How To: Replace/Rebuild torn CV boot and/or Axle

Problem is not the boot. It is the clamps. Subaru clamps come loose very quickly and leak grease. Might just need to re-tighten clamps.

So then is it possible to replace the clamps without removing the axle and losing a lot of grease? Sorry for the stupid question. Edited August 14, 2011 by legacy360
Clarification

Try lockwiring the boot's. Wrap a length of .041" lock wire around the boot and twist it.

So my passenger side CV boot is leaking grease as of sometime this last week. I'd much rather rebuild/repair the seal then purchase the entire axle assembly. Would it be best to purchase all the necessary parts from a dealer or purchasing a rebuilt kit from Napa, Oreily's, etc? Looking to try to get this fixed this weekend.

 

I can't really say which one would be best. In my case, I used an OEM kit and it cost me around 40-50$ iirc, bought online. Not sure which kit (i.e. OEM vs. the rest) provides a more durable boot though..

 

the oem parts (boot replacement kit as well as full half shafts incl. boots) seem to be about four times the price of aftermarket 'direct fit' parts, so long as they are available.

i'll post as soon as i have tried the empi brand replacement gear. seems like those posting above have had good fitments with that brand; the clerk in the auto parts store that had them let me know about an ABS sensor ring, a castellated ring just before the hub on the halfshaft, (which seems to be what caused posters above problems with some of the Mac Auto-sold halfshafts) that can be removed if the ABS sensor is elsewhere.

Try lockwiring the boot's. Wrap a length of .041" lock wire around the boot and twist it.

 

what is lock wire?

Bailing wire. Saftey wire. Get it form a bike shop, we use it to wrap our grips. Tool to tie off and cut is available at bike shop too. Motorcycle (clarification).

Try lockwiring the boot's. Wrap a length of .041" lock wire around the boot and twist it.

 

The right lower ball joint on my 05 has it around the ball joint boot.

How tight are the bands supposed to be? I pussied out on the small one and of course I ruined it. Once I get it snug, how much do I continue to tug on the band tool? Quarter turn, half turn? The inside of the boot has some grease in that area so it spins freely on the axle no matter how ridiculously tight I get it. I didn't get to the big one yet, not until I get the technique down

Also, the boot I got from the dealer seems to be different than the one from the kit used a year ago on the other halfshaft. This one doesn't seem to cover the entire channel/groove on the green cup. Does that make sense? I pushed it on until it covered the groove entirely but it doesn't look right; the halfshaft seems squished and the boot raises up and doesn't sit flush. I'm thinking it's normal for that space to be there and I can just clamp it down like that.

Yeah, on pic 3 the boot sits real funny. Did you go underneath the car with this axle and boot, to compare with the other "good" one on the car already? I'd say pix 1 and 2 look OK.

 

Interesting that you're having problem tightening the smaller band. I am really wondering if you got the right boot. When I tightened mine, it did not move even though it had some grease too. I can't recall how many 'turns' I did to tighten it. It was more to the feel.

 

part number?

I did and they do look a bit different but not significantly. I'm thinking it's just a redesign. Might want to drop by the dealership and have them look at it. The old one seems to be a bit longer in order to fit over the whole groove. I tightened the clamp enough so that it bent the lip on the clip. Compared to some of the vids I saw online I think I definitely put enough pressure on it and then some but the fact that I could spin it on the axle with some pressure made me uneasy.

 

I'd hate for the boot to start losing grease in the middle of the winter ... I considered maybe I should use hose clamps that you can tighten on with a screw but it was a hose clamp that cut the boot in the first place ...

Edited September 16, 2011 by fishbone

Whelp, not a redesign; wrong goddamn boot. Why would parts sell me the right part when they can screw with me. Now I get to play with grease, undoing the axle again. Yay! Let it be a lesson. If the boot doesn't even have bumps to match the 3 grooves in the green cup, it's the wrong one, stupid. I took the axle with me and had the Subaru mechanic look at it, he confirmed it from first glance.

Whelp, not a redesign; wrong goddamn boot. Why would parts sell me the right part when they can screw with me. Now I get to play with grease, undoing the axle again. Yay! Let it be a lesson. If the boot doesn't even have bumps to match the 3 grooves in the green cup, it's the wrong one, stupid. I took the axle with me and had the Subaru mechanic look at it, he confirmed it from first glance.

