Prop shaft bolts
Discussion
I got a new set as I thought I’d lost mine but found them in the prop shaft when I got it out of the cupboard, the new ones have a lot less shank than the old so I think I’ll reuse the old bolts with the new nuts. The shank on the old bolts goes right through from the prop shaft into the pinion flange, so I think I’ll stick with that & old bolts.
Anyone else noticed that with new bolts?
I was going to replace mine when I put it all back together as the bolts are very well worn. I dont know what effect it would have with or without shank, When its done up tight I dont think it will effect it at all. It looks like the bolt on the left is so well worn its neary lost its thread. Where did you get them from? I will be going to my fixings specialist when I come to replace my nuts and bolts, it I find a matching bolt with similar shank I let u know
When I got mine, I was very lucky that the slave cylinder failed pretty much immediately. The clutch had been replaced by a professional 1000 miles before and the gearbox to bellhousing and propshaft bolts were finger tight. Actually, the propshaft bolts weren't even finger tight - the nuts were just threaded on and left.
The shanks of the bolts were beaten down in diameter a little and I need to get new ones. They're torqued up tight for now, but the flanges still clonk loudly upon torque reversals when driving.
In summary, I don't think the threads would last long at all if used as above. The friction between the flanges isn't enough. A decent unthreaded shank is needed through both flanges to remove all the clearance IMO.
The shanks of the bolts were beaten down in diameter a little and I need to get new ones. They're torqued up tight for now, but the flanges still clonk loudly upon torque reversals when driving.
In summary, I don't think the threads would last long at all if used as above. The friction between the flanges isn't enough. A decent unthreaded shank is needed through both flanges to remove all the clearance IMO.
jamieduff1981 said:
.... The clutch had been replaced by a professional 1000 miles before and the gearbox to bellhousing and propshaft bolts were finger tight. Actually, the propshaft bolts weren't even finger tight - the nuts were just threaded on and left....
Holy Dingbats ! A professional what ?? 
Mr Cerbera said:
Holy Dingbats ! A professional what ??
Shocking I'd agree. Everyone can have off days but that's a bit much! That's why I'd rather do everything my self. Even the most trusted names can have a new bloke working for them who is utter rubbish. I got stung like that recently on some pro engine work had to send out, luckily I saw it before I fitted the parts but I was not impressed.
The new prop bolts were from one of the big TVR parts suppliers, think I'll be having words!
I had the same thing. If you look at the smaller bolts in this pic of some of the bolts I have replaced they have a shoulder but not as deep as the originals:
The original bolts were all in good condition so I just cleaned them up - run them through a die to clean the threads and put them back on.
At least doing all this work myself means I know nearly every bolt from the gear box back is new and every bolt is torqued to the correct setting.
The original bolts were all in good condition so I just cleaned them up - run them through a die to clean the threads and put them back on.
At least doing all this work myself means I know nearly every bolt from the gear box back is new and every bolt is torqued to the correct setting.
When I bought my Tuscan I drove it 500 miles home and put it on a mates ramp for a look, every bolt on the drive shaft to hub l on the offside was slack! It had just had some work done to it in that the area, a well trusty Indy and the poor lad that worked on the car lost his job as he had a habbit for things like this. Not my doing as I only told the previous owner who worked for them and he said the guy was let go a few days ago!!! But that could have been very nasty, it was only the rubber gator holding them in.
The best () story I ever read was a bloke who had his car serviced prior to a blast to Belgium and a track day at Spa.
He had a great time there but prior to his return trip he had a quick check underneath and found a pair of Mole grips still attached to the steering arm.
As you say, anyone can have an off day but all mechanics' work should be "four eyed" before it leaves the workshop because of that possibility.
at £1500 a service it should be automatic.
(Sorry, too much coffee
)
) story I ever read was a bloke who had his car serviced prior to a blast to Belgium and a track day at Spa.He had a great time there but prior to his return trip he had a quick check underneath and found a pair of Mole grips still attached to the steering arm.
As you say, anyone can have an off day but all mechanics' work should be "four eyed" before it leaves the workshop because of that possibility.
at £1500 a service it should be automatic.
(Sorry, too much coffee
)I'm using eBay more & more for bolts these days there are some really good suppliers on there. With these I making an order for some other bits so added them in to save time...
