Possible to change syncros? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

mmdb · 05-20-2003, 02:10 PM

How is the difficulty changing the syncros for a manual tranny and how much am i looking at? Cuz 3rd gear grinds pretty bad w/o double clutching.

adey · 05-20-2003, 02:13 PM

As I understand it, synchro changing means a tranny rebuild, which means lots of money.

I'd guess somewhere in the $600 range including labor... up to maybe $800, using OEM parts and doing it at a not-too-ghetto place.

Sucks to have a 10 year old car when it comes to trannies.

Dousan_PG · 05-20-2003, 02:21 PM

Quote:

Originally posted by adey
As I understand it, synchro changing means a tranny rebuild, which means lots of money. I'd guess somewhere in the $600 range including labor... up to maybe $800, using OEM parts and doing it at a not-too-ghetto place. Sucks to have a 10 year old car when it comes to trannies.

trannies dont care about how old your car is only how much money you have...oh wait......er.......

buy a new transmission! its cheap! just change them. even if you have a shop do it its cheaper then a rebuild im sure. KAs are easy to find too!

adey · 05-20-2003, 02:54 PM

Quote:

Originally posted by dousan36
buy a new transmission! its cheap! just change them. even if you have a shop do it its cheaper then a rebuild im sure.

Not if you're like me... I'm looking at the HKS tranny... :drooooool: of course, they only make trannies for SR20DET and RB26DETT (afai remember)... so I'd have to get an SR first, but I guarantee you that's one somewhat-OEM (but not really) tranny that won't be cheap.

kandyflip445 · 05-20-2003, 04:24 PM

Rebuilding a manual tranny is actually pretty easy if you're pretty good at mechanical stuff. Especially a RWD tranny. But if you don't have the time, money(for parts), or know-how then just buy a new one like they said. The hardest part for me is keeping track of the damn little detent balls. It's good to have one of those little magnetic dishes around. The only thing you would need to replace (assuming everything wore like it was supposed to) is the 'blocking ring' or I think my FSM calls them 'baulking rings' , anyways, those are the things that get shoved by little inserts onto a cone shaped part of the speed gear. They are usually made of a lot softer material than the speed gear and that is what is supposed to wear.

mmdb · 05-20-2003, 05:19 PM

would those speed gears be the syncros? It kinda of sounds like it. Btw how long did it take you to do that and how much do you think the parts cost? Thanx!

chairmnofthboard · 05-21-2003, 01:31 AM

just get anpther trans. my friend opend his KA trans, and it was a biatch to reassemble, as soon as you crack the trans open, shims, washer, and lil parts fall out, and good luck putting it back together

FYI, a FWD honda trans is the EASIEST to rebuild, super simple. take about 20 minutes to an hour to rebuild one, if all the parts are on hand.

Xavier

mmdb · 05-21-2003, 02:18 AM

damn... i wish i had a honda... lol... nothing wrong with 'em i drove 'em once... just not a REAL sports car : )

GotDriftS14 · 05-21-2003, 06:15 AM

synchros and speed gears are two totally different things.

in order to change just the synchronizer blocking rings, you would have to take down and completely disassemble the transmission and then replace the rings. also, it is recommended to replace most (if not all) of the bearings and oil seals and what not when taking a transmission apart. if you do it yourself, it shouldnt be all that expensive.

getting alot of gear clash in 3rd sounds like it is most likely a worn blocking ring. if you have a FSM, it should show you the recommended specs and clearances for the transmission parts, so to check for wear on the ring, press the blocking ring against the 3rd speed gear and check the clearance between then with a feeler guage. if the blocking ring is worn, then the clearance between the ring and the speed gear will be BELOW the recommended specs. you should then take the whole thing apart and replace that ring. while you're in there, take a look at the other rings and speed gears and check for any damage. then have fun putting it all back together and test driving, hehe. good luck.

kandyflip445 · 05-21-2003, 06:28 AM

GotDrifts14 has got it exactly right. Your bearings won't need to be replaced unless they are in bad condition. If the don't have any scoring or anything then replacing them would be a waste of money. Also, if you open your tranny and sh*t just falls out then it was REALLY messed up or you didn't do it right. IMO I think old 4-spd's are easier than Honda trannys.

