an upgraded fluid from factory?

CDR it's not a dogbox

Originally Posted by bur****jp

I went to the thread. It talks about the symptoms, but doesn't say what actually broke in the transmission. For all we know, it could have been a shift collar, which this gear set wouldn't fix.

Ask @Reaper bro.

[RockySDS]

Originally Posted by crazyfrenchbiker

Well that was quick! When are you installing it?

Right now! This is what it looked like when it was taken apart by the guys at Jacks Transmissions...

[cdrazic93]

Originally Posted by Koa

CDR it's not a dogbox

I thought the spines on straight cut gears were called dogs, thus called a dog box because it has straight cut "dog" gears. also having the same characteristic of the loud whine that the gears cause.

The only thing that doesnt fit is that i thought dog boxes were sequential

[brianhj]

Originally Posted by cdrazic93

I thought the spines on straight cut gears were called dogs, thus called a dog box because it has straight cut "dog" gears. also having the same characteristic of the loud whine that the gears cause.

The only thing that doesnt fit is that i thought dog boxes were sequential

"Dog box" just refers to how the gears engage. Dog boxes don't use synchros. Dog boxes can have helical or straight cut gears.

[cdrazic93]

Originally Posted by brianhj

"Dog box" just refers to how the gears engage. Dog boxes don't use synchros. Dog boxes can have helical or straight cut gears.

Didnt know that, so this is just a straight cut trans gear set? Thx for the clarification

[brianhj]

Originally Posted by cdrazic93

so this is just a straight cut trans gear set?

Yeah exactly, it's probably more strongly built than stock, also, so it can handle more torque

[brianhj]

Also, straight cut gears don't produce any "axial loads" which I don't quite understand. Haha. I think that allows for more torque capacity

[Koa]

Originally Posted by brianhj

Also, straight cut gears don't produce any "axial loads" which I don't quite understand. Haha. I think that allows for more torque capacity

Axial load is what it sounds like- load (force) along an axis

Look at the dude's GIF posted a few up. It shows very plainly the load's vector when it comes to a sequential gearset application

[cdrazic93]

Originally Posted by Koa

Axial load is what it sounds like- load (force) along an axis

Look at the dude's GIF posted a few up. It shows very plainly the load's vector when it comes to a sequential gearset application

helical gears literally more surface area for the gears to mesh, thus more area for the load to translate to the axles. Since straight cut gears have less surface area to mesh on, there is less load on the axles. There is however more stress on those dog splines (if shifting wrong its easy to sheer straight cut gears as well), which is a cause of the whine that a lot of people hear with these kind of gears.

[Koa]

Originally Posted by cdrazic93

helical gears literally more surface area for the gears to mesh, thus more area for the load to translate to the axles. Since straight cut gears have less surface area to mesh on, there is less load on the axles. There is however more stress on those dog splines (if shifting wrong its easy to sheer straight cut gears as well), which is a cause of the whine that a lot of people hear with these kind of gears.

more stress on every component horizontal to the helical spline direction as well- main bearings, main/input shafts etc..

the efficiency of helical gears, all else being equal to spur (or straight cut) gears is less as well- since this load is a sliding contact, the system both projects an axial thrust downstream and generate more heat. Power losses that translate to a less efficient system than if spur gears were used.

Helical gears also need additional supports then as well. Ball bearings alone won't work for most applications of helicals, yet with spurs ball bearings are usually the only required assembly support parts, along with the shafts to mount them of course.

Both are positive-power transmitting members of a mechanical system- unlike belts, these are always engaged

The noise reduction alone is why most manufacturers have gone helical- spur gears are easier to manufacture by a longshot,

[cdrazic93]

Originally Posted by Koa

more stress on every component horizontal to the helical spline direction as well- main bearings, main/input shafts etc..

*cracks knuckles* you wanna go Koa? I can do this all day lemme at em, LEMME AT EM!




yeah, basically what he said. I got nothin.

[D K]

Spur gears are stronger AND more efficient than helical gears.

The only reason for helical gears to exist is less NVH.

Helical gears are also much more prone to damage from shaft flex than spur gears.

Originally Posted by lamawithonel

It depends...

All else being equal, straight-cut teeth are "weaker" than helical teeth. In a helical gear (diagonal-cut) the teeth gradually come together at the sides, rotating through and gradually lifting at the opposite side. With straight-cut gears the teeth smack into each other all at once. This creates the characteristic whine, but also a lot of shock stress on the teeth. Helical gears also distribute the forces through more material. All else is probably not equal here, though. I'm guessing the alloy and manufacturing process for these are far better than the stock gears.

There's also a trade-off with helical gears as they transmit forces axially (red arrows), putting stress on the bearings and transmission case. Lower angled gears reduce these forces, and straight-cut gears nearly eliminate them. With our boxes, though, AFAIK this hasn't been been an issue. But if the teeth can hold, it's one less thing to worry about down the line.

Anyway, I'm interested to see how these perform. Keep us updated.

[spitfire481]

Originally Posted by RockySDS

Right now! This is what it looked like when it was taken apart by the guys at Jacks Transmissions...

I'm headed to the track tonight, hopefully my trans will make it through the night haha. Looking forward to your results and can't wait for jacks to get my set worked out. I just want a few clean passes before I have to pull this trans