I am in the process of planning an F40 swap into my Fiero. I have read all of the posts I can find in Pennocks, and by accident I stumbled into two other F40 installs on other forums. One install was in a Grand Prix and the other was in a Grand Am. According to his posts, the Grand Prix guy put wheel bearings from a 2002 Malibu with ABS into his car and it accepted the F40 CV axle splines. Has anybody looked into this approach for the Fiero? BTW, one axle worked fine, but the other was too short. He only had to have one custom axle made.
Jim

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87 T-top 2.8 5sp Camaro Dash Bonneville door panels; 86 355 body & interior kits 3.1 Auto; 85 SE 2.5 5sp, 86 SE 2.8 auto parts car

The outer CV spline is really a moot point for the F40 axles from a fitment standpoint. By disassembling the CV race/balls you can swap on a fiero compatible end.

Now there are some ongoing dicsussions about upgrading the outer CV to one with a larger spline area to reduce breakage... on several high power fieros the are twisting off the CV right at the splines for the wheel bearing.

Here is the stock fiero size:


Stock F40/G6:


Large format 33 spline on most larger FWD GM cars:

Fieroguru, can you tell me if the actual axle diameters in the pictures you posted above are also as large as the CV joint stub shaft diameters? I seem to remember measuring a difference in various Fiero axle diameters (perhaps between auto (0.900") and manual trannies (1.020")) but regardless, you'd think the weak link would be the area of the smallest diameter. If the stub shafts aren't the same diameter as the axle shafts, then you would probably need to upgrade one or the other part to the larger diameter of the two to get any benefit.

I am confused now. My understanding is that the F40 axle shaft will not fit a Fiero CV. Are you telling me that there is a CV that will accept the F40 axle and fit the Fiero spindle/bearing? If so, why does Archie use custom axles that fit the Fiero CV? What CV assemblies will work? What have other people used? Is the length of the F40 axles correct for the application?
Jim

quote Originally posted by Bloozberry: Fieroguru, can you tell me if the actual axle diameters in the pictures you posted above are also as large as the CV joint stub shaft diameters? I seem to remember measuring a difference in various Fiero axle diameters (perhaps between auto (0.900") and manual trannies (1.020")) but regardless, you'd think the weak link would be the area of the smallest diameter. If the stub shafts aren't the same diameter as the axle shafts, then you would probably need to upgrade one or the other part to the larger diameter of the two to get any benefit.

I can get those when I get home this evening. I do not mess much with the skinny automatic axles, just the manual transmission axles and similar thicknesses. The thing to keep in mind is this portion of the CV shaft is also in tension holding the wheel bearing together while it is esposed to the torsional stresses... The axle is just hanging around and only resiting torsional forces.

quote Originally posted by bowrapennocks: Is the length of the F40 axles correct for the application? Jim

As I understand from all the F40 threads, there are no stock GM axles that are the correct length for using the F40 in a Fiero.

quote Originally posted by bowrapennocks: I am confused now. My understanding is that the F40 axle shaft will not fit a Fiero CV. Are you telling me that there is a CV that will accept the F40 axle and fit the Fiero spindle/bearing? If so, why does Archie use custom axles that fit the Fiero CV? What CV assemblies will work? What have other people used? Is the length of the F40 axles correct for the application? Jim

When looking at the outboard CV joint assembly you have: the actual AXLE shaft, it slides into a STAR, BALLS surround the STAR, and the BALLS fit within the CV stub housing.

The F40 axle shaft is 34 spline vs. fiero's 32 so you can't just slide the AXLE into a Fiero CV STAR. But the STARs are the same between the two, so by swapping the F40 axle and corresponding STAR you can put them into a fiero CV housing on the end.. details of all this are in the Diyer 6 speed thread. This is also the same process the 3800 guys take to build the appropriate length axles.

Custom axle shafts for the F40 install is really all about length due to the wider and offset differential. These custom lengths all boil down to engine/tranny side to side placement. Archie's F40 kit is based on the tranny bellhousing being 7" offset to the driver side of the cradle centerline. About 5" is as far as you can go before the DS frame rail needs a trim and tuck.

