yessewey

iTrader: (2)

Hi everyone,

I'm having an issue with a rebuilt B16 transmission with a GSR 4th and 5th gear in a 99 Civic Si. The 3rd and 4th gear synchros were replaced with synchrotech synchros.

The problem I'm having is that now that it's installed it would only go into 3rd and 4th but won't go left and right to reach any other gear and now won't even go into 3rd or 4th.

Does anyone have any ideas or recommendations before I pull off the transmission and send it back to the shop that rebuilt it? Thanks for any input.

yessewey

iTrader: (2)

I also forgot to mention that this is with the car off and no fluid in there yet.

I had pretty much the same issue with the previous gsr transmission that was originally rebuilt for me. I'm not sure what parts were used from the gsr transmission on the B16.

Spiff671

Did it shift normally BEFORE the rebuild?

Sounds as if they did not install the shift change holder correctly. I think the tranny needs to be opened up again. Who rebuilt it? Were they familiar with the B-series transmisisons?

If it doesn't shift right, don't force anything. Take it back or have a Honda expert fix it. If you lived in Alaska I would offer my assistance!

Good luck!

yessewey

iTrader: (2)

I never ran the B16 transmission but the GSR did up until one night that I was shifting into 2nd and it wouldn't go in at all even though I had no previous issues with 2nd just a 3rd gear grind. That's when I pulled it and had it rebuilt and when I received it and installed it realized that it didn't want to go left or right while in neutral and would make a popping sound when I pushed it out of my garage so I had to pull it again.

I took it back and the person who had rebuilt it had me buy another transmission as he wasn't sure what the exact issue was and didn't want me to keep throwing money at it plus the casing was cracked and had been re-welded.

That's when I bought the B16 and he rebuilt that one as it also needed rebuilding and built a working transmission from both and used the B16 housing. I just installed it today and behold I have nearly the same issue as before. I don't know if there's anything that I'm missing that I need to check or if I should just go ahead and pull it again.

The person that fixed it I would consider a Honda expert, but I'm thinking that transmissions may not be his forte.

Spiff671

Based on the symptoms you mentioned, it seems as if the interlock needs to be replaced. Luckily, it isn't expensive at all ($17.63). The part number is 24432-P21-000. You can order a new OEM one here: http://www.oemacuraparts.com/parts-c...ft-holder-dohc

It is item number 6... 'Interlock'.. it's the same for the GSR, B16, and LS transmissions.

It is very common for the interlocks to get bent out of shape and cause shifting problems. I have rebuilt numerous B-series trannies with this issue. If you have a little more money to spend, you could also replace the 'Change Holder Assembly' — item number 4, p/n 24400-P21-020.

Here are some examples of bent interlocks:
https://honda-tech.com/forums/drag-racing-36/transmission-interlock-2433293/
As you can see, the two metal tabs are bent and no longer line up. This will prevent shifting LEFT to RIGHT.

As for not being able to shift into 3rd and 4th — there are a few things that need to be inspected:
1) The 3-4 shift fork for straightness
2) The entire Shift Change Holder Assembly for straightness and clearance specs.
3) 3-4 Synchro hub and Sleeve for spline wear/binding
4) Shift Rod may be bent (the rod that sticks out of the trans and attaches to the linkage) **this is rare, since the shift rod is fairly thick**

Try to get your hands on a Factory Service Manual so you or your mechanic can reference the clearance specs. It also contains detailed rebuild procedures. I can email you a PDF version if you need one. Just PM me your email address.

I hope I helped.

David @ Synchrotech

iTrader: (1)

Great reply!!

yessewey

iTrader: (2)

Wow, you've helped and then some. Thanks so much.

However, I do feel the need to mention that both the Interlock and Shift Change Holder Assembly have been replaced as I am looking at some pictures I received from the person rebuilding the transmission showing me how both those parts were bent.

He also mentioned he replaced the shifter cage (i believe it was called) and said he realized what was wrong with my GSR transmission in a voicemail when he was using both transmissions to build me the working one.

I am feeling a bit inclined to look further into the Shift Rod as he stated that he was able to get into every gear before he turned it over to me since he didn't check it the first time with the GSR transmission. Is there any way to check the Shift Rod without removing the transmission?

Caspersej1

So did you ever find out what the actual problem was?

yessewey

iTrader: (2)

I did not, at least not based on what I described here. I had further issues later which turned out to be some bad luck with a Quaife LSD (somehow I would get their one-off defective unit), but I don't think I had it at this time.

Im pretty sure I was too broke to afford an LSD at the time though so I don't think that was the issue with that particular transmission. I ended up giving up on it and buying another one.