4+3 Problem
Thread Starter
Heel & Toe
Joined: Jun 2006
Posts: 23
Likes: 0
From: Spotsylvania Virginia
4+3 Problem
Just became the owner of an 85, have no idea on the history, but I want to make the car right. It has 111,000 miles, motor good, but the 4+3 when it is in 2nd gear sometimes the shifter pops out, it only does this in second in my neighborhood because of the speed limit, on normal roads 55 MPH and up you are through second so it does not matter, no grinding noise or bad smell, any ideas and can I just hold the stick to keep it from jumping out? Thanks
Burning Brakes
Joined: Jul 2004
Posts: 806
Likes: 0
From: Langley B.C.
I am no transmission pro but I think if the second gear syncros are worn it will tend to spit out of gear!!!So no it should not hurt it to hold it in.JUst my opinion,someone more wise than I will step in.
Le Mans Master
Joined: May 2004
Posts: 5,389
Likes: 535
I'm about to pick up a 4+3 I purchased for a good price. THEN, I read on an internet timeline of the Corvette that the 4+3 is an "absolutely crummy excuse for a transmission". The exact words of the timeline.
QUICK, somebody tell me it isn't so and make me feel better about my purchase!
"At least it's era correct!" --1985 Corvette
QUICK, somebody tell me it isn't so and make me feel better about my purchase!
"At least it's era correct!" --1985 Corvette
Team Owner
Joined: Oct 2004
Posts: 20,178
Likes: 0
From: middle of nowhere Pa
Cruise-In VI Veteran
Cruise-In VII Veteran
St. Jude Donor '06
Originally Posted by 1985 Corvette
I'm about to pick up a 4+3 I purchased for a good price. THEN, I read on an internet timeline of the Corvette that the 4+3 is an "absolutely crummy excuse for a transmission". The exact words of the timeline.
QUICK, somebody tell me it isn't so and make me feel better about my purchase!
"At least it's era correct!" --1985 Corvette
QUICK, somebody tell me it isn't so and make me feel better about my purchase!
"At least it's era correct!" --1985 Corvette
Thread Starter
Heel & Toe
Joined: Jun 2006
Posts: 23
Likes: 0
From: Spotsylvania Virginia
Is it a big deal to replace the 2nd gear fork?, anybody done it before.?
Originally Posted by c4cruiser
The shifter forks on the side cover may also be worn enough so that the 2nd gear slider is not allowing the gears to fully mesh.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
That 4speed has been in use since about 1964. The small block in front of it has been around since 1955, both for good reason.
If maintained, they're very reliable. Hopefully it's just your 2nd gear synchro, but if a syncro is going, usually the dog teeth and shift collars go next. (I don't think a syncrho does anything to keep the car in gear).
Mine was dropping out of 3rd gear, and the 3rd gear dog teeth were chewed. A new gear is about $150. If you need a new gear or two and a rebuilt, I'd seriously consider upgrading to the 6 speed. A rebuild will cost you about $250 in parts, plus labor ($400 or so?).
If maintained, they're very reliable. Hopefully it's just your 2nd gear synchro, but if a syncro is going, usually the dog teeth and shift collars go next. (I don't think a syncrho does anything to keep the car in gear).
Mine was dropping out of 3rd gear, and the 3rd gear dog teeth were chewed. A new gear is about $150. If you need a new gear or two and a rebuilt, I'd seriously consider upgrading to the 6 speed. A rebuild will cost you about $250 in parts, plus labor ($400 or so?).
Team Owner
Joined: Aug 2004
Posts: 22,310
Likes: 216
From: Sussex,Wi
2023 Corvette of the Year Finalist - Unmodified
2022 C3 of the Year Winner - Unmodified
I know this is a fairly common problem on the 4 speeds that has nothing to do with the OD unit. I've had this problem since I bought the car 4 years ago, and the previous owner told me of it and the fact that he replaced the synchros didn't help any.
My 2nd gear will pop out when I'm transmission braking (letting off the gas in 2nd- never while accelerating), and it only happens in 2ng gear.
To me, it's just an annoying problem, that will remain until I need to replace the clutch.
My 2nd gear will pop out when I'm transmission braking (letting off the gas in 2nd- never while accelerating), and it only happens in 2ng gear.
