I've just purchased a pair of brand new driveshafts from renault, but they appear to be a lot less thicker than a normal gt turbo shaft.
Does anyone have any experience of this? Anyone actually fitted and used these or just return them?
I see even cgb supply them
I bought a pair from Renault a few months ago, compared to an old driveshaft in the shed and the new ones are much thinner. I didnt think they seemed right so returned them to Renault to get my money back.
I do want to buy a pair of driveshafts however only want the original thicker version as these are the ones Ive got fitted on my Raider, the thinner ones seem like Campus shafts to me and not as 'heavy duty' for a turbo engine/gearbox.
Campus ones are skinny and GTT ones are thicker.
Exactly, have heard that GT shafts are thicker and hollow, where as campus as thinner and solid so apparantely it makes no difference however it would to me.Originally Posted by Fordy
I would stick to the oe thicker driveshafts as they seem to last pretty well.
That's what I'm worried about, I was hoping someone may of taken the plunge and fitted some
Has anyone ever broken a shaft?, only ever seen cv joint splines sheared off?
Last campus i worked on with gt turbo conversion was running standard campus jc5 gearbox and slim drive shafts. Car was running t25/t2 turbo at 21psi with no issues to drive train. Not sure how long they would off lasted but there was no issues.
Have you ever heard of any drive-shaft failure due to shaft thin-ness?
No, neither have I. I think the tolerances they are made to are way more
than they'll ever encounter.
I've just fitted new SKF shafts and they both have different shaft radii, but with
their reputation, I have no worries at all - maybe saved a kg of weight to boot
Regards,
Steve
I could have sworn we've had a number of drive-shaft shearing failures in the club down the years due to the Campus variants being fitted.
I'd source the correct ones.
Renault are telling me they are correct and the thickness is ok as they're more denser than the originals
They'll be happy to fix the car then if the D/S shears right?
In all seriousness, I've done a search and can't find threads with sheared Campus shafts. So perhaps I'm wrong. It's been known.
I'm pretty sure that back in the day Renault were supplying both types (thick/hollow for GTT, thin/solid for Campus). Which is economically inefficient if the latter do the job ok, so makes no sense but it is what it is.
I don't want to be the Guinea pig thats first to try them
You wont be. You just might be the first to report back after a successful 10,000 mile road-test. As that's what we seem to be missing on here.
Thundercat has given some insight that these should be ok at least for a time.
The alternative is to source some of the thicker type. I thought they were still available? If they are, you have to wonder why?!
Guy from Norwich who used to be on here Tricky Nicky had an O/S driveshaft shear off. A campus version was fitted, after a seafront joint plus some dual carriageway blast back to Norwich it was make a really strange noise, in the car park TNT Andy hopped in and went to take it up the road to see if he could hear anything it sheared. Cue standing around in the car park for well over an hour awaiting for the flat bed truck to turn up.
Karl, the only thing missing from your report, how many BHP was TN's car
throwing out at the time? As long as an established manufacturer "specifies"
a particular shaft for a car, then I'm happy to use it. They will have done all
the needed shear tests...
Regards,
Steve
I've heard of the thinner shafts breaking on higher powered/torque cars. I suspect you'll be fine if you're running a standard engine.
If it was me I'd be looking at refurbishing the old shafts to be on the safe side. It'd probably work out cheaper too.....
Renault dealerships have been reported on many occasions to have supplied parts saying, "yes, that a part is definitely for a GTT", because that's what the computer told them. Then it turned out the part numbers had become obsolete and reused (confused, or some similar issue), and the part was actually either for a Clio or an R5 Campus and was not suitable.
The manufacturing/stress/shear tests Renault will have done on Campus parts will have been for Campus applications. I agree with Alex. If these thinner shafts are for a standard-ish power car then even if they are Campus-type, you'd imagine the stress tolerance contingency in the part would suffice. If it's for a higher torque car then I'd err on the side of safety and get new or refurb'd originals
Think it was only running standard boost around 10-12 PSI at the time, could just have been bad luck with a second hand campus shaft, I would have to ask him for more info.
