signs of bad synchros?

[bryant2482]

what are common signs of bad synchros in a fs5w71b?

[DanielC]

Before you condemn syncros, make sure your clutch is adjusted properly.

[ggzilla]

crunch-crunch when shifting 2, 3 or 4 gear, even though the clutch pedal is fully depressed --- that's why it is important to check the clutch adjustment first.

[datzenmike]

On a 720 there isn't much to adjust. The pushrod connecting the peddle to the clutch master should have about 2mm or 1/16" of free play. Other than that check that the master hasn't gone dry. If it's empty you will have to bleed the system of any trapped air. If low or empty you have to ask yourself where it went. Time to check for leaks in the system.

[bryant2482]

well there isnt any crunch feeling when shifting. i was just wondering if bad syncros made noises. im buying the bearing rebuild kit this weekend and wasnt sure if i should get the one with syncros. but i think my syncros are good then

[wayno]

well there isnt any crunch feeling when shifting. i was just wondering if bad syncros made noises. im buying the bearing rebuild kit this weekend and wasnt sure if i should get the one with syncros. but i think my syncros are good then

 

I had a bad second gear syncro, everytime I shifted into second gear it would grind unless I shifted really slow, it did not grind in any other gear, that would be a sign of a bad syncro, the odds of all of them grinding and the syncros being bad is very low, it would likely be another issue.

Now the odds of you losing a lower cluster gear bearing that is making noise is high, quit driving it, otherwise you might need a new transmission if it binds/catches and explodes.

[ggzilla]

If you have any other noise, get out and check the transmission lube level now! With proper level of 90W a slightly noisy one can last a long time.

[datzenmike]

Change second gear synchro. Most commonly hammered gear.

[Z-train]

If you can't shift thru the gears WITHOUT the clutch,you have a synchro issue.

[blackwolf]

ive had my trany rebuild but it still grinds a little in 2nd unless i shift really slow like wayno said but its done this since my parents bought it new off the lot it also backfires in every gear no one knows why but still runs great and scares the crap out of ppl when its cold and backfires lol

[ggzilla]

it also backfires in every gear no one knows why

That's easy to fix. Take it to an old mechanic -- he'll know how to fix it even if all the modern mechanics do not.

[Stupid_fast]

 

Now the odds of you losing a lower cluster gear bearing that is making noise is high, quit driving it, otherwise you might need a new transmission if it binds/catches and explodes.

 

Sooooo if my bearings growl loudly and make a horrid scraping noise taking off from 1st I should probably not be pushing them at 6,000RPM? Uhhhh Okay.

[ggzilla]

You can change the bearings now. They are only a few dollars. Or keep driving it until it breaks, then replace the entire transmission. That's what I do they are cheap.

[datzenmike]

Sooooo if my bearings growl loudly and make a horrid scraping noise taking off from 1st I should probably not be pushing them at 6,000RPM? Uhhhh Okay.

 

I would check the oil. If low replace.

[Stupid_fast]

You can change the bearings now. They are only a few dollars. Or keep driving it until it breaks, then replace the entire transmission. That's what I do they are cheap.

I have a new trans to drop in ... just abusing it and getting better using an old gearbox in the meantime. Learning to extend the life of a bad gearbox while driving it hard is interesting.

I would check the oil. If low replace.

Oil has hardly 6000 miles on it ... its full.

 

I don't mean to threadjack ... back to topic.