CV Boot Split

[hohieu]

Driver's side inner (SFJ) boot split with 107K miles on my 99 forester. I just discovered it as I was checking the front brakes. The inner boot on the passenger side split at 90K miles when my wife had the car in vermont last summer -- she had a rebuilt one installed up there.

 

I'm going to replace just the boots because I think the factory NTN half shafts are of much higher quality than the aftermarket units and because OEM ones are a bit pricey. I discovered the split boot before any damage was done -- very little grease leaked out -- so original joints should be fine.

 

The FSM says to replace the boots on the car without removing the axle shaft. Ideally, I'd replace both boots, but I'm wondering if there's enough room to work on the outer joint (BJ side) without pulling it from the hub, especially getting all the old grease out of there and seating the new boot clamps? Has anyone tried doing it this way?

 

If I can do only the the inner joint without pulling the halfshaft from the hub, how much longer could the outer boots last? Has anyone had front outer fail, and if so, after how many years and at what mileage?

 

As side note, has anyone had any of their rear boots fail, and if so, after how many years and at what milegage?

 

 

Thanks.

[Legacy777]

Replace the axle, you don't know how long the boot has been torn. I had a similar occasion, had them repacked & boot replaced. Several years later I had issues with the axles.

[hohieu]

Thanks for the response -- I thought this thread would die so I already went ahead and ordered the boots and grease for the job. I discovered the split early -- from the grease splatter patterns, it looks like the split ocurred the last time I drove the car. In any case, it definitely hasn't been split open for more than 1K miles because I checked all the boots when I performed the t-belt service and rotated the tires last month. I'm just waiting for parts and will do a write-up on the on-car boot service.

 

I know some Porsche guys do preemptive boot and grease changes on their axle shafts. I've had both inner front ones fail in the past year and am wondering if it's worth it to go ahead and replace all the rear boots before the split (in the middle of winter with my luck).

[cookie]

I haven't had any fail yet at 128,000 miles on my 99 Forester. the mild weather in CA may have someting to do with this with no freezeing cycles.

We used to do boots on VWs and Porsches regularly with bolt ons. you usually got a couple more years out of the axle if it din't get dirt in it and was not already too worn.

[hohieu]

As I look at the FSM instructions for removing the lower ball joint on the transverse link from the nuckle -- will it pop right out or will I need a separator fork to wedge it out?

[jon38iowa]

Driver's side inner (SFJ) boot split with 107K miles on my 99 forester. I just discovered it as I was checking the front brakes. The inner boot on the passenger side split 90K miles when my wife had the car in vermont last summer -- she had a rebuilt one installed up there.

 

I'm going to replace just boots because I think the factory NTN half shafts are of much higher quality than the aftermarket units and because OEM ones are a bit pricey. I discovered the split boot before any damage was done -- very little grease leaked out -- so original joints should be fine.

 

The FSM says to replace the boots on the car without removing the axle shaft. Ideally, I'd replace both boots, but I'm wondering if there's enough room to work on the outer joint (BJ side) without pulling it from the hub, especially getting all the old grease out of there and seating the new boot clamps? Has anyone tried doing it this way?

 

If I can do only the the inner joint without pulling the halfshaft from the hub, how much longer could the outer boots last? Has anyone had front outer fail, and if so, after how many years and at what mileage?

 

As side note, has anyone had any of their rear boots fail, and if so, after how many years and at what milegage?

 

 

Thanks.

Howdy:

Just two months ago the passenger side innerboot split on my'99 forester; I had it replaced, moreover, my service person stated it was possible that parking with the wheels stronglys in one direction ( other than staight) could be a factor- and due to poor parking at work, that was something I had recently and done regularly. The car has132,000 K and so far the rear boots are original.

John

[hohieu]

Cool, John -- I can't imagine the rear ones fail all that often, and when they do, I imagine it's the inner ones that tend to go because the rear wheels don't steer.

 

As for the front ones, I think it's true that the outer boots tend go faster with extreme steering angles. I live in the city, and parallel parking puts a great deal of stress on the outer boots. The passenger side inner boot tends to be the first to go because it gets cooked by the catalytic converter.

[tcspeer]

After taking the nut off you must remove the bolt completely, I have always been able to pull the ball joint out by hand or with a small bar against the control arm, others have really had tough times getting them out. But I have mine apart more often then most.

As I look at the FSM instructions for removing the lower ball joint on the transverse link from the nuckle -- will it pop right out or will I need a separator fork to wedge it out?