In my experience with 5 gt turbo shafts and campus ones in drag racing believe it or not campus ones are stronger as there thinner solid shafts, as gt ones have ticker shafts so the shaft is stronger with causes the cv joint to break or spline will snap, when using campus shafts the cv or splines won't break as the shaft will twist as its a thinner solid shaft, but after a while the shaft is so twisted it goes out of balance at high speeds.
The only reasons I can see why gt shafts are ticker in diameter is to do with keeping everything balanced at high speeds
Hi Ted. Interesting insight.In my experience with 5 gt turbo shafts and campus ones in drag racing believe it or not campus ones are stronger as there thinner solid shafts, as gt ones have ticker shafts so the shaft is stronger with causes the cv joint to break or spline will snap, when using campus shafts the cv or splines won't break as the shaft will twist as its a thinner solid shaft, but after a while the shaft is so twisted it goes out of balance at high speeds.
The only reasons I can see why gt shafts are ticker in diameter is to do with keeping everything balanced at high speeds
"campus ones are stronger as they're thinner solid shafts, as GT ones have ticker shafts so the shaft is stronger"
Looking at what you said afterwards it seems you're saying that the GT shafts are stronger and twist less, which puts greater strain on the CV joint and/or the shaft splines, making them the weaker link in the drive-train. This might have been designed in purposefully by Renault. I've not seen CV joint or spline issues reported by members as a recurring issue on road-going GTTs, which is the application here.
That's it the gt shafts do not twist causing the cv joint to break and campus shafts twist and last longer
All this sounds like the blind leading the blinded. I guess this is how rumours start.
Thicker or thinner? All these answers assume that the World has stood still in the
past 25 or more years. With computerisation, maching tolerances will bear no
comparison for starters. This omits design improvements over that period. So, just
because it was a thicker shaft back in the day, doesn't mean that it still passes
muster today.
As long as it's the manufacturer who's specifying their part for a particular
application, then there's little to worry about. They will have done all the necessary
shear, wear and tear and load bearing tests way before bringing the part into
distribution. You can rest assured that their test limits will be at the severe end of
the scale.
I'd far rather have a new shaft from a trusted supplier than a refurbed one where
I'd have little idea of the stresses it has already endured...
Regards,
Steve
What we have so far:
- OE GTT shafts - thick during the time of GTT production
- Campus shafts - thin during and after GTT production
- Development in design of shafts - no evidence
- Renault - proven to be untrustworthy on supplying GTT parts in the modern setting
- Member experience - Campus shafts less strong, twisting under high-load, some shearing in GTT applications
- Member experience - GTT shafts causing no problem to road-going GTTs
You pays your money
Heck, weren't Renault guilty of supplying Campus oil filters to members, you know the ones that can cause a drop in oil pressure and screw up your engine?
Weren't Renault the ones saying 'sorry, part NLA' to members who'd go to the next dealership in town and get the same part ordered no problem?
Weren't Renault the ones shying away from working on members GTT's because 'they can be problematic and don't want to have customers coming back over and over'?
One missing piece of info Trevor, Renault aren't the manufacturers of drive
shafts. At no point have I mentioned them. The shafts I purchased came from
SKF and I have a matched pair. This to ensure there is the minimum of play
feeding back to the diff each time the car starts to move. They bear little or no
physical resemblance to the OE fittings taken off the car, but I have no reason
to doubt that they will do their job for the next 70K miles or so. The reputation
that SKF has in this field I find very assuring. It is they who specified the items.
With drive shafts there are all sorts of considerations, not least the amount of
flex needed to overcome the inertia of a stopped vehicle, no matter whether you
have a lead foot or not. It has to flex a little, else it would snap like wrought iron.
Over time it is bound to have some weakening effects. For me, it's just another
reason to avoid using refurbished units.
The causes of shear are plenty, but I would contend probably much more through
heavy use than most other reasons.
Regards,
Steve
Good point about this not being Renault. Maybe someone should get in touch with SKF then and find out. I'll be quite happy to discover these thinnies really are good for GTT applications. Until then everything else points the other direction for my personal choice.
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