Trouble getting into 4th
Thread Starter
Instructor
Joined: Jun 2003
Posts: 101
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From: West TX
Trouble with ZF getting in 4th
Recently, I have been having trouble getting my LT4 from 3rd to 4th gear at slow cruising speeds (20 - 30 MPH). It is noticably harder to go in to 4th than any other gear, and I never try to force it so I usually end up skipping it and shifting into 5th. However, at higher speeds, it doesn't seem to be a problem, maybe because I shift more aggressively rather than the very gentle shifts I perform at cruising speeds. BTW, I have a B&M Ripper and my clutch is on its way out. Is this a clutch or hydraulic issue, or is there a tranny rebuild in the near future? If a synchro is going out, should I take care of it when I replace my clutch/ flywheel in the next few months? My car has just turned 63,000, I'm the 2nd owner, and is in great shape. Thanks in advance.
[Modified by LT4 2 Fast, 12:55 AM 7/11/2003]
[Modified by LT4 2 Fast, 12:55 AM 7/11/2003]
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: Trouble with ZF getting in 4th (LT4 2 Fast)
If only 4th is affected, 4th synchronizer must be worn and not working properly. I would have it replaced when you remove the transmission to do the clutch repair.
Thread Starter
Instructor
Joined: Jun 2003
Posts: 101
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From: West TX
Re: Trouble with ZF getting in 4th (jfb)
Well that sux. So about how much $$$ do you think it will set me back??? Can a dealer be trusted to work on the ZF (I think I already know the answer to that one, especially the idiots around here......) I know next to nothing about trannies in the 1st place, so what could have caused this? I really baby my car unless I drag race and don't really slam the gears or powershift when I do, so what am I doing wrong?
:skep:
:skep:
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: Trouble with ZF getting in 4th (LT4 2 Fast)
I don't think I can answer any of your questions. I had to have my 87's OD rebuilt and that was $1200. Dealers are rather expensive and I would look for a transmission shop that you can find recommendations on. If there is a local Corvette club, look them up, or post this question on C4 tech. Synchronizer rings usually last the life of the transmission in manuals, but a missed shift can damage them.
Instructor
Joined: May 2003
Posts: 183
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From: San Jose CA
Re: Trouble with ZF getting in 4th (LT4 2 Fast)
I hope your sitting down. I lost my 2nd gear synchro and soon after I couldn't shift into anything. I had been warned about ZF's so I wasn't as stunned by the repair cost as you might be, There are only three qualified ZF shops in the U.S. Rockland Gear, ZF official rebuilber, White Motors in FL and The ZF Dr., Bill Boudreau in Phoenix. Rockland charges $4400 plus exchange for a rebuilt. White Motors and The Z Dr. said rebuilds start at around $2200 but the cost depends on the parts they have to replace which all come from Rockland. I checked my local Corvette reapair shop and was told the average rebuild cost was about $3200. Off the floor yet. From a wrecking yard ZF's run about $2200 to $2500 if you can find one. Sorry to ruin your day. :nopity :nopity :cuss :nono: :crazy:
Thread Starter
Instructor
Joined: Jun 2003
Posts: 101
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From: West TX
Re: Trouble with ZF getting in 4th (larrybsp)
:cuss :rant: :banghead: How will I know when the syncro is screwed completely? I've only put roughly 12,000 on the car since I've had it, and don't know much of the maintainance history, so the tranny oil should probobly get changed, right? I can hear a strange whirring sound at low RPM in 5th and 6th which sounds like its coming from the ZF. It gets louder under acceleration, any idea WTH that is? This isn't looking too good......
Instructor
Joined: May 2003
Posts: 183
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From: San Jose CA
Re: Trouble with ZF getting in 4th (LT4 2 Fast)
Changing the trany fluid and checking it with a magnet would be a good idea.
The noises you descride are not nornal but would be consistant with a bearing going south. Rockwell (ZF) charges$1700 for the bearing set! You need special tools to take apart and reassemble a ZF which is why an experienced Corvette mechanic like myself has to send the job out. It's all due to the way the ZF was designed. The gears are shrink fit to the shafts! You need ovens and freezers. Good luck :smash: :smash: :smash:
The noises you descride are not nornal but would be consistant with a bearing going south. Rockwell (ZF) charges$1700 for the bearing set! You need special tools to take apart and reassemble a ZF which is why an experienced Corvette mechanic like myself has to send the job out. It's all due to the way the ZF was designed. The gears are shrink fit to the shafts! You need ovens and freezers. Good luck :smash: :smash: :smash:
