Locking Diff????

[SlowProtege]

When I had my GTX tranny in my Pro the actuator for the diff locknever worked, so when i put GTR tranny in i took out the actuator and put a new rod where the actuator bolted up to and grinded to notches in the rod to have a codder pin hold the rod for whatever possition the selector would be... sorry if that was confusing. well when i pull the rod out (locking the diff) and drive around my rear inside tire chirps as if it was a limited slip. Just wondering if this is normal? and when i push the rod back in it goes back to normal. Just checking to see whats up with that.

[323driver]

The GTX or GTR don't have locking diff. They have an LSD though.

[SlowProtege]

Hmmmm im not sure whats happening then, bc when the rod is pulled out (locking the diff inside the tranny) and i make a sharp turn it chirps like i welded my diff or something. but it returns to normal when i push the rod back in. And when i jack up the car and turn the wheels it acts like a normal diff..... so basically i dont know what the f*** is happening. It wouldnt make sence that something on the tranny could make the rear diff act differently.

[323driver]

If you have a rod to block the diff, it means that you have a north american tranny, not GTX or GTR. The rod simply ties the front wheels to the rear wheels so that the front diff and the rear diff rotate at the same speed but has no effect on the locking of your rear wheels with each other (or the fronts perhaps); your rear is still open (unless you swapped for a GTX/GTR or miata one) so it doesn't care if the center diff is locked or not.

[323driver]

Wait a secont, are you talking about the BF GTX tranny (pre 90)? By GTX/GTR, i'm referring to the JDM BG version. The BF GTX has a lock, very similar to the BG NA tranny.

[SlowProtege]

Not to sure what one it was. but the rod wasnt there before the tranny got put in it something was messed up with the selector rod so i put one in that i can manually move with my hand instead of the electronic actuator for the switch on the dash. All i know is that when i have the diff in the tranny locked it makes my read diff completely locked. I never put a different read end in so i have no clue if its the stock rear end or not. the only 2 trannys i have are a GTX and GTR and the GTX came with a front clip and it was RSD so i dont think it could be a north american tranny.

[323driver]

I had a norrth american tranny with the lock that I swapped out for the current GTX tranny that has no diff lock but an LSD. anyways, I'm not sure on what you have, take pics. The lock doesn't lock the rear diff, just the center, meaning that the front diff and rear diff are tied together when locked and that is why you shouldn't take corners on dry pavement with the diff locked as none of your tires will slip causing grinding. In the wet, you'll have one front and one rear tire slip. If you jack up the car and rotate one tire and see the other one rotating in the opposite direction, that means that your diff is open. If you haven't swapped the diff, then it is open from factory.

[SlowProtege]

Man im confused now on what EXACT tranny i put in. i had 2 and on one of them the axles input shaft bearing went due to a big pothole hidden by water IN A PARKING LOT, and i only had the tranny and car running for a day before i had a wiring f*** up. Thats just weird i might be able to take pictures of the one i took out bc i had both side by side and everything was the same dimensions and everything. When i bought the car it came with a spare tranny and blown engine and i was told the on that was in it was the GTX(which is the one that is now dead) and the one i just put in was the GTR. Are there any differences in the wat the NA tranny and the GTX/GTR look? and i noticed the one i put it seems like 5th gear is longer that the one i took out.

[jay]

The BPT GTX and the GTR trans both have the rod that allows you to lock the centerdiff (I know cold this is true cuz I have one of each). But the factory didn't install a difflock motor. Since the centerdiff on both of these gearboxes is a viscous LSD, there's no real reason to lock it. Just run the thing unlocked and your chirp goes away and your centerdiff will live. According to the service manual 323 GTR supplement, the only difference between the 1.8 GTX carrier/tranfer unit and the GTR stuff is a different speedo gear ratio for the GTR. Everything else is identical, 'cept that they shotpeened 1st and 2nd at the factory. The difflock rod is there for fwd only dyno tests and such... here's a screenshot of the page in the manual showing the how's and what's of locking and unlocking the centerdiff...Now if your trans came with a difflock motor, either someone was messing around or you got a 1.6l, BF GTX tranny with an open diff and weak-ass internals. But that one won't bolt straight up to a 1.8 BP engine, the bottom bellhousing bolts are a bit different.

[cruzzer26]

How about pulling the drive shaft that leads to the back tires.. that what I did,i made my AWD a FWD...I removed the drive shaft and turn the car on and my didn't go anywhere,so i had to look the diff.. and it work so now it's fwd.. hehehehe..

[almighty4wd]

interesting.... thoughts? would this be a viable solution to being stuck, or would the rear/center lsds just make up the difference? think in deep snow where traction is spotty, locking the old 4wd made a huge difference in traction. Would my GTR tranny benefit as well?

[jay]

hmmmmmmmmmm. Maybe next time it snows I'll try it. I know on gravel I prefer to let the centerdiff do it's job without being locked up. And I had so damn much grip in the snow in the street car last winter I didn't bother turning the boost down. I thought my bpt GTX was the best snow car evar. Nope, these awd frankenproteges are...more wheelbase!

[808]

I thought my bpt GTX was the best snow car evar. Nope, these awd frankenproteges are...more wheelbase!

Shut up Jay, I'm already jealous, don't make me question my 2 GTX's now too...

But yes like Jay said, the bpt awd (gtx/gtr) trannies both have manual difflocks.

[SlowProtege]

Cool thanks to all of you. Ya i just left it open. When i first noticed it i thought i ran out of oil and melted my rear diff together, but i checked it and everything was fine.

[323driver]

For some reason, I was thinking you were talking about the difflock using a motor so my bad, didn't fully understand what you were doing. I guess Jay has put it all out for you. And yeah, don't lock the diff, there is no point.