Shortening a tailshaft the cheap arse way, with pics

Gannon · Post by **Gannon** » Thu Sep 22, 2011 7:51 pm

So seeing as the only place that shortens a tailshaft for 200kms wants close to $350 to cut 60 odd millimetres from mine, I decided to give it a hack myself

Step one. Remove the bearing by undoing the 27mm nut, then use a gear-puller to remove the flange from the splines. Then very carefully, using a copper hammer, tap the end of the shaft to remove the bearing

Step 2. Cut the shaft about 30mm from the bearing end.

Step 3. Put the bearing end in a lathe and turn down the weld enough to remove the short length of shaft (a huge thanks to Nev's dad for letting me use his lathe)

Now I just have to press the shaft onto the bearing end, and then with it back in the lathe (to hold it dead straight)
I'll weld it back up and put the bearing back on and all should be sweet.

I'll update as I progress

guyph_01 · Post by **guyph_01** » Thu Sep 22, 2011 8:08 pm

What about balancing?

Gannon · Post by **Gannon** » Thu Sep 22, 2011 8:14 pm

guyph_01 wrote:What about balancing?

I'll take my chances.

Im doing the work at the bearing end, not the uni end, so there really shouldnt be any problems. There isnt even any balancing weights at this end

guyph_01 · Post by **guyph_01** » Thu Sep 22, 2011 9:02 pm

Oh ok, I'm no pro and was just asking. Weird that yours cost so much, Mine cost $180 to get done by drive shaft Australia.

mud_king91 · Post by **mud_king91** » Thu Sep 22, 2011 10:03 pm

You could balance it on the lathe how ever giving the weld a quick shave would have the same effect

YouTube · Post by **El_Freddo** » Fri Sep 23, 2011 10:37 am

Good work Gannon!

We've done two - one to a 71 torana after a manual conversion and another to a 78 lancer after another manual conversion. Both turned out really well without any balance issues! We didn't use a "fancy" lathe, just careful use of an angle grinder to cut the weld then shaved off the required amount with a fancy electric hacksaw - bunged the end back on, weld, cool, paint and install.

Both were done on the rear section so that if the welds failed and the tailshaft split it would simply drop out from under the car, if we did the front and it split the tailshaft would drop onto the road, grab and flip the car instantly! Not fun I reckon!

Cheers

Bennie

Post by **Alex** » Fri Sep 23, 2011 10:45 am

nice job mate.

Good way to save a few hundred smackers

alex

Gannon · Post by **Gannon** » Sat Sep 24, 2011 2:58 pm

Update

Now I have a friend (Matt) who works in a windmill factory and he let me use his big press to push the bearing end into the pipe. We then put the shaft into the lathe and set a dial gauge against the bearing section. Will a little manual persuasion from a copper hammer, we got it down to 3 thou on the dial gauge.

Next I got Matt (who's welding skills are 1000 times better than mine) to tack it in 4 positions and recheck the run out. Matt then ran a full bead around the circumference with the MIG and when rechecked with the dial gauge, was out by 9 thou (0.22mm). Good enough for me.

The finished result

With the bearing back on, ready to throw under the car

discopotato03 · Post by **discopotato03** » Sun Sep 25, 2011 1:11 am

Almost 23 thou doesn't sound like a lot but it can be .
Some of the rubber mounts for those bearings can be pretty soft and still transmit a surprising amount of vibration .

Time will tell .

steptoe · Post by **steptoe** » Tue Dec 11, 2012 5:56 pm

Speaking of time will tell.....Gannon , how is the project coming along ???

littlewhiteute · Post by **littlewhiteute** » Tue Dec 11, 2012 8:35 pm

discopotato03 wrote:Almost 23 thou doesn't sound like a lot but it can be .
Some of the rubber mounts for those bearings can be pretty soft and still transmit a surprising amount of vibration .

Time will tell .

He said .22mm, not 23 thou.

Make sure you have the universals phased correctly (front to rear) on reassembly.

tambox · Post by **tambox** » Wed Dec 12, 2012 5:09 pm

I did the same to my tailshaft when I put the Viscous box into my L series.

A couple of points, if you look at the L series tailshaft/s all seem to have balance weights on three ends, none on the splined end.
When I spun my tailshaft in the lathe, all the ends with weights on them were slightly out of alignment.

When I cut and machined the splined end I could see, due to its construction, it should run true. And it does.

Once pressed on, when you weld a tailshaft;
Tack it at 90 degree points, check.
Weld opposed welds, but leave a 2mm gap on the last weld.
When it has cooled down, weld the 2mm gap.

Tailshafts are leathal weapons, I have seen/heard results of what happens when it goes wrong.
Ever thrown one in a bonfire ?? Stand well back.
Hot air as powerfull.