Crunching into gears - Warranty Issue

[GreenSpring 13]

Around a year ago I had to take my 86 into the dealership to get repaired because every time I shifted into 6th, especially when higher revs, it made a horrible crunch sound and felt as bad as it sounded. They replaced the 6th gear synchro and everything was good until a few months ago it's started happening when shifting into 4th. Never been track driven, tried changing the oil to millers oil and seeing the same results.  I have a service due so I'll see if I can get them to look at it then but I'm curious if anybody else has had this issue and if so, how did your dealership resolve it? New gearbox, new synchro?   TIA

[Deacon 1357]

5 minutes ago, GreenSpring said:

Around a year ago I had to take my 86 into the dealership to get repaired because every time I shifted into 6th, especially when higher revs, it made a horrible crunch sound and felt as bad as it sounded. They replaced the 6th gear synchro and everything was good until a few months ago it's started happening when shifting into 4th. Never been track driven, tried changing the oil to millers oil and seeing the same results.  I have a service due so I'll see if I can get them to look at it then but I'm curious if anybody else has had this issue and if so, how did your dealership resolve it? New gearbox, new synchro?   TIA

I had synchro's replaced due to crunching into 4th at high rpm

[Church 209]

I'd try adjusting clutch pedal travel/grab point/dead travel first (in case if clutch operation is at fault (for some cars were) and as it's relatively simple job). Just get two wrenches, 12 & 14, move seat back, steering wheel up and lie on floor on back, turning back with 14 screw on clutch engagement sensor switch, adjusting pedal, then readjusting sensor (used for gear indicator & cruise control) to new pedal position.

http://www.ft86club.com/forums/showthread.php?t=8040

I'd try both adding dead travel and taking out, by eg. counting turns.

Some warnings:

- don't look on just simpler checks like rowing through gears when stationary, engagement of 1st & reverse, and if you can start going w/o using accel. I wouldn't look also on clutch pedal height relative to others, only how it does or doesn't it's job. Do short drive and check engagment of all gears, 1-6, eg. i had a bit worse engagement of reverse-1st-2nd at one position, and a bit worse 5th & 6th at another position. Check all.

- don't dial out all dead travel. I usually leave some in. It's very easy to miss slight clutch drag, which will add extra wear on synchros, can make engagement of some gears worse especially when cold, and you may need some readjustment with clutch wear by time, and you'll cut quickly through stock flimsy & thin rubber clutch stopper (IIRC SU00301639) as you'll more often will press with extra force clutch pedal to disengage it "for sure", if with no dead travel & clutch bite point right near beginning of travel.

- i don't remember exactly, but it might be more PITA for RHD cars.

[GreenSpring 13]

1 minute ago, Church said:

I'd try adjusting clutch pedal travel/grab point/dead travel fiirst. Just get two wrenches, 12 & 14, move seat back, steering wheel up and lie on floor on back, turning back with 14 screw on clutch engagement sensor switch, adjusting pedal, then readjusting sensor to new pedal position.

http://www.ft86club.com/forums/showthread.php?t=8040

I'd try both adding dead travel and taking out, by eg. counting turns.

Some warnings:

- don't look on just simpler checks like rowing through gears when stationary, engagement of 1st & reverse, and if you can start going w/o using accel. I wouldn't look also on clutch pedal height relative to others, only how it does or doesn't it's job. Do also short drive and check engagment of all gears, 1-6, eg. i had a bit worse engagement of reverse-1st-2nd at one position, and a bit worse 5th & 6th at another position. Check all.

- don't dial out all dead travel. I usually leave some in. It's very easy to miss slight clutch drag, which will add extra wear on synchros, can make engagement of some gears worse especially when cold, and you may need some readjustment with clutch wear by time, and you'll cut quickly through stock flimsy & thin rubber clutch stopper (IIRC SU00301639) as you'll more often will press with extra force clutch pedal to disengage it "for sure", if with no dead travel & clutch bite point right near beginning.

- i don't remember exactly, but it might be more PITA for RHD cars.

I've done this and like you said, adjusted it so there is still a slight bit of dead travel just to ensure it's not always engaged (And yes, it definitely is a huge PITA for RHD cars haha). The 6th gear was crunching a bit even before I made the adjustments so it looks to have made no difference to the life of my synchros unfortunately

 

14 minutes ago, Deacon said:

I had synchro's replaced due to crunching into 4th at high rpm

They replaced all of them? From what they told me, they only replaced my 6th gear one. Have you had any problems with it since? It's horrible! Especially when downshifting, makes me cry hearing that noise! 

[Church 209]

BTW, i recently also had gearbox overhaul (for some rattle/some gear lashing noise, when car jumped on road defects). By dealership diagnosing some bearings needed to be replaced. Used chance of it getting disassembled to install verus/synchrotech carbon lined synchros & some clutch enhancements (also from verus) like forged clutchfork/pivot & latest toyota's/subaru TOB (SU003-07349 / 30502AA150)

Also if ever by chance one needs countershaft bearing that comes only together with gearbox casing ($1300) one can get bearing alone from mazda or nissan.

[Deacon 1357]

They replaced all of them? From what they told me, they only replaced my 6th gear one. Have you had any problems with it since? It's horrible! Especially when downshifting, makes me cry hearing that noise! 

Mine was the third to fourth shift at high rpm. If I remember correctly they replaced all the parts concerned with the third to fourth shift.

Sent from my ONEPLUS A3003 using Tapatalk

[Nails 18]

Mine did it from 2nd to 3rd, looking back I adapted my driving style to suit the gearbox so I could avoid it happening. I guess the question is, should you have to do that? On one hand, yes it is a sports car, on the other hand, it is not exactly a 500bhp exotic car that should need nursing through the gears. 

[Church 209]

On the even more point of views, it's relatively very cheap car, and not everybody have those issues. Increased quality, lessened failure rate .. if it will mean eg. +5k GBP base price, i'm not so sure it's right compromise to go for carmaker.