Out of control propshaft

[Daley Down Under]

Spire had its 2nd track day outing at Hullavington on Friday.  Going well until final run of the day when the propshaft flange bolts let go (engine end).  12 inch propshaft had a whale of a time destroying anything in its path including clutch slave cylinder housing (part of the engine casing), water pump housing, gear linkages/paddle shift cable, fuel regulator and hoses, clutch aeroquip hose, various electical components, battery leads and electric reverse housing.  To cap it all, the diff input shaft couldn't hack the pace and sheared off at the splines.  I now have a large box of assorted bits and lots of work to do.  Hopefully I'll get the engine out over the next couple of weeks and see what else needs fixing.  Anyone know of a good engine casing welder and supplier of ZX14 bits?

As to why, I know the bolts were tight at the start of the day and there's no reason to suggest they loosened on the day.  Get the feeling it might be gearbox gremlins and sudden take up of transmission slack.  At a loss to understand it really.  Reminds me that propshaft 'catchers' are a must - even with short props.  I'll get rid of the reverse and replace it with a catcher.

Car wont be Cheddar and I will probably miss Stoneleigh and the next few club meets.  Bug**r eh

Adrian

[Bulldog Bri]

Bad luck Adrian, Hope your Ok... 

Is the engine casing Ally? One member is pretty good at welding aluminum (Aliwizard) maybe give him a PM see if he can help...

[Daley Down Under]

Thanks - I'm fine.  Video/microphone was on when it went bang.  When I've got a moment I'll upload to YouTube.  I'll PM member as you suggest.  Thanks again.

[Daley Down Under]

Started the search for 3.14:1 Sierra LSD diff input pinion and shaft.  Not looking hopeful.  I've got both bits of the broken one.  What would be the implication of welding to repair?  I'm assuming the whole lot would have to be heat treated post welding.

Any views welcomed and any ideas about who could do it also welcomed.

Cheers Adrian 

['The Gaffer']

Really sorry to hear of your mishap Adrian, at least you are ok and still have both your legs

Try Nigel at Chards of Feeder Road for prop repairs and upgrades, he really does know his stuff.

As for diff rebuilds and parts try Phil Jones http://www.pjed.co.uk/index.htm

Ali work, as above, Aliwizard is the man, if no one else can put you in touch I have his number.

All of the above have done work for me and I can recommend them 100%

Shame you are off the road for a while, but just ask on here if you need another pair of hands to help with the work.

[paintman]

What a bummer.....last thing you wanted now the weathers improving.

Hope its not as bad as it sounds!!

[Daley Down Under]

Really sorry to hear of your mishap Adrian, at least you are ok and still have both your legs

Try Nigel at Chards of Feeder Road for prop repairs and upgrades, he really does know his stuff.

As for diff rebuilds and parts try Phil Jones http://www.pjed.co.uk/index.htm

Ali work, as above, Aliwizard is the man, if no one else can put you in touch I have his number.

All of the above have done work for me and I can recommend them 100%

Shame you are off the road for a while, but just ask on here if you need another pair of hands to help with the work.

Thanks for the post and the pointers.  I'll give Phil Jones a call this morning.  Prop seems to be ok but will get that checked out also.

Cheers Adrian

[Martin Higgs]

Bad luck Adrian at least you are ok good luck with the rebuild

[Richard]

Glad you are alright other than a bit p'd off.

That really must have made a awful mess, doubt you could fail to miss something was wrong ?

Were the bolts re-used old ones from the original refit ?
I think replacing transmission holding bolts with new when refitting / rebuilding is a good move but may or may not have helped but then as you were supercharged they would have been under a bit more load yet again.

Best of luck on the rebuild, hope it all goes smoothly and quickly.

[Daley Down Under]

Richard,

Car was a new build and bolts are 8.8HT.  I will use 12.9 allen bolts when rebuilding.  Got a quote for new Crown wheel and pinion/shaft this morning (£495!!!!).  I have the feeling this is going to be an expensive job

[Richard]

Yikes, one expensive bang and clang !

12.9 I'd agree with.

Certainly an area not worth compromising on with the people doing the work for you.

