Grinding in 2nd?

[pkwon131]

Hey guys, just picked up my new to me FL5 last week. Love the car, however i noticed intermittently, there is a grind going into second. It could be either upshifting from first, or downshifting from third. It almost sounds like a synchro grind. Only happens if i'm shifting aggressive, but still intermittent. I've seen some issues from the FK8 (honda tech forums) that are similar.

Anyone having similar issues?

Thanks

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[Higgs Boson]

mine has done it twice when I was lazy with the clutch pedal. user error.

 

[jtlctr]

I’ve never had a proper grind in the FL5, but past experience with Hondas has taught me to shift more carefully from 1-2. However, one thing I have experienced is occasionally (usually the same exact spot) when I downshift from 3rd to 2nd before making a turn, I can feel a little roughness as 2nd is engaging. It feels more like a syncro thing, I guess.

 

[Websitesdown]

I’ve never had a proper grind in the FL5, but past experience with Hondas has taught me to shift more carefully from 1-2. However, one thing I have experienced is occasionally (usually the same exact spot) when I downshift from 3rd to 2nd before making a turn, I can feel a little roughness as 2nd is engaging. It feels more like a syncro thing, I guess.

There's a pedal mod that I just read about for the clutch pedal, and it stops the clutch from overextending during higher rpm shifting which will cause the plate to start collapsing a little if that happens. All it does is back your pedal engagement bottom off a little with a spacer. Apparently if you shift when your 5/6 pedal engaged rather then %100 to the floor during higher rpm shift, it won't happen.

I read this and it finally makes sense to me. Apparently, a stiffer rear motor mount will help as well a little. I didn't have this issue in my 19 SI that I had all modded out with 320 whp so, I noticed it right away with my 24 fl5.

 

[jtlctr]

There's a pedal mod that I just read about for the clutch pedal, and it stops the clutch from overextending during higher rpm shifting which will cause the plate to start collapsing a little if that happens. All it does is back your pedal engagement bottom off a little with a spacer. Apparently if you shift when your 5/6 pedal engaged rather then %100 to the floor during higher rpm shift, it won't happen.

I read this and it finally makes sense to me. Apparently, a stiffer rear motor mount will help as well a little. I didn't have this issue in my 19 SI that I had all modded out with 320 whp so, I noticed it right away with my 24 fl5.

I saw that post too. I may give that a shot and see what happens. Oddly, when I feel the roughness, it’s when the revs are low. I’ll have to do some experimenting with different engine speeds when making that downshift to see exactly when it happens.

 

[Websitesdown]

I saw that post too. I may give that a shot and see what happens. Oddly, when I feel the roughness, it’s when the revs are low. I’ll have to do some experimenting with different engine speeds when making that downshift to see exactly when it happens.

I tried shifting stand still to feel it out and it feels better going in to first which I usually feel. I've done it going into second at slower speeds and it's fine. Second gear getting on it will be harder to test.

 

[cryptolime]

i get a rough downshift into 2nd in my Si too if i let the rpms drop too much. what i imagine happening is that the trans needs to be spinning to circulate fluid and it's causing a slightly rougher shift at lower rpms. that, and seems to happen more when it's hot. could be the thin MTF.

 

[Websitesdown]

i get a rough downshift into 2nd in my Si too if i let the rpms drop too much. what i imagine happening is that the trans needs to be spinning to circulate fluid and it's causing a slightly rougher shift at lower rpms. that, and seems to happen more when it's hot. could be the thin MTF.

I'll give you this, I don't remember having issues in my 10th gen si downshifting to second but, I blew out fourth gear early on with that car " I wasn't even getting on it when it happened at all " and replaced all the gears with a racing gear set " PPG gearset " which consisted of 1st through 4th gears, fairly early on in ownership of the car / once I dumped money into boltons for it.

Either way, I honestly think it's just not set percentage wise within tolerance close enough at this point honestly from the factory sometimes, clutch pedal travel wise.

 

[Spart]

could be the thin MTF.

Folks have been using ACDelco Synchromesh 10-4014 to help with second gear grind in Hondas of various stripes for a long time now.

It would be the first thing I would try if this happened to me (hasn't yet.)

Only happens if i'm shifting aggressive, but still intermittent.

Since you mentioned specifically aggressive shifting, it may also be worth your time to explore deleting the CMC damper. It causes a delay between pedal movement and clutch fork movement, and could be one component of the issue.

But try the fluid first.

 

[jtlctr]

i get a rough downshift into 2nd in my Si too if i let the rpms drop too much. what i imagine happening is that the trans needs to be spinning to circulate fluid and it's causing a slightly rougher shift at lower rpms. that, and seems to happen more when it's hot. could be the thin MTF.

This, or possibly the auto rev match is slightly off (I always have it on) at this point.

 

[jtlctr]

Folks have been using ACDelco Synchromesh 10-4014 to help with second gear grind in Hondas of various stripes for a long time now.

It would be the first thing I would try if this happened to me (hasn't yet.)



Since you mentioned specifically aggressive shifting, it may also be worth your time to explore deleting the CMC damper. It causes a delay between pedal movement and clutch fork movement, and could be one component of the issue.

But try the fluid first.

I have the AC Delco fluid in my trans now. I have noticed this phenomenon with both the stock fluid and the Delco.

I’m going to try downshifting at a higher speed and then by manually rev matching to see how it effects this.

 

[T41WN.1]

Hey guys, just picked up my new to me FL5 last week. Love the car, however i noticed intermittently, there is a grind going into second. It could be either upshifting from first, or downshifting from third. It almost sounds like a synchro grind. Only happens if i'm shifting aggressive, but still intermittent. I've seen some issues from the FK8 (honda tech forums) that are similar.

Anyone having similar issues?

Thanks

I found that if you are shifting up from 1st to 2nd at high rpm's (5000ish) theres a chance that it grinds. I've found that its also harder to smoothly shift into compared to all the other gears.

But if you stay aware that it may grind and shift it more carefully then you shouldn't grind. I grinded it once and it pained my soul and havent grinded 2nd since.

 

[Websitesdown]

If he is shifting aggressively say at high rpms, the issue I have brought forth here is probably what his issue is which I believe is mine as well. The clutch pedal is overextending a tiny bit thus closing a little and bam, he grinds.

From what I have read in other communities as well, this is a known issue with manual transmissions for a very long time in racing communities which leads to people only depressing their clutch 5/6 of the way during faster racing / shifting.

It's a tolerance threshold issue that they need to account for better at the manufacturing plants in regard to clutch pedal adjustment.

They could make the tolerance tighter and make it within +/- 3% and fix the issue at the plant.

 

[pkwon131]

Folks have been using ACDelco Synchromesh 10-4014 to help with second gear grind in Hondas of various stripes for a long time now.

It would be the first thing I would try if this happened to me (hasn't yet.)



Since you mentioned specifically aggressive shifting, it may also be worth your time to explore deleting the CMC damper. It causes a delay between pedal movement and clutch fork movement, and could be one component of the issue.

But try the fluid first.

Appreciate this, will definitely try to replace the fluid, i got the car with 16k and did my trans fluid in my previous car (wrx) at 15k, so will definitely be giving this a try along with the cmc damper.

Crossing fingers, but if it does persist, i'll try and see if Honda will warranty the trans

 

[KushySoles]

mine has done it twice when I was lazy with the clutch pedal. user error.

Happened to me twice also, while being lazy. I release the clutch slower now and it never happened again.

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