Outer CV Boots Torn, please help.

[Gunter]

That's correct; the M8 Allen bolts come loose CCW.
Torque is 30 ft-lbs.

Is there some confusion about ft-lb vs. Nm?
I see 330 ft-lbs (and higher) mentioned on this post by various people.
The torque for the M20 nut (30 mm socket) on the rear axle is given as 300-320 Nm (~220 ft-lbs) for an SC.
What thread-size is the nut on a Carrera?
And what torque is recommended for the Carrera axle nut?
Is it really 100 ft-lbs more than the SC axle nut?

[Paul Ferradas]

I'll take a look at that and get back to you.

Iv'e made progress. After spraying some CNC Freeze Lock on one of the bolts and going at it with the impact wrench for over 10 minutes it finally broke loose! It still boggles me because this impact wrench is rated at a crazy 450 ft/lbs of torque. Now just 11 more bolts to go!! Sucks to be me right now.

[Paul Ferradas]

Stub axle nut M22 non -castled is 430NM / 339 ft lbs. Per the Bently manual.

[KTL]

The impact wrench may not be working because of the long length of extensions you're using. Believe it or not, the extensions can twist/flex and reduce the amount of torque you're applying to the screw. Especially considering you've got multiple ones connected which makes for more slop. Plust the extensions are 3/8 in. drive size = less torsional stiffness.

I'd suggest working on the CV screws with a breaker bar and take your time. CV screw heads are notoriously easy to strip out. Impact wrench makes it all that much easier.

And yes, the torque spec for the castle nut on the pre 85.5 axles is much lower (220 lb-ft) vs. the later 85.5-up axles (340 lb-ft)

[KTL]

Originally posted by Paul Ferradas


Also, while I was under the car I loosed a bar and I'm trying to determine what it is because it's broken on one end and I need to order a replacement. The bar attached from on bolt on the bottom of the engine casing to another bolt somewhere on the exhaust. I attached a picture of it below.

Don't worry about that bar. It's supposed to be attached to the engine block/case and the exhaust system. Most cars that i've seen don't even have that bar. My car didn't, my other friends' 87, 88, 88, 89 didn't either. It's something that Porsche added to the exhaust system towards in 87 and it doesn't seem to provide the benefit that it was originally intended to provide. If you really want to replace it, it's part # 950 301 401 00

[A930Rocket]

Kevin hit the nail on the head. All the work of the impact is absorbed by the extensions and the joints between the impact and bolt. I use a 3/8 ratchet with just the socket to remove the bolts. You can add a piece of pipe to the end of the ratchet/breaker bar to help loosen them.

If you are just rebuilding/replacing your CV joints, why is there talk of 350 ft/lbs and the stub axle? All you have to do is pull the alxe out by removing the bolts on each end of it. Now if you want to replace the bearings, then I can see removing the stub axle.

[Paul Ferradas]

Thanks guys. That makes sense why the impact ratchet isn't working in this case. I'm using the breaker bar now and it seems to be working. Ive pulled 3 out so far.

I'm actually replacing both rear axles instead of rebuilding the CV joints. For a noob like me it seemed like an easier task. THats why the stub axle nut needs to come off.

[KTL]

Originally posted by wcc


**snip**........... But to change both the inner and outer CV boots you don't even have to mess with that ~350ft-lbs of torque. I personally think that's a dumb way of doing it. I had to change both the inner and the outer boots, and I did it without messing with that high torque setting. I removed the axle from the trans and let it hang. Then I removed the inner boots and CV joint. Then I removed the outer boot by sliding it down the axle. Next I cleaned up the outer joint and the ENTIRE axle shaft. I then repacked the outer joint and slid down the new boot. After the outers were done, I repacked the inner joint and reinstalled it. Covered it up with a new boot and reconnected the axle to the transmission. Very easy, but messy............... **snip**

No offense, but I think it's pretty dumb to do all that struggling underneath the car when all you have to do is remove the two big nuts and you can work on the axles at your workbench in a vise. Like the old saying goes, "To each his own."

If one doesn't have a workbench? Then it's not a bad idea to leave them in the car since the car will hold the axle for you. Still quite a struggle to do the outboard ones on your back.

[88-diamondblue]

On Carrera's the stub axle is part of the CV on the outboard side. To remove the CV the stub axle needs to come out as well. The turbo and earlier cars use a stub axle that is seprate from the CV axle assembly.