[hohieu]

No triumphant CV boot service to report -- I've been having a heck of a time trying to break the bolt holding the lower ball joint to the knuckle. In the past 4 hours, I've hit with an electric impact wrench rated at 7.5 Amps and 250 ft-lb. of torque -- along with with about half of a can of PB Blaster. I 've decided to wait until tomorrow to see if the PB Blaster will do its magic.

 

Any advice would be greatly appreciated. Thanks.

[idosubaru]

on the bolt....a socket and a very long pipe.

 

but rear boots typically last much longer as they don't flex nearly as much. the ones closest to the exhaust will fail first, particularly if one is fairly close obviously.

 

that being said, split boots don't typically last very long. unless you're offroading hardcore your CV's won't fail with a split boot so you can leave it alone as long as you want. i've gone 50,000+ miles on front and 100,000+ miles on rears with the boots gaping open. my XT6 had split rear boots when i bought it at 105,000....still had the same split boot axles at 220,000 and i just had the carcass towed away a couple weeks ago. axles were fine, never made a noise or gave me issues. i'd leave them before worrying about putting a split boot on. save your efforts for a job down the line. maybe when both are broke in a year or 2 or you have to replace a rotor or something else, then do the axles. that's what i do and i drive a fair amount off road...still no problems. i got split boots on my rears now on my new XT6...i don't plan on replacing them ever.

[hohieu]

on the bolt....a socket and a very long pipe.

I have the car on jack stands and can't really get good leverage. When I did try to get my 16" breaker bar w/ pipe extension on there, I fcould feel that something was going to give -- don't want to fuss with drilling out stuck bolts.

 

that being said, split boots don't typically last very long.

I think the title of my post is a bit misleading -- I wish there were a way to edit titles but know that it makes searches more difficult. Just to clarify, I am intalling regular boots -- not the quick split boots. Nonetheless, your approach is quite brave. I just returned from a trip up to Brooklyn with a plastic bag duct-taped around the joint. I think your experience would indicate that OEM axles are bomb-proof. This is great to know.

 

save your efforts for a job down the line. maybe when both are broke in a year or 2 or you have to replace a rotor or something else, then do the axles. that's what i do and i drive a fair amount off road...still no problems. i got split boots on my rears now on my new XT6...i don't plan on replacing them ever.

I'm afraid I'm past the point of no return -- I've ordered all the parts and have the car up on stands, and I'm far too anal to heed your good advice.

[aldug]

What are the "FSM Instructions"?

[2X2KOB]

Factory service manual.

[hohieu]

What are the "FSM Instructions"?

And they are sometimes worthless.

 

With the control arm method, you only need to remove one, front mount bolt (17 mm head and nut), plus the sway bar link bolt. There is enough play in the other bushing for the inner joint to clear the stub shaft. The caveats are that re-tightening must be performed with wheels on the ground, or at least on low ramps, and the nut is officially not reusable (mine is OK with blue Loctite). But same things already apply for the sway bar bushing bolt.

I gave up on trying to remove the lower ball joint -- things weren't much different this morning, even after letting the PB Blaster soak in overnight. I guess I just got too attached to my impact wrench. Those of you who don't see much salt might be okay following the FSM, but on my car, that sucka's staying put until I need to replace the ball joint. The method quoted above was much easier on my car -- thanks, avk. I had no problems tightening the bolts down with all four wheels on the ground.

 

A Few Notes on CV Boot Replacement:

• Obviously, I wouldn't recommend following the FSM instructions to remove the ball joint from the knuckle.
  
• However, it is possible to change both inside and outside boots without removing the axle from the hub as stated in the FSM.
  
• I would recommend buying OEM grease for the outside joints because the BJ side does not disassemble, making it nearly impossible to get all the old grease out even if you pull the cv axle shaft out of the hub. My original outside boot was still good so I just reused the old grease and slid the new boot on for the time being.
  
• OEM front outside boots are made of plastic, which is why they must be discarded if ever removed. I used aftermarket EMPI boot kits for both joints which were neoprene rubber. The plastic ones probably withstand the radical steering angles of the BJ much better, but neoprene is much easier to seal. Plastic boots also require heavier duty clamps.
  
• Scribe all the alignment marks on the SFJ (inside -- differential side) as you disassemble things, making sure to avoid contact surfaces. My permanent marker was useless as all the marks wiped away as I cleaned the old grease off the joint and outer race. Maybe there's a better way.
  
• 3/16" punch knocked the spring pin out with no problem -- this can be done from below on the driver's side.
  
• I used zipties to secure the boots, but will attach the cv boot clamps when I have time to pick up the necessary tool.
  
• For those who care, there was quite a bit of lateral play where the axle shaft goes into the front differential (manual trans.).