Why are CV Axles different after 2002?

[RangerJoey]

Hi,
I'm looking to buy new axles & bearings to convert from a PVH setup on a 1999 to the live axle setup found on 2001 and later models. I'm going new and finding all sorts of issues.

Short of it is this article mentions taking the axle and bearings from a '95-01 Explorer and swapping them in the 1998-2000 Rangers. First thing I noticed is that the Hubs listed for the 01-02 have different part numbers than those listed from 2003+ Rangers. Looking at Timken's site, the mounting setup on the 01-02s are almost a half inch bigger in diameter than the 2003+. The '95-01 Explorers and 1998-2000 Rangers look like they share the same diameter as the 2003+ models.

At that point, I figured I'd look under 2005 or something on RockAuto, get the bearings and axle, right? But I compared the axles too. The '95-01 Explorer axles are shared with 01-02 Rangers but then there are different axle numbers beginning in 2003+.

I know there was a new knuckle introduced in 2003, but what I'm not understanding is how folks have success with donor vehicles. Like if I went to a scrapyard and pulled everything from a '02 Ranger, it sounds like the bearing would be too big for the 99 spindle but the axle would be on point. But if I found a '06 Ranger, the bearings would work but the axle might not. Am I missing something here?

 

[RonD]

Have a read here about the Dana 35 SLAs : https://www.therangerstation.com/tech_library/dana_35_sla.shtml
Explorers did get Dana 30 in 2002, but Rangers used the Dana 35 SLA from 1998 thru 2011, as far as I know, only difference is axle spline ends for locking hubs and threaded ends for live axle

Most people want to do the REVERSE of what you are doing so......................there may be some trading possible with another member thats been thinking about getting manual hubs on their 2001 and up Ranger 4x4

Basically just swapping axles and hubs

 

[RangerJoey]

Thanks Ron! That's so weird. Like I'd understand if the axles on the PVH Rangers would be different to the 01+, but now I'm shying on pulling the trigger on getting new axles. Even ordering the hub/bearings is taking a risk with the differences there. I'm kind of putting blind faith in the earlier tech article and assuming my 99 is the same bolt pattern as the '95-01 Explorers (and for some reason, only the 03+ Rangers).

Curious though: where's the recent interest in going back to PVH axle? I had always read how unreliable they were and there was a lack of quality options on the market to fix them.

 

[rubydist]

If you start with the pvh parts, you can convert them to manual locking/unlocking which some people want to do v. the later ones which are always engaged. Personally, I would rather not have to get out in the mud to engage the manual locking hubs, but everyone is different.

 

[RangerJoey]

Totally with you. To be honest, this thing won't see much mud. I just want a more reliable 4WD if/when I need it. I had just hoped buying the right parts was going to be more clear cut.

 

[don4331]

Unlike my usual SOP where I research the heck before I pull the pin, I just pulled the CV axles and unit bearings out of the '97 Explorer and inserted into my '98 Ranger. (I was after the 5.0, but getting rid of the PVH I considered a bonus). My truck has ran that way for 6 years now without issues.

But your questions have lead me to research if I had blind good luck or if it should actually assemble and work just fine.

The front hubs:

Both have the same Ø2.83" brake pilot and 5 x Ø4.5" x 1/2" thread wheel side​

Both have the same Ø3.94" pilot and 3 x Ø5.23 x M12 x 1.75 thread knuckle side​

Both have same 27 splines.​

The 95-01 Explorer/01-03 Ranger has offset of 2.220", while the 04-11 Ranger has 2.208" offset.​

I doubt if you notice 0.024" less track.​

So, no question the hubs are interchangeable.

The CV axles:

Both have 27 splines on both inner and outer​

95-01 Explorer/01-03 Ranger OEM drivers CV is 590 mm, passengers is 527 mm compressed.​

08-11 Ranger OEM drivers CV is 584 mm, passengers is 513 mm compressed.​

So, Ford has thought it worthwhile to shorten drivers by 6mm, passengers by 14mm. But thinking out loud - that's when Ford lowered the Rangers by a couple inches for aerodynamics. And a conscience engineer would want the CV operating in the center of its travel in the neutral aka sitting on showroom floor. So, shortening the shaft achieves that along with saving 20mm (3/4") of axle shaft multiplied by a couple hundred thousand 4x4 Rangers over the 3 year. That would add up to significant $$$ saving.​

Hence I note while the aftermarket has different part numbers for the newer vs. old vehicles, a number of the vendors shafts have the same 590mm drivers/527mm compress.​

​

So, there is a slight possibility if one has installed the newer shafts in an older vehicle of the shaft separating. In 99% of cases, the shock will limit suspension travel and you will be fine. However, if you mess with the shocks to add droop travel, there is probably some risk - you probably want to add limit straps in that case. But, for the way I drive my Ranger - the shafts can be considered interchangeable.