['Mendip Wurzel']

Started the search for 3.14:1 Sierra LSD diff input pinion and shaft.  Not looking hopeful.  I've got both bits of the broken one.  What would be the implication of welding to repair?  I'm assuming the whole lot would have to be heat treated post welding.

Any views welcomed and any ideas about who could do it also welcomed.

Cheers Adrian

This chap has a warehouse full of Sierra bits ..... Rob - 07804 833334. Probably a bit of a long shot. He specialises in the kitcar market.

As I am sure you know the 7.5inch 3.14 LSD is like gold dust. I think they were only fitted to the 2.8 V6 automatic. I have a 7 inch 3.14 non LSD diff on my kit car which came off a 2.3 V6 Sierra. My car is not really a track car so the non LSD is fine for what I use it for...

Best of luck

Kevin 

[Hairy Santa]

looks like we are going to have a season of probs with drive shaft bolts

my car first

Adrians car second

and just been informed that my son in laws diff/drive line blew on his rally car this weekend

lets hope thats the last of them

all the best Adrian - I have wired all mine now  - might be worth considering on yours

Pete

['Mendip Wurzel']

looks like we are going to have a season of probs with drive shaft bolts

my car first

Adrians car second

and just been informed that my son in laws diff/drive line blew on his rally car this weekend

lets hope thats the last of them

all the best Adrian - I have wired all mine now  - might be worth considering on yours

Pete

I'm going to show my ignorance here....
Pete; I like the wiring idea, but aren't HT bolts hard to drill?. I'm assuming we are talking about threading a piece of wire through the top of each bolt. I've had my propshaft off this winter and have the usual worries about have I tightened the bolts enough, so I quite like your suggestion.

Thanks

[David H]

Adrian, i know how you feel having been there a couple of times with larger mechanical nightmares stopping play. That sounds like a total ball ache!!! you have my sympathy mate. Phils recommendations are good, ive used Nigel myself.

Cars......

Just finished rebuilding mine in the last few days, putting her on a trailer tomorrow and popping to the Ring for a few days then coming home. Hope the weather isn't too bad. Was going to do Spa on the way but a tunnel has collapsed damaging the track so its shut. Shame.

I hope you get it sorted soon!

[Hairy Santa]

looks like we are going to have a season of probs with drive shaft bolts

my car first

Adrians car second

and just been informed that my son in laws diff/drive line blew on his rally car this weekend

lets hope thats the last of them

all the best Adrian - I have wired all mine now  - might be worth considering on yours

Pete

I'm going to show my ignorance here....
Pete; I like the wiring idea, but aren't HT bolts hard to drill?. I'm assuming we are talking about threading a piece of wire through the top of each bolt. I've had my propshaft off this winter and have the usual worries about have I tightened the bolts enough, so I quite like your suggestion.

Thanks

yes they can be a bit of a pain to drill but if you persevere and keep putting a cutting edge on your drills you will win

when wiring, yes you put the wire through the holes but you also put it through in such a way that the tension is kept on the bolt head in the tightening direction if you can  - hope this makes sence - if not pop over and I will show you

could I ask did your prop bolts have any shanks on them or were they threaded all the way down ??

[Daley Down Under]

Kevin/Pete/Dave,

Thanks for the replies.  Started the dismantling process today - having trouble getting the diff out of the space between the chassis spars (bit like automotive origami).  Process will continue over Easter weekend.  Hopefully I will have the engine out by then and I can see what's going on in the gearbox etc. 

Thanks for Rob's contact details.  I'll give him a try (just in case).  Kevin - ignorance here - can I use 7 inch 3.14 crown wheel with LSD I already have or will mine be a 7.5 inch?

Drilling 12.9 (esp M8) is a challenge.  I'm going to use the usual loctite and a prop catcher.

Dave - enjoy the Ring.  Catch up soon.

Adrian

['Mendip Wurzel']

Kevin/Pete/Dave,

Thanks for the replies.  Started the dismantling process today - having trouble getting the diff out of the space between the chassis spars (bit like automotive origami).  Process will continue over Easter weekend.  Hopefully I will have the engine out by then and I can see what's going on in the gearbox etc. 

