1998 S70-T5 Rebuild Aftermarket Axle vs OEM

[800artfreed]

I thought I would share some of my experiences while rebuilding an aftermarket LEFT propeller axle from a 1998 S70-T5. Both boots were ripped. Fortunately the car was sitting unused and the C.V. joints were in good condition. What could go wrong? Well plenty. I brought the axle to a shop that allowed me to use their parts washer. In the past it was recommended to clean out old grease and I wanted to do it again on this axle. At the time I did not pay attention to anything other than the condition of the C.V. joints which looked good.

I also had on hand the original OEM propeller shaft I had swapped out with an aftermarket shaft. I had attempted to repair the outer C.V joint using a DORMAN replacement boot from a local auto parts store. It was too small (different size CV joints on Volvo NA and turbo vehicles). Since I needed the car at that time I purchased the after market axle under discussion. This was about 3 years ago.

Although the axle worked OK, I will list the issues that arose during the rebuild. I used a REIM boot kit supplied from FCPEuro.

On the aftermarket CV joint I could not shift the inner spline part of bearing enough to disassemble the entire joint for inspection and cleaning. This is usually not a problem on OEM joints.
The inboard CV joint was slightly larger in diameter than the OEM. The boot had to be stretched over it.
The outboard CV joint was slightly smaller in diameter than the OEM. This made the boot too loose.
The grooves on both CV joints are narrower than the OEM and the grooves on the axle are "stamped" or forged grooves not a machined groove. They are NOT FLAT at all. Instead the axle clamp areas are more like concave grooves. This meant that the rubber boot area for the clamp does not sit flat in the axle groove. The rubber sitting at an angle in this groove forces the clamp to slide off when attempting to close the clamp around the boot. They are also narrower than the OEM grooves and made the process of clamping the boot to the axle shaft more difficult.

Since the aftermarket joint grooves are more narrow and the outboard boot is too loose, tight clamping is crucial to achieve a tight seal between the boot and the joint. I ruined 2 standard width clamps. Fortunately the universal clamps supplied with the a CV clamp tool are extra narrow, approximately 6/64" wide", as opposed to 5/32" wide for standard clamps

This type of universal clamp requires a puller tool to tighten the clamp sufficiently. This tool wraps the tail of the clamp around a slotted shaft in the tool and you turn it to pull the clamp tight. Unfortunately the clamps supplied with the tool were too short to go around the diameter of the boot and leave enough of a tail to be gripped by the pulling shaft of the tool.
I realized I could use 2 of these bands to make the diameter large enough for the boot and get it gripped by the tool. There was just enough room to pull the second clamp's grip around the boot and create a tight seal around the C.V. joint.

Lastly and related to the disassembly note above, when the shaft was in the car but the lower control arm was not yet
pre-loaded (hanging down as much as possible), the CV joints made clacking noises at idle speed. After pre-loading the lower control arm and driving the car the axle was quite.

In the past when I read that we should grab OEM axles out of the PnP I thought it was a bit too much. Now I know better. Rebuilding after market shafts comes with their own set of challenges.

I have attached photos comparing the OEM and aftermarket shafts. The quality of the photos is poor, sorry.

[scot850]

Thanks for taking the time to share!

Neil.

[FireFox31]

Interesting. Would it be cheaper in parts and labor to simply replace the aftermarket axle with another aftermarket one? They seem so disposable.

I wonder how we could rebuild OEM axles with damaged CV joints from cut boots letting in dirt. I just asked a local engine machine shop if they'd check and smooth out a CV joint but the would not. Seems like smoothing out pits in the races would involve cutting them wider, thus needing larger ball bearings and maybe throwing off the specs. I found a rebuilder who claimed they didn't expand the grooves but I can't imagine another way.

I pulled a nice pair of axles at a junkyard but one boot has a leak so I'm doubting it's CV. They're otherwise so clean that rehab is quite worth it. This is why I ask.

I still kick myself for sending an OEM Mercedes axle to scrap metal because I let it's CV get work by driving with a cut boot. Kept it for a year or two, then just scraped it.

[scot850]

If the axle CV boot has only recently split, a good clean of an OE unit and it will be fine. Aftermarket, no idea.

I replaced the RH axle in a 2000 V70 that when I got the paperwork with invoices, showed the car had been run with the boot split for nearly a year. I did eventually take it a part out of curiosity, and there were no noticeable pits or damage that I could see. I have kept it as a core to rebuild at some point.

Neil.