When I did take the cerb to be worked on when it was still a new car I used the Indy who does the work him self, you know what you are getting that way & it's never disappointed!
Mr Cerbera said:
As you say, anyone can have an off day but all mechanics' work should be "four eyed" before it leaves the workshop because of that possibility.
at £1500 a service it should be
Exatly, the well known boss was quick to point the finger at the new guy in my case but didn't once say sorry I should have checked it. You have to let the new blokes start some where but it's the bosses rep on the line they should check the work them selves till they are happy to trust their guys. at £1500 a service it should be
When I did take the cerb to be worked on when it was still a new car I used the Indy who does the work him self, you know what you are getting that way & it's never disappointed!
Luckyone said:
I'm using eBay more & more for bolts these days there are some really good suppliers on there. With these I making an order for some other bits so added them in to save time...
Do you have a eBay seller recommendation?I was looking for Rear Shock bolts and found these, but they are hardly cheap.
http://www.ebay.co.uk/itm/370513748438
Remember that the prop shaft bolts aren't carrying the torque - they're just clamping the mating face of the prop shaft CV joint to the mating face on the diff. Think of it like 2 clutch plates - the spring isn't being sheared, it's just putting a clamping load on the plates.
Shouldered bolts are ideal, but I've used 'ordinary' bolts with some 630ft/lb going through it, so as long as they're torqued-up properly the bolt choice isn't so critical in my experience at least. Where it would all go horribly wrong is if they were loose and then the clamping force wouldn't be locking the faces together and then the bolts would be taking all torque load.
Shouldered bolts are ideal, but I've used 'ordinary' bolts with some 630ft/lb going through it, so as long as they're torqued-up properly the bolt choice isn't so critical in my experience at least. Where it would all go horribly wrong is if they were loose and then the clamping force wouldn't be locking the faces together and then the bolts would be taking all torque load.
Yesterday I received my order from Arun fasterners....20+ 7/16 and 1/2 UNF high tensile bolts for the Grifff rebuild....came to around 16 quid + delivery + VAT....they were recommended on the Griff forum late last year. 
They have email but don't appear to use it mind,
so phone is best. 
They have email but don't appear to use it mind,
so phone is best. Just in case you're looking to get them, they're not called shoulder bolts... They're just standard bolts. The ones with threads to the head are screws.
Shoulder bolts are different altogether with a step in the shank.
If anyone knows the size, I may be able to get some if you still need them.
T
Shoulder bolts are different altogether with a step in the shank.
If anyone knows the size, I may be able to get some if you still need them.
T
Propshaft bolts are purpose made, they have a different shoulder to thread ratio.
a "normal" bolt that short will have very little if any shank, just like the new one in the first picture.
To get a long enough shank you will probably have to buy bolts too long and cut off some thread.
ukkid35 said:
I was looking for Rear Shock bolts and found these, but they are hardly cheap.
you think 2 quid for a big high tensile bolt expensive ? Edited by phillpot on Tuesday 4th March 21:23
According to the well known TVR parts suppler who sold me these “prop shaft bolts” they were made to the specs given to them by TVR.
Odd seeing as the old ones in the picture I bought from Mole Valley TVR parts department when they were still a TVR main dealer!
Odd seeing as the old ones in the picture I bought from Mole Valley TVR parts department when they were still a TVR main dealer!
phillpot said:
Propshaft bolts are purpose made, they have a different shoulder to thread ratio.
a "normal" bolt that short will have very little if any shank, just like the new one in the first picture.
To get a long enough shank you will probably have to buy bolts too long and cut off some thread.
Sounds like they just went for thread & length in a normal bolt then.a "normal" bolt that short will have very little if any shank, just like the new one in the first picture.
To get a long enough shank you will probably have to buy bolts too long and cut off some thread.
Tada
HT PROP SHAFT BOLTS 3/8 x 1 1/4" UNF C/W 3/8" NYLOC NUTS
Double Tada
http://www.ebay.co.uk/itm/HT-PROP-SHAFT-BOLTS-3-8-...
HT PROP SHAFT BOLTS 3/8 x 1 1/4" UNF C/W 3/8" NYLOC NUTS
Double Tada
http://www.ebay.co.uk/itm/HT-PROP-SHAFT-BOLTS-3-8-...
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