Ford Focus ST Forum banner
1 - 20 of 20 Posts

·
Registered
Joined
·
1,694 Posts
Discussion Starter · #1 ·
Well yet again ive broken done, 3rd time since August. This time i was driving on the Loop road in Leeds when i heard a big bang followed by clunk clunk cluck. I called the RAC out who had a look and told me it was a complete failure on the passengerside driveshaft so he towed me home. Ive managed to source another one for £115 inc VAT from a breaker so ive ordered that. Ive decided im gonna take off all the aftermarket parts and return it to standard. Maybe stick with just a remap, 300bhp/342lb ft torque is too much for the standard driveshafts in my honest opinion.
 

·
Registered
Joined
·
2,263 Posts
Sorry to hear about your misfortune Daz
You better off getting diff fitted rather then powering down the engine. All that wheel spinning does damage driveshafts. Out of 54k+ miles i had only one driveshaft problem and that was to do with certain greasemokeys damaging the boot so it was not down to power.

Don't give up mate
 

·
Registered
Joined
·
1,548 Posts
I'd have thought that a diff would make things worse, not better?

With an open diff, if a wheel spins up, torque is transferred to the freely spinning driveshaft which is met with no resistance at the wheel end, so the shearing force on the driveshaft will be low.

With a limited slip diff, if a wheel spins up, torque is transferred to the grippier driveshaft, which is now receiving more of the engines torque whilst simultaneously being gripped by the road at the wheel end.

No?

Though I would still get a diff, best mod you can make


Also, it's torque that kills driveshafts, not power....
 

·
Registered
Joined
·
2,263 Posts
correct Razzle, diff does move the power away from the slipping wheel....

except wheel is never slipping freely per se, it is jumping up and down vibrating like mad rattling the
out of CV joints, hence the failures.
 

·
Registered
Joined
·
1,548 Posts
QUOTE(vladSTer @ 24 Nov 2009, 03:40 PM) <{POST_SNAPBACK}>correct Razzle, diff does move the power away from the slipping wheel....

except wheel is never slipping freely per se, it is jumping up and down vibrating like mad rattling the
out of CV joints, hence the failures.

Good point.

In that case, does that mean that open diffs are easier on driveshafts but harder on CV joints, while LSDs are harder on driveshafts, but easier on CVs?
 

·
Registered
Joined
·
2,263 Posts
QUOTE(razzleultra @ 24 Nov 2009, 03:51 PM) <{POST_SNAPBACK}>Good point.

In that case, does that mean that open diffs are easier on driveshafts but harder on CV joints, while LSDs are harder on driveshafts, but easier on CVs?

I suppose it is a different kind of stress. Torque applied smoothly produces twisting force on driveshaft and presses CV bearings against the cup undoubtedly stronger with LSD then without. However if torque is applied suddenly anything with slight bit of play is accelerated and then hit against what's stationary with massive force [whatever twisting power of the engine is].

If wheel being spun by driveshaft is suddenly released by tyre grip it outaccelerates driveshaft making loose elements move as if the car is being driven in reverse then when the wheel hits the ground again driveshaft catches up hitting lose elements again and so on with wheel bobbing up and down.
 

·
Registered
Joined
·
24,177 Posts
QUOTE(razzleultra @ 24 Nov 2009, 03:51 PM) <{POST_SNAPBACK}>Good point.

In that case, does that mean that open diffs are easier on driveshafts but harder on CV joints, while LSDs are harder on driveshafts, but easier on CVs?

As far as im aware nobody has ever broken a driveshaft? Theyre a
great lump of steel after all! Its the CVs that break! As Vlad has said its the jumping up and down that kills them combined with the CVs being tiny and unable to handle the torque of even a standard car!
 

·
Registered
Joined
·
1,694 Posts
Discussion Starter · #12 ·
QUOTE(fishface31a @ 24 Nov 2009, 10:26 PM) <{POST_SNAPBACK}>
As far as im aware nobody has ever broken a driveshaft? Theyre a
great lump of steel after all! Its the CVs that break! As Vlad has said its the jumping up and down that kills them combined with the CVs being tiny and unable to handle the torque of even a standard car!


Yeah its the CV that has broken on mine. I collected my new driveshaft today so will be fitting tommorow so ill be able to see what exactly has happened to it. A little off topic here but I was at Fords today and they had the Focus RS that i had ordered delivered today she was stunning. WHY did i have to go cancel it
 

·
Vendor
Joined
·
2,677 Posts
Its very rare for a N/S drive shaft CV to fail - you are unlucky - Had the CV joint rubber boot failed?

We are starting to see quite a few cars (std & tuned) through the workshop with wear in the O/S shaft inner CV
 

·
Registered
Joined
·
1,694 Posts
Discussion Starter · #14 ·
OK ive got everything off upto the cv that goes into the gearbox and tried everything it just will not come out. Ive tried brute force, wedging behind it, it just wont budge. Is there some sort of tool i need to pry it out with. The rest of the driveshaft with the bearings still attached is out it came off pretty easy. Cheers.
 

·
Registered
Joined
·
1,694 Posts
Discussion Starter · #15 ·
Another update. It looks like the engine mount on the gearbox side has snapped. The CV is sat on the arm so locked up, in the process breaking the CV internals. The whole of the engine is tilting downwards im just hoping it hasnt shattered the gearbox inside.
Im sick to death of having problems with the car its just costing me money all the time so ive decided to put it back to standard and sell up.
 

·
Registered
Joined
·
1,694 Posts
Discussion Starter · #17 ·
It does have a vibra torque on yes. ive had a look at it and its not what has snapped. It does look loose though i can touch the bolt on the inside with my finger. Im gonna take some photos later and upload em after ive got the battery off to take a look at the mount on the top of the gearbox.
 

·
Registered
Joined
·
1,694 Posts
Discussion Starter · #18 ·
Ok a little update. Ive got the battery off and discovered the reason the gearbox dropped is due to the main bolt that holds it in place coming loose and dropping out. Id originally feared the whole bracket may have collapsed but fortunately this wasnt the case. Ive got a few photos so as soon as they are downloaded from my phone (when ive figured out how to get em off lol) ill put them on.
 

·
Registered
Joined
·
1,694 Posts
Discussion Starter · #20 ·
Just to let you all know i got it all fixed today. I borrowed a really good drift from Ferrybridge powerstation, the shaft just popped out with that. Been on a test run and everything is OK. Thanks for all the help and advice everyone im very grateful.
 
1 - 20 of 20 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top