[This message has been edited by fieroguru (edited 11-04-2010).]

quote Originally posted by fieroguru: But the STARs are the same between the two, so by swapping the F40 axle and corresponding STAR you can put them into a fiero CV housing on the end.. details of all this are in the Diyer 6 speed thread.

Not exactly. I mentioned this somewhere before and Bloozeberry addressed it by referencing the difference in diameter among the axles. There is a smaller joint probably used on the automatics that will not work. I discovered this while in the process of building a second axle. As long as you use the internals from the manual tranny joints there shouldn't be a problem.

quote Originally posted by fieroguru: I still haven't given up...

Me either, but I haven't gotten around to getting the engine/trans mounted to the cradle for fitment yet.

I have been looking at various sources to get G6 axles. What I found was a little disturbing. The part numbers shown below are for 2006 3.9L F40 6SP manual transmission axles. I have been told but have not been able to confirm that the manual transmission axles for the 3.5L are the same.

10357933 SHAFT KIT, FRT WHL DRV - RH superseded by 15918505
10357932 SHAFT KIT, FRT WHL DRV - LH superseded by 15918504
22668353 SHAFT, FRT WHL DRV INTERMEDIATE

I spoke with Archie and he told me that GM made a change in design on the RH and LH axles without changing part numbers. The design change was the number of splines on the axle shaft. The early ones were 33 splines and the others were 34. GM said they did not need to change the part numbers because each side is sold as an assembly. Archie carries custom LH and RH axle shafts in both spline counts. Notice there is also a new part number. I do not know if that represents a third design that might affect what we need.

Joseph Upson and others doing F40 installs:

What is your final configuration of axles, including intermediate shaft, outboard joint, axle shaft, tripod?

To All: Thanks for all of the information above.
Jim

Any comments on the part numbers?

When did we rule out the supposedly weak axles from the supercharged Cobalt SS with F35?

Has anybody used these successfully? If so, which axles were used where? Intermediate shaft, LH, RH?

I make a combination with stock axle and 2 driver side axle G6, i used inner side (bell housing) of G6 and center shaft of the fiero, I custom made the tripod bearing for use the bell housing G6 and the fiero center shaft, one of the bell housing you have to make a 1 inch sleeve for seal this one is for the passenger side, basic you have same setup like stock fiero axles!!!!!! and I been driving for 3 year and no problem!!!!

Elitopr
Thank you for your solution, I would love it if you could provide a hand sketch of exactly what you did, which parts go where, and any dimensions.

Thanks
Jim

Bowra, keep in mind that these solutions somewhat hinge on your engine choice and positioning. Or may require moving your engine, and maybe cutting metal to clear the engine. The F35 axles should be fine for fitting a V6, but might not allow an SBC, for example.

I recognize the engine position issue, and that is why I would like to hear about the solutions that have actually worked on the street. Since I have not chosen my engine yet I have the freedom to explore what the possibilitie are so I can look at both cost and HP. One of the reaseons for thinking about an LS4 is that it was made for FWD, is shorter, and delivers incredible power. It also relocates the water pump making installation easier

My son has a 3800 S/C auto and while not as powerful as an LS4, the wine of the supercharger is fantastic. Low mileage 3400s and 3800s are fairly cheap here. LS4s are more pricey. As I recall Feiroking paid well over $2000 for the LS4+auto that he swapped into a Fiero.
Jim

quote Originally posted by bowrapennocks: Elitopr Thank you for your solution, I would love it if you could provide a hand sketch of exactly what you did, which parts go where, and any dimensions. Thanks Jim

