915 cv boot

[85targa]

Hi

ive just done a quick look around the car for its mot on Wednesday and have found one of my inner CV boots has split

I can get GKN lobro boot kit for a tenner from Eurocarparts but trawling through the forum there has been questions about there quality, are they a false economy and should I go for original Porsche or another brand.

iv found maxdiesels post where he changes both inner and outer boots by taking off the inner CV joint and leaves the hub nut in place on a G50 can I do this on a 915

i also found sophors post saying split CV joints aren’t a fail on a rwd car, is that still the case.

 

thanks

tim

[GrahamTompkins]

If it’s not badly split you may be able to glue it and if you tell the tester you’ve just spotted it and are replacing I’m sure it will be ok.Technically it should be an advisory only as long as it’s not a sign of serious neglect and imminent joint failure..

[Fuchs915]

2 hours ago, 85targa said:

Hi

ive just done a quick look around the car for its mot on Wednesday and have found one of my inner CV boots has split

I can get GKN lobro boot kit for a tenner from Eurocarparts but trawling through the forum there has been questions about there quality, are they a false economy and should I go for original Porsche or another brand.

iv found maxdiesels post where he changes both inner and outer boots by taking off the inner CV joint and leaves the hub nut in place on a G50 can I do this on a 915

i also found sophors post saying split CV joints aren’t a fail on a rwd car, is that still the case.

 

thanks

tim

The drive shaft on a 915 comes off by removing 12 bolts, 6 inner, 6 outer, so you can easily rebuild off the car.  I re-used my old ones so have a couple of the new ones sitting on a shelf.  Note the flange on the new ones is different so you may need add washers or something for the bolts to fit properly. I can post them to you but they won't be there by Wednesday unfortunately. 

[Ian Comerford]

As already mentioned the flanges are different and you are best fitting the half moon washers, three for each flange.  These spread the load and limit deformation of the thin steel flange.  The quality of new ones isn’t great and I’m not sure whether buying from Porsche improves the situation.

[85targa]

Hi Thanks for the replies, as I’ve time I’ll put the MOT back a week and have a go next weekend.

its a later 85 car so I believe it should have M10 bolts, has anyone got a link for the moon washers.

i think the only possible problem may be releasing the bolts, will a 100mm 10 hex socket be enough or should I get a longer hex socket.

thanks

tim

[Phill]

Here you go

https://type911shop.co.uk/epages/de867ca1-377e-432e-84fd-bdccf2206766.sf/en_GB/?ObjectPath=/Shops/de867ca1-377e-432e-84fd-bdccf2206766/Products/8648

Don't forget the gaskets as well.

I've taken my drive shafts off several times. I don't know if you have done it before but it's a pig of a job to get them back on keeping the gaskets in place and not getting grease everywhere (you need Moly Lithium grease (buy a 500gram tub) and some white spirit or similar to clean up afterwards). Apologies if I'm giving an egg sucking lesson.

I have Sporto shafts so only 4 bolts each end and two rolled metal stubs. I think these make the job harder as you have to locate them while trying to keep the gasket in place and not tear them!!

[Ian Comerford]

I would offer a different view on the grease.  Consider synthetic CV grease rather than the standard moly that has been used for years.  The synthetic grease reacts far less to temperature and so stays with the joint rather than being ‘thrown’ out a little as it thins due to the heat.

This is what I use.https://www.opieoils.co.uk/p-1039-red-line-cv-2-grease-with-moly.aspx  

[Fuchs915]

2 hours ago, 85targa said:

Hi Thanks for the replies, as I’ve time I’ll put the MOT back a week and have a go next weekend.

its a later 85 car so I believe it should have M10 bolts, has anyone got a link for the moon washers.

i think the only possible problem may be releasing the bolts, will a 100mm 10 hex socket be enough or should I get a longer hex socket.

thanks

tim

I used a 100mm hex and some extensions for comfort/access.  If you rotate the shaft as you undo the bolts, you'll get better clearance in certain positions, it'll be obvious when you do it.  I dd a short thread - 'Mission creep - driveshaft refurb' recently.  If any of the bolts round out, I used a 12 point 12mm socket tapped onto the end of the offending bolt and all was good, but mine are the smaller M8s so you will probably have to find something bigger.

