G50-01 seems a good buy

[Lynn]

There is a G50-01 on sale on eBay that, if it is in good shape, looks to be a pretty good buy. It has a starting price of $500 and a "Buy It Now" price of $1600. Located in Sedalia, Missouri.

Click Here To See Auction


Lynn

[Tim Kay]

Inviting. I am considering the purchase of a G50 but uneducated in the different models and number disignations. What do the two digits after the G50-(??) represent? And, which one is most desirable for the GT40?

[Bill Bayard]

Tim,

There used to be a link to the GT40 Forum "library", where

I posted a bunch of G50 info. The link disappeared when the

Forum was upgraded. If you can't find the info, let me know.

I have it all on file somewhere.

Bill

[Tim Kay]

I spent some time searching, "G50" and "Bill Bayard" but did not find anything specifically identifying different G50's. No hurry but if you happen to stumble across that info, post it again. I'll keep my eye out for it.

Thx in advance

Tim

[Bill Bayard]

Maybe Ron has the address of Shannon's info site and can add a link to it again.
I have a lot of info(numbers, ratios, etc.). I can fax them to you if you'd like.
Let me know.

Bill

[Lynn]

1987 911 G50s have an 8 digit code stamped in the bottom, for example 'G50/0073H'_'12/00050'

* G50/00 = G50 trans
* 7 = trans for 6 cylinder
* 3 = 5-speed Rest of World; 4= 5-speed USA/Japan/M298)
* H = 1987 model
* 00050 = serial number

A 1988-89 trans has a 12 digit code, such as 'G5000 1 J 00903'

* G5000 = trans type (see below)
* 1 = normal differential (0= no diff, 2= ZF ltd. slip diff)
* J = 1988 model (K= 1989)
* 00903 = serial number

Transmission types:

* G50/00 = 911 Carrera, R.o.W.
* G50/01 = 911 Carrera, USA/CND/J/AUS
* G50/02 = 911 Switzerland (very short gear ratios)
* G50/50 = 911 Turbo world wide, 1989 only
* G50/52 = later Porsche turbo boxes ZF ltd. slip

Visit Powerhaus II for alternative gear ratios

My Ratios


Please send information on the following:

Model Gearset Teeth Ratio
G-50 1st 13:34 2.615:1
G-50 2nd 16:31 1.937:1
G-50 3rd 22:39 1.772:1
G-50 4th 30:29 0.966:1
G-50 5th 41:31 0.756:1

G50 Stock Ratios from Porsche Tech Manuals
Final drives are all 3.44:1, unless noted

G50/00...1st-3.500...2nd-2.059...3rd-1.409...4th-1.074...5th-0.861 after 1988, 5th gear was 0.868

G50/01...1st-3.500...2nd-2.059...3rd-1.409...4th-1.125...5th-0.889 after 1988, 5th gear was 0.892

G50/02...1st-3.154...2nd-1.895...3rd-1.333...4th-1.036...5th-0.861 after 1988, 5th gear was 0.868

G50/03...1st-3.500...2nd-2.059...3rd-1.407...4th-1.086...5th-0.868

G50/04...1st-3.154...2nd-1.895...3rd-1.333...4th-1.029...5th-0.868

G50/05...1st-3.500...2nd-2.059...3rd-1.407...4th-1.086...5th-0.868 Final drive-3.333:1

G50/10...1st-3.154...2nd-1.895...3rd-1.407...4th-1.086...5th-0.868

G50/50...1st-3.154...2nd-1.789...3rd-1.269...4th-0.967...5th-0.756 Beefier internals, differential cover, and case

G50/52...ratios are identical to G50/50, however, doesn't have the beefed up internals, differential cover, and case



The structure of G50, etc., 12 digit serial numbers goes as follows:

G5001, G5002, G5003, etc. = transaxle type

The next digit indicates variations in that particular transaxle, eg., 0 = no differential, 1 = "normal" differential, 2 = ZF limited slip

The letter code designates the model year. H = 1987, J = 1988, K = 1989, L = 1990, M = 1991. The model year "letter" was

omitted, as of 1992.

The last four digits designate the serial number of the specific gearbox in question.

Some Porsche tranaxles had 8 digit serial numbers.

The first digit (7) indicated that the transaxle was built for a 6 cylinder car.

The second digit indicated location (4 - USA, Japan----3 - rest of world)

The third digit indicated differential type - 0 = no differential, 1 = "normal" differential, 2 = limited slip differential (40/60)

The letter designates the model year.

The final four digits designate the serial number of the specific gearbox.


The following is a list of which cars the different transaxles were installed in, where, when, lube oil capacity.

