What is the worth of my rebuild 915 gearbox?
 

So the gearbox was for my dads project car (dad died), and now when we´re selling it i don´t have any clue what could be the right price to ask.

The gearbox is a 1980´s 915 for the 3.2 i believe, it looks really clean from the outside, and it has been rebuild with at least a new clutch (this one: Centerforce Performance Clutch Product | Dual Friction - Clutch Cover & Disc (PN# DF200199)) , new bearings and new shortened gears. I only know about the bearings and gears because we have two boxes with the markings "915 old bearings" and "915 old gears", the clutch is quite obvious because we have the box of it in our carage with an old clutch inside of it.

So, the buyer that is interested suggests 2000 euros, isn´t that a bit low?

$ 3000.00 sounds fair to both.

Isn´t that a bit low? I can find + 100.000 miles driven ones from ebay for 3000-4000 bucks? And they aren´t even rebuild ones so just wondering.

Without receipts and proof of the works it's worth the same. Might have $4000 worth of race gears inside but if you can't prove it or even provide the ratios then it's just another 915.

Gears...
 

If you can't find the documentation on the rebuild and what type of gears went in the rebuild, try locating the shop that did the work and get the work documented again by the shop (they should have records).

As a last resort, it might be worth tearing that box open by an "expert" to determine what gears are inside - it might help a sale if the combo is deemed as desirable by someone.

Gears are expensive - I have new 2nd through 5th for my 915 (sold the 7:31 R&P I was going to install after much reading) and I'm saving for JW in Seattle to rebuild my 915 (I also have a Wevo internal gateshift, one piece bearing plate, and reinforced side cover).

Your 915 might have some "good" surprises inside like I will put in my 915 - that could raise the asking price.

Good Luck!

Well i´m not sure who did the rebuild, i´m only sure about the fact that it was rebuilt by an individual porsche guy and not a shop, but i don´t have idea by who the work was done because my dad knew so many of them.

But yes those parts seem quite expensive so maybe opening the gearbox would be the right thing to do.

I've paid between $1,000 and $1,500 for 915 with only a reassurance that they "worked fine when I last used it". To rebuild and add LSD costs about $5,000 from a reputable shop. No LSD and a question on the rebuild would be $2,500 to $3,000 IMO.

I have a rebuilt 915 with LSD $3000 will not buy it from me!

There are 3 levels of valuation: a trans just sitting there, with or without anecdotes is a core. A trans in a car you can drive is a 'known good' or 'known problematical' purchase. And a freshly rebuilt trans from a reputable shop with receipts is the third level.

$2000 would be the price I would pay for the described transmission

Add $1000 for LSD-equipped; several hundred for 7:31 ring and pinion.

It's not terribly difficult to open up a core transmission for a clearer view of the condition.

These days, good used 7:31 ring and pinions are trading hands for $800-1500 each. Anyone who can get one for several hundred bucks is scoring.

Unobtanium.

Absolutely. Plus, you could say that about many parts on any car. The value of the parts is (almost) always greater than the value of the whole. I have spent over 2,000.00 in parts on my race car transmission in the last year, but I rather doubt that I increased the value of either the transmission or the car by $2,000.00.

No one makes them now ?

I do. They are $3000 New.

Can someone tell me what the benefit of the 7:31 is?

lower ratio puts you in the torque curve quicker....

Can't that be accomplished by swapping gears without buying unobtanium? My understanding was that the 8:31 ring was stronger...

Sort of. My gears are $850 each and you usually need 3 or 4 for a regear. Used factory race ratios are usually $400-500 each.

And we make an 8:35 for just the reason you mention, strength. The factory did the same thing starting with the 3.0 RSR. But racers will still buy the $1000 used 7:31 over the new 8:35 when they can find one.