Old tranny, new car. Bad idea?
09-18-2009, 01:08 PM
#1
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Old tranny, new car. Bad idea?
After driving the 87 around for a few days, I'm in love. If I put my 79 5 speed tranny in this car, will it be sufficient enough. Or will it quickly blow out?
Somebody please talk me out of this...
BBX
Somebody please talk me out of this...
BBX
09-18-2009, 01:14 PM
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It will work fine. Biggest difference is the old-vs-new style synchros. I would get the early-style 2-disc clutch setup as well...lots of info here from others who have done this conversion.
09-18-2009, 01:21 PM
#4
Nordschleife Master
That early tranny is a different case and spline design that requires a different torque tube than came on an '87. Then you'd have to change the clutch on the front end.
09-18-2009, 01:24 PM
#5
Nordschleife Master
Glen his 87 is an auto.
you would have to use the TT and tranny that came out of the 79 but that can be used with the 87 auto cross member iirc.
You will still need to get a clutch setup $$$$$ and then you will have to cut a hole in the firewall and mount the MC bracket. I would not recommend this given the trouble you had with the ISV
No offence intended but it is not an easy or for the faint of heart!
you would have to use the TT and tranny that came out of the 79 but that can be used with the 87 auto cross member iirc.
You will still need to get a clutch setup $$$$$ and then you will have to cut a hole in the firewall and mount the MC bracket. I would not recommend this given the trouble you had with the ISV
No offence intended but it is not an easy or for the faint of heart!
09-18-2009, 01:39 PM
#6
Nordschleife Master
I've opted out of signatures and too many are stoopid and, worse, stoopid political statements. Ain't that what OT is for?
Let me change this:
Several guys (many?) have done this. Lots of work and parts are involved.
The practical man would sell the auto and buy a 5-speed. I totally understand that the 928 tends to attract impractical people or those, like me, who express their impractical sides through it.
Ya just need a 3-pedal assembly, cut a hole for the clutch master and put that in, get a clutch and put that in, maybe a new console for the shifter and then put in the torque tube and tranny. You're done! Should be a good weekend project. OK...multiple weekends but on the weekend nonetheless.
Parts from the early cars (78-79) will be cheapest and easiest to find as those cars are worth less and had the largest percentage of 5-speeds. However, there were a lot of changes to the driveline until mid-80 and that stabilized until the S4 came out. The trannies were improved in '85. I'd say get the bits from an '85 or '86 car or at least something after mid-'80. Check for gear ratios, too. You want a higher final drive if you can get it.
Let me change this:
Several guys (many?) have done this. Lots of work and parts are involved.
The practical man would sell the auto and buy a 5-speed. I totally understand that the 928 tends to attract impractical people or those, like me, who express their impractical sides through it.
Ya just need a 3-pedal assembly, cut a hole for the clutch master and put that in, get a clutch and put that in, maybe a new console for the shifter and then put in the torque tube and tranny. You're done! Should be a good weekend project. OK...multiple weekends but on the weekend nonetheless.
Parts from the early cars (78-79) will be cheapest and easiest to find as those cars are worth less and had the largest percentage of 5-speeds. However, there were a lot of changes to the driveline until mid-80 and that stabilized until the S4 came out. The trannies were improved in '85. I'd say get the bits from an '85 or '86 car or at least something after mid-'80. Check for gear ratios, too. You want a higher final drive if you can get it.
09-18-2009, 01:52 PM
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No offense taken bud!
I have everything needed already, like tranny, TT, pedal assembly, clutch firewall bracket, crossmember, clutch, cables, etc...
I was just worried about the strength of the transmission. Everyone complains about early tranny's not holding power.
I have everything needed already, like tranny, TT, pedal assembly, clutch firewall bracket, crossmember, clutch, cables, etc...
I was just worried about the strength of the transmission. Everyone complains about early tranny's not holding power.
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09-18-2009, 02:06 PM
#8
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How much HP are you planing to push through it? Also are you planning to inspect the box fully first and replace what is needed before you RR the setup?
09-18-2009, 02:24 PM
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Andre, the tranny was rebuilt in 91 by Andial. I have a receipt for 3940.00 in parts and 1440 in labor to do it!!! (previous owner)
HP, I'm sure 400 at the rear wheels is as much as this car will ever see... (maybe?)
HP, I'm sure 400 at the rear wheels is as much as this car will ever see... (maybe?)
09-18-2009, 03:20 PM
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Blythe,
If it were me, I'd sell the old tranny setup to someone wanting to do a conversion on an OB simply to make it easier to keep track of replacement parts. Or you can sell the auto car altogether and find a 5 speed with trashed or missing interior and lowball them... It is going to be a track type car anyways right?
On the track, the newer style transmission syncros will make some difference, though the new style syncros helped most between 1st and 2nd (or at least thats what I experienced). Good Luck!
If it were me, I'd sell the old tranny setup to someone wanting to do a conversion on an OB simply to make it easier to keep track of replacement parts. Or you can sell the auto car altogether and find a 5 speed with trashed or missing interior and lowball them... It is going to be a track type car anyways right?
On the track, the newer style transmission syncros will make some difference, though the new style syncros helped most between 1st and 2nd (or at least thats what I experienced). Good Luck!
09-18-2009, 03:35 PM
#12
Nordschleife Master
Good idea. I would like to help with the conversion. Worry about it if and when it blows up. A local Porsche specialist who has done at least a dozen conversions: "If you know how to drive, you won't blow it up."
09-18-2009, 03:54 PM
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