well lets try!!!! my english it's not good at all.
1- (G6) you will need two driver side bell housing and tripod bearing from G6 F40 (why two driver side? cuz G6 on passernger side used intermediate shaft holding by the engine and you will not used)
2- (G6) one of the bell housing you have to make a 1 inch sleeve to press fit on the input shaft of the bell housing why that? cuz that side of the tranny is one inch shorter
3- (Fiero) take two original fiero tripod bearing and cut 5mm each side all 3 why? cuz the fiero tripod is too big for the G6 bell housing (fiero tripod bearing got a bigger diameter but smaller bearings and G6 tripod bearing has small diameter and bigger bearing)
4- (Fiero) when you finish cut each side of the fiero tripod you have to make a groove on each side that is for relocaded the bearing clips (you will need everyting on the fiero tripod)
5- (fiero tripod) cut 5mm each roll bearing (little pins) that is hard to do it and do it rigth its more than 100's
6- (fiero tripod) cut 5mm each roller (the big ones has 3 roller each tripod)
7- (fiero tripod) the out side of the roller (big ones) has to slowly wear out until those press fit on... continus on 8
8- (G6 tripod) each G6 roller (big ones 3 on each tripod)
9- you will need the G6 inner axle boot
10- isntall the boot and this custume make tripod bearing on to your Fiero center shaft and instal the G6 bell housing
11- you ready!!!!
Resume!!!!!
my car has this set up its like have fiero axle with G6 bell housing when is finish looks like the stocks fiero axle
if you need something else let me know.
good luck!!!!!!!

Thanks for the detail, I will study it tomorrow.
Jim

If the transmission is located between 5.5 and 5.0" offset from the centerline of the cradle to the driver side and you can cut/weld, you can go the hybrid tripod approach and use stock axle shafts.

The driver side uses a Torrent/equinox inboard tripod housing for the proper 27 spline and a 96 Corsica tripod case. Essentially you cut both in half, machine to fit and then weld them up together making a hybrid tripod that will fit the F40, but use a 96 corsica axle shaft & outboard CV (fiero compatible).

The Passenger is the same except you use a 99 Saab 9-5 tripod for the F40 side (it is about 1/2" longer and helps make up the distance from the offset differential) and a stock fiero manual tripod for the cage. Cut, machine and weld, then you can use a factory PS fiero manual axle shaft/out board CV. Now a traditional tripod will not fit all the way in on the passenger side and some have added a seal sleeve and reuse the original oil sleeve. I machined an aluminum housing extender and installed a fiero axle stabilizer bearing/seal to seal up the area and help stabilize the tripod sticking out further that it was designed for.

quote Originally posted by fieroguru: Axles The tripods spline for the F40 is 27 and there are several sources of tripods that will fit the F40 transmission: G6/F40 stock axles Cobalt/Redline Supercharged 5 speed axles 1999 Saab 9-5 GM 5 speed autos (Torrent, Equinox, Aura, etc...) For my first set of axles, I will be using hybrid tripods and factory GM axles. Essentially taking 2 tripods, and using the F40 compatible spline part with fiero and corsica style tripod cages and welding them together. The driver side will be using a 96 Corsica axle (Passenger side, 4speed auto). It has fiero compatible outer CV, the shortest GM axle shaft, and the same axle shaft splines as the maual fiero. The corsica rollers are different than the fiero, so I will use the Corsica roller cage. For the splined part for the transmission, I will use an OEM torrent tripod. With the help of a 4 1/2" cut off wheel and a hand held grinder, I quickly rough cut the tripod housing off the Torrent shaft portion: Then with a flapper disk on the grinder, I took off the excess material then chucked it in the lathe to finish the machine work. Next the shaft portion was cut off the Corsica tripod housing, then put in the lathe to remove all the needed material to slide the 2 parts together. Test fit to check how much more material to remove off the shaft end: Just needs welding inside and out: This is what I was after, a shorter hybrid tripod so the 96 corsica axle shaft will work on the driver side. Wrapped the machined surfaces with some tape and fired up the welder... Corsica/Torrent on driver side: On the passenger side, I want to reuse the stock passenger fiero manual axle. A hybrid tripod between a stock fiero and Saab 9-5 yielded a hybrid tripod that was 1/2" longer than the Corsica/Torrent. This helps make up for the differential being offset to the driver side about 1": To support the tripod further out and to provide a means to seal it, I made a pressed in bearing housing to use one of the fiero axle stabilizer bearings. Here is the axle stabilizer bearing (same for all manual tranny fieros). Techpack #75125LRB (replacement seal is TC-1.375). Price: $23.45 each + shipping from http://www.transmissionpart..._p/609-075125lrb.htm Upon test fitting the DS corsica axle, I noticed the tripod cage was too long and not allowing full axle articulation. To fix this issue, I cut the outer set of CV boot grooves off and will use the inside ones instead (boot only uses 1 set). Driver Side Corsica Axle Clearance with Modified Torrent/Corsia tripod: While the lateral links were level and the axle nut removed, you can push the axle shaft through the hub so it becomes fully bottomed in the tripod cage. On the driver side the distance from the outer cage face and the outer surface of the tripod roller was 1 1/16". Once the axle nut was installed and the axle fully seated in the wheel bearing, the distance became 1/2, which is just about dead center of the shortened length of the tripod cage. Passenger Side Fiero Manual Axle Clearance with Modified Saab 9-5/Fiero tripod Same setup and the fully compressed distance was 2 3/8 and the tighented axle nut resulted in 1 1/16, again just about centered. This is how I measured the outer cage face to the outer edge of the roller: These axles and hybrid tripods have the tripod rollers within 1/16" of being centered on each side with the current placement of the engine/tranny. Which also has about 3/16 to 1/4" of clearance between both frame rails and the tranny/balancer.

