GT4 CV Boots in Heat, MeeeooOW.

I have right inner CV boot that hasn't lasted 200 miles. It's now torn all the way around. It looks like it was turning slightly with the shaft, because the tear would work its way around, before finally completely separating.

I've had a couple of local mechanics look at it, including BH that confirmed they replaced it for the PO in November of 2006. Both mechanics suspect that heat from the exposed rear manifold and header is weakening the rubber boot. The manifold is missing it's heat casing. And there is also, I think, supposed to be a braked metal heat shield above the inner right and maybe inner left CV joints.

I hesitate taking it back to BH. They do come VERY well recommended. But it seems pointless to have replaced a soft rubber part under a very hot manifold, and to offer a "yup it's hot in there" now.

I'm also worried that a new rattling noise at 2500 rpm is an out-of-rounding alternator or tensioner bearing. This could be either from overtight belts, or the same heat exposure.

The heat shields are available. I'm not sure which one really covers the RH inner CV boot.

superformance:
http://www.superformance.co.uk/a-308/exhausts.htm
lists: 4070HS and 4071HS as rear heat shields.

maranello has:
116583 (ex 107207)
117252 (ex 107208)
and
118783 (ex 108188, 114084, 601273)

Are there US sources? Or I've read about aircraft grade blankets and tape here: http://www.ferrarichat.com/forum/showpost.php?p=136695638&postcount=11
This is easily the hottest engine bay I've experience. How long do CV boots last? What about the rest of the rubber and plastic in there?

This is my first YIKES!-post, forgive all the arm waving. I did fix the first fuel leak all by myself thank you.

 

Hi Frank
There is something else wrong. Perhaps the boot was damaged while being installed?
I have a 308GT4, no boxed shield like on the US cars (it is Euro). I do have the shields shown on the Superformance site. And I do think there is a space for shield over RH CV joint although not shown in any parts manuals. There is even a boss on the manifold to hold it. None of the shields shown in the manual directly protect the CV joints. If I added the one not shown then it would help that one. But so far no GT4 I have seen (>6) has that extra protection.
So, yes it is a hot engine compartment. No, it doesn't result in CV boots dismembering themselves in 200 miles.
Contributors to heat: bad advance behaviour on distributors, bad timing, bad carb tuning and balance.
Heat shield 4072HS is typically missing as well. This directs air up into the engine compartment when driving. This makes a noticeable difference on the highway and track. And it would help cool both CV joints somewhat.

Gerrit
http://dino308gt4.com

 

I was just recently under a 348 and it had heat shields for the inner CV boots that bolted up to the differential. I was thinking of making something similar for myself, but not because I was having heat problems but to keep an oil leak from being flung all around the engine bay.

Might check the 348/355 parts manual to see if it something you could use.

 

Frank, I installed new CV joints about 8 months ago, and drove 5000 miles with no heat shields anywhere in the engine bay and they stilll look like new.
Even after a long drive, when I inspect the engine bay it doesn't seem to be hotter than any other engine.
If you're looking for a mechaninc who really knows these cars call Onofrio at Alfa Italia in Burbank.

Rocco

 

Thanks Everyone,

Rocco, does your car have exposed manifold, or is it still encased? Mine is bare tubes coming out of the block.

Gerrit, amazing car, I really wish i could have found a Euro. Maybe my next trip to italy... Mine is running well, though it's possible that advance or mixture is off. The other boots are in great shape, still very "supple". so it might have been damaged on install. This boot is also the most directly exposed to radiant heat from the rear manifold. Also, most of the driving has been city miles, so the benefit of air circulating is minimized. In this case even the diverter shield would be ineffective.

Thanks to another amazing thread I've seen these pictures:
http://www.ferrarichat.com/forum/showpost.php?p=135920100&postcount=30
http://www.ferrarichat.com/forum/showpost.php?p=136065292&postcount=110
which ultimately lead me to the superformace site.

Brian, is this what you saw on the 348? I'll check for cross parts I could use.

Pardon my stupidity here, the last time I rebuild CV Joints was 15 years ago, but does the CV boot rotate with the shaft, or is it stationary and the shaft rotate within it? It could have simply been improper installation that caused the boot to bind on the shaft (or?), ultimately shearing it circumferentially.

Also, Anyone have any idea of driveability in in this condition?
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I got bare tubes just like yours.

Rocco

 

No, the part I saw hugged the joint and boot and just protected the joint and boot. The curved part was asbestos or some fibrous material. I was thinking I could make something just like it with tin snips and the right sized tin can, but it would look like something I hacked out a tin can certainly wouldn't pass for OEM with out help.

The boot rotates with the shaft and joint, no sliding surfaces. Could it be improper installation? The only thing I can think of is that perhaps the boot was stretched out too far and secured to the shaft so that when the joint expanded it pulled the boot apart, but that seems pretty darn unlikely that it would pull apart even then.

What does an exchange axle cost? Usually they are surprisingly cheap for average cars, if there is any other car with this same axle it may be worth it to swap it for a rebuild. I wouldn't drive the car without the boot intact. Fine grit will get in the joint and grind it away. Plus that grease is tenacious stuff and it will get flug all over the engine compartment in a big thick nasty line.

 

New joints are readily available from Porche parts places. It would be hard to imagine why you would need a whole new shaft!

What also could have happened is over filling the joint with grease or not packing it into the joint. The shaft at one end also has some ridges for the boot to fit in between. It would be easy enough to stretch it out too far that way as well. You can see the ridges in this photo: http://visser-scully.ca/tools/coppermine/displayimage.php?album=18&pos=48

Gerrit
http://dino308gt4.com

 

You can certainly drive the car to have it serviced.
Even if the boot is split, there's lots of grease in there.
The boot turns so you'll get grease flung around
but sounds like that may have already happened.

Had the same problem, same location, and the manifolds are shielded.
Changed all of them 5 years ago - still look perfect.

You mention 200 miles ago in 06 - may still be under warranty.


Re: Euro GT4's - In the .eu they're often selling for more
than the GTB/S. I'm in the process of buying one (for use in .eu)
and with the current exchange rate, it's around $42k,
which is about 12K more than the nice US model I will be selling shortly.
Add shipping/export costs/headaches and hmmm ...

 

that's what I was hoping, but getting the shop that performed the service to buy it was not promising.

I noticed that price jump too. It's almost worth it. I think EU has less appetite for retro style (indifferent to VW newBeetle) and the edginess of GT4 is still distinctive.