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Popping out of 5th after LSD install

1159 Views 34 Replies 6 Participants Last post by  rgm_93si
I installed an MFactory LSD, a Synchrotech carbon synchro kit as well as various OEM bearings and any items that were not included in the kit in my 93 Si hatch with a D16Z6. I referenced the service manual and several videos. The installation went smooth as well as the first test drive where I went through all the gears keeping it under 50mph. However, on the highway it pops out of 5th between 55 and 65mph. The transmission was not making any noises or grinding and shifted smoothly. I drained the fluid and checked to make sure the snap ring was on the counter shaft bearing which it was. I pulled the transmission again and opened it up and there is no sign of an issue. The car has new Hasport motor mounts, energy suspension bushings on the shift rods and a K-tuned shifter. I’ve had no prior issues with the transmission which has less than 150k miles.
The first thought was that 5th gear may be bad so I am attaching some pictures. To me it looks fine, but maybe there is an expert out there that can verify. At this point I am stumped, the only other thing I can think of is to take it to a tranny shop and have them look for any issue. If anyone knows of anything else I should be checking, I would appreciate their input.

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Have you tried bench shifting the assembly with the outer case off to make sure the 5th gear slider is fully engaging the synchro and gear?

Also, what does the shift fork on 5th look like? If its worn out, it may not be pulling the slider all the way down to the gear.

What about your detent balls? Are all of the detents in place? If you're missing any, the slider could be trying to wiggle its way back to neutral when its running.
Yes, I manually shifted through the gears and 5th looked good. The 93 Si doesn't have dentent balls in the housing like 96's and up. (It's a S20 B000.)
The new slider appears to be fully engaged. I did notice when I removed the main shaft from the shift fork that the 5th gear slider seemed to move a lot easier over the gear than the other gears.
One thing I am confused about is the honda parts shift fork diagram shows springs and balls, #8 and #13 in the diagram. Are these between the shift fork and the shaft where you can't see them?
Right now I have the main shaft disassembled. Once I have everything put back together, I will try everything manually again.

Thanks for your help
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What does the face of the 5th gear selector fork look like? This guy:

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If its worn out, it wont push/pull properly/fully
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Are you able to hold it in 5th, pushing on the gear lever hard? Or is it still able to forcibly push itself out of gear, like with very strong force?
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