G50-00 - 911 series---worldwide---since 1987 model - 3.4 liters SAE 75W90

G50-01 - 911 series---USA, Japan, Canada, Australia---since 1987 model - 3.4 liters 75W90

G50-02 - 911 series---Switzerland---since 1987 model - 3.4 liters 75W90

G50-03 - 911 Carrera 2---worldwide except Switzerland---since 1990 model - 3.6 liters 75W90

G50-04 - 911 Carrera 2---Switzerland---since 1990 model - 3.6 liters 75W90

G50-05 - 911 Carrera 2 & 911RS America---USA---since 1992 model - 3.6 liters 75W90

G50-10 - 911 Carrera RS---worldwide---since 1992 model---factory installed limited slip (40/60) - 3.6 liters 75W90

G50-50 - 911 Turbo---worldwide---1989 model---3.7 liters 75W90---beefed up internals, differential cover, case, some factory LSDs

G50-52 - 911 Carrera---worldwide---since 1990 model - 3.6 liters 75W90 - same ratios as G50-50 - some factory LSDs


Lynn

PS: sorry, I've been on the road all week.

[Tim Kay]

Hence the reason I have this insatiable addiction to this forum. It never ceases to amaze me the knowledge that is stored here [img]/ubbthreads/images/graemlins/shocked.gif[/img] Thx Lynn and Bill.

Would it be safe to say that the G50/10, /50 & /52 are the only G50's with factory LSD?







Thx Lynn & Bill

[Tim Kay]

When refering to 'final drive', is that the ring and pinion ratio?

In off-road we refer to 'final drive' as the actual overall ratio of input to axle in each gear.

[Lynn]

On, the LSD question: The answer is absolutely not. It would be quite possible to find a factory LSD, most likely of ZF manufacture, in any Porsche transaxle.

As to final drive: it appears that in the instances where it is used here, it does refer to the differential ratio. I agree that in a general sense it is used to describe the ratio of engine rpms to wheel rpms (assuming a locked diff.)

Regards,
Lynn

PS BTW, I attached a matrix of the various ratios of G50/XX gearboxes. Do be advised that not all of the G50 family of gearboxes are suitable for use in a GT40. Indeed, without drastic repackaging, most aren't.

[Tim Kay]

Indeed, I did review all the gear ratios listed above. Most seem a bit tall. In fact the Swiss G50/02 resembled closest to my Renault gearing. In fact, I didn't realize I am geared quite low compared to the G50's and extemely low compared to a ZF I found.

[Lynn]

Tim,

And we, in the US anyway, view most Porsche transaxles as geared to low, with 1st being considered unusable by many for anything other than creeping along in stop & go traffic. The G50/50 has the best gearing for a V8 and is the strongest of the 87-89 vintage, which are the most suitable for use in a GT40 because of their length. Indeed the diameter of the tire drove the choice I made for my rear tires because of this. The 915, 930 and 901 have more widely available rack & pinion and gearset ratios than the G50 series. Or, at least, more affordable ratios: the overall cost of changing all 5 gear ratios will have an averaged cost >$300/gear. (1st gear being one with the main shaft is roughly double the cost of the other 4 gears.) There are a number of reasons the G50 is considered better suited than the older transaxles: stronger and more modern sychros, but primarily because it marked the beginning of the use of hydaulic clutch actuation. This and the fact that it is a 4 speed cause many to overlook the 930/935 which is a very stout transaxle as well.

Regards,
Lynn

[Tim Kay]

Lynn,

Good info. I realize the 930/935 is a viable option but I think having a 5th gear is more desireable.

[Chuck]

It is that fifth gear that makes the G50-50 for turbo's the best (and most valuable) gearbox of the old generation Porsche boxes. Lynn got a good deal on his and somebody here in Houston recently snagged a good deal on one. Keep your eyes peeled to ebay, rennlist and pelican parts classifieds. You'll find a g50-50 and be glad you made the switch.

Chuck
working too dang hard to enjoy my car lately. Crap. [img]/ubbthreads/images/graemlins/frown.gif[/img]

[Tim Kay]

Lynn,

If I may ask, what did you pay for your G50/50, condition, did you go through it to replace\change gearing, ect?

Tim

[Lynn]

I got VERY,VERY lucky and got it for $3K plus shipping. The G50/50 really has the best gearing of the lot, so no I will not change the gearing. I do plan to put a pump, cooler and spray system to some extent on the transaxle. I already have the parts for this except the spray system. The configuration of the spray system will depend on what I can get a nozzle on without having to break down the shaft structure. At a minimum, I will spray the R&P. With the use I plan for the car, this would be adequate; if I can spray the gear sets it will just be a plus.

Regards,
Lynn

[Tim Kay]

"Spray System" what is this?

[Bill Bayard]

Tim,

It's a pump pressurized spray setup,
which continuously "bathes" the R&P,
as well as 1st through 5th.
Reduces friction and thereby heat.
They are generally used in conjunction with a
gearbox oil cooler.

Bill

[Bill Musarra]

Look up the thread on "Porsche transmission oil coolers. You'll find a great discussion of these:

Bill