Thanks for Rob's contact details.  I'll give him a try (just in case).  Kevin - ignorance here - can I use 7 inch 3.14 crown wheel with LSD I already have or will mine be a 7.5 inch?

Drilling 12.9 (esp M8) is a challenge.  I'm going to use the usual loctite and a prop catcher.

Dave - enjoy the Ring.  Catch up soon.

Adrian

Adrian
I'm not sure if you can use the 7inch crown wheel on the 7.5inch LSD, I doubt it. Yours will be a 7.5 inch,  they only did LSD in the 7.5 inch. The 7.5 inch is a much heavier and bigger unit. You probably have bolt on drive shafts and not the push in type like I have on my 7 inch.
The next lower ratio is the 7.5inch 3.36 in LSD which could be an option. They did a 7 inch in 3.38. As I am sure you know the standard Sierra diff was the 3.62.
Kevin

['Mendip Wurzel']

looks like we are going to have a season of probs with drive shaft bolts

my car first

Adrians car second

and just been informed that my son in laws diff/drive line blew on his rally car this weekend

lets hope thats the last of them

all the best Adrian - I have wired all mine now  - might be worth considering on yours

Pete

I'm going to show my ignorance here....
Pete; I like the wiring idea, but aren't HT bolts hard to drill?. I'm assuming we are talking about threading a piece of wire through the top of each bolt. I've had my propshaft off this winter and have the usual worries about have I tightened the bolts enough, so I quite like your suggestion.

Thanks

yes they can be a bit of a pain to drill but if you persevere and keep putting a cutting edge on your drills you will win

when wiring, yes you put the wire through the holes but you also put it through in such a way that the tension is kept on the bolt head in the tightening direction if you can  - hope this makes sence - if not pop over and I will show you

could I ask did your prop bolts have any shanks on them or were they threaded all the way down ??

Pete

There was a small shank, washer width...

[Daley Down Under]

Kevin/Pete/Dave,

Thanks for the replies.  Started the dismantling process today - having trouble getting the diff out of the space between the chassis spars (bit like automotive origami).  Process will continue over Easter weekend.  Hopefully I will have the engine out by then and I can see what's going on in the gearbox etc. 

Thanks for Rob's contact details.  I'll give him a try (just in case).  Kevin - ignorance here - can I use 7 inch 3.14 crown wheel with LSD I already have or will mine be a 7.5 inch?

Drilling 12.9 (esp M8) is a challenge.  I'm going to use the usual loctite and a prop catcher.

Dave - enjoy the Ring.  Catch up soon.

Adrian

Adrian
I'm not sure if you can use the 7inch crown wheel on the 7.5inch LSD, I doubt it. Yours will be a 7.5 inch,  they only did LSD in the 7.5 inch. The 7.5 inch is a much heavier and bigger unit. You probably have bolt on drive shafts and not the push in type like I have on my 7 inch.
The next lower ratio is the 7.5inch 3.36 in LSD which could be an option. They did a 7 inch in 3.38. As I am sure you know the standard Sierra diff was the 3.62.
Kevin

Thanks Kevin - let's see what Rob can come up with

[Hairy Santa]

Hi Adrian -- have sent you a PM

[Daley Down Under]

Thanks - I've replied

[Quarrycars]

Sorry to hear of the problem, propshafts are pretty scary when they get loose, never had one fail on a car, but did have one let go on a dyno. One thing to remember is that like an engine flywheel the drive is through the friction between the flange faces, the bolts are there to provide the pressure not the drive. Like a flywheeel it is a good idea to lap the faces using valve grinding compound. The flange faces should be clean and dry when assembled. Shoulder bolts or dowels might not be a bad idea but shouldn't be necessary.
Chain drive may not be such a bat idea, chains break but have little inertia and don't do so much damage, plus you could get rid of that nasty, heavy, power sucking bevel gear!

