Replacing 915, 1984 with 915 from 1980

Burint · Burint's Garage

Hello,
My 915 came with the 1984, 3.2 U.S. is gone bad and will be really expensive to rebuild it. I came across another good condition 915 from the 1980 SC, Euro spec.
I am wondered if this is a good match since both engines have the same 210 hp.
Thanks
Burint

ljowdy · 07:22 AM

I know you'll have to grind the 1980 case to accept the sensor, not sure if the new 915 has an electronic speedo drive. Both have a 3.88 final drive but I believe the ROW 1980 car was rated at 204 HP

I have a 3.2 buttoned up to my 1973 915 Transaxle and so far, no problems.

Burint · Burint's Garage

ljowdy
Grinding shouldn't be a problem if needs to. The car is 1970 with the 3.2 engine so my speedometer is a mechanical already.
Thanks for your input

ljowdy · 12-26-2007, 07:45 AM

OK, but the speedo on the later transaxle may be electronic and not cable driven. If you have the stock 1970 speedometer in your dash then it needs to be cable driven.

spuggy · 12-26-2007, 08:51 AM

915 speedo drives were electronic from '76, '77? I know my mag-case '77 915 had an electronic drive. So if the 915 on your car has a mech speedo drive, it was either modified to provide that or the 915 is older than that.

Is it magnesium or aluminium? If it's magnesium (castings oxidise to a dark-grey, almost black color), it's likely the original box from the car, rather than the aluminum 915 that "belonged" to the 3.2.

I believe the diff cover plate (at least) was reinforced by the factory when they went aluminum with the SC, and then reinforced yet again when they went to the 3.2.

So the SC 915 is probably slightly weaker than the 3.2 915. You could use the WEVO reinforced diff plate (that takes a 930 differential carrier bearing as well).

That said, it's unlikely to be an issue for practical purposes unless you start getting substantially more power than stock from the 3.2.

The WEVO one-piece bearing retainer plate is well worth it for the money if the box is open anyway. I'd not fit the SC 915 without a "look-see" anyway - a "refresh" is way cheaper than fixing it when it breaks...