Ok, JDM Y1 LSD transmission, coupled to a JDM type-R engine, the whole thing in a 91 hatch body.

The 3rd gear started to grind up to a point it would always grind at high RPM under acceleration only on the track.

Took the tranny out, brought it to a shop to have the 3rd syncro replaced. Back into the car, drove it for 500 miles under very little stress (new cluth brake in at the same time). Then, first time on the track, after 15 minutes, the problem comes back. Exactly the same, 3rd gear, only during hard accelerations.

Anybody has a clue as to what to check? Shift linkage, although it worked fine for over 6 months of use. Someone told me to check the oil. I'm using amsoil racing oil and I've been told honda syncros need some friction to work properly. Might try honda oil.

So what are your guesses?

 

Oil? Its ok if you need it on the street... definately dont use synthetic oil in the gearbox, its too slippery. The fluid cushions the synchros.

Try a good gear fluid. I'm using Motul Gear300, and IMHO Honda MTF sucks ***. Its nothing special 10W30 motor oil with a few additives. Redline MTF, NEO are also good.

 

Did the shop give you back the old (bad) synchro, I thought you could not get synchros for the JDM B-series cable transmissions. Is it possible they tried to fix the old synchro? Just a thought.
BTW, does anyone know where to get a third gear synchro for a JDM B-series cable trans, I have four of them that need a third gear synchro!

 

It's a shop with a good reputation that did it, but you still never know.

I was told syncros from a 94-96 delsol with B16 engine would fit. The shop that dit it however told me there are 3 different sets of syncros that can be found in those trannies. I believe they used 90-94ish integra syncros in mine.

I did get the old parts back, although I don't seem to have the brass part that actually makes contact.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Oil? Its ok if you need it on the street... definately dont use synthetic oil in the gearbox, its too slippery. The fluid cushions the synchros.

Try a good gear fluid. I'm using Motul Gear300, and IMHO Honda MTF sucks ***. Its nothing special 10W30 motor oil with a few additives. Redline MTF, NEO are also good.</TD></TR></TABLE>

thats a pretty bold statement to make. It's actually more along the lines of a non-detergent 5w-30 Honda oil....with extra additives to aid in longevity. Honda designed the MTF to work with the tranny....it just needs to be changed more often when racing. Sure, other lubes such as GM synchromesh may get rid of grinds..... but the tranny feels really notchy and shouldn't be used until the tranny is at a certain point

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by charjacq &raquo;</TD></TR><TR><TD CLASS="quote">It's a shop with a good reputation that did it, but you still never know.

I was told syncros from a 94-96 delsol with B16 engine would fit. The shop that dit it however told me there are 3 different sets of syncros that can be found in those trannies. I believe they used 90-94ish integra syncros in mine.

I did get the old parts back, although I don't seem to have the brass part that actually makes contact. </TD></TR></TABLE>

well, usually it's the synchro sleeves that goes bad before the ring, but the ring still does go bad. I could be concerned if you did not get back the ring as well as everything else

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote"> IMHO Honda MTF sucks ***. .</TD></TR></TABLE>

It's all we use, unless using an aftermarket diff (clutch type).

 

I think I did get all the parts back, I'm just unsure as what each part does. I've looked it up in the haynes and everthing seems to be there. I don't think the problem is related to the syncro, maybe the selecting fork, oil, shift linkage

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">...definately dont use synthetic oil in the gearbox...

...Redline MTF, NEO are also good.</TD></TR></TABLE>

This contradicts itself... which is it. And FWIW I refuse to believe Honda MTF "sucks ***."

