Tranny Grinds
11-06-06, 11:35 PM
#1
Tranny Grinds
Hey, my situation is this. My car will grind from 1st to 2nd, and 2nd to 3rd if I shift fast. I believe my synchros are worn. If that is true, where can I get replacement synchros? Or even, where can I get a good rebuilt at in Southern California?
11-07-06, 09:47 AM
#3
Senior Member
Join Date: May 2002
Location: San Diego, CA
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
If it's grinding up top near redline, you might be able to get away with new tranny fluid. I recommend Neo.
If it's grinding anywhere from 2-5k rpm range, than you syncros are definitey shot or on it's way out.
If it's grinding anywhere from 2-5k rpm range, than you syncros are definitey shot or on it's way out.
Trending Topics
11-07-06, 05:01 PM
#8
The low mileage tranny is attractive, but unfortunately there is a chance it will not work. I'll explain:
Worn synchros are *usually* the item blamed for rough shifting and clunky engagement. These parts are indeed the most influential, but 3 other things also have a major effect - wear on the gear teeth, wear on the clutch sleeve teeth, and choice of gear oil.
Using a true GL-4 gear oil (Redline MT-90 75w-90 stands out) is the best oil choice for synchros that aren't gripping well. The least effective gear oil for the synchros is a thicker, GL-5 or racing type gear oil, since their additives interfere with the grip of the synchros. If you don't get a non-GL-5 rated GL-4 oil, I at least recommend making sure the GL-5 you buy claims to be "yellow metal-" or synchro- friendly. Cold weather also causes these symptoms because the oil is thick until it warms up. If the cold weather is the big problem, go with a thinner oil, or simply take a moment and move the shifter more deliberately into each gear. (If you're already running a 75w-90, just slow down the shifts).
Second and third, the gear teeth and clutch sleeve teeth are the parts you feel and hear go 'clunk' when you get a rough shift. If you're getting this at high rpms, you'll round the sharp edges of these teeth and visibly distort their shape. So even if you replace the synchros, if these parts are damaged it still won't shift like new. Usually the more the synchros are worn the more these parts are worn too. These so-called 'hard parts' usually don't get replaced in a rebuild because of the cost - it adds a couple grand to a rebuild to change these parts, and in fact just doing the hub/sleeve/gear for say, 2nd gear, will cost $500.
So a low mileage tranny gets you all different synchros and all different hard parts. If it's a good one, you're getting a helluva deal. If it's been ragged on, it may not be any better than the one you have. I suggest that if you possibly can, go to the tranny importer, remove the lower cover, and inspect the tranny you're interested in. Sharp synchro teeth and sharp gear teeth are what you want.
Dave
Worn synchros are *usually* the item blamed for rough shifting and clunky engagement. These parts are indeed the most influential, but 3 other things also have a major effect - wear on the gear teeth, wear on the clutch sleeve teeth, and choice of gear oil.
Using a true GL-4 gear oil (Redline MT-90 75w-90 stands out) is the best oil choice for synchros that aren't gripping well. The least effective gear oil for the synchros is a thicker, GL-5 or racing type gear oil, since their additives interfere with the grip of the synchros. If you don't get a non-GL-5 rated GL-4 oil, I at least recommend making sure the GL-5 you buy claims to be "yellow metal-" or synchro- friendly. Cold weather also causes these symptoms because the oil is thick until it warms up. If the cold weather is the big problem, go with a thinner oil, or simply take a moment and move the shifter more deliberately into each gear. (If you're already running a 75w-90, just slow down the shifts).
Second and third, the gear teeth and clutch sleeve teeth are the parts you feel and hear go 'clunk' when you get a rough shift. If you're getting this at high rpms, you'll round the sharp edges of these teeth and visibly distort their shape. So even if you replace the synchros, if these parts are damaged it still won't shift like new. Usually the more the synchros are worn the more these parts are worn too. These so-called 'hard parts' usually don't get replaced in a rebuild because of the cost - it adds a couple grand to a rebuild to change these parts, and in fact just doing the hub/sleeve/gear for say, 2nd gear, will cost $500.
So a low mileage tranny gets you all different synchros and all different hard parts. If it's a good one, you're getting a helluva deal. If it's been ragged on, it may not be any better than the one you have. I suggest that if you possibly can, go to the tranny importer, remove the lower cover, and inspect the tranny you're interested in. Sharp synchro teeth and sharp gear teeth are what you want.
Dave
Last edited by dgeesaman; 11-07-06 at 05:04 PM.
11-07-06, 10:43 PM
#10
Originally Posted by TRISPEEDFD3S
Hey, my situation is this. My car will grind from 1st to 2nd, and 2nd to 3rd if I shift fast. I believe my synchros are worn. If that is true, where can I get replacement synchros? Or even, where can I get a good rebuilt at in Southern California?
put some neo in there and see what all goes down! i had the same problem, but neo did the trick :-D
11-07-06, 11:03 PM
#11
Senior Member
Join Date: May 2002
Location: San Diego, CA
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
http://www.bakerprecision.com/neogear.htm
Make sure you purchase 75W90 HD Competition Gear Oil. Since your down there changing the tranny oil, you might as well change diff oil too. One gallon is enough to complete both jobs.
Make sure you purchase 75W90 HD Competition Gear Oil. Since your down there changing the tranny oil, you might as well change diff oil too. One gallon is enough to complete both jobs.
11-08-06, 06:31 AM
#13
Originally Posted by Karack
usually the hubs do not wear near as fast as the syncros since the syncros are a much softer material, you REALLY need to mash on a tranny to beat up on those parts.
Dave
11-08-06, 06:50 AM
#14
Full Member
Join Date: Jul 2006
Location: North Florida
Posts: 109
Likes: 0
Received 0 Likes
on
0 Posts
Ive noticed a very similar problem in mine, the car will grind something serious when i first start it cold.. and after about 5 minutes (or until warm) the grind goes away..
ill have to check the oil.. as this is the first time the car has seen the cold weather.. is there anything else i can check besides the oil that is a 'quick fix'? ive looked at used trannies too, but now im thinking twice
ill have to check the oil.. as this is the first time the car has seen the cold weather.. is there anything else i can check besides the oil that is a 'quick fix'? ive looked at used trannies too, but now im thinking twice
11-08-06, 07:14 PM
#16
Rotary Enthusiast
Join Date: Aug 2003
Location: SC
Posts: 959
Likes: 0
Received 0 Likes
on
0 Posts
11-08-06, 07:26 PM
#17
When I shift slow, it doesn't happen. The oil I used before was Royal Purple 75W90 gear oil. I guess I'll give neo or the other one, redline it was? a chance. I hope it fixes it. Freaking car! I just bought 2 gallons of Evans NPG+, 2 gallons os Sierra to flush the system out before I use NPG+, a GReddy radiator cap, and that cool yellow no spill cooling system burping thing. Now I'm going to have to buy freaking gear oil. When does it stop! haha! It's all good.
