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Spitfire Spitfire Drv Line Balance ??

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Norton47

Jedi Warrior
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Got the engine and trans out, took the drive line out and am going to have u-joints replaced and have it balanced.
Does anyone know what Canelys means when they state:

Propshaft Problems

I've got this sort of vibration that comes in at 55mph...
(My problem exactly)

They can make all the difference between a pleasant driving car and something horrible! Even the smallest wear, stiffness, or misalignment can cause an incredable amount of vibration through the car.

Just changing the Universal Joints can put a shaft out of balance - please note that unlike the halfshaft UJs, the ones in the propshaft should not be set tight. The type of propshaft you have fitted determines the cure.

Strap Drive (what I have)

Check for any broken straps and that there is no wear in the pin which fits into the prop end - a worn pin means the prop is scrap as it will not balance on the car even though it may balance on the machine. If all is OK, change UJs and rebalance.

end of quote.
Ok
Now the straps are ok, The question is what pin are they refering to? There is a blue tapered item in the center of the differential flange, that looks like it could help center the flange alignment. Is that the pin they refer to?
Camera's on the blink, right now, sorry.
Thanks
 
OK, now you guys are starting to worry me about all the problems i might run into.
what year spitfire are you referring to ?
 
Now, let me say before you read any further that I know nothing about this!!
However, a friend has just had his prop shaft rebuilt and has told me all about it. His was the strap type and he said that there was a vibration at about 55 - 60. He put new UJs in the drive shafts, but sent the prop off for a professional rebuild. He said the he knew it was worn because when it was fitted to the car there was movement at the strap end. This allows the prop to move slightly and causes the vibration. Interestingly when the prop shaft specialist rebuilt it they substituted the stap arrangement for a splined joint. They also renewed the UJs and then balanced it all.
Hey, that almost sounded as though I knew what I was talking about.
 
sabot said:
OK, now you guys are starting to worry me about all the problems i might run into.
what year spitfire are you referring to ?
Click to expand...
Assuming all is still fairly original in your early Mk3, you shouldn't need to worry about strap-drive propeller shafts. They're usually found on mid-1970s Spitfire 1500 models.

Apparently these strap-drive shafts can be a problem as they wear, and each of the eight straps -- although they don't exactly look like precision-manufactured bits, I suppose they must be -- sells for about $8.00. This past summer, I had a friend who had just finished putting together someone else's project 1500 and was having a bit of trouble with vibration. In looking at his car, I realized that some previous owner had simply eliminated the presumbably worn or broken straps and bolted the remaining pieces of the propeller shaft together with cheap nuts and bolts that had loosened a bit. The looseness was bad enough, but even if tight they resulted in the u-joints at each end being out-of-phase. Luckily for both my friend and my wallet, I had a good used shaft to sell him! :angel:
 
Sorry about that! This is on a 1975 Spitfire 1500.
 
I'm naive about this but will be looking at driveshaft issues when fitting the later single rail gearbox to our '72 project Spit. Can any of you direct me to pictures that show the difference between a strap-drive shaft and the "other" type?
 
Mark- The drive shaft on the Wedges is a hokey C-V style, probably in the same funky style as yours and I had Drive lines NW build a spline unit for me.
 
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