question about transmission
Thread Starter
7th Gear
Joined: Jan 2012
Posts: 7
Likes: 0
From: miramar fl
question about transmission
i bought a 1985 corvette that was a dream come true for me the only issue is that I know the car came with the 4+3 tranny but it has a 6 speed transmission that is not working very well I'm assuming it needs rebuild has anyone have any idea of how much this would cost and I have no idea what kind of transmission it has.The transmission says on the side jk46 I don't know if that will help.
I would greatly apreciate any advice
I would greatly apreciate any advice
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Do a search in the C4 Corvette forum, both general discussion and technical using 'Doug Nash' as the search term, as that's who built the transmission, DNE or Doug Nash Engineering. You'll find plenty of information and no, it won't be cheap to rebuild.
Burning Brakes
Joined: Nov 2009
Posts: 828
Likes: 103
From: Olney MD
Some people convert to the newer ZF 6 speed that came in later models. They're available cheaper than a rebuild, and get your car back on the road quicker.
Somebody correct me if I'm mistaken, but I think it's a drop in (if you can call a transmission swap a drop in).
Good luck, whatever you decide.
Somebody correct me if I'm mistaken, but I think it's a drop in (if you can call a transmission swap a drop in).
Good luck, whatever you decide.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Define NOT working?
What is the shift pattern ; where is R
ZF6 trans from later C4 has raised diagonal ribbing on the side of trans case and a cover at drv side rear held on by 6 bolts
What is the shift pattern ; where is R
ZF6 trans from later C4 has raised diagonal ribbing on the side of trans case and a cover at drv side rear held on by 6 bolts
Last edited by rodj; Jan 12, 2012 at 04:18 PM.
Thread Starter
7th Gear
Joined: Jan 2012
Posts: 7
Likes: 0
From: miramar fl
Define nor working?
second and specially fourth gear makes a wining noise and six sometimes pops out of gear but rarely and shifts sometimes are hard to get into but 1,3,5 are fine and reverse is fine.
What is the shift pattern ; where is R
ZF6 trans from later C4 has raised diagonal ribbing on the side of trans case and a cover at drv side rear held on by 6 bolts
second and specially fourth gear makes a wining noise and six sometimes pops out of gear but rarely and shifts sometimes are hard to get into but 1,3,5 are fine and reverse is fine.
What is the shift pattern ; where is R
ZF6 trans from later C4 has raised diagonal ribbing on the side of trans case and a cover at drv side rear held on by 6 bolts
Thanks for your response really appreciate it
Le Mans Master
Joined: Oct 2004
Posts: 6,314
Likes: 508
From: South-central Missouri
Often manual "transmission problems" are actually the result of issues with the hydraulic clutch.
For example, if it doesn't shift smoothly, e.g., takes some effort to push it in gear or "notchy", as sometimes described, it may well be the clutch.
If that is the problem, here's a simple test to see if it might be the clutch:
With the engine off, press the clutch in and shift through the gears. After going through them once (to align the gears), if shifting is void of the problem exhibited when the engine is running, it may well be the clutch.
Let us know and get back. BTW,
w/ buying a new one rather than rebuilding - it is cheaper.
P.
For example, if it doesn't shift smoothly, e.g., takes some effort to push it in gear or "notchy", as sometimes described, it may well be the clutch.
If that is the problem, here's a simple test to see if it might be the clutch:
With the engine off, press the clutch in and shift through the gears. After going through them once (to align the gears), if shifting is void of the problem exhibited when the engine is running, it may well be the clutch.
Let us know and get back. BTW,
w/ buying a new one rather than rebuilding - it is cheaper.P.
Drifting
Joined: Jun 2010
Posts: 1,853
Likes: 8
From: Westerly RI
Often manual "transmission problems" are actually the result of issues with the hydraulic clutch.
For example, if it doesn't shift smoothly, e.g., takes some effort to push it in gear or "notchy", as sometimes described, it may well be the clutch.
If that is the problem, here's a simple test to see if it might be the clutch:
With the engine off, press the clutch in and shift through the gears. After going through them once (to align the gears), if shifting is void of the problem exhibited when the engine is running, it may well be the clutch.
Let us know and get back. BTW, w/ buying a new one rather than rebuilding - it is cheaper.
P.
For example, if it doesn't shift smoothly, e.g., takes some effort to push it in gear or "notchy", as sometimes described, it may well be the clutch.
If that is the problem, here's a simple test to see if it might be the clutch:
With the engine off, press the clutch in and shift through the gears. After going through them once (to align the gears), if shifting is void of the problem exhibited when the engine is running, it may well be the clutch.
Let us know and get back. BTW,
w/ buying a new one rather than rebuilding - it is cheaper.P.
Also, another test for clutch release is whether the shift into reverse is difficult. Absent clutch problems, the ZF6 is fairly robust.
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
I own a 1988 C4. It has 191,000 miles ! The motor still runs strong not one single issue. Regular maintenance is about it aside from simple electrically problems here and there. I changed my tranny fluid and filter recently. 70 miles later I lost 3-4th gears. I was so bummed that I took the gamble and did this but I did. The quotes started at $1500 ! I was going to go ahead and remove it for $300 and take it to a guy's bench for the rebuild. That was $675 plus a 2 year gurantee. I found a shop in Phoenix Hercules Transmission that quoted me at $830 out the door. A savings of almost $200 without the headache of transporting the transmission to and from. Will I be safe driving my car in 2nd gear 40mph max 2300 rpm's about 30 miles ?
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Safety Car
Joined: Oct 2004
Posts: 3,830
Likes: 3
From: Granada Hills CA
It's possible as long as the traffic will allow it to be safely done. Maybe early in the am. If you have to get on a highway it sounds risky. It would be better to flatbed. AAA is the best option if you are a member or know someone who is that has the plan that has a premium plan. Maybe the shop has a tow company who will give you a deal.
Racer
Joined: Sep 2011
Posts: 352
Likes: 6
From: Centreville Maryland
It's possible as long as the traffic will allow it to be safely done. Maybe early in the am. If you have to get on a highway it sounds risky. It would be better to flatbed. AAA is the best option if you are a member or know someone who is that has the plan that has a premium plan. Maybe the shop has a tow company who will give you a deal.
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
Thanks !
I took the advice to heart and when I was reading noticed a post of a shop in Chandler AZ. I called him up and he will give me 12,000 mile guarantee for $750 ! Not bad and I just hope the guy does good work. I do not want to deal with this headache in a couple years from now because I didnt spend and extra $150.