[85targa]

6 hours ago, Phill said:

 

. Apologies if I'm giving an egg sucking lesson.

Ive not done it before and any advise is always welcome

just a quick thought is this a job where I finally bite the bullet and get a cordless impact driver

thanks again for all the replies

tim

[Phill]

6 minutes ago, 85targa said:

Ive not done it before and any advise is always welcome

just a quick thought is this a job where I finally bite the bullet and get a cordless impact driver

thanks again for all the replies

tim

No. You will be fine with a decent hex key and perhaps a bit of tube to extend it if necessary. I've got a set of super dooper Allen keys which are 8 inches upwards in length and I don't need an extension (perhaps a rephrase is in order).

Don't forget new Schnorr washers too.

[flappa2]

Some times it's worth tightening bolts first if you expect trouble. I can't explain the science behind the theory but it does work. Also if the hexagon profile is worn in the bolt head it can result in some angst.

Good luck with it.

Flappa2

[Chris T]

Done this job a few times..... new CV boots are rubbish, consider race parts low speed motorsport alternatives. Use a long bar of some sort to hold wheel studs whilst undoing bolts (air tools help here) and drop whole CV driveshaft CV assembly. If not awful you can swap L-R but easy to replace all 4 CVs Fill with new grease and then wipe outer surface with brake cleaner and stick on new gasket before joining it all up. 
not a fun job, sorry..

[85targa]

Hi

the 6 cv joint bolts where easy, but the hub but is bending my new 750mm breaker bar, should I just change them in situ

tin

[sopor]

On 30/08/2020 at 17:11, GrahamTompkins said:

If it’s not badly split you may be able to glue it and if you tell the tester you’ve just spotted it and are replacing I’m sure it will be ok.Technically it should be an advisory only as long as it’s not a sign of serious neglect and imminent joint failure..

It used to be the case that split CV joints on a RWD car were not an MOT failure point but the test changed in 2018 or thereabouts and any split CV joint is a major item. I dodged an MOT failure on this in 2017 - https://www.impactbumpers.com/forum/index.php?/topic/31453-when-is-an-mot-failure-not-an-mot-failure/

 

But now the manual reads differently - https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles/6-body-structure-and-attachments#section-6-1-7

[GrahamTompkins]

41 minutes ago, sopor said:

It used to be the case that split CV joints on a RWD car were not an MOT failure point but the test changed in 2018 or thereabouts and any split CV joint is a major item. I dodged an MOT failure on this in 2017 - https://www.impactbumpers.com/forum/index.php?/topic/31453-when-is-an-mot-failure-not-an-mot-failure/

 

But now the manual reads differently - https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles/6-body-structure-and-attachments#section-6-1-7

Yep agree there, your only hope is if it’s glued, it’s not technically split , but you do need a simpatico tester....the problem seems to be with the quality of the boots being poor in the first place.I replaced mine with Porsche ones last year and so far so good.

[85targa]

All done, thanks for all the advise, wasn’t  to bad in the end just filthy.

thanks again

tim

[topcarrera]

So, removed r/h driveshaft over weekend  (replaced other side complete over 10 years ago) in hope that rebuild with new CV joints will cure recent light tapping noise coming from rear.

I received two new GKN Lobro joint kits this morning. I have read the numerous comments on here regarding the fragility of the new boots that come with these kits but was shocked at the truly Christmas Cracker quality of both the boots themselves and the horrible tinny end covers.  I just don't get why GKN would provide such rubbish?  Even starts to make me question whether the actual CV joints themselves are actually very much better than items from other sources at significantly less than half the price (same joints used in various other mainstream vehicles, Ford Scorpio, Alfa 156 etc...).

Original boots and the flanges that they are joined to still look fine after 37 years so will just clean up and re-use.  Have ordered some extra gaskets for the flange covers as the kits only include 1 gasket.