2001 XC-70: faulty rear differential. Options?

zeep100 · Post by **zeep100** » 18 Sep 2015, 17:55

I need some insight from those of you with greater knowledge. Please pardon my limited understanding of AWD systems (they're new to me and I'm not a mechanic):

I have a 2001 v70 xc that I purchased a couple weeks ago form a private seller. Excellent condition, 119,000 miles. The owner assured it was mechanically sound and test driving supported this. We paid $2300 for the vehicle.

A couple of days later after some light driving and getting to know the car, we began to notice a light whirring sound when driving that seemed to be coming from the rear passenger side. Since then, the sound has gradually become louder so we took it to a couple different local mechanics to see what was causing the noise. They informed us that the rear differential is toast and that the previous owner had to have known about it.

Unfortunately, having it replaced is out of the question due to the high cost (more than we paid for the vehicle) and we're stuck with this car. Aside from whirring I love the car and don't really mind the noise but I don't know what will happen over time if I fail to address the r. differential. So for now it sits until until I figure out options have (if any).

Replacing with a used differential is an option (much cheaper) but it seems risky since this seems to be a common issue with the v70 series.

Are there any possible workarounds options?

I see that many people have bypassed certain rear AWD issues by converting their vehicles to FWD (removing the drive shaft, VC). I'd be fine with that but unless the rear differential were also removed I would think the whirring sound would persist. I'm not sure if the differential be removed (since it connects to the r. axles). Or if the axles can also be removed or somehow swapped. Is this even a possibility? Again, my understanding of this system is limited, sorry for any dumb questions.

Thank you. Any insight offered is appreciated.

waffleshill · Post by **waffleshill** » 18 Sep 2015, 18:16

How's the transmission... 01 have tranny issues. The rear diff is bulletproof, it's a differential. It's simple and sees very little stress comparatively. First I have heard of one failing What fails is the angle gear and center bearing in the driveshaft. Swapping the diff isn't that bad. Are you sure it's the diff? it might be a wheel bearing or stuck parking brake shoe.

zeep100 · Post by **zeep100** » 18 Sep 2015, 21:32

waffleshill wrote:How's the transmission... 01 have tranny issues. The rear diff is bulletproof, it's a differential. It's simple and sees very little stress comparatively. First I have heard of one failing What fails is the angle gear and center bearing in the driveshaft. Swapping the diff isn't that bad. Are you sure it's the diff? it might be a wheel bearing or stuck parking brake shoe.

The transmission is flawless as far as I can tell. The mechanics were positive it was the rear diff. I was skeptical at first but after researching the subject heavily these past couple days I've come across quite a few instances where the rear diff failed and their symptoms (whirring sound) have been identical to mine. There is a youtube video of a failed rear diff and it sounds the same as mine. The ball joints have been ruled out. So at this point I'm fairly certain the mechanics were correct in identifying the problem. But I will have a look at the parking brake shoe. Thank you for your suggestions. It's good to hear that rear diffs are generally bulletproof. If that's the case then it makes me a little more comfortable with the option of swapping it out with a used rd.

Since my original post I've continued digging and luckily stumbled on a post on another forum that addresses and answers all of my questions regarding conversion to FWD and rear diff removal. It's definitely a do-able option according to that thread.

I can see now that either options (FWD conversion vs swapping used rear diff) will require roughly the same amount of labor. I need to think this one over. In the meantime I welcome any additional input any of you have to offer.

waffleshill · Post by **waffleshill** » 19 Sep 2015, 07:01

Keep the AWD. An XC without AWD is useless and will spin tires... especially if you leave the diff in... It's heavy. It's pretty simple in theory... Drop the exhaust, pull the propshaft, pull the axles, pull the diff. Go backwards. There's no HALDEX to worry about so it's a purely mechanical endeavor. eBay has rear diffs for $200. I wouldn't pay a shop to do it though... Way too pricey.

V70xc1999 · Post by **V70xc1999** » 10 Apr 2019, 19:04

Just a question on this topic....I was told if you remove the rear axles there is a speed sensor that is conected to the out sides of the axle....wont this trigger some codes or is there a way I can delete my dif and axles....its a 1999 v70xc....if so with out any codes I am in....I want the extra wiggle room down there.....Also could I put the rear end off a v70 on my v70xc so it's completely fwd minus the angle gear in the front end and so on...If so what FWD years will fit the v7xc?

Post by **IdahoBob** » 11 Apr 2019, 21:52

I'm facing this differential replacement job now.
We have two 2002 XC70's, and one (192,000 miles) needs the rear diff NOW, and the other one (260,000 miles) is starting to make the same scraping/dragging.
I'm at n=2 level anecdotal evidence, but my learning is that when you start to hear that scraping you have 3-4000 miles before you get critical.
Start shopping for a low mile (100,000 miles) replacement for around $200. Be patient, one will come up on eBay for $200 or less, delivered.

Yes, check the handbrakes shoes first. They occasionally lose their friction surface. It just pops loose and floats around inside the drum, on the inside back of the rear rotor. I think (but am not really attached to this theory) that if you leave the handbrake on, in the cold part of winter (sub-freezing) for days on end (parked at the airport, etc.) or back up too jerkily without releasing the brake this friction surface will skin off.
I bought a box of four replacement shoes a few years back, and replace these, one-at-a-time when one breaks loose.
And, get the replacement spring set from IPD before you remove that dumb corkscrew spring design (Hey, Volvo, look at how GM does this spring, it's simpler, & better!). The spring breaks some % of the time you torture it getting it off and back on.

And...the reason the seller gave you a good deal at 119,000 miles was possibly because they didn't want to do the major engine service due at 115,000. The dealer quoted $1400-1600 to do it, but you'll spend less than $300 for quality parts and a day doing it yourself. Lotsa tube videos on this job. It's all stuff you can do in the driveway. Use OEM parts, not the cheap ones. Get/rent a cam lock before you start - it will save you hours of re- assembly time if you avoid slipping the cam gears out of alignment. You don't need to replace the water pump at 115. It should be good until 230,000. If you have a cam lock, a long-ish 10mm socket to remove the cover on the timing belt and the torx bit for tensioning the serpentine belt, you're set.

EngineeringBloke · Post by **EngineeringBloke** » 12 Apr 2019, 16:33

I did the parking brake for my first brake repair about a year ago. Well worth watching a video or two. The corkscrew spring is pushed in, and then slid towards the front (or the back? Sorry, I don't recall), while pushed in, so that the J shaped hook that is at the center of the corkscrew can be slid to the slotted opening and then the whole spring removed. Having a replacement spring shows you what is hidden, and looks really good when you are replacing something 10 to 15 years old and rusty.

I was going to replace the expander, but I could not release it.

I needed to fix the brake as the shoe pads had come loose and the brake was needed to pass state inspection - which it then did.