[KTL]

Originally posted by A930Rocket

If you are just rebuilding/replacing your CV joints, why is there talk of 350 ft/lbs and the stub axle? All you have to do is pull the axle out by removing the bolts on each end of it. Now if you want to replace the bearings, then I can see removing the stub axle.

The later axles on Paul's car are not bolted and both the inboard/transaxle side and outboard/wheel side. Only the inboard side has bolts. The outboard side has no bolts and the CV joint is welded to the shaft- which sucks IMO for when you're cleaning and repacking a perfectly good CV joint.

edit............. Michael beat me to it. I think we've pretty much covered all the bases on this job, no?

[Paul Ferradas]

OK. I got all 6 bolts out on one side. I thought my struggles were over. Nope, not yet, but I see the light at the end of the tunnel. Here's my next snag. I'm trying to pull the axle out of the wheel hub but the rear strut is in the way. Iv'e tried different angles but it's not coming. It's close though. The axle stub isn't clearing the housing where it sits in. My next thought is to take the wheel hub off but I'm not sure about that since the bearing are in there I think. More suggestions will be appreciated.

[Paul Ferradas]

Here's a shot of where I'm at. By the way, I slice off the boot with a razor to give me more clearance.

[Don Plumley]

IIRC, I had to raise the trailing arm or disconnect the bottom shock to get the stub axles out...I forget which...

[88-diamondblue]

The lower shock mount bolt needs to be taken off and it will slide right out

[wcc]

Originally posted by KTL
No offense, but I think it's pretty dumb to do all that struggling underneath the car when all you have to do is remove the two big nuts and you can work on the axles at your workbench in a vise. Like the old saying goes, "To each his own."

If one doesn't have a workbench? Then it's not a bad idea to leave them in the car since the car will hold the axle for you. Still quite a struggle to do the outboard ones on your back.

You're right, that would be dumb. I wouldn't do that job laying on my back trying to reach the outer ones either. Good Luck with that. It would WAY easier to get to kneeling on the ground reaching over the brake disk to repack the outer joint and to rotate the axle as you go. Or you could use a lift, or remove it like you guys say, or lay on your back, or just pay to have it done by someone else, etc.. There seems to be 10 different ways to the same thing. Just cause the vast majority thinks ONLY one method is the correct one doesn't make it so. No offense taken...

Also, on this related topic and since I'm part of the minority. If I were you, Paul Ferradas, I would at least look into, or just consider using wide band Zip Ties instead of those metal bands around your boots. They hold and seal just fine, but allow the boots to rotate a little as needed. Therefore, reducing the chances of tearing. I have used them on tons of cars including both the P-cars with no ill affects. Non believers flame away...

[KTL]

Flame on............. Metal bands withstand heat and age better than zip ties. Flame off.

Most would even question the act of repacking and re-booting 20 yr. old axles. Given the time involved and the mess involved, the extra $ it costs to swap in replacement axles is arguably the best way to go. Time spent doing something else vs. rebuilding axles is worth something in my mind. Kinda like the time spent on this topic instead of wrapping the 10 Christmas gifts I haven't wrapped yet................

[Paul Ferradas]

Time to run to the tool store. THat stubborn shock mount bolt is on tighter then my axle nut!! ARGH.. I only have SAE size impact sockets (except for axle nut). I'm off!

[wcc]

Originally posted by KTL
Flame on............. Metal bands withstand heat and age better than zip ties. Flame off.

Well this is true, can't argue that. But they (ZT) require maintenance, and by realizing that when you put them on it's easy enough. For example, every time I change the fluid in the tranny I would replace ALL zip ties. They are easily snipped off and replaced. I would rather change out ties once in a while instead of risking another rebuild in 5k or so miles. If you have ONE hard launch you could tear your brand new boot. Not saying it WOULD, but COULD. That COULD happen with Zip ties too, but it lessens the chance. Basically, zip ties help prevent this.

[88-diamondblue]

It would be great to just put in new axle assemblies in but the cost difference is significant (at least to me). It cost me $45.00 for the boot kits and my time, new axle assembly is over $300.00 each.. I inspected the CV's and they looked good. You can actually take the outboard CV apart to clean and inspect it. I didn't find that out until after I had finished mine. If they are good no reason to replace them. JMO

[Paul Ferradas]

I picked up a pair of used axles for $150.00 a piece at Parts Heaven. I figured since the boots were intact that the CV's aree good.