 

Oh man! Sorry to hear that. kina sucks. gonna get your hands dirty again. I hope they gave you the right one free of charge. They better especially if they screwed up.

 

So what really happened then? they gave you the right part number with the wrong boot inside the box? Or they just gave you the wrong part number?

^ sorry to say it but, that's one of the reasons, we all sa, just buy the axle. There are only like $80.00.

OK, just did this today, took about 45 minutes. This is the 3rd time I've done this. My 2006 OBXT-Wgn has 165k miles on it.

 

Note that I've never been a fan of breaking the steering ball joint loose for this repair and have seen many people say it is a must. I've never done it in the 3 times. You would end up having to replace the ball joint 'cause the 'pickle fork' damages the boot. Then you may need to realign your steering.

 

I'll give a quick walk through for those that want to know how. Sorry, no pics as I was going as fast as I could to get'er done and take care of other errands.

 

Safety first... Before jacking up the car, ensure it is in park (auto) or 1st (manual), pull the handbrake, chock the opposite side rear wheel. Finally, when you do eventually get it jacked up, always use a jackstand to make sure it won't come down while you're under there.

 

Begin...

 

Removal...

 

1) Don't jack up the car, yet. Using a jeweler's screwdriver or other small tool, pick out the Subaru emblem in the center of the wheel. You'll see the big axle nut inside.

 

2) Slip a 32mm socket in the hole and on the nut. Don't worry about the crimped part locking the nut to the axle. I use a 1/2" drive with breaker bar and slip a 2' blk iron pipe over the handle for leverage. The nut is standard thread - ccw to remove. Put some pressure behind it and it will blast through the crimp and loosen the nut. Just crack the nut so it is loose. Don't begin to back it out.

 

3) Jack up the car just enough to begin to take weight off the wheel. Using your lugnut wrench, loosen them too - just a crack.

 

4) Now jack up the car to almost full height - a bit higher than you would to take off the wheel. The trans fluid will begin to shift to the opposite side of the transfer case.

 

5) Remove the wheel.

 

6) Remove the 2 bolts and 1 nut holding the plate on the rear of the lower control arm (LCA). They're all 19mm. Lay the plate and nut/bolts aside. Don't try to pull the LCA off as it simply won't go.

 

7) Remove the inner nut and bolt on the lower control arm. Use a 17mm socket and 17mm box. Wriggle the LCA a bit to get it out of there. Once removed, the rear LCA bushing will now slip down off of the stud. The axle is held up by the strut, swaybar, etc.

 

8) Grab the brake disk at 10 and 5 o'clock. Give it a good snapping pull backwards, putting your weight into it. You don't want to try to pull it off, just a popping pull with the aim to only move it 3". You'll feel the axle come loose from the inner joint. You may have to pop once or twice, but once it comes loose, you'll feel it.

 

9) Now back off of the axle nut on the wheel hub. Back it out until the threads of the nut are just at the end of the axle, forming a little cup around the axle with the crown of the nut.

 

10) Using a solid bar of metal, center punch, or something that can transfer energy without splitting (I used a 3/8" square drive extension, don't use a screwdriver!), place the bar in the center of the axle in the cup formed by the axle nut and hit it sharply with a heavy hammer. The axle will pop backwards, but not out because the nut is there protecting the threads.

 

11) Remove the axle nut.

 

12) Pull the wheel hub as far forward and out away from the car as you can. While doing that, back the axle out of the wheel hub. You will have to take the axle out at an angle and work it out, but it comes out easily. It may help if you angle the wheel a bit before you start the project. For the Driver's side, park with the wheels about half way turning to the right. Pull the back end of the axle out of the transfer case now and the whole thing comes out and away. You can let the wheel hub dangle.

 

Installing replacement...

 

Make sure your new axle is clean and oiled. The inner bearing/races can be wiped down with Subaru transmission fluid using a lint-free cloth. You don't want even a piece of lint in there. The outer spline can be lubed with a light bit of lithium grease - very light. It doesn't move when installed, so you just want to make sure it doesn't seize up over time for when you may need to remove it.

 

13) Insert the rear of the axle in first into the transfer case. Guide it in straight and carefully so as not to pinch the seal around the outside. Once you get it in, give it another popping push to seat it into the case. If yours is like mine, there is a small snap-ring in the end that pops in place when seated. You'll know.

