F40 Differential Spline Data - CV Spud options

[FieroWanaBe1]

I have been looking into this more.
What I know so far:

F35 Application such as a HHR/Cobalt Axles have the same spline engagement for this app in a Fiero. These cars run jackshafts. Supercharged cars have matching outboard splines to the Fiero, Probably a GM Econo Box Carry over (J-Body ETC)

The G6 F40, This also runs a jack shaft but a female splined passenger side CV cup. Axle shaft changes mid production make this tough to nail down.

Saab 9-5 F40 Application, OG F40 Usage, Jackshaft as well. Slightly stronger axles it seems, and is a closer matched with the Regal application/Turbo Cobalt F35. (which I know nothing really about) But I believe they used the same axle L and R.

I bought a 9-5 Jackshaft.
The F40 design has different seal placement L and R to accommodate always having a Jackshaft, seal placement isn't equal.

My Idea is to have custom Stub shafts made/modified for a 934 CV joint, and have axle shafts splined to use the 934 Spider sets.

I am looking into feasibility of this, as far as plunge depth, and max angularity.

Stub shafts for the outboard joints are available for the Corvette 33 spline, I haven't found any for the S10 27 Spline, yet.

Quaife Publish F40 Differential Data, 27 Spline, 24/48 DP 45Deg Pressure angle:

Screenshot 2023-09-14 103340.jpg (149.36 KiB) Viewed 5488 times

Measurements from a cobalt axle:

source: ccfiero350 the tulip side, the cobolt (top) is bigger, the dia. is 1.175 with the spline at 1.150"

Spline Data as calculated:

Screenshot 2023-09-14 104029.jpg (111.8 KiB) Viewed 5488 times

Good data on axle shafts from Mark Williams:
https://www.markwilliams.com/axles-schmaxles.html

[FieroWanaBe1]

Example of the end goal:

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[Series8217]

The 934 joint is massive and heavy. It is used for applications like unlimited class Baja trucks. At the low angles you are running with a Fiero, I can't imagine you would need more than a high quality 108mm joint, or maybe a GKN size 18 if you're going to be drag racing on a treated surface with slicks.

You can buy EMPI 33-spline stubs that take the 930 joint that is commonly used in the high torque axle builds from Driveshaft Shop.

Note that 930 was just the Porsche application for the joint. It's actually a GKN "size 15" and used in many different cars. There are a few different versions of it depending on if you want it to plunge and by how much, and if you want a 28 or 30 spline star.

There is also a GKN size 18 which has a diameter of 115mm, 25.4mm balls, and is used in high HP RWD applications like modern Camaro ZL1s. It has a 100mm bolt circle and takes a 30 spline axle shaft.

You don't have a lot of options for S10 27-spline outer CVs, but check if the E36 BMW 27 spline happens to be a match. It might have the wrong pressure angle though. If it does fit, those outer CVs should take a 28 spline shaft that mates with a 930 CV on the inboard side.

[FieroWanaBe1]

We have used the GKN CV 15 in some applications at my work, and a we have a driveshaft using the the GKN 18 joint at both ends, They hold power very well.

I like to refer to them as their colloquial usage terminology as the auto aftermarket does as well, and offer "upgraded" interchangeable parts referencing the application, not the catalog GKN size. it is similar to the U joint sizes and compared to what is listed in the Spicer catalog as their P/N sizing.

I did see the light duty BMW's e30 and e36 had a 27 spline hub, Maybe I can find one local to check out, I know someone with a 6.0L powered 318 and he ruins axles regularly.

I think if it can interact ok with Jeep/S10 hubs, these may be useful:
https://www.seemslegitgarage.com/produc ... axle-stubs

[Series8217]

Unfortunately it looks like the BMW stubs use a 30 degree angle instead of the 45 deg that GM likes to use.

[FieroWanaBe1]

Unfortunately it looks like the BMW stubs use a 30 degree angle instead of the 45 deg that GM likes to use.

That's a Bummer.

[Series8217]

Will these plug into the F40? Compatible with GKN size 18, based on the Camaro axle I have for reference.
https://www.summitracing.com/parts/ado-84371225

[FieroWanaBe1]

The seal surface on that stub appears to be much larger diameter than the f40's seals, but the splined end looks promising.

[FieroWanaBe1]

Since I only currently have the Saab 9-5 Intermediate Shaft, I ordered a set of GSP axles (same for length for passenger and driver) from Rock Auto at $55 a piece.
These are new axles, so I will assume the inner shafts will be in now way compatible with stock GM parts, but Ill have some starting point for the stubs, and they were cheaper than used parts.

https://www.summitracing.com/parts/gna-ncv62001

If the Corvette/CT6 stubs can be modified to work, it requires machining and grinding the seal/bearing surface at the cost of the hardened surface. I imagine it would cost over $200 a pair to have modified by machining chrome plating, and finish grind, bringing it to $400 for the set, I should compare that option to fully machined set from Mark Williams or similar outfit.

