Building a race tranny

[GreenStreak]

I decided that I wanted to tackle the job myself and any input would be great. So far I'm going to order these parts:
Galant vr4 1st gear w/ double syncro
2nd gear double syncro
new syncros
evo shift forks
spool
trash magnet and other misc. stuff.
Is this going to be enough for my race tranny? Am I missing something? Well any input that I get would be great.

 

[nukefission]

I think some heavy duty shift rails would do more good than a double syncro 1st gear, that is unless you're rallying or autoxing the car.

 

[GreenStreak]

Yeah I read up a little more and decided I dont need double syncroded 1st and I added stronger rails to the list. I'm also thinking it would be better to weld the center diff. instead. It would be pretty convinient for dyno days. Another thing I noticed when searching was that not many people think it's a good idea to build your own tranny. Oh well I'm going to give it a shot.

 

[DSM Storm]

I honestly dont think you need the "heavy duty" shift rail ends. If you break them then you are putting more abuse on that tranny than it really needs. Im almost complete with my rebuild. Im just waiting for my shims and snap rings to arrive from the dealer. I ended up with a GVR-4 inputshaft & 1st gear. Had to replace the intermediate shaft. Double syncro 2nd gear, HD double syncro 3/4 gears. Billet shift forks. KAAZ front differential. Speed design center with a welded VC. Of course the tranny is getting all the neccesary rebuild parts. So far, so good! I assume the gearbox should be complete by the weekend. You really dont have anything to worry about if it is done correctly. Of course those shops that do this every day do have some aces up their sleve as to how they manage tolerances and things of that nature. I keep hearing how much of a bad idea it is to rebuild a tranny without the experience. I do have to say that the tranny had to be put together by someone, so it is not something that is impossible. You live and learn I guess, if I have to disassemble it again to make things right then I will do so. I refuse to send this or any other part out to be rebuilt. If I cant do it myself than I dont want it. And dont think its because of the money either. I have probably spent a good $600- on tools alone to complete this task, and going by the parts list I can assure you that it was equally expensive. Good luck with your build. If your looking for some parts, try JON @ TRE, hes a stand up guy with some really good parts to offer.

Storm

 

[nukefission]

If you've disassembled your trans then you probably noticed how brittle the stock material is. The heavy duty rails are more a preventive measure against breaking a weak stock part from normal use, rather than fortifying it to take unnecessary shift abuse.

 

[DSM Storm]

If you've disassembled your trans then you probably noticed how brittle the stock material is. The heavy duty rails are more a preventive measure against breaking a weak stock part from normal use, rather than fortifying it to take unnecessary shift abuse.

Im going to have to disagree with you. They are not brittle at all, they are made of iron. Im aware that the heavy duty rails are stronger and made of treated steel. Ive been crashing 2nd gear all summer and I have yet to break a rail, or anything at all on my stock 93 tranny and its a tranny that should have been retired long ago. I have never seen anyone break a stock rail end from normal or agressive abuse. Im sure there are cases out there of such, however I feel that if you break a shift rail end you obviously deserve it. In my opinion most people feel they have to force that shifter into gear... Im sure we can argue the point back and forth. If you have the money to buy them, and it gives you a piece of mind then go for it. After all...$120- for some rail ends is a drop in the bucket compared to what you will spend for a thorough rebuild. In the gearbox im building, I personally dont feel a need for them so I did not purchase them. I can understand your point. Ive seen first hand some of the abuse these trannies take...

Storm

 

[CYCLONE]

Tow things you might want to consider for your tranny build up.
1st the gvr4 1st gear is weaker that a tsi 1st gear.
2nd if you plan on doing any auto-x or road racing do not weld you
center diff. I would put a 4 spider center diff in. Welded diffs tend
to cause wheel hop at the track if you don't have a very stiff suspension.