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kb58 &raquo;</TD></TR><TR><TD CLASS="quote">
And FWIW I refuse to believe Honda MTF "sucks ***."</TD></TR></TABLE>

good, because it doesn;'t

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Emerika &raquo;</TD></TR><TR><TD CLASS="quote">

good, because it doesn;'t</TD></TR></TABLE>

I'll second that.

http://www.bobistheoilguy.com has some VAO and UAOs on it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keithg &raquo;</TD></TR><TR><TD CLASS="quote">Did the shop give you back the old (bad) synchro, I thought you could not get synchros for the JDM B-series cable transmissions. Is it possible they tried to fix the old synchro? Just a thought.
BTW, does anyone know where to get a third gear synchro for a JDM B-series cable trans, I have four of them that need a third gear synchro!</TD></TR></TABLE>

I'm ordering some synchros for my JDM S1 cable, her's a post I made

https://honda-tech.com/zerothread?id=890165

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Emerika &raquo;</TD></TR><TR><TD CLASS="quote">thats a pretty bold statement to make. It's actually more along the lines of a non-detergent 5w-30 Honda oil....with extra additives to aid in longevity. Honda designed the MTF to work with the tranny....</TD></TR></TABLE>

And honda designed their motor oil and brake fluid to use in the car. Are you using those for track use? There's nothing special about honda MTF.

I would not use a synthetic motor oil in the gearbox. Synthetic base gear oil will be fine, and thats what i'm using.

I was changing the MTF every other track weekend or even every weekend and it always felt like crap after it hit the track for a few sessions. Maybe there's something wrong with my gearbox, but the trans shifts a hell of alot better on and off track with the Motul fluid, and I should be able to leave it in alot longer.

UOA for Honda MTF: http://theoildrop.server101.co...00100

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Titanium -0
Silver - 0
Copper - 0
Lead - 0
Tin - 0
Aluminum - 0
Nickel - 0
Iron - 0
Chromium - 0
Sodium - 0
Boron - 1
Silicon - 0
Water - 0
Soot - 0
Glycol - 0

Moly - 0
Magnesium - 11
Calcium - 2652
Barium - 0
Phosphorous - 1401
Zinc -1564
Visc@100C - 11.26
Tan mg/g - 0.30</TD></TR></TABLE>

 

if it was a good shop, they should have inspected the shifter forks. did they? if one of the forks was bent or cracked, it can cause this. this was especially true on D series trannies.....

good luck.

todd

ps i have about 20k + track miles on my race honda, and have always used 10w-40 Durablend Semi-synth motor oil in my trannies. zero tranny probs. thats just my experience...

 

Every other track weekend? IMO, thats WAY too often.

 

Yes, they have inspected the shifter fork and all parts. The gears itself seemed to be slightly damaged, although I do not believe this would be causing the grind in 3rd. I am about to drain the Amsoil 0W30 and put some honda MTF in. We'll see how it goes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FAST4DR &raquo;</TD></TR><TR><TD CLASS="quote">Every other track weekend? IMO, thats WAY too often.</TD></TR></TABLE>

After 2 weekends it was notchy, felt like crap and grinding downshifting into 2nd gear.

Will sez he changes after every track weekend.

 

As stated above, it is more than just a synchro. You have to also look at the selector hub(or sleeve) as well as the actual engagement teeth on the gear itself. Just changing the synchros can sometimes be like putting a bandaid on something that you know damn well needs stitches!! Yes it will hold but, not for long!!!! If you feel that you need just the synchros, we have them available with a carbon coating for 3rd 4th and 5th @ $100 shipped for the three synchro rings. Check out our website as well.


Modified by GearSpeedEF9 at 6:47 PM 6/9/2004

 

If you need the full synchro set with the synchro hubs for the Y-1, look here:

https://honda-tech.com/zerothread?id=204245

You'll probably have to email Dave to get a reply - and ask real nice, as it's been awhile since he offered.

Also, I have not had a chance yet to rebuild my Y-1, but I do have a 3rd gear set (these are the actual gears for both the mainshaft & countershaft).
I imported them from Japan. New in bag. IM if you're interested.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by charjacq &raquo;</TD></TR><TR><TD CLASS="quote">Yes, they have inspected the shifter fork and all parts. The gears itself seemed to be slightly damaged, although I do not believe this would be causing the grind in 3rd.</TD></TR></TABLE>if the synchros are worn enough, they can make the actual gears start to wear as well, becuse on some gears they have a separte section of teeth that looks similar to a synchro and they can wear down too, ask me how I know.... and the parts list gets very costly when you need to replce gears as well as synchros becuse you didnt fixed it sooner....