ASAP needed buy advice porsche G50,

[Thomas Rouw]

Hey all,

I've been offered an in "good working order" Porsche G50-03 transmission,
from an accident car for a good price. NON LSD type, 5 speed. 80.000km

The problem is, I'll need to go and look tomorrow, and appart from the obvious of carefully inspecting the case for cracks etc etc, I would like to have a few tips on what to look for.

so are there any problems that can be detected from the outside on this sort of box? any parts that woul be good to have with it?

grtz Thomas

 

[Bill Musarra]

If you have a good porsche mechanic, have him look at the internals. That box may need rebuilding, unless you know the history of the box.

Bill

 

[Joe T]

If you can only do a visual inspection prior to purchase,
check the oil level, and see visually what the oil is like. if you get enough out stick a magnet in it for particles.
Try turning the spigot shaft by hand check for lost movement before output shafts turn.
Check the clutch splines on the spigot shaft, could give an indication to usage, any steps in the end of the shiney part of the splines etc.
Check the end of the spigot shaft for burrs or damage.
Try selecting some gears.

Cheers

Joe T

 

[Thomas Rouw]

Thanx for the help all,

Joe I tried everything in you post and all seems ok, I couldn't find any scuffing on the splines, so I took the step and bought it.
the only thing missing is the release fork itself, the hydraulics are all on the box as are the shaft flanges etc etc....
it's a G50-03 1L so 5 speed non LSD and very heavy! compared to a UN1, I'll post a piccie with dimensions in the near future.

I'm Happy man. now lets bolt it up to the twin supercharged 1uzfe

Grtz Thomas

 

[Torgeir Maurangsnes]

Thomas

Can you tell me where you get the adapterplate and flywheel to G50/03 - 1UZFE combination?

Thank you

 

[flatchat(Chris)]

:embarassed: Here !

 

[Erik Johnson]

I am going to highly recommend that you make sure that the inversion process on this gearbox is down completely correct. Meaning that you have new oiling passages drilled into the case to ensure that you get proper oiling.

I would highly recommend a cooler and pump, as well. But most important I would recommend that you have a billet side plate installed to ensure that you get no deviation of the ring and pinion with that kind of HP and Torque.

The G50.03 is a good strong gearbox, but is not ideal in my opinion for applications over about the 600 HP range. I am assuming here that your twin supercharged engine is going to be be north of that mark.

If you take a few precautions I think that you will enjoy substancially longer life to the gearbox. If not, do not be surprised if you see it fail.

Just my .02 cent on this, hope that this information is helpful in some way.

Warmest Regards,


Erik Johnson
Carquip Sales
(303) 443-1343 ext 2 work

 

[Darnel A.]

I am going to highly recommend that you make sure that the inversion process on this gearbox is down completely correct. Meaning that you have new oiling passages drilled into the case to ensure that you get proper oiling.

I just bought a G50 trans for my GT40 project. You mentioned drilling new oiling passages into the Case for an inverted G50. Can you elaborate? I thought just swapping the Vent with the Fill and increasing the amount of oil would suffice for the street.


Darnel

 

[Eric]

I thought just swapping the Vent with the Fill and increasing the amount of oil would suffice for the street.

Darnell

For a street application, it is my understanding you are correct. The G50-0x should be fine for any reasonable street horsepower/torque values with stock internals. Just invert it as you indicated. If you're running say 400 HP and 350 ft-lbs or thereabouts, you'll be fine. A couple of different GT40 manufacturers have told me this; one even told me the non-LSD version is better for the street. To paraphrase that manufacturer, I was told "don't let the forums talk you into something you don't need."

FYI, transaxles was the one area where I was completely oblivious, so when I started down this road, I did a lot of research. In a nutshell, I found that all of the upgrade recommendations are for race applications, but not needed for street-only use.

I'm sure there will be many posts telling me how wrong I am, so take what I have said here for what you want.

Eric

 

[Woody]

I am going to highly recommend that you make sure that the inversion process on this gearbox is down completely correct. Meaning that you have new oiling passages drilled into the case to ensure that you get proper oiling.

I would highly recommend a cooler and pump, as well. But most important I would recommend that you have a billet side plate installed to ensure that you get no deviation of the ring and pinion with that kind of HP and Torque.

The G50.03 is a good strong gearbox, but is not ideal in my opinion for applications over about the 600 HP range. I am assuming here that your twin supercharged engine is going to be be north of that mark.

If you take a few precautions I think that you will enjoy substancially longer life to the gearbox. If not, do not be surprised if you see it fail.

Just my .02 cent on this, hope that this information is helpful in some way.

Warmest Regards,


Erik Johnson
Carquip Sales
(303) 443-1343 ext 2 work

HI Erik
I am new to this forum so I am still finding my way around.
I have been building my 40 for a year now and have purchased a G50/01
and I'm interested in your comments about drilling into the case to make a new oiling passage. Are there any drawings or info on how to do this?
Also is there any drawings for building a stronger side plate.
Any info would be appreciated
Cheers
Woody.

 

[Peter]

Anybody buy a G50 from these guys?
California Motorsports G50 5 speed section

They seem to sell them outright which is great for kit car guys.

Mention on their site about "inversion prep" and oiling, etc. Tons of upgrade parts. But man.... gets expensive. Even a new cable shifter is $900. Ouch. :cry:

Here's another link for kit cars http://www.californiamotorsports.net/Kit car.htm

They list all the specs and have great pics of all the Porsche transaxles suitable for kit cars.

 

[Julian]

I have a CMS G50/52 with side shifter, billet side plates, oil spray bars, cooling etc. in my Ultima. It's a great box and the CMS guys really do know their stuf, with great customer service and tech information.

That said my G50 was $13.5K transaxle when all done, which does what it was intended for in the Ultima, but for a GT40 if I were spending that money I would get a fully rebuilt ZF or a ZFQ and I'd still have change with a period correct look.

My 2 cents

 

[Woody]

Does anyone have spec's or drawings on modifying a G50 case for the spray bars and / or extra oiling

 

[Pete T]

I agree with Joules5 about CMS. I ought the dog teeth for my G31 from them. The G31 uses dog teeth that are different from any other Porsche transaxle. They know about these and have dog teeth made for them. They are great to work with and really know their stuff.