To me, it's just an annoying problem, that will remain until I need to replace the clutch.
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Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Originally Posted by shellman
Is it a big deal to replace the 2nd gear fork?, anybody done it before.?
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
I doubt it's the forks, but worth checking, they're only about $25 or so.
Shift the car into 2nd gear before pulling the side cover off. This will allow you to pull that shift fork out easily, then if you move the shift collar back, you'll see the dog teeth on the 2nd gear. Lemme know next time you're ready to dig in, I have some pics that'll show you what's what.
You could also carefully set your neutral alignment, that'll help tremendously.
Shift the car into 2nd gear before pulling the side cover off. This will allow you to pull that shift fork out easily, then if you move the shift collar back, you'll see the dog teeth on the 2nd gear. Lemme know next time you're ready to dig in, I have some pics that'll show you what's what.
You could also carefully set your neutral alignment, that'll help tremendously.
Team Owner
Joined: Aug 2004
Posts: 22,310
Likes: 216
From: Sussex,Wi
2023 Corvette of the Year Finalist - Unmodified
2022 C3 of the Year Winner - Unmodified
Originally Posted by shellman
Thanks for all the advice. Touringmike how many miles have you put on it with it popping out over the years? Also not sure how to set Neutral
Alingement. Thanks
Alingement. Thanks
I don't know how long the previous owner had the problem.
As I said, until I need a clutch, I'll live with it. I just can't coast
or engine brake in 2nd gear.
Team Owner
Joined: Aug 2004
Posts: 22,310
Likes: 216
From: Sussex,Wi
2023 Corvette of the Year Finalist - Unmodified
2022 C3 of the Year Winner - Unmodified
4k miles ago.
Still working (most of the time) properly. Has a bad habit of turning itself off when the temp get around 200.
These things are tempermental, to say the least (but I like the manual, so I'll live with this also)
Still working (most of the time) properly. Has a bad habit of turning itself off when the temp get around 200.
These things are tempermental, to say the least (but I like the manual, so I'll live with this also)
Thread Starter
Heel & Toe
Joined: Jun 2006
Posts: 23
Likes: 0
From: Spotsylvania Virginia
Thanks I am going to change soon since I have no history on this ride.,
except that ever time I take it out I get a BIG SMILE from that 350 that had some work done to it!
except that ever time I take it out I get a BIG SMILE from that 350 that had some work done to it!
Intermediate
Joined: Aug 2005
Posts: 28
Likes: 0
From: fargo nd
on mine it was that the cog on the shifter arm to linkage bracket was worn so it didn't even go all the way in, check for any play on your linkage arms. it was never getting all the way into 2nd
Last edited by 85 Z-51; Jun 11, 2006 at 09:58 PM.
Intermediate
Joined: Aug 2005
Posts: 28
Likes: 0
From: fargo nd
call these guys and talk to brian, they stock all the nos parts for the 4+3 transmission, he can answer any and all questions. was great to deal with when I rebuilt my overdrive unit(and it wasn't as bad as everybody says).and I do like my 4+3, the manual is basically a super t-10 with a modified case, these are heavy duty, mine looked like new inside. I don't know the name of the part off hand, but it's the part that the fork goes into and sticks out through the case, $65.00 + shipping.
S-K Speed Manual Transmissions
1075 Route 109
Lindenhurst, NY 11757
Please Call (631)957-9427 and ask for Brian for more information, or Fax him at (631)957-1341
http://www.skspeed.com/aboutsk/transshop/default.asp
S-K Speed Manual Transmissions
1075 Route 109
Lindenhurst, NY 11757
Please Call (631)957-9427 and ask for Brian for more information, or Fax him at (631)957-1341
http://www.skspeed.com/aboutsk/transshop/default.asp
Intermediate
Joined: Aug 2005
Posts: 28
Likes: 0
From: fargo nd
looked it up. It was the 1-2 gear shaft that was worn where the outer shift lever is bolted on, giving me play in the shift lever. I'd check this first(I guess it's fairly common over time), and then the linkage adjustment before opening the gearbox. there is a process for adjusting the linkage. I've got all the 4+3 fsm info on pdf if needed, just pm me and i'll get you the files.