 

14) Working from between the wheel hub and the firewall, bend the front spline joint as far as you can towards the wheel hub. Using one hand to pull out and forward on the hub and the other to guide the bent axle spline, insert the spline into the hub and work it all back together. It is tight, but it goes in pretty easily - first try. You may have to rotate the wheel hub to line up the hub splines with the axle splines as the axle wont rotate much (in gear). Compress the two as much as you can with your hands/body weight, then thread on and snug up the axle nut by hand and then using the 32mm socket. DON'T try to torque it down yet, just nice and tight using the socket and your strength.

 

15) Re-install the inner LCA bolt, making sure that you have the REAR LCA bushing up on the pin/bolt in the rear. You'll never get it on once the inner bolt is in. Use the 17mm box wrench and socket to get it started up and snugged - not tightened.

 

16) Re-install the rear LCA bushing plate - 2 19mm bolts and 1 19mm nut. Snug them up, then torque down the nut holding the bushing first, then the 2 bolts in the rear LCA plate, then the inner 17mm nut and bolt.

 

17) Re-install the wheel, again, snugging the bolts, not torqued down.

 

18) Lower the car until there is weight on the tire, but not the full weight of the car. You're going to use the wheel/tire's friction to aid in holding it still when you torque down the axle nut.

 

19) Now torque down the axle nut - get it good and tight. You don't want this baby working loose over time. Don't try to crimp the nut yet.

 

20) Jack the car back up and remove the tire again.

 

21) Using a center punch or very small chisel, crimp down the axle nut. You would not have enough angle on the nut to do a good job with the wheel on there. That's why you should take the wheel off when doing this after the nut has been fully tightened.

 

22) Tire back on. Lower the car to the friction point on the tire. Torque the lug nuts.

 

23) Lower the car.

 

24) Pop in the wheel center cap with the Subaru emblem.

 

I made an effort to clean up the underside of the engine compartment while I had the axle out. It slings the foul smelling moly grease all over. You'll probably have a pile of it on some of the lower frame members. Just make sure you don't accidentally sweep in debris into the transfer case opening. If you're concerned, wait to clean up until after you've installed the axle and before you've put on the tire the first time.

Edited September 18, 2011 by Apex-XT

For the write-up above, I used a rebuilt axle from NAPA - $75. I had read from others that you should repair your OE axle with a new boot kit and had figured that a boot kit was about $20 per boot for $40 in parts for an axle. So, I ordered an inner and outer boot kit to repair my OE axles that I've had laying around. The repair boots came in on the same day I had planned to use the replacement axle. So, I went ahead with the replacement axle and fixed up an old OE axle for spare.

 

I'll give a bit of a walk through for that, too, for those who want to do this.

 

First - I replaced both the inner and outer boots, but only the inner boot was damaged. I figured as long as I'm in there... In fact, only the inner boot has ever been damaged in the 3 axles I've replaced. I've heard and read that the outer almost never goes, but I know there are exceptions. YMMV.

 

But, having had both sides apart, I'll never do another outer boot unless it is damaged as it is very difficult cleaning out the bearing. I'm almost of the opinion that if the outer boot is damaged, always use rebuilt. Again YMMV. I'll never do another outer boot - not worth it for my time. More comments on this at the end.

 

Begin...

 

Removal....

 

Starting with the Inner Boot

 

1) Remove the two ring clamps around the ends of boot. Pry them up with a screwdriver or pliers or whatever. No need to try to 'save' them as a repair kit comes with new clamps and molly grease.

 

2) Pry up the large end of the inner boot - the one on the 'tin can' next to the engine. Push the boot slightly down the axle away from the can so you can work in there.

 

3) It's really messy. Have plenty of paper towels, rags, etc on hand to clean out the old grease. I used some plastic grocery bags that I would pull over my hand, scoop out grease out of the can and around the bearings, then pull the end of the bag from around my forearm over my hand clutching the grease so the grease ended up inside the bag.

 

4) Remove a inner snap ring at the back of the 'tin can', the end where the boot joined the can. You may have a hard time seeing it because of all the grease. Find the end and it pulls inward/off pretty easily. Set it aside on a clean paper towel so you don't collect grit on the grease.

