My 1988 LFX F40 build. (Page 55/68)
RandomTask OCT 12, 06:33 PM
Daryl, question for you; How do your axles look installed? I used the cobalt axles. I mounted up the suspension to get the car on the ground and while the drivers side looks good, the passenger side seems a little stretched. If I don't have the strut on, at max drop (not possible in running condition) you can feel the axle bearing start to leave the cup. While its fully in the cup on max drop with the strut installed, the boot seems a little stretched. Just wondering if you ran into this. I think I may need to move everything to the passenger side by a half inch.
Joseph Upson OCT 13, 07:06 AM

quote
Originally posted by RandomTask:

Daryl, question for you; How do your axles look installed? I used the cobalt axles. I mounted up the suspension to get the car on the ground and while the drivers side looks good, the passenger side seems a little stretched. If I don't have the strut on, at max drop (not possible in running condition) you can feel the axle bearing start to leave the cup. While its fully in the cup on max drop with the strut installed, the boot seems a little stretched. Just wondering if you ran into this. I think I may need to move everything to the passenger side by a half inch.



Centering the assembly to help accommodate optimum axle arrangement is part of the deal unless you have custom axles made, although keeping the driver side axle as long as possible, which favors repositioning the assembly is probably better to avoid axle/joint separation when lifted. It has been several years since I swapped the F40, so I don't recall which side, but the axle seal to axle seal width is 1" wider to one side on the F40, compared to the stock options. I recall the Cobalt axles being equal length, so the difference will need to be adjusted for.
RandomTask OCT 13, 09:35 AM

quote
Originally posted by Joseph Upson:


Centering the assembly to help accommodate optimum axle arrangement is part of the deal unless you have custom axles made, although keeping the driver side axle as long as possible, which favors repositioning the assembly is probably better to avoid axle/joint separation when lifted. It has been several years since I swapped the F40, so I don't recall which side, but the axle seal to axle seal width is 1" wider to one side on the F40, compared to the stock options. I recall the Cobalt axles being equal length, so the difference will need to be adjusted for.



Thanks,

I think at this point I'm going with custom axles. Couple issues;
1.) These cobalt axles look thin/weak, especially compared to the ones that came out of the saab. Since I plan on going boost after I put some miles on the swap, its nearly going to be a must
2.) The outer cups dont allow for the seal on the back of the upright.
3.) Lengths aren't ideal. I only have about an inch before the cam phaser connector starts hitting the strut tower. Half inch is all I would be comfortable with and honestly, I don't think that would be enough.
4.)I already (stupidly) pretty much completely welded the engine mounts to the subframe. Would require lots of work to cut them off and re-install.

Anyone have a good company to work with to get this done?

Thanks,
Daryl M OCT 13, 11:32 AM

quote
Originally posted by RandomTask:


Thanks,

I think at this point I'm going with custom axles. Couple issues;
1.) These cobalt axles look thin/weak, especially compared to the ones that came out of the saab. Since I plan on going boost after I put some miles on the swap, its nearly going to be a must
2.) The outer cups dont allow for the seal on the back of the upright.
3.) Lengths aren't ideal. I only have about an inch before the cam phaser connector starts hitting the strut tower. Half inch is all I would be comfortable with and honestly, I don't think that would be enough.
4.)I already (stupidly) pretty much completely welded the engine mounts to the subframe. Would require lots of work to cut them off and re-install.

Anyone have a good company to work with to get this done?

Thanks,



It will be a while before I get everything assembled again, but I may be in a similar situation. If you find a good place to have axles made, let me know.
Joseph Upson OCT 13, 06:22 PM

quote
Originally posted by RandomTask:


Thanks,

I think at this point I'm going with custom axles. Couple issues;
1.) These cobalt axles look thin/weak, especially compared to the ones that came out of the saab. Since I plan on going boost after I put some miles on the swap, its nearly going to be a must
2.) The outer cups dont allow for the seal on the back of the upright.
3.) Lengths aren't ideal. I only have about an inch before the cam phaser connector starts hitting the strut tower. Half inch is all I would be comfortable with and honestly, I don't think that would be enough.
4.)I already (stupidly) pretty much completely welded the engine mounts to the subframe. Would require lots of work to cut them off and re-install.

Anyone have a good company to work with to get this done?

Thanks,



If possible and practical, it might not be a bad idea to take on a surgical attitude along with a 2 lb hammer and see if you can create a tasteful relief in the strut tower, if not cut and weld one in for a little more clearance. I've just been reminded that you're working with the 3.6L and have different clearance limitations than what I faced.

Axles. Now that you've brought it up, the Cobalt SC axles are weak and have had a tendency to break near the outboard joint, which you have probably realized is tapered in that area for some limiting reason. The Turbo SS axles if I recall correctly, have splined shaft ends like those of the Saab which are not even close. The additional pwr of the 3.6L coupled with better traction potential than the fwd Cobalt will likely tax the axles a bit more, so your concern is not without merit.

The best option for a possible hybrid axle and a long shot given the age since they were made, would be to find the shortest axle shaft from the driver side of one of the old 440T transaxles, which I believe has the 32 spline count necessary (Don't waste your time at the major parts stores, they're likely all made in China now as I discovered when trying to replace my broken G6 axle and they are not interchangeable with GM parts.