My LS4/F40 swap will have the transmission about 5.0" offset from the centerline to the DS. With this setup I want to use all factory axles/hardware and will be starting with a set of G6 axles and swap in oem shafts that are longer & shorter than the factory G6 ones, but should have the same axle shaft splines allowing the swap. I am still researching the intermediate shafts to see which way I decide which one to use. The Saab 9-3 and 9-5 accepts the DS axle, but not the female passenger side the F40 intermediate shaft... it will all come down to the relative lengths and the ability to pair the axles up with factory lengths...

Joseph Upson used the factory F40 axles. The passenger intermediate, passenger axle and just swapped in the fiero outboard joint. For the DS he has the F40 axle cut/resplined about 2" shorter and used a fiero outboard... this is the simplest approach, but I want factory axle shafts so when I brake one away from home I can get one the same day.

The 5 speed auto and 6 speed auto are starting to be produced in great numbers and these transmissions have F40 compatible tripods (like the Torrent/Equinox one I used) and also have intermediate shafts which might be slightly shorter than the F40's...

[This message has been edited by fieroguru (edited 11-08-2010).]

So Upson has to carry a spare shortened DS axle. It's very small, and weighs virtually nothing. But your 4.3 will never break an axle anyway, even with nitrous and drag radials, so why worry?

This is great...keep your solutions coming.
Jim

Any more insight into the axle PNs that I gave above or any other axles solutions?

Thanks
Jim

I believe we've covered everything that's been researched. Either copy something proven, from guru, upson, Archie or elitopr, or pioneer something else for us. :-)

[This message has been edited by Isolde (edited 11-11-2010).]

