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G50 gearbox, ever had any problems???

 
Old 12-12-2003, 04:48 AM
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Arjan B.
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Question G50 gearbox, ever had any problems???

Question,

Did anyone ever had any problems with the G50 gearbox of the Carrera 2, or had a rebuilt on it?
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Old 12-12-2003, 09:53 AM
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Jeff Curtis
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The only problems I'm hearing of is that some people are experiencing a slight grind going into 3rd gear...I am hearing of this ONLY when the trans. is good and hot, at the track.

I have the same issues and wonder if it is lightweight flywheel related as the stock flywheel/clutch setup is 19lbs more rotating mass, so rotational intertia is greater - hence keeping the internals "up to par" in regards to engagement speeds when selecting the different gears at high RPMs.

In other words, when one lets off the gas to go for a gear shift/downshift - everything starts to slow down but needs to be at a certain speed for smooth engagement of the transmission internals - with the lightweight clutch/flywheel setup, 19lbs missing might allow for things to slow down too rapidly.

This is also the same physical issue that causes the stalling issues in a 964 with lightweight flywheel setups.

Anyway, that's about the only issue I've experienced...but have heard from a few others that they experience the same thing.
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Old 12-12-2003, 11:00 AM
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Arjan B.
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I was just curious Jeff, I have no problems so far, only when I have a autobahn drive with speeds from 150 Miles/h for a few minutes, there is a problem with the selection of the gears. The gear selector inside he car goes very hard front and back, but that is normal because of the heat.
After 20/20 seconds fells smooth again. I think it gets pretty hot in there at that speed.

I hear a littile humming sound in 3, 4 and 5th gear, but that sounds o.k. to me.

Did a oil change with the service last November, and the oil came off pretty clear and had no burning smell. The magnet on the control plug was just a little dirty of metal parts, normal to me.
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Old 12-12-2003, 12:01 PM
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Granted my car is a C4, but it has still managed to cope with 600HP without a glitch... The car has about 15K miles with this new power.
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Old 12-12-2003, 01:29 PM
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Tom W
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The transmission in my 964 was repaired just before I bought it due to a failing 3rd gear synchro. I had some problems shifting into and out of 3rd at Laguna Seca last weekend, so maybe the repair wasn't the best. (This car has 70k miles and has been a track car for a few years.) If it persists I'll have to have it pulled apart and, as long as I'm in there, will probably add steel synchros.

My 993 had the spider shaft fail (some chips came off and jammed up the shifting). I had the gears changed to shorter ratios when this happened.
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Old 12-12-2003, 08:32 PM
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3rd gear and 4th syncro grinding with fast shifts at that track. Since then, I've slowed the shifts down, and the grinding doesn't occur.

Erick
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Old 12-12-2003, 08:52 PM
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I had increasing difficulty with the the 2nd to 3rd shift at the track, - which was provisionaly diagnosed as worn synchro`s, until the selector fork broke. On examination the warped clutch wasn`t helping things.
I have a 993RS box and I fear it`s going the same way
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Old 12-13-2003, 02:54 PM
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So, mainly because of track use the gear box gets problems with the syncro rings...................
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Old 11-23-2007, 10:37 PM
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I noticed a bit of grinding also going from second to third gear at the track, but always 2->3, never 3->2... could this be a hint?

Anyway my solution was to be a little more careful on my 2->3 upshifts and give the synchro more time to, well, sync. It wasn't on every 2->3 shift, just the ones where I wasn't paying attention and probably putting too much pressure on the stick.
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Old 11-23-2007, 11:49 PM
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I had some 2>3 and 3>2 problems at the track last weekend, but no grinding. It's weird. In a couple of specific places on the track I ran last weekend, I would try to shift and the shifter would be difficult to get into gear and sometimes it would just stop and not go into gear, but no grinding. Let the clutch out and in again and then it would go into gear. Since I have a DE next weekend, I took it to my local race shop guy last week and he couldn't find any obvious problems with the linkage or reproduce my problem before the holiday weekend started. It's intermittent and no grinding, so I don't think it's synchros. I'm starting to wonder if it's motor or transmission mounts maybe?
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Old 11-24-2007, 01:40 PM
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JW in Texas
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I'm starting to wonder if it's motor or transmission mounts maybe?
Steve,
Yep, I bet that's your problem. When I was DEing the '90 way back when, I used to have the same thing happen @ MSR in one specific spot when the car was loaded up. It was like the 2nd gear gate wasn't there. General consensus was tranny mount. You can go to steel but it's going to transmit a lot of noise into the cabin. My RSA had all steel motor/tranny mounts & it sounded a lot like my cupcar inside the cabin. Probably not the best answer for a street car. Pelican offers an upgrade mount. You might take a look @ that as well.
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Old 11-24-2007, 01:47 PM
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Manny Alban
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at 110K miles, I had my shift fork and 2nd and 3rd gear synchros/bearings replaced. Everything else looked fine.
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Old 11-24-2007, 10:36 PM
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Originally Posted by JW in Texas View Post
Steve,
Yep, I bet that's your problem. When I was DEing the '90 way back when, I used to have the same thing happen @ MSR in one specific spot when the car was loaded up. It was like the 2nd gear gate wasn't there. General consensus was tranny mount. You can go to steel but it's going to transmit a lot of noise into the cabin. My RSA had all steel motor/tranny mounts & it sounded a lot like my cupcar inside the cabin. Probably not the best answer for a street car. Pelican offers an upgrade mount. You might take a look @ that as well.
Jay, thanks for the feedback. I may just go ahead and install some WEVO's. They have some with a urethane insert to cut down on the noise and vibration. As for the Tranny mount, the euro RS mount is probably the steel one you mention. I'll have to decide whether to do that or go with the OEM stock 964 one. Maybe just a new stock one will be enough to cure my problem?

Manny, thanks too. Yup, that's the next step I reckon. I guess I'll see if new motor mounts/transmission mount fixes it. I only have 53k miles, so as long a there's no grinding, I don't think I want to have it opened up. But if all else fails, I'll have no choice if I want it fixed. I'll probably go with steel synchros if I do. Just another problem with tracking a street car. I really gotta cut that out.

Thanks a ton guys. I knew I'd get some good responses.

Regards,
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Old 11-25-2007, 12:19 AM
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race911
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136K on RSA #2, and it started popping out of 4th sometimes a couple thou ago. No history, no records, no nothing prior to my ownership @ 130K. I'll likely throw the steel synchro box I built for RSA #1 but never used. In any case, Rob @ SCARGO was pretty adamant that steel synchro setups weren't necessary. I had already bought everything anyway so I went ahead and used it.....
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Old 11-25-2007, 09:51 AM
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The G50 in both 5spd and 6spd versions is a very good and reliable box. There were a few things that have been changed in the motorsport version to help with some of the issues that have been discussed. They are Steel vs Aluminum shift fork, steel syncros, better plates and 40/65 ration on the locking rings in the differential. Those items combined with the proper gear lube should yield you a track ready transmission.
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