 

5) With the snap ring gone, hold the axle straight up and slide the tin can up and off. Set it aside as well. While holding the axle straight up still, slide each of the small roller bearings you will now see off and set aside. They aren't held on by anything. If you had held the axle horizontal, one or more would have fallen off and rolled around in the grit.

 

6) Using snap ring pliers, remove the snap ring on the end of the axle that holds the tri-bearing race on the axle. You just removed the roller bearings off each of these 3 races. With the snap ring removed, the 3 leaved component slides up and off the splined end. Set the snap ring and tri-bearing race aside. My boot repair kit also included a new snap ring for this.

 

I highly recommend you stop here and skip to the reassembly piece below, unless your outer boot is also damaged.

 

Outer boot disassembly is simply sliding the boot off the now clear end where the inner boot used to be. I could not find a way to remove the outer spline or bearing and believe they're pressed in at the factory. Not much to do here except clean up as much as you can, re-lube with molly grease, and put the new boot back on.

 

Clean...

 

Use lots of hot soapy water to cut through the grease you couldn't wipe off with your hand, rags, or paper towels. I used Dawn dish washing detergent with hot water and it did a good job for me. Rinse well, dry.

 

Reassembly...

 

7) Slip on the inner boot with the smaller crimp band first. Push it a bit down the shaft so you have space to work on the end.

 

8) Reinstall the tri-bearing race and secure with a new (or old) snap ring.

 

9) Cut the corner off the grease bag and put a dab of grease on each of the 3 lobes of the tri-bearing race. Set the axle aside, propping the end up off the workspace.

 

10) Squeeze in some of the molly grease into the tin can, putting the dollop on the surface where the wear shows. Set aside.

 

11) Holding the axle vertical, slip on the 3 roller bearings, squishing them into the healthy dab of grease you put on the race earlier. This helps to hold the bearings on while you...

 

12) Place the tin can onto the vertical axle with roller bearings. It should fit nicely. Push the tin can about half way in and set the assembly on the work surface. The axle is now held up by the tin can.

 

13) Replace the larger tin can snap ring. It should go on smoothly if you have it aligned with the dimension of the tin can.

 

14) Squeeze in a goodly portion of the molly grease into the tin can on top of the bearings, turning as you fill to get a somewhat even distribution.

 

15) Squeeze the remainder of the bag of grease into the boot.

 

16) Slip the boot up so that the small and large ends fit into their grooves on the axle and tin can, respectively.

 

17) Position the tin can where the boot wants it positioned, based on the flexibility of the boot.

 

18) Using a small jeweler's screwdriver, vent the boot by slipping the screwdriver under the small end opening. You'll hear the air hiss out.

 

As I'm in Denver, I've wondered if the boots on Subies here undergo additional stress because we're a mile up and less air pressure. The boots would be pressurized (i.e. ballooned out) and may not flex correctly.

 

19) Crimp the inner and outer bands. The kit I used required you to pull the band's free end with a pair of pliers while holding the 'clamping' end stationary. When you got it tight, you folded the band backwards over the clamping end, clipped it to length, then folded two 'wings' over to hold the clipped end down. I lightly hammered each step to form good distinct bends and folds.

 

After all is said and done, I don't think I'll do this again. It took me about an hour to do the job right. You can't hurry through the cleaning step if you want it to last. I was able to use a $75 rebuilt axle spec'd to factory on the bearing surfaces and 2 new boots/grease and get the job done in about 45 minutes. Or, I could spend about $20 for an inner boot kit and spend about an hour R&R and then cleaning up, then spend 45 min installing, and have a used axle with a single new boot/grease on the inner side with used bearings and surfaces.

 

It's just not worth it to me. I realize the purists might poo poo this and highly recommend sticking with stock. But then where would all those aftermarket up/down pipes, FMICs, monster turbos, etc. be? To each his own. I enjoy my Subie and I enjoy wrenching on it. I just didn't enjoy doing this job.

OK, just did this today, took about 45 minutes. This is the 3rd time I've done this. My 2006 OBXT-Wgn has 165k miles on it.

 

Thanks for your write-ups. So u have 165k?? dang! sorry to go off topic but still running stock turbo and never had major engine problems? just curious..

Yup, stock turbo, no engine probs. I do have a stock catless UP and an Infamous1 tune.

