4+3 to 6 speed conversion
Thread Starter
Burning Brakes
Joined: Apr 2004
Posts: 792
Likes: 1
From: Stanfield NC
4+3 to 6 speed conversion
Have an 88 L98 that I am setting up to run at the track. This car will also see some limited street and stip use. I am not a big fan of the 4+3 as I need to lock out the overdrive during track events.
How difficult is the conversion to the 6 speed. I have searched through all the old posts using the search engine but am not finding anything. I have seen some comments that this is an often asked question, but I have not had any luck finding the threads.
Questions include: Does the bell housing need to be changed? Does the drive shaft need to be shortened? Are the clutch and preassure plate the same? What about clutch linkage? Are there other issues with the swap that I have over looked?
ANy and all help is appreciated.
How difficult is the conversion to the 6 speed. I have searched through all the old posts using the search engine but am not finding anything. I have seen some comments that this is an often asked question, but I have not had any luck finding the threads.
Questions include: Does the bell housing need to be changed? Does the drive shaft need to be shortened? Are the clutch and preassure plate the same? What about clutch linkage? Are there other issues with the swap that I have over looked?
ANy and all help is appreciated.
Spending his inheritance
Joined: Oct 2001
Posts: 3,150
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From: If the RV's arock'n, don't come aknock'n FL
Cruise-In VIII Veteran
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
NCM Sinkhole Donor
MY 95 did this on his wife's car, contact him for details.
Safety Car
Joined: Sep 2003
Posts: 3,599
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From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Originally Posted by WNDOPDLR
Have an 88 L98 that I am setting up to run at the track. This car will also see some limited street and stip use. I am not a big fan of the 4+3 as I need to lock out the overdrive during track events.
How difficult is the conversion to the 6 speed. I have searched through all the old posts using the search engine but am not finding anything. I have seen some comments that this is an often asked question, but I have not had any luck finding the threads.
Questions include: Does the bell housing need to be changed? Does the drive shaft need to be shortened? Are the clutch and preassure plate the same? What about clutch linkage? Are there other issues with the swap that I have over looked?
ANy and all help is appreciated.
How difficult is the conversion to the 6 speed. I have searched through all the old posts using the search engine but am not finding anything. I have seen some comments that this is an often asked question, but I have not had any luck finding the threads.
Questions include: Does the bell housing need to be changed? Does the drive shaft need to be shortened? Are the clutch and preassure plate the same? What about clutch linkage? Are there other issues with the swap that I have over looked?
ANy and all help is appreciated.
yes the bell housing needs to be changed. so does the slave cylinder(and possibly the master, too). you really just need the front yoke from a ZF driveshaft (the shaft lengths are the same), but i went with a new yoke/driveshaft altogether. now comes the fun part - deciding which flywheel you are going to use, as it will dictate your clutch set up. you have the option of using your single mass flywheel and either a ZF clutch set up (with a special longer pivot ball stud) or the 4+3 clutch set up with a throw out bearing conversion. OR you can get a dual mass flywheel or aluminum flywheel and use the ZF clutch set up.
you'll likely need a new starter (the stock one will probably not fit the new bellhousing), and you'll need to cut out the recessed portion of the transmission tunnel (and reform the tunnel with no recess) in order to install the ZF.
i'm sure i didn't cover everything, but these are the basics. get ready to curse a lot (especially when putting the support beam back in), but in the end, it's fullly worth it!
Melting Slicks
Joined: Oct 2001
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From: Salem Oregon
Safety Car
Joined: Feb 2001
Posts: 4,397
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From: Looks like I picked the wrong week to stop sniffin glue Orlando
Don’t forget about the Richmond 6-speed. It’s a direct 4+3 swap and you won’t have to replace your clutch, flywheel or bell housing.
I just performed and auto to Richmond conversion and love it
I just performed and auto to Richmond conversion and love it
Safety Car
Joined: Feb 2001
Posts: 4,397
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From: Looks like I picked the wrong week to stop sniffin glue Orlando
I think the 4+3 uses cables attached to the shifter; it’s not a “rod” style like the Richmond.
I’m not 100% on this, but I think that’s how the 4+3 works
I’m not 100% on this, but I think that’s how the 4+3 works
Drifting
Joined: Sep 2004
Posts: 1,638
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I am getting ready to do this. In researching the project I eliminated the ZF6 because of complications - needing a new cluth - needing a new flywheel etc - and it was very costly. Then I looked at the richmond - and really liked the bolt in - but the cost was a little high - and stories of roadracing turing the tranny into a giant boat anchor swayed me from that idea.
I eventually went with the group purchase of the tremek 5 speed from Keissler engineering. Bolt in - no cutting no adding or changing parts like drive shafts clutches bell housings etc. Complete kit - including shipping was just under 3K - I expect delivery at the end of Feb.
