Nostalgia Dragster Rebuild

**Preen59** · 10-07-2010, 08:36 PM

Well... We've had a driveline failure.

Not as bad as it sounds, but damn it made a mess. We were using a circlip to retain the jackshaft and allow it to float just a little. What i/we (probably I i guess) didn't think of was how much pressure would be inflicted on that circlip when the clutch was operated. Long story short, it's pulled the circlip out of the groove and wrecked it, pulled the jack shaft back out of the crank and that has in turn meant it had no support, so it's gone off-centre and whipped around, making a real mess of things. That shook some bolts loose, which went around the bellhousing like in a pinball machine and dinged everything up, too.

This all started this morning when Dad adjusted the clutch linkage and got in to check the position and operation. The clutch wouldn't operate, so we set about trying to figure out why.

Here's some pics.. And you'll notice a change in design.

I turned down the damaged bearing surface of the shaft, then turned up a 4340 sleeve for it and heat shrunk it on with .035mm cold interference fit (The shaft is .035mm bigger than the hole). Then turned down the sleeve to the appropriate bearing diameter, leaving a 4mm shoulder in place of the previous 3mm circlip. That's not all we had to do, but that explains the pictures i've got.

It will now have a greater surface area, more support and we aren't relying on a damn circlip.. So i'm much happier.

**Jarred** · 10-07-2010, 08:59 PM

good work mr metal man!

**alex g** · 11-07-2010, 04:34 PM

very tidy repair bro

it still amazes me how much trust is place on circlips split pins and so on

**Preen59** · 12-07-2010, 06:08 PM

Originally Posted by alex g

very tidy repair bro

it still amazes me how much trust is place on circlips split pins and so on

Cheers dude.

I don't trust circlips or split pins for a lot of things. I'd much rather a definite solid locking mechanism. But i had assumed there would be bugger all force on it, so i wasn't concerned. Really should have thought that through a bit more, but ah well, you live and learn.

On the up side we breezed in getting it all back together yesterday and it's all sweet as. We also trialled a method of boiling the Nitro out of the old oil too, which seems to work quite well..