[Daley Down Under]

Contemplated moving to chain but it needs to handle 270bhp, which I imagine is special order/build

[Daley Down Under]

Also engine would need to be turned through 90 degrees

['Mendip Wurzel']

Sorry to hear of the problem, propshafts are pretty scary when they get loose, never had one fail on a car, but did have one let go on a dyno. One thing to remember is that like an engine flywheel the drive is through the friction between the flange faces, the bolts are there to provide the pressure not the drive. Like a flywheeel it is a good idea to lap the faces using valve grinding compound. The flange faces should be clean and dry when assembled. Shoulder bolts or dowels might not be a bad idea but shouldn't be necessary.
Chain drive may not be such a bat idea, chains break but have little inertia and don't do so much damage, plus you could get rid of that nasty, heavy, power sucking bevel gear!

I never realised your point about friction between the  flange plates. Would you beleive it, I have only recently re-fitted my prop shaft and smeared oil on the flange plates because they were rusty. Damb, I think I need to take it apart again and do what you have suggested.
Kevin 

['The Gaffer']

One thing to remember is that like an engine flywheel the drive is through the friction between the flange faces, the bolts are there to provide the pressure not the drive.

Interesting, I didn't know that.

[Daley Down Under]

Update on Marlboro Car progress.  Engine is out (no crackcase damage) and is with a bike specialist to check the gearbox for damage.  Replacement clutch slave cylinder and water pump have been sourced.  Clutch aeroquip replacement is in hand.  New Digidash speedo sensor has been purchased as has new fuel regulator and pressure gauge.  Went to see Nigel at Chards today - he rubbished the existing propshaft in terms of capability and installation angle.  Long and the short of it is that I need a new beefier prop - much heavier duty with M10 bolts on both flanges.  Gearbox output flange also needs serious attention at the same time.  Supercharger oil, belt and idler pulley will be changed while the engine is out. Biggest problem remains the diff.  3.14 sierra is proving difficult to get hold of and I need to raise the diff by an inch to overcome the extreme prop angle.  All being well, car should be back on the road by mid May.  I just need to come to decision about the clutch - currently fine, only done approx 8k miles but completely standard.  It's at the wrong end of the engine bay to be able to change in situ.

Cheers Adrian

['The Gaffer']

Went to see Nigel at Chards today - he rubbished the existing propshaft in terms of capability and installation angle. 

He said that about mine, I had to move diff forward by about 7cm to get a better angle to my drive shafts. It reduces wear and makes the car smoother as the UJ's dont have to work so hard.

['The Gaffer']

Spotted a couple of 3.14 diffs on eBay.

Both from the same zero rated seller in Poland. Not sure if they are LSD.

Link http://cgi.ebay.co.uk/Sierra-7-Diff-3-14_W0QQitemZ270561650372QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item3efebb26c4

['Mendip Wurzel']

The advert states 7 inch which I do not think is a LSD, I may be wrong....

As far as I am aware the 7" 3.14 Non LSD went on the 2.3 diesels and 2.3 V6 and the 7.5" 3.14 LSD went on some of the 2.8 V6. 

['The Gaffer']

The advert states 7 inch which I do not think is a LSD, I may be wrong....

My 3.62 7" is a LSD

[David H]

mine was too, also my current 7"

[Daley Down Under]

Update ...

New 7inch 3.14 CWP sourced via Spire Sports Cars for £200.  Off to Phil Jones this week to get the good CWP swapped with broken items.  Engine goes back in next weekend and should be running again over Stoneleigh weekend.

Cheers Adrian

[Richard]

Good news and good progress, nice to hear !

['The Gaffer']

Well done Adrian, so will be seeing you guys on the run up?

[Daley Down Under]

Not sure about Stoneleigh weekend yet.  Obviously would love to be there but does depend on progress.  I will keep you all posted.  Have a good run down to Cheddar tomorrow.  Sorry I cant be there.  It should be a great day out.

[David H]

well done mate

[Daley Down Under]

Update on the Marlboro Car - slight glitch with the gearbox.  A couple of the selector forks need to be replaced and there's some other minor damage (new parts on order and due in this week).  Long and short of it is that the engine wont be going back in until Stoneleigh weekend.  Everything else is sorted except new prop which cant be made until engine is back in.  Estimate for back on the road is Monday 10th May.

See you at Stoneleigh in the tin top on BH Monday.

[Bulldog Bri]

Unfortunate that the car won't be ready in time for Stoneleigh but pleased to hear it's gonna be sorted soon...