Dogbox, Sheptrans, etc. Questions

[fmars62]

Hey everyone I got some questions about trannys. I know one of our vendors is Sheptrans and he specializes in rebuild transmissions. Also I have heard of a dogbox, or sequential, transmission which has strait cut gears.

With the dogbox you dont need a clutch right? Correct me if I am wrong.

Is it possible for me to get gears 1-3 strait cut and then a long 4th gear and normal 5th gear? If so, where do i go to do this?

How will this work though if strait cut gears dont use a clutch? Thanks.

 

[pauleyman]

dog box is not Sequential and it does use a clutch. What it doesn't have are synchronizers. The engagement is different. A dogbox generally isn't considered suitable for a street car. A quick google search turned this up. Straight Cut Transmission - Dog Box Transmission - Modified Magazine

 

[fmars62]

dog box is not Sequential and it does use a clutch. What it doesn't have are synchronizers. The engagement is different. A dogbox generally isn't considered suitable for a street car. A quick google search turned this up. Straight Cut Transmission - Dog Box Transmission - Modified Magazine

Alright thanks for the response that was a cool article. I still have some questions though...

1. It say premature wear is caused from misuse or granny shifting. So if I drive it gently around town, that will cause it to wear...? So i need to be banging gears all the time?

2. Like I asked before, can I get my first 3 gears strait cut (for fast acceleration) then a regular 4th and 5th gear? If so how much would something like this cost and where would I go?

 

[dacowgod]

I dont know if you could have 4th helical... but you can definitely have 5th helical w/ Syncros...

I had a Shep Dogbox in my Spyder and It would shift FAST but is loud and obnoxious for a street car..so I ended up parting the car out due to not being able to get a transmission that would hold the power my car was making and be street friendly... 1-4 was the Shep (PPG) straight cut gear set and 5th was the standard DSM gear..

Its very easy to round off the "Dogs" in a dog box which makes the car pop out of gear .. to fix it the gear and hub has to be replaced which costs between 800-1500 per gear/hub depending on what gear you've ruined... Street driving a Dog Box really raises the chances of ruining the dogs because of the amount of times you have to shift VS at the drag strip.. With a Dog Box you really have to grab the gears smoothly and quickly...even at slow speeds ..to reduce the chance of the dogs colliding not fully engaged... That is not a problem at the track..but is more of a challenge then you would think on the street...



A new dogbox w/ 1-4 straight cut gears will be in the neighborhood of $7000 bucks if you have a good core transmission.. To add a helical/syncronized stock 5th will be just a little extra... as long as your core has a good 5th ..

Again though I would not recommend this on the street at all.. They whine VERY LOUDLY which gets annoying quickly .... Banging gears will BANG loudly like somebody is hitting your transmission with a sledge hammer...its amazing how loud it is..... With correct timing and finness you can get it to shift a bit smoother but the financial risk, and noise made me decide against continuing to drive it on the street..

 

[fmars62]

I dont know if you could have 4th helical... but you can definitely have 5th helical w/ Syncros...

I had a Shep Dogbox in my Spyder and It would shift FAST but is loud and obnoxious for a street car..so I ended up parting the car out due to not being able to get a transmission that would hold the power my car was making and be street friendly... 1-4 was the PPG straight cut gear set and 5th was the standard DSM gear..

Its very easy to round off the "Dogs" in a dog box which makes the car pop out of gear .. to fix it the gear and hub has to be replaced which costs between 800-1500 per gear/hub depending on what gear you've ruined... Street driving a Dog Box really raises the chances of ruining the dogs..



A new dogbox w/ 1-4 straight cut gears will be in the neighborhood of $7000 bucks if you have a good core transmission.. To add 5th will be just a little extra... as long as your core has a good 5th ..

Again though I would not recommend this on the street at all.. They whine VERY LOUDLY which gets annoying quickly .... Banging gears will BANG loudly like somebody is hitting your transmission with a sledge hammer...its amazing how loud it is..... With correct timing and finness you can get it to shift a bit smoother but the financial risk, and noise made me decide against continuing to drive it on the street..

Damn, thanks man. I didn't think they would be that expensive. But how is it driving them? In the article it said you dont need a clutch cause you can just force it in there quickly. But if you want to drive it easy can u use the clutch and just move it in? Thanks.

 

[dacowgod]

With a dogbox for racing You don't need the clutch except for taking off... but you have to do something to briefly let the load off the transmission in order to shift....(i.e bump the clutch, or lift the gas quickly, or use ignition cut..something)...it will shift at ANY rpm and engage quickly... for drag racing only its by far the best manual transmission you'll ever get.... for street driving I found double clutching it when shifting and rev matching helped a bunch to keep it from banging the dogs... but again to me it was more of a pain in the ass than its worth..and the financial risk is just not worth it to me at all... If you want something thats going to shift as fast as possible and handle the power..go Auto ... If you wanna bang gears and make big power (mainly big torque) Then expect to become very familiar with tearing your transmission out and rebuilding it ;-) ..

 

[fmars62]

With a dogbox for racing You don't need the clutch except for taking off... but you have to do something to briefly let the load off the transmission in order to shift....(i.e bump the clutch, or lift the gas quickly, or use ignition cut..something)...it will shift at ANY rpm and engage quickly... for drag racing only its by far the best manual transmission you'll ever get.... for street driving I found double clutching it when shifting and rev matching helped a bunch to keep it from banging the dogs... but again to me it was more of a pain in the ass than its worth..and the financial risk is just not worth it to me at all... If you want something thats going to shift as fast as possible and handle the power..go Auto ... If you wanna bang gears and make big power (mainly big torque) Then expect to become very familiar with tearing your transmission out and rebuilding it ;-) ..

Thats all i needed to hear, thanks man, appreciate it.

 

[1fastlaser]

You could contact Liberty gears, and have them faceplate the factory gears. It makes the car dog engagement with no syncros, but you are still dealing with the factory gear.