building a gearbox

[BENE38A]

i broke my gearbox,who here has had a gearbox built, i am working towards a 400hp-500hp engine (not an exact number but its how it is) so i want to do it once and do it right what can you do to a gearbox to improve it over factory and strengthen it, i have an e38a rs so has different ratios than an e39a and trying to find a gearbox in New Zealand is a gamble

 

[transparentdsm]

JACKS/TRE/SHEP - if they wont ship it to you, im sure someone would be willing to help get it shipped to you. id def help ya.

 

[cheekychimp]

How much money do you have?

Albins Off Road Gear in Australia will take your E38A RS box 3.909 final drive and make you a six speed box with custom ratios.

If I was doing all this again. I would have spent THAT money first and neglected a lot of other stuff on the car which in retrospect is just not needed as much. A good gearbox is a lot of money but in my opinion it is an area of the car that is really neglected in terms of the massive potential for performance gains it offers.

 

[donniekak]

Don't waste a ton of money. They all have the same weak mitsubishi gears, unless you get a ppg gear set. I don't know what kind of power you are making, but after about 450 ft/lbs they are going to eventually break, all of them.

 

[brisvr4]

For those sorts of power numbers I'd just shim it a bit tighter and call it a day.
As mentioned, they all break!
There is a guy in Germany that has manufactured his own straight cut 3rd and 4th gears. Those are the ones that usually break,3rd will take the centre diff gear out as well.
Evo box upgrade

I rebuilt my own box a couple of years ago and shimmed the input and intermediate shaft and it's held up fine to a lot of hard work.
I don't have an exact dyno figure (I dont really care about power figures)but the mine makes enough to run 132mph in the 1/4.

 

[BENE38A]

thanks for the input guys, ive emailed for some quotes and transparentdsm i will pm you when i know what im doing appreciate your offer

 

[BENE38A]

i found an evo 3 rs gearbox transfer case and axles for a pricey $3000nzd i hear good things about evo 3 gearboxes

 

[transparentdsm]

thats what you'll pay for just a built trans from any of the companies i recommended, maybe a little less. and that doesn't include shipping, but the trans will be able to handle the 450-500hp you plan on having your car put down.

 

[brisvr4]

Shipping and import duties into NZ will suck though!

 

[MX4]

Hit up Jeremy @ www.evoparts.co.nz . He has just done some engine work for me. I know he does do gearboxes, and if he is as good on the boxes as he is with other types of mechanical and engine building then I would have no worries recommending him.

 

[BENE38A]

yes import duties are out of control here so i might skip the importing unless i really had too going to look at this evo3 gear

 

[BENE38A]

so i pulled the gearbox today one of the top bolts going into the block was missing along with that corner of the gearbox and some were even threaded YAY, look at the state of the fly wheel after having no inspection plate for god knows how long. i have decided to bite the bullet and get rid of all my money and buy the evo rs gearbox t-case and axles. does anyone know if you can use your standard vr4 axles with an evo 3 rs setup maybe i can knock off a couple hundred bucks. quite dissapointed with the previous owner especially after how well the car had been maintained to skimp out on one of the cars weaker points the driveline.







and i thought i was going to have a good day installing this, guess it will have to wait.

 

[BENE38A]

here it is my new (to me) EVO III RS gearbox, transfer case and axles





going to clean it up and paint it tommorow can you pressure wash a gearbox or am i better to scrub it and whats a good paint, hard wearing would like a standard alluminum look.
also the evos had three mounts on the gearbox and the one on the timing side of the engine, was told by the person i brought this of was because the bell housings weren't strong enough to take the loads created by having one mount on the gearbox and 3 on the block, can anyone confirm this and wether or not the evo cross member will bolt up, it looks similiar and comes with new polyurethane mounts so if it works ill buy it for cheap and free up some room under the turbo.

 

[strokin4dr]

All of your mounts will stay the same. You will still use the 3 on the engine and one on the trans. Just remove all mounts and brackets from the evo trans and bolt on your vr4 parts.
You will be using the stock vr4 cross members as well. Only parts from the evo you will need is the trans itself and the transfer case. Also, you may need one of the axle cups from the evo axle for the front lsd. I'm sure someone else will chime in to confirm this.

 

[BENE38A]

yea understood that but was more looking at wether the evo crossmember will bolt up so i can use the evo mounts

 

[brisvr4]

It won't bolt up. You could use the front mount on the box but you would need to weld a new mount to the front crossmemeber to make it work.
It would free up a lot of space under the turbo though!