Is it feasible to upgrade the early 80s' 5 spd. to later 87' and newer? Cost should be considered. Anyone that has done this?

 

The 85-95 trans is a direct replacement for the 1980-1984 unit with no other parts needed,

 

Don't mean to question experts here but isn't there slight (5 to 10 mm) difference between position of torque tube clamp bolt hole and gearbox mounting surface? I mean hole/opening/whatever it's called in gearbox input shaft where this

bolt goes through is some mm's forward on '85 and later boxes, isn't it? If it is, torque tube needs to be little modified to accept that bolt. Other than that I don't think there is anything different in any meaningful measurement.

Regards,

Erkka
1992 928 GTS 5-speed, I think
Oak Green Metallic 22L
Classic Gray MX

 

Doc, what is the gain for replacing the tranny as you have outlined?

 

Deb, better synchro's! Actually you can get the BorgWarner trans from an '85 and up. The earlier transmissions all seem to suffer from worn synchros and can be pretty notchy 1st to 2nd and my '82 is very tough 3rd to 2nd.

Hey Doc, we're neighbors...email me at jim928@ptd.net please.

Jim

 

Yes, better syncros. The earlier 928s' suffer drom poor 1st/2nd up and down. How big of a deal is it to change the trans? Mark, do you have any for sale that would fill the bill? JIM: I will e-mail you.....maybe you can recommend someone locally to the job.

 

I put an 89 transmission in my 80 track car. Bolted right in.

 

Interesting. Now when thinking more about it I could swear there is difference. At least there was between those two gearboxes we had on floor side by side. They were '78 that was in car originally and '85 that we installed in it's place. Think we even have pictures somewhere where all outside differences are visible. It seems that we get second change to do comparisons as torsion spring broke inside gearbox and it needs to come down again. While it's out might as well do torque tube and engine. In next photo session there will be three boxes, '78, '85 & '92.

Regards,

Erkka
1992 928 GTS 5-speed gets company in garage soon
Oak Green Metallic 22L
Classic Gray MX

 

The 78-79 trans are a different size compared to the 80-95 5 speeds.

 

[QUOTE]Originally posted by Vilhuer
.................1992 928 GTS 5-speed gets company in garage soon[/URL]

Hi Erkka,
Has your vife decided to 'export' you to the garage?

Regards from Erik in Denmark

 

That explains differences we saw then and Marc. A. knows those I bet. Should have read his and your text more carefully. So G28/03 is different than later ones. Maybe they changed design to get more torque tube inside input shaft and more surface area for bores.

By the way there are two other meaningful difference between G28/03 and G28/10 I forgot earlier. On newer box there isn't place where to mount lower side bolt for battery box. That part of casting isn't there. We made maybe 3 inches long flat iron piece and drilled new thread to nearest suitable spot some 2 inches back from original place. Wonder why factory didn't keep that part of casing same as this change means new models don't directly work with separate battery box. At least original bexes endplate can be used in later ones.

Other thing missing were mounting points for gearbox shock absorbers. Castings for those were still there but no threads. This is easier to understand as it can be taken care by changing to new design gearbox mounts.

Regards,

Erkka
1992 928 GTS 5-speed G28/57
Oak Green Metallic 22L
Classic Gray MX

 

[QUOTE]Originally posted by Erik - Denmark

Quote:

Originally posted by Vilhuer
.................1992 928 GTS 5-speed gets company in garage soon[/URL]

Hi Erkka,
Has your vife decided to 'export' you to the garage?

Regards from Erik in Denmark

Erik, no wife, no problems It seems fixing 928 is full time job. Too bad no-one is paying to do it. Maybe I should move to garage to be able to get GTS running by 2010. Or better yet move garage to living room.

Regards,

Erkka
1992 928 GTS 5-speed so far away
Oak Green Metallic 22L
Classic Gray MX