Mate that to CV joints from the MANUAL Fiero transmission axles, as I found that the automatics had weaker joints with smaller internal parts/splines. I used axles from the Pontiac G6 GTP. The out board joint cups could be swapped with the Fiero cups. I used the full length passenger side, and sent the driver side off to Moser racing to have it shortened and resplined to work on the driver side.

They can make a pair of custom length shafts for your application. You'll just need to send them a shaft and a hub from either end. If they can't cut the simple snap ring groove in the axle by now, tell them not to bother. They put the typical rwd groove in mine and I put the snap ring in without thinking about it and put the joint on. Since the groove was too deep, the snap ring went eccentric and the joint was permanently locked on to the axle, which wasn't a problem since I figured I would never need to disassemble it, until I did when I managed to break the threaded end of the joint with the nut that keeps the bearing assembly together.

I did get the joint off to avoid having to have another shaft modified, but it involved a plasma cutter.
RandomTask OCT 15, 12:19 AM

quote
Originally posted by Joseph Upson:


If possible and practical, it might not be a bad idea to take on a surgical attitude along with a 2 lb hammer and see if you can create a tasteful relief in the strut tower, if not cut and weld one in for a little more clearance. I've just been reminded that you're working with the 3.6L and have different clearance limitations than what I faced.

Axles. Now that you've brought it up, the Cobalt SC axles are weak and have had a tendency to break near the outboard joint, which you have probably realized is tapered in that area for some limiting reason. The Turbo SS axles if I recall correctly, have splined shaft ends like those of the Saab which are not even close. The additional pwr of the 3.6L coupled with better traction potential than the fwd Cobalt will likely tax the axles a bit more, so your concern is not without merit.

The best option for a possible hybrid axle and a long shot given the age since they were made, would be to find the shortest axle shaft from the driver side of one of the old 440T transaxles, which I believe has the 32 spline count necessary (Don't waste your time at the major parts stores, they're likely all made in China now as I discovered when trying to replace my broken G6 axle and they are not interchangeable with GM parts.

Mate that to CV joints from the MANUAL Fiero transmission axles, as I found that the automatics had weaker joints with smaller internal parts/splines. I used axles from the Pontiac G6 GTP. The out board joint cups could be swapped with the Fiero cups. I used the full length passenger side, and sent the driver side off to Moser racing to have it shortened and resplined to work on the driver side.

They can make a pair of custom length shafts for your application. You'll just need to send them a shaft and a hub from either end. If they can't cut the simple snap ring groove in the axle by now, tell them not to bother. They put the typical rwd groove in mine and I put the snap ring in without thinking about it and put the joint on. Since the groove was too deep, the snap ring went eccentric and the joint was permanently locked on to the axle, which wasn't a problem since I figured I would never need to disassemble it, until I did when I managed to break the threaded end of the joint with the nut that keeps the bearing assembly together.

I did get the joint off to avoid having to have another shaft modified, but it involved a plasma cutter.



Spoke to a company in Canada who is going to make some custom axles. Im trying to see if any upgrades can be done to the outer bearings to accommodate a larger spline but as of now, run the saab inners (which seem beefy) and the fiero outer at custom lengths is about $500.
Joseph Upson OCT 15, 06:00 AM
I'd check with Moser and Strange first. I believe Moser still runs about $300 a pair for axle shafts. The cross the border deal would make me nervous, especially if your quote range is not anticipating any potential surprises at the border. Unless you're dealing with some pretty intense torque loads, the Fiero outboard joints will be fine, I'd focus on joining the different joints together.
pmbrunelle OCT 15, 08:45 AM

quote
Originally posted by Joseph Upson:
The cross the border deal would make me nervous, especially if your quote range is not anticipating any potential surprises at the border.



Some three quarters of my Fiero parts purchases are cross-border... it's really nothing complicated.

At worst, anticipate 2 weeks of extra delay, and $200 of extra fees.
Will OCT 15, 02:39 PM

quote
Originally posted by Joseph Upson:

I'd check with Moser and Strange first. I believe Moser still runs about $300 a pair for axle shafts. The cross the border deal would make me nervous, especially if your quote range is not anticipating any potential surprises at the border. Unless you're dealing with some pretty intense torque loads, the Fiero outboard joints will be fine, I'd focus on joining the different joints together.



The Fiero outers are the first weak links in the driveline. There are 27 and 33 spline outers that readily replace the Fiero outers.
Joseph Upson OCT 15, 07:47 PM

quote
Originally posted by Will:


The Fiero outers are the first weak links in the driveline. There are 27 and 33 spline outers that readily replace the Fiero outers.



I'm speaking of the shaft itself, which is the same spline count as that of the G6, with the same outboard joint internals except the hub I believe which may be the spline confusion for me. I'm recollecting the axle shaft being 32, if it's 33 okay, I fiddled with several so getting them mixed up comes easy.

I did specify the manual trans shafts as being the stronger of the two earlier, and I just don't recall any instances here that would make the stronger of the two joints weak points for the naturally aspirated 3.6L and the Ecotec SC given how well they appear to have held up behind various other 300 hp range swaps and for me.

My joint failure was the result of an axle nut backing off and a subsequent break in the threaded portion of the joint. I also broke a bearing cage in the opposite axle, which I attributed to too much engine torque for the lowered ride height and axle angle at the joint. I don't remember if it was before, or after the transmission was taken out for the same reason, but know they were in close proximity to each other. If there's stronger stuff out there, by all means stick it on.

[This message has been edited by Joseph Upson (edited 10-15-2020).]