The disadvantage of full time hubs is really that the chain in transfer case is constantly moving. For Ford, the warrantee repairs to PVH far exceeded chain failure - chain failure before Ranger had either too many miles or months would have been almost non existent. But for those of us who are keeping our Ranger running 25 years/250k miles or more, the wear on the chain starts to be come an issue. And replacing chain in the transfer case is a bigger job than turning the front hub in. Especially, when you can anticipate adverse conditions that you would need to have 4wd at the ready.

 

[RangerJoey]

OMG Don, where did you get all this information? This is amazing! And maybe there's no Ford engineer to confirm, but your suspicions about the shortening on the CV axles in later years seems solid. I plan on doing an entire suspension overhaul so maybe droop wouldn't be a huge concern, but that's day 1. You're not talking long term on pothole city around here.

I'm thinking of pulling the trigger right now (take my money!). You mentioned you pulled from a '97 Explorer. The Timken part number for that generation Explorer is SP450200. The Timken hub/bearing for the later Rangers (after 03), is SP450202. I'm not a pro, but just looking at the specs on their site, (I can't figure out how to directly link to the parts on their site), I'm almost willing to bet the only difference is the length of ABS wire.

 

[RonD]

Yes, the PVH system was flawed, but can be converted to manual locking hubs which are reliable

2001 and up can not be converted to manual hubs, unless you swap in PVH axles

Article here on converting your PVH to manual, for FREE: https://www.therangerstation.com/Magazine/Summer06/pulsevacuumhubs.shtml

PVH to manual hub swap seen here: https://www.therangerstation.com/tech_library/AVM_hub_swap.shtml

 

[don4331]

OMG Don, where did you get all this information? This is amazing! And maybe there's no Ford engineer to confirm, but your suspicions about the shortening on the CV axles in later years seems solid. I plan on doing an entire suspension overhaul so maybe droop wouldn't be a huge concern, but that's day 1. You're not talking long term on pothole city around here.

I'm thinking of pulling the trigger right now (take my money!). You mentioned you pulled from a '97 Explorer. The Timken part number for that generation Explorer is SP450200. The Timken hub/bearing for the later Rangers (after 03), is SP450202. I'm not a pro, but just looking at the specs on their site, (I can't figure out how to directly link to the parts on their site), I'm almost willing to bet the only difference is the length of ABS wire.

https://www.showmetheparts.com/timken/ that's where I got the information on pilot diameters and bolt circle diameter.
Gleaning the required information from manufacturer's web pages for my company's purposes is part of my day joy, so I am comfortable say the difference is the 2 bearings (from an external fit prespective), is the 0.012" of flange offset.

6 years driving in the potholes around here*, several thousand miles with either my Adventurer 76r camper in back, or my 5th wheel in tow, wheeling in mud so deep that we could get out of 2nd (an engine is reasonably built 331) and pushing through snow bumper deep with no failures says there aren't major issues.

Aside: The Jeep Wrangler/Cherokee bearing of similar vintage ('95-03) has same mounting and pilot diameters but an offset of only 1.908". So, in an emergency (out wheeling with your Ranger and their Cherokee) if one of you has a spare bearing, you could install in the other's vehicle and it would get you back to town to get the correct part (Jeep in Ranger might need a couple extra washers but it would beat waiting for someone to bring parts from town)

*Actually, as the ice melts in the spring, the side streets are usually in worst shape.

 

[RangerJoey]

I can't thank you guys enough! Don, I'm sure whoever you work for is happy you're on their team. I just couldn't understand why no one's ever addressed the axle/hub discrepancy before. But it's all making sense now. Looking at the parts, I think I'm going with the hubs from the later Ranger, (03+), but any two cents on the axles? I like the idea of the Explorer/ 01 axles having a bit more reach but it seems the only options are aftermarket. If I want Motorcraft, I'd have to go with the 03+. To me, this is kind of a one and done (I hope!), so I'd like to stick with OEM. The quarter inch on the driver side seems negligible but the half inch plus on the passenger is the only cause of concern. It would be consistent though if I went that route with the "found a '08 donor vehicle and everything was fine" sort of tone. I don't intend to adjust the stock height but want to swap out the 235 tires on there now with the original 245 stance.