Hey everyone.

Since the last autocross event I was at on 22/09/13 I noticed an infrequent but worrisome situation where second will pop out of gear in my '93 del Sol Si (z6, S40B000 5-speed apparently from Japan with Quaife LSD - was recently swapped AT-MT this spring).

It doesn't happen often at all but I thought I would test to see when it happens since this is a new occurence. If I shift into second and keep it there while driving on the street, coasting in second and frequently blipping the throttle, it will stay in second for a while. But every so often it will pop out of second.

The only incident I can think if that may have led to this was during the last autocross event I missed second gear and then accidentally power-shifted into second without depressing the clutch.

It's less a concern when driving it on the street which isn't often, but more concerning since for autocross and time attack I'll be using second a lot.

Could I have bent a shift fork? In doing some reading I came across a situation were it was someone's countershaft bearing.

Any ideas?

 

I think I found my answer from someone on another forum with extensive experience with transmissions.

Sounds like it's the Countershaft Bearing - turns out that it has walked out of the transmission case and needs to be tapped back into place and staked to keep it from moving again.

If there are any other suggestions please keep them coming.

 

Usually it's the countershaft bearing, but make sure you check the condition of the sleeve and engagement teeth on the gear.

 

Luckily the car is rarely driven so I'm not terribly concerned about making it worse but I do think I'll have to call it quits for the season on the remaining autocross and time attack events. There are only a couple remaining.

I'll get the work done in the spring and this will make a good excuse to look into a carbon synchro rebuild kit and maybe a gear set since the transmission will be out of the car and open.

I was looking at the Mfactory 1.565 3rd gear, moving OEM 3rd to 4th and keeping 5th for the long drives to the track. Possibly a 4.9 final drive...

Decisions, decisions...

 

Maybe look at a VX 3rd for 4th. I think you'll find the OEM Si 3rd for 4th a bit low. They're a bit hard to find used is all and discontinued new.

 

I had all that info worked out - which gears, the ratios, etc.

But like you said, they're hard to find and some modification is necessary. Looks easier to just pick up an Mfactory gear or Gear-X gear set.

 

No modification is necessary. I built on trans with VX 3rd for 4th. I couldn't tell you how it feels though, I only ever drove it about half a km just to try it. It was in a car with an expired inspection, registration and no insurance. Hopefully next year I'll have it on the road.

There's nothing wrong with an aftermarket gear set, it's just expensive.

 

Looks like I wasn't researching the VX gears.

Here's what I was considering back when I was researching this in 2010 with my old EK:

1. 3.250 (stock)
2. 1.909 (stock)
3. 1.346 (CRX ZC)
4. 1.033 (CRX ZC) or 1.066 (3rd CX/VX)
5. 0.702 (stock – for long drives) or .0878 (ZXi – for track only)
FD. 4.25 (stock)

ZC 3-4 swap will need to machine 4th gear on the mainshaft to clearance the 3-4 hub.

 

Yeah the ZC 3rd does require some machining. I remember reading up on it years ago as well. I'm guessing those ratios are from Bense's info?

 

Don't remember exactly where I sourced the info but it was likely from d-series.org, more specifically Mista Bone/Transzex. He's the guy you hope chimes in when you have a transmission related question.

 

Charles is a good guy and he knows his stuff, I wish he still posted here

Bense also had a lot of good hybrid D-series trans info: http://bensebuilt.livejournal.com/3768.html

 

Good to know! Thanks for the info.