A syncronizer is a combination of parts that bring the gears up to speed so that you can shift. There is the blocking ring, inserts, sleeve, and depending on the type there could be other parts. The shifter moves shift forks which are wraped around the sleeve. Each sleeve is used for 2 gears 1-2, 3-4, 5-R. When you shift into a gear the fork moves the sleeve toward the speed gear. little inserts force the blocking ring onto the speed gear making it match speeds. Then the sleeve moves all the way over locking the output shaft(well not exactly but simplifing)with the speed gear. It's a LOT easier to understand if you rebuild a tranny. But if you haven't before get someone who knows what they are doin to help you out.

P.S.- If some of the stuff doesn't make sense then just ask and I'll try to clarify. I've been runnin on 2hrs of sleep since yesterday night....

Chew Slice · 05-21-2003, 09:56 AM

what's the average price I'd be looking at if I wanted to get a new tranny?

chairmnofthboard · 05-21-2003, 12:15 PM

you think an old 4 spd is easier?

lets see. honda trans

#1 about 12-15 14mm bolts opens trans
#2 remove sap ring
trans is now open
#3 3 12mm blolts removes all shift forks
both shafts & diff can be pulled out
#4 22-24mm bolt on top of shafts, and
all gears, syncs, etc comes apart.

thats pretty easy, your turn how easy is an old 4 spd. LOL

PS just get another trans.

talk to you guys later
Xavier

*transient* · 05-21-2003, 12:25 PM

also, what about rebuilding a tranny? I've got a CA18DET coming and i'm going to have my old (busted) ka tranny here doing nothing. I was thinking about rebuilding it and selling it, or possibly trying to make it bulletproof and then swaping it for use with the CA18DET. If I remember correctly, you can change the bellhousing so it will fit... I could definately be wrong there though.

Edit: Meant to ask what the cost was in rebuilding a tranny, if I was to do it myself.

GotDriftS14 · 05-22-2003, 12:28 AM

i have to agree that the 4 speed is probably as easy as they come. i have also put together an old 3 speed Muncie that was pretty damn easy. for the most part, i dont really like dealing with transaxles, and RWD transmissions are easier for me. i've never taken apart/ put together a KA tranny, but ive done a toyota 5 speed and i can't imagine that it would be too much different. its not that hard to rebuild, but have some help from someone who knows about transmissions and have some type of manual so you make sure you are putting things together the right way.

kandyflip445 · 05-22-2003, 12:50 PM

Organization is key to rebuilding a tranny. Price is something you'd have to look up. It depends on what is worn and what you lose when rebuilding it.

If you're doin it yourself I'd look in to getting the blocking rings and maybe the speed gears cryo-treated when they are out. At Performance Cryogenics it is $8.00/lb. You could also do all the little needle bearings but I wouldn't bother with it. You'd probably lose most of them trying to get them done. The other bearings however may be worth cryo-treating.

05-20-2003, 04:24 PM	#5
kandyflip445 Post Whore! Join Date: Sep 2002 Location: Arden, NC Age: 40 Posts: 4,460 Trader Rating: (1) Rides Gallery: kandyflip445 Feedback Score: 1 reviews	Rebuilding a manual tranny is actually pretty easy if you're pretty good at mechanical stuff. Especially a RWD tranny. But if you don't have the time, money(for parts), or know-how then just buy a new one like they said. The hardest part for me is keeping track of the damn little detent balls. It's good to have one of those little magnetic dishes around. The only thing you would need to replace (assuming everything wore like it was supposed to) is the 'blocking ring' or I think my FSM calls them 'baulking rings' , anyways, those are the things that get shoved by little inserts onto a cone shaped part of the speed gear. They are usually made of a lot softer material than the speed gear and that is what is supposed to wear. __________________ My 240 vBgarage