 

I change oil every 3k mi with Mobil 1. I think this is somewhat overkill - I change it every 5k on my BMW. But, with the turbo, I feel it is a must. When I first got the car, I experimented with going to 5k, but the turbo consumes a small bit and I was having to add oil at around 3k. So, I just resigned myself to the 3k changes. I did install a Fumofu valve in the oil pan so it would be pretty easy. I only need a Phillips to change oil now - takes about 15 minutes.

 

I performed the scheduled maintenance to replace the timing belt at about 120k mi at Subaru service. I looked into it, but didn't feel I had the necessary tools to ensure the timing was correct. Everything else I've done.

 

To anyone with a turbo... I highly recommend pulling off the top cowl and taking a look at your TMIC for oil/wet areas at the bottom corners where the plastic endcaps mate to the radiator vanes. If you see any oil or discoloration, your endcaps have separated and are allowing pressurized air to escape - ie you're not receiving full boost. Mine went pretty early - before the Infamous1 tune. There are plenty of write-ups on how to do this, but you can re-seal them with JB Weld pretty easily. Time well spent IMO.

Edited September 18, 2011 by Apex-XT

Good write-up, thanks!

Oh man! Sorry to hear that. kina sucks. gonna get your hands dirty again. I hope they gave you the right one free of charge. They better especially if they screwed up.

 

So what really happened then? they gave you the right part number with the wrong boot inside the box? Or they just gave you the wrong part number?

It wasn't that bad to redo but I should not have had to. I am not fully confident of the job I did clamping the small part of the boot, I hope I got it tight enough, I think I put a bit too much pressure on the tool when I turned the band over the clasp and it seems like it's bent and raised just a very very bit on one side.

Either way I think the guy just assumed all boots are the same and grabbed whichever one was handy.

 

And yes, next time I'm buying a new axle. I guess I just didn't want to have to worry about an unknown aftermarket quality axle. I know OEMs are solid, so ...

 

I wasn't able to undo the axle nut without undoing the crimp, which I ended up chewing completely up so I can't crimp it again. I am not sure if that's a big deal so I ordered a new nut through the dealer. Is that part crucial, shouldn't some thread locker and a good amount of torque on it be enough?

Edited September 19, 2011 by fishbone

I wasn't able to undo the axle nut without undoing the crimp, which I ended up chewing completely up so I can't crimp it again. I am not sure if that's a big deal so I ordered a new nut through the dealer. Is that part crucial, shouldn't some thread locker and a good amount of torque on it be enough?

 

You have to order a new nut? Cause when I bought the OEM kit to change my boot, it came with a brand new nut. Huh...

IMHO, I'd get a new nut and make sure it is properly torqued and crimped. You don't want to waste a wheel bearing.

 

Yup, stock turbo, no engine probs. I do have a stock catless UP and an Infamous1 tune.

I change oil every 3k mi with Mobil 1.

 

^ daaang. good on you. I actually meant original stock turbo and engine. If that is really the case, then you may be the only one that I know of with that many miles still on the original turbo. Awesome!

IMHO, I'd get a new nut and make sure it is properly torqued and crimped. You don't want to waste a wheel bearing.

 

Agreed.

 

^ daaang. good on you. I actually meant original stock turbo and engine. If that is really the case, then you may be the only one that I know of with that many miles still on the original turbo. Awesome!

 

FWIW - scobaru05 is at 193K on original stock everything. Scotty is at 191K on original stock everything.

FWIW - scobaru05 is at 193K on original stock everything. Scotty is at 191K on original stock everything.

 

That's outstanding. I hope that I'll get there. only @ 50000 though.. It'll be a while since I only drive it for trips and stuff (ride bicycle to work).

I'm 8K shy of 100K and I've been Stage 2 for just about 50K miles. I checked the turbo for shaft play and it's basically like brand new.

+1 on New axle nut...

 

The NAPA kit I used in the write-up above came with a nut. You can also pick them up pretty cheaply from your local dealer. If you're ordering a non-OE replacement, ask the seller if it comes with a new nut and with neoprene boots.

^ daaang. good on you. I actually meant original stock turbo and engine. If that is really the case, then you may be the only one that I know of with that many miles still on the original turbo. Awesome!

 

Yes, *Original* stock turbo, and a Subie stock up pipe from a STI. And as noted, there are others who have higher mileage on stock, although mine is a '06. I doubt that is any sort of a record.