quote Originally posted by fieroguru: If the transmission is located between 5.5 and 5.0" offset from the centerline of the cradle to the driver side and you can cut/weld, you can go the hybrid tripod approach and use stock axle shafts. The driver side uses a Torrent/equinox inboard tripod housing for the proper 27 spline and a 96 Corsica tripod case. Essentially you cut both in half, machine to fit and then weld them up together making a hybrid tripod that will fit the F40, but use a 96 corsica axle shaft & outboard CV (fiero compatible). The Passenger is the same except you use a 99 Saab 9-5 tripod for the F40 side (it is about 1/2" longer and helps make up the distance from the offset differential) and a stock fiero manual tripod for the cage. Cut, machine and weld, then you can use a factory PS fiero manual axle shaft/out board CV. Now a traditional tripod will not fit all the way in on the passenger side and some have added a seal sleeve and reuse the original oil sleeve. I machined an aluminum housing extender and installed a fiero axle stabilizer bearing/seal to seal up the area and help stabilize the tripod sticking out further that it was designed for. My LS4/F40 swap will have the transmission about 5.0" offset from the centerline to the DS. With this setup I want to use all factory axles/hardware and will be starting with a set of G6 axles and swap in oem shafts that are longer & shorter than the factory G6 ones, but should have the same axle shaft splines allowing the swap. I am still researching the intermediate shafts to see which way I decide which one to use. The Saab 9-3 and 9-5 accepts the DS axle, but not the female passenger side the F40 intermediate shaft... it will all come down to the relative lengths and the ability to pair the axles up with factory lengths... Joseph Upson used the factory F40 axles. The passenger intermediate, passenger axle and just swapped in the fiero outboard joint. For the DS he has the F40 axle cut/resplined about 2" shorter and used a fiero outboard... this is the simplest approach, but I want factory axle shafts so when I brake one away from home I can get one the same day. The 5 speed auto and 6 speed auto are starting to be produced in great numbers and these transmissions have F40 compatible tripods (like the Torrent/Equinox one I used) and also have intermediate shafts which might be slightly shorter than the F40's...

Awesome research and I'm glad you've found a solution, but I don't think I'm alone in my reservations about attempting this myself. I don't have a lathe and I would be concerned about my ability to accurately get the centerline of the cut tripod shafts lined up with the centerline of the cut tripod cups. How did you do that?

Another question I have is about the mounting location of the tranny/engine combo. I see people talk about axles a lot, but rarely mentioned is where their particular engine is mounted. Without a standardized set of engine mounts I had assumed that it would matter where exactly the engine sits. Then I see in your posts that there is just a little bit of clearance on either side, so maybe there isn't much choice for where the engine goes? Can somebody clear this up for me? Is there not much room so all these combinations basically have the engine mounted in the same location on the cradle?

Finally, that seems like a lot of different axle pieces to purchase. I assume you sourced these mostly from a U-pull-it type junk yard. I personally have never been to one, can someone give me an idea of what axle components should cost from a yard?

Thanks

quote Originally posted by TG oreiF 8891: Awesome research and I'm glad you've found a solution, but I don't think I'm alone in my reservations about attempting this myself. I don't have a lathe and I would be concerned about my ability to accurately get the centerline of the cut tripod shafts lined up with the centerline of the cut tripod cups. How did you do that? Another question I have is about the mounting location of the tranny/engine combo. I see people talk about axles a lot, but rarely mentioned is where their particular engine is mounted. Without a standardized set of engine mounts I had assumed that it would matter where exactly the engine sits. Then I see in your posts that there is just a little bit of clearance on either side, so maybe there isn't much choice for where the engine goes? Can somebody clear this up for me? Is there not much room so all these combinations basically have the engine mounted in the same location on the cradle? Finally, that seems like a lot of different axle pieces to purchase. I assume you sourced these mostly from a U-pull-it type junk yard. I personally have never been to one, can someone give me an idea of what axle components should cost from a yard? Thanks

Precision machining will keep the centerlines of the splined portion aligned with the tripod cup...

Transmission placement is a critical dimension for axle lengths. Some want to keep the transmission in the same place as stock or where there swapped engine is now to save from making/modifying existing mounts/brackets/exhaust. My SBC/F40 setup using a 1/8" adapter plate had less than 1/2" combined clearance between the frame rails, so not much ability to move side to side without notching a frame rail. The 4.3/F40 had several inches to play with, but I kept it in the sam location as the SBC/F40 (used the same cradle). My LS4/F40 has about 2" of room between the frame rails at the harmonic balancer, but there are other factors coming into play that will limit the area where the F40 must be.

All my axles have been purchased off ebay... most of them used for about $65 shipped on average... but all told just for the F40 R&D I have purchased about 15-20 different axles for measuring/dismantling/education... purchased 5 of them just a couple of weeks ago.