05-21-2003, 01:31 AM	#7
chairmnofthboard Zilvia Member Join Date: Apr 2003 Location: So Cal Age: 47 Posts: 262 Trader Rating: (0) Feedback Score: 0 reviews	get another trans just get anpther trans. my friend opend his KA trans, and it was a biatch to reassemble, as soon as you crack the trans open, shims, washer, and lil parts fall out, and good luck putting it back together FYI, a FWD honda trans is the EASIEST to rebuild, super simple. take about 20 minutes to an hour to rebuild one, if all the parts are on hand. Xavier

05-21-2003, 06:15 AM	#9
GotDriftS14 Zilvia Junkie Join Date: Dec 2001 Location: San Jose Age: 42 Posts: 556 Trader Rating: (0) Feedback Score: 0 reviews	synchros and speed gears are two totally different things. in order to change just the synchronizer blocking rings, you would have to take down and completely disassemble the transmission and then replace the rings. also, it is recommended to replace most (if not all) of the bearings and oil seals and what not when taking a transmission apart. if you do it yourself, it shouldnt be all that expensive. getting alot of gear clash in 3rd sounds like it is most likely a worn blocking ring. if you have a FSM, it should show you the recommended specs and clearances for the transmission parts, so to check for wear on the ring, press the blocking ring against the 3rd speed gear and check the clearance between then with a feeler guage. if the blocking ring is worn, then the clearance between the ring and the speed gear will be BELOW the recommended specs. you should then take the whole thing apart and replace that ring. while you're in there, take a look at the other rings and speed gears and check for any damage. then have fun putting it all back together and test driving, hehe. good luck. __________________

05-21-2003, 06:28 AM	#10
kandyflip445 Post Whore! Join Date: Sep 2002 Location: Arden, NC Age: 40 Posts: 4,460 Trader Rating: (1) Rides Gallery: kandyflip445 Feedback Score: 1 reviews	GotDrifts14 has got it exactly right. Your bearings won't need to be replaced unless they are in bad condition. If the don't have any scoring or anything then replacing them would be a waste of money. Also, if you open your tranny and sh*t just falls out then it was REALLY messed up or you didn't do it right. IMO I think old 4-spd's are easier than Honda trannys. A syncronizer is a combination of parts that bring the gears up to speed so that you can shift. There is the blocking ring, inserts, sleeve, and depending on the type there could be other parts. The shifter moves shift forks which are wraped around the sleeve. Each sleeve is used for 2 gears 1-2, 3-4, 5-R. When you shift into a gear the fork moves the sleeve toward the speed gear. little inserts force the blocking ring onto the speed gear making it match speeds. Then the sleeve moves all the way over locking the output shaft(well not exactly but simplifing)with the speed gear. It's a LOT easier to understand if you rebuild a tranny. But if you haven't before get someone who knows what they are doin to help you out. P.S.- If some of the stuff doesn't make sense then just ask and I'll try to clarify. I've been runnin on 2hrs of sleep since yesterday night.... __________________ My 240 vBgarage

05-21-2003, 12:15 PM	#12
chairmnofthboard Zilvia Member Join Date: Apr 2003 Location: So Cal Age: 47 Posts: 262 Trader Rating: (0) Feedback Score: 0 reviews	you think? you think an old 4 spd is easier? lets see. honda trans #1 about 12-15 14mm bolts opens trans #2 remove sap ring trans is now open #3 3 12mm blolts removes all shift forks both shafts & diff can be pulled out #4 22-24mm bolt on top of shafts, and all gears, syncs, etc comes apart. thats pretty easy, your turn how easy is an old 4 spd. LOL PS just get another trans. talk to you guys later Xavier

05-20-2003, 02:10 PM	#1
mmdb Zilvia FREAK! Join Date: Apr 2003 Location: 240sx Posts: 1,558 Trader Rating: (20) Feedback Score: 20 reviews	Possible to change syncros? How is the difficulty changing the syncros for a manual tranny and how much am i looking at? Cuz 3rd gear grinds pretty bad w/o double clutching.