Carl "soon to be shifty" johansson
I eventually went with the group purchase of the tremek 5 speed from Keissler engineering. Bolt in - no cutting no adding or changing parts like drive shafts clutches bell housings etc. Complete kit - including shipping was just under 3K - I expect delivery at the end of Feb.
Carl "soon to be shifty" johansson
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Race Director
Joined: Feb 1999
Posts: 12,772
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From: Indianapolis IN
Originally Posted by Carl Johansson
I am getting ready to do this. In researching the project I eliminated the ZF6 because of complications - needing a new cluth - needing a new flywheel etc - and it was very costly. Then I looked at the richmond - and really liked the bolt in - but the cost was a little high - and stories of roadracing turing the tranny into a giant boat anchor swayed me from that idea.
I eventually went with the group purchase of the tremek 5 speed from Keissler engineering. Bolt in - no cutting no adding or changing parts like drive shafts clutches bell housings etc. Complete kit - including shipping was just under 3K - I expect delivery at the end of Feb.
Carl "soon to be shifty" johansson
I eventually went with the group purchase of the tremek 5 speed from Keissler engineering. Bolt in - no cutting no adding or changing parts like drive shafts clutches bell housings etc. Complete kit - including shipping was just under 3K - I expect delivery at the end of Feb.
Carl "soon to be shifty" johansson
On the ROD, I just dont like the linkage and I dont know of any aftermarket shifters, but too each his own.
Congrats on the Tremec purchase, I would do the 5 speed if I did it gain, no need for a 6th gear IMHO.
Safety Car
Joined: Feb 2001
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From: Looks like I picked the wrong week to stop sniffin glue Orlando
Originally Posted by LD85
On the ROD, I just dont like the linkage and I dont know of any aftermarket shifters, but too each his own.
Congrats on the Tremec purchase, I would do the 5 speed if I did it gain, no need for a 6th gear IMHO.
Congrats on the Tremec purchase, I would do the 5 speed if I did it gain, no need for a 6th gear IMHO.
LD, just out of curiosity, what exactly don’t you like about the ROD shifter? I know it’s not as smooth as internal rail shifters, but after I got used to it its normal for me now.
As for the whole 5 speed and 6 speed thing. If I had it my way I would like to have a 4 speed over drive. That’s 4 gear over drive not a 5th gear over drive.
I like the long pulls between gears.
Race Director
Joined: Feb 1999
Posts: 12,772
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From: Indianapolis IN
Originally Posted by IBEAM700
LD, just out of curiosity, what exactly don’t you like about the ROD shifter? I know it’s not as smooth as internal rail shifters, but after I got used to it its normal for me now.
As for the whole 5 speed and 6 speed thing. If I had it my way I would like to have a 4 speed over drive. That’s 4 gear over drive not a 5th gear over drive.
I like the long pulls between gears.
As for the whole 5 speed and 6 speed thing. If I had it my way I would like to have a 4 speed over drive. That’s 4 gear over drive not a 5th gear over drive.
I like the long pulls between gears.
I have driven a ROD in a 406 4-5 times, same car, and the shifter just felt a little loose, and I heard some rattling that drove me crazy, maybe it was just something loose, I dont know.
Safety Car
Joined: Feb 2001
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From: Looks like I picked the wrong week to stop sniffin glue Orlando
Originally Posted by LD85
I agree 100% on the 4+OD, I loved the Doug Nash tranny but the OD is what it is,,,,
I have driven a ROD in a 406 4-5 times, same car, and the shifter just felt a little loose, and I heard some rattling that drove me crazy, maybe it was just something loose, I dont know.
I have driven a ROD in a 406 4-5 times, same car, and the shifter just felt a little loose, and I heard some rattling that drove me crazy, maybe it was just something loose, I dont know.
I can’t remember his forum name, but there was a guy in San Diego that had one in his C4. That was the only other C4 that I knew of that had one.
Drifting
Joined: Sep 2004
Posts: 1,638
Likes: 3
Originally Posted by WNDOPDLR
Great response everybody. Keep it coming. Carl-do you have an email address or link for the place you got your 5 speed?
http://www.keislerauto.com/
They are a sponsoring member of the group (you can click on their link on the left side of the forum - under transmissions)- If you are interested call em up - I bet you can convince them to give you the group purchase rate.
We bought 2 setups from them
we are currently doing a complete switchover from Auto to manual in a C-3 - got the complete kit - soup to nuts - from Keisler
My setup for the C-4 is expected in late Feb - I will get pictures (Hopefully, my brother may be a mechanical whiz - but he can't use computers or cameras or anything like that)