[FieroWanaBe1]

The seals used on the F40:

NATIONAL 3543 Specifications
Flanged Outside Diameter (in) 2.441
Flanged Outside Diameter (MM) 62.000
Helix Type Bi-Directional Lip Design
Housing Bore (IN) 2.162
Housing Bore (MM) 54.915
Inside Diameter (IN) 1.378
Inside Diameter (MM) 35.000
Material Silicone
Outside Diameter (IN) 2.167
Outside Diameter (MM) 55.042
Overall Width with Side Lip (in) 0.577
Overall Width with Side Lip (MM) 14.656
Redicoat Yes
Sealing Material Silicone
Shaft Diameter (IN) 1.378
Shaft Diameter (MM) 35.000
Thickness (IN) 0.425
Thickness (MM) 10.795
Type 57
Width (IN) 0.425
Width (MM) 10.795

[FieroWanaBe1]

Camaro/CT6 Seals, cross ref'd to gm parts direct catalog:
GM GENUINE 291352 Specifications
Color Brown, Black
Inside Diameter (IN) 1.89
Inside Diameter (MM) 47.92
Material Rubber
Outside Diameter (IN) 3.26
Outside Diameter (MM) 82.69
Rim Shape Round
Seal Type Gasket
Sealant Included Yes
Shape Round
Thickness (IN) 0.58
Thickness (MM) 14.83
Width (IN) 3.48

[Series8217]

You thinking to cut the tripod and weld on a flange to the stub? I don't see why that couldn't work. Even some of the OE Audi/VW tripods have a welded on flange.
Now that I think about it I talked to Chris West about 930 axles a few weeks ago and he said he has done exactly that for an F40 before.

[FieroWanaBe1]

You thinking to cut the tripod and weld on a flange to the stub? I don't see why that couldn't work. Even some of the OE Audi/VW tripods have a welded on flange.
Now that I think about it I talked to Chris West about 930 axles a few weeks ago and he said he has done exactly that for an F40 before.

That's one of the options, and the most achievable, provided enough weld strength is achievable in the joint.

[The Dark Side of Will]

F35 Application such as a HHR/Cobalt Axles have the same spline engagement for this app in a Fiero. These cars run jackshafts. Supercharged cars have matching outboard splines to the Fiero, Probably a GM Econo Box Carry over (J-Body ETC)

The G6 F40, This also runs a jack shaft but a female splined passenger side CV cup. Axle shaft changes mid production make this tough to nail down.

I thought the F23 used the same differential splines as the Fiero and the F35 used the same as the F40.

[The Dark Side of Will]

I have a set of the Ecotec racing inner flanges. I can install to my 282 along with the F150 33 spline outer flange and take flange to flange measurements throughout suspension travel. This will give the plunge requirements. That will take a few months, though.

[FieroWanaBe1]

All those data points would be helpful.
of my cars, non currently have a transmission in them, and only one has the cradle in it at this point.

[FieroWanaBe1]

https://www.kartek.com/parts/930-micro- ... ength.html

These should work with

https://www.kartek.com/parts/timken-513 ... -hole.html

Which is a timken 513013.

Interchange applicaitons from Rock Auto:

BUICK RIVIERA 1979-1985
CADILLAC ELDORADO 1979-1985
CADILLAC SEVILLE 1980-1985
CHEVROLET BLAZER 1991
CHEVROLET S10 BLAZER 1983-1991
CHEVROLET S10 PICKUP 1983-1993
GMC S15 JIMMY 1983-1991
GMC S15 PICKUP 1983-1990
GMC SONOMA 1991-1993
OLDSMOBILE TORONADO 1979-1985

I do believe the s10 27 spline matches the jeep 27 spline (which has rebuildable hubs- Crown

TIMKEN 513013 Specifications
Bearing Type BALL
Bolt Circle Diameter B (IN) 4.750
Bolt Circle Diameter H (IN) 4.750
Bolt Quantity 3.000
Bolt Size (IN) M12x1.75
Brake Pilot Dia (IN) 2.780
Driven or Non Driven? Driven
Flange (#) 2.000
Flange Diameter (IN) 5.689
Flange Offset (IN) 1.861
Flange Shape Modified
Generation Type 3
Hub Pilot Dia G (IN) 3.209
Roll Form (Y) N
Spline Quantity 27.000
Wheel Pilot Dia (MM) 70.100
Wheel Studs (Y/N) Y
Wheel Stud Qty 5.000
Wheel Stud Size (IN) M12X1.5

Crown 53000228 Interchange (Timken 513107):
TIMKEN 513107 Specifications
Bearing Type BALL
Bolt Circle Diameter B (IN) 4.500
Bolt Circle Diameter H (IN) 4.750
Bolt Quantity 3.000
Bolt Size (IN) M12x1.75
Brake Pilot Dia (IN) 2.828
Driven or Non Driven? Driven
Flange (#) 2.000
Flange Diameter (IN) 5.669
Flange Offset (IN) 1.811
Flange Shape Modified
Generation Type 1
Hub Pilot Dia G (IN) 3.937
Roll Form (Y) N
Spline Quantity 27.000
Wheel Pilot Dia (MM) 71.300
Wheel Studs (Y/N) Y
Wheel Stud Qty 5.000
Wheel Stud Size (IN) 43832.000


They also make these:
https://www.kartek.com/parts/kartek-off ... -hole.html

[FieroWanaBe1]

Chromoly 930 drive flanges for a type 1 and type 2 VW's are very cheap:

https://kingoffroadparts.com/chromoly-9 ... -cv-joint/

I'm not a fan of welding chromoly, but it can be done by a competent shop.
A better option would be a double male spline stub F40 spline to VW spline (with a tight fit in the flange)

VW Trans Output seal SKF 14045
SKF 14045 Specifications
Width (IN) 0.315
Shaft (IN) 1.417 (36mm)
Bore (IN) 2.362 (60mm)
Outer Diameter (IN) 2.368
Boretite Y

[FieroWanaBe1]

Recieved the 9-5 Axles.
Confirmed the match the F40 spline and diameter, and the 9-3 intermediate shaft.
Outer spline matches the Fiero spline, the 9-5 hub seal diameter is different.

Some time down the road I will compare the CV joints, but the fact that my Fiero axles are all GM OEM units and these Saab axles are new aftermarket I wont hold my breath on any compatibility.

However these should be a good candidates for the inner CV cups to become part of some VW inner 930 CV Stub axles.

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