What could be the cause of this? I had a new 3/4 slider assembly installed in my B16 tranny and GearSpeed Syncro's and after about 1500 miles I noticed a nice grind in the 3/4 shift. It only seems to do it when I short shift a gear or I am lugging 3rd and shift into 4th, it also does it when I downshift from 5th to 4th sometimes just driving normally. I have not really had a chance to shift any higher than 8k in 3rd as it is just blazing tires at that point and I just shift into 4th. I thought maybe I wasnt pushing the clutch all the way down but I definately am. Could the slave be the cause of my problem? It only does it in the 3/4 so I am assuming the issue is isolated in that area. The fluid is GM Syncromesh TIA

 

Anybody?? Problem seems to be getting worse, did it a **** load today just driving normally

 

did you personally install these? or did you take it somewhere to be installed? do you know if they scuffed the friction cones on the gears?

hmmm makes me wonder that it would start doing it after 1500 miles...either the friction cones are too shiny and there is not enough gear brake. or the synchro spring over 3rd gear synchro is squared off or has broken off. either not enough friction (on friction cone) and/or pressure when the sleeve bumps the synchro spring because it's no longer round or has broken off.

 

No I did not assemble the tranny, all I know is that whole assembly is new and the last thing I thought in the world was I would be getting a grind in these 2 gears, when I have a whole new hub/slider assembly and Carbon Coated Syncro's, I spent a good amount on money on this tranny hoping I wouldnt have to worry about it for the rest of the year but I guess not.

 

let me ask this...did you have the slightest issue or hint of grinding on either 3rd or 4th before the install? and is it on 3rd shift only or 3rd and 4th shifts?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by not so civic &raquo;</TD></TR><TR><TD CLASS="quote">let me ask this...did you have the slightest issue or hint of grinding on either 3rd or 4th before the install? and is it on 3rd shift only or 3rd and 4th shifts? </TD></TR></TABLE>

I have never used this tranny before, so I dont know if it ground previously. I gave a friend 3 Gearsets and he picked what was good out of them and made me one tranny. My old 3/4 hub was screwed up so I just bought a whole new assembly from majestic and I bought the carbon 3/4/5 syncro's from gearspeed. It grinds going from 3rd to 4th and sometimes just driving normally from 5th to 4th.

 

How were the dog teeth on the 3/4 gears? If the sleeve was trashed, likely the cones on the dog teeth were too....

 

as long as you trust the installer and there was indeed a brand new sleeve/hub installed on 3/4 and carbon synchros...either the synchro springs are square (supposed to be round) and not bumping and catching to put pressure against the synchros, or it could be a worn and not new sleeve where the section of sleeve spines that protrude to hit the synchro springs are too far worn not letting them do there job. or like i said that the friction cones are shiny and slick.

ask the installer if he scuffed/deglazed the friction cones with sandpaper (kind of like surfacing a rotor or flywheel). you always want to do this when installing carbon synchros to maximize the gear braking when the sleeve puts pressure on the synchro spring which in turn forces the synchro against the friction cone in turn slowing the gear down.

the last carbon synchro set i installed i tested by hand to see if it was really necessary. the friction cones had normal glazing and wear from the brass oem synchros. you can always check the synchro to gear braking by hand by literally forcing them together by hand as you twist them against each other. more pressure and you should not be able to turn the two whatsoever or have good amount of resistance which is what you ultimately want. well without scuffing friction cones and twisting the new synchros, there wasn't enough gear braking at all. i was able to twist them easily with much force...then i scuffed (i normally use 800 grit to brake the glaze w/ circular hatching patern. some use small flap wheel) and then retried it which gives the braking plus the rougher surface would allow the carbon to form completely or break in surfaces.

so...ask the installer if he roughed the friction cones on gears 3, 4, and even 5 though there isn't a issue with 5 itself.

 

all of my gearsets were in good shape besides slider wear, if there was noticeable wear on parts that would affect the shifting cabability I dont think the parts would of been used, guess I will know for sure sometime this fall when I pull it out. I want to try to drain it and find some of the GM friction modified before I pull it out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by not so civic &raquo;</TD></TR><TR><TD CLASS="quote">as long as you trust the installer and there was indeed a brand new sleeve/hub installed on 3/4 and carbon synchros...either the synchro springs are square and not bumping and catching to put pressure against the synchros, or like i said that the friction cones are shiny and slick.

ask the installer if he scuffed/deglazed the friction cones with sandpaper (kind of like surfacing a rotor or flywheel). you always want to do this when installing carbon synchros to maximize the gear braking when the sleeve puts pressure on the synchro spring which in turn forces the synchro against the friction cone in turn slowing the gear down.

the last carbon synchro set i installed i tested by hand to see if it was really necessary. the friction cones had normal glazing and wear from the brass oem synchros. you can always check the synchro to gear braking by hand by literally forcing them together by hand as you twist them against each other. more pressure and you should not be able to turn the two whatsoever or have good amount of resistance which is what you ultimately want. well without scuffing friction cones and twisting the new synchros, there wasn't enough gear braking at all. i was able to twist them easily with much force...then i scuffed (i normally use 800 grit to brake the glaze w/ circular hatching patern. some use small flap wheel) and then retried it which gives the braking plus the rougher surface would allow the carbon to form completely or break in surfaces.

so...ask the installer if he roughed the friction cones on gears 3, 4, and even 5 though there isn't a issue with 5 itself.</TD></TR></TABLE>

thanks for this post, yes I trust the installer but I have a feeling the things you mentioned were not done. If this is necessary I would think that Gearspeed should include a note with their products about this. I have grinded it enough already that I know something needs to be replaced again in there.

 

yeah it's actually only mentioned in their install article in a past honda tuning mag...maybe some few online write ups, if any, mention or even know to hand check the gear/synchro braking. common sense comparing to a rotor or flywheel would indicate there would be a 'break in' if you will on these type synchros. maybe send them a note about including that small instruction with their 3-5 sets.

*my past two recent trans that i worked on with grinds had absolutely perfect hub and sleeves (like new). synchros even looked unworn at the mesh teeth. they both came down to glazed friction cones...just picture glazed flywheel/pressure plates and brake rotors...they just loose trememdous amount of friction stopping abilities.

*it's not always necessary though and would truly depend on the friction cone surface and how worn it is. it doesn't always need to be done, but should in any case imo. that's why regardless, i check the braking by hand.


Modified by not so civic at 4:09 PM 7/13/2008

 

the sooner you fix this, the better chance your sleeve synchro mesh is still pointy. and you would hopefully just need to break the glaze on the cones. the very last civic '04 i did was grinding for a good month to two months and it was surprising to see the hub splines and sleeve mesh were damn near perfect and the synchro springs were perfectly round. but just checked the braking by hand and it was slipping majorly and this is the grinding because it can't match speeds.

 

whats up fellas, i actually built bens trans.

i myself have the gs carbon coated syncros in my trans, and never scuffed the friction cone and never had an issue with that.

ben you got pm.
the new sleeve hub did go in.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostedcivicsir &raquo;</TD></TR><TR><TD CLASS="quote">whats up fellas, i actually built bens trans.

i myself have the gs carbon coated syncros in my trans, and never scuffed the friction cone and never had an issue with that.

ben you got pm.
the new sleeve hub did go in.</TD></TR></TABLE>

I know it went in, I have no worries about that mikey.