Transmission mods (secrets)

[rstchris]

I am finishing up a transmission rebuild and so far I have replaced lots and lots of stuff. Anything that showed signs of wear got replaced with new or like-new parts. I found a writeup on preloads so everything will be tight as far as the center diff, input shaft, intermediate shaft, ect, what I am looking for and not finding are the secrets. I have cams and bse so I plan on turning 8k and I don't want my trans to make me wait an hour to shift gears.(like it does now) The oil will be Amsoil 75-90. What are the secrets to making a dsm trans shift like "butter"?

 

[turboglenn]

couldn't tell ya how to set it up but talking with Jon at TRE when he built mine, the bearing preloads and gear and synchro detail work is what makes a tranny shift better at high RPM.

Actually how i came to bring it up was when mine was new it was cold out (winter) and my new TRE stage 3 wouldn't shift at low RPM at all, and Jon said something about setting up the preloads to where my trans like to shift between 4 and 10k RPM where the OEM setup is good from 0 to 5k RPM

Of course the oiling system, shift rails and forks all play their part... I would have to say that if ya don't know what to do, don't mess with it unless you don't care to experiemtn and possibly have to start all over. If you could shot peen and detail your gear set it would help hold power better but that's not shifting... or if you could clean up the edges and detail them out on the synchros and slider grooves and such it will all help ( i can build motorcycle trannies great but i'm honestly a tad lost on non sequential manual trans)

 

[donniekak]

Not many secrets, it's all out there by now. Shimming the input shaft tight helps with upshifts. You also want a double synchro 2nd, and 3rd/4th if you can spring for it. The gear teeth, and slider teeth must be in new condition, or it will still be "notchy", and slow to shift.

 

[rstchris]

Gears 2 and 3 were replaced due to wear as well as 2-3 hub/slider. 1-2,3-4 forks and synchros are new. I don't have double synchro anything. I measured everything and everything gets preloaded except the front diff. I read that there are other money maker mods that builders do but idk so hence the questions. I don't mind expermenting cause this is an extra trans I just like the way my 420a trans ripped lightning fast and three AWD trannys and all are shy about shifting fast. I got mad one night next to an ls1 and jammed it into 2nd killing a shift cable and lucky it wasn't a fork.

 

[Lofty]

Hand deburring the gears. By far. The best thing I could really tell you.

 

[1995gsx20g]

420a trans ripped lightning fast and three AWD trannys and all are shy about shifting fast.

The clutch plays a big part, most of all the pressure plate.

i had a center diff and rear diff slowly go out on me and i felt my trans progressively shifted worse as they got worse..

solid shifter cable mounts help, along with all of the little things but the only real way to not deal with this is to go automagic i will be making the swap before the dsm gets back on the road.

 

[rstchris]

My friction point is about half way out unlike most dsm's having the clutch engaged a half inch off the floor. The clutch is a xtd 6 puck el cheapo but works very well. The shifter is a bit floppy but I plan on making it tight.
What burs would I be removing from the gears?

 

[1995gsx20g]

i believe by burrs he means the ones on the helical gears that are in constant mesh. 3rd gear is especially important because that is the gear that all of the power has to be transferred threw at all times no matter what gear you are in.

 

[Lofty]

i believe by burrs he means the ones on the helical gears that are in constant mesh. 3rd gear is especially important because that is the gear that all of the power has to be transferred threw at all times no matter what gear you are in.

x2!