05-20-2003, 02:13 PM	#2
adey Post Whore! Join Date: Mar 2002 Location: Hong Kong Posts: 3,072 Trader Rating: (0) Feedback Score: 0 reviews	As I understand it, synchro changing means a tranny rebuild, which means lots of money. I'd guess somewhere in the $600 range including labor... up to maybe $800, using OEM parts and doing it at a not-too-ghetto place. Sucks to have a 10 year old car when it comes to trannies. __________________ Instagram: @SX180HKG

05-20-2003, 05:19 PM	#6
mmdb Zilvia FREAK! Join Date: Apr 2003 Location: 240sx Posts: 1,558 Trader Rating: (20) Feedback Score: 20 reviews	would those speed gears be the syncros? It kinda of sounds like it. Btw how long did it take you to do that and how much do you think the parts cost? Thanx!

05-21-2003, 02:18 AM	#8
mmdb Zilvia FREAK! Join Date: Apr 2003 Location: 240sx Posts: 1,558 Trader Rating: (20) Feedback Score: 20 reviews	damn... i wish i had a honda... lol... nothing wrong with 'em i drove 'em once... just not a REAL sports car : )

05-21-2003, 09:56 AM	#11
Chew Slice Zilvia Member Join Date: Jun 2002 Location: Vancouver, BC Age: 41 Posts: 215 Trader Rating: (0) Feedback Score: 0 reviews	what's the average price I'd be looking at if I wanted to get a new tranny?

05-21-2003, 12:25 PM	#13
transient Premium Member Join Date: Jun 2001 Location: Los Angeles, California Age: 41 Posts: 2,947 Trader Rating: (0) Feedback Score: 0 reviews	also, what about rebuilding a tranny? I've got a CA18DET coming and i'm going to have my old (busted) ka tranny here doing nothing. I was thinking about rebuilding it and selling it, or possibly trying to make it bulletproof and then swaping it for use with the CA18DET. If I remember correctly, you can change the bellhousing so it will fit... I could definately be wrong there though. Edit: Meant to ask what the cost was in rebuilding a tranny, if I was to do it myself. __________________ Learn everything you can, while you still have the chance. Last edited by transient; 05-22-2003 at 05:00 AM..

05-22-2003, 12:28 AM	#14
GotDriftS14 Zilvia Junkie Join Date: Dec 2001 Location: San Jose Age: 42 Posts: 556 Trader Rating: (0) Feedback Score: 0 reviews	i have to agree that the 4 speed is probably as easy as they come. i have also put together an old 3 speed Muncie that was pretty damn easy. for the most part, i dont really like dealing with transaxles, and RWD transmissions are easier for me. i've never taken apart/ put together a KA tranny, but ive done a toyota 5 speed and i can't imagine that it would be too much different. its not that hard to rebuild, but have some help from someone who knows about transmissions and have some type of manual so you make sure you are putting things together the right way. __________________

05-22-2003, 12:50 PM	#15
kandyflip445 Post Whore! Join Date: Sep 2002 Location: Arden, NC Age: 40 Posts: 4,460 Trader Rating: (1) Rides Gallery: kandyflip445 Feedback Score: 1 reviews	Organization is key to rebuilding a tranny. Price is something you'd have to look up. It depends on what is worn and what you lose when rebuilding it. If you're doin it yourself I'd look in to getting the blocking rings and maybe the speed gears cryo-treated when they are out. At Performance Cryogenics it is $8.00/lb. You could also do all the little needle bearings but I wouldn't bother with it. You'd probably lose most of them trying to get them done. The other bearings however may be worth cryo-treating. __________________ My 240 vBgarage