DIY tailshaft

[mullett]

Ok, so I got quoted $800 to replace the uni joints in a normal Toyota 3 peice tailshaft. Seems a little on the excessive side. Turns out that because they're not the serviceable variety, it's basically cut them off and replace (which is basically a new tailshaft anyway).

So that got me thinking...it's basically two bits of pipe and some commonly-available uni joints. So what's stopping you making your own? (obviously you'd have to give it to the tailshaft shop for balancing, but that's only $120 or so).

[white_sandshoe]

Mate of mine did a Manual conversion on a Cressie, and he had the same issue... It turned out to be cheaper to get a single piece shaft done with Ford unis...

[1JZ-Rolla]

So what's stopping you making your own?

only common sense



Seriously though, if you have machining/welding skills, and source the correct tube (CDS or similar of the right tensile strength) then its not rocket science. Uni joints need to be indexed very accurately to keep them in phase & avoid vibration/wear, then as you said, off to the shop for balancing.

If however your workshop consists of exhaust pipe, a hacksaw, a hammer (borrowed from Aloshan), and an old ARC welder, then i'd probably say leave it alone

Its really not something that you want to get wrong....... I've had a tailshaft snap in the middle at speed, lets just say its "life changing"

[oldcorollas]

i'd rather get it done by someone who welds that gauge of material all day in circles

or fit a number of tailshaft loops

[1JZ-Rolla]

A handy way to get a nice consistent weld bead around the full circumference is to use the lathe (assume you have access to a lathe to begin with if you are planning to size up the tailshaft tube and cut it accurately).

Your yokes should be a snug fit into the tube, so get them indexed and then place in the lathe chuck and set the speed to match your welder settings (do a test first!). You can then basically hold the MIG torch in a set position and let the lathe control laying down a nice weld bead with no variation.

[mullett]

Handy trick, although I wouldn't want to get splatter etc all over the bed/chuck etc of my own lathe

The single-peice is an option, although I've got one in the shed and it vibrates at high speed. I think the tube length on one-peices could be getting a bit high and start to wander at high rpm

[andrew_mx83]

yeah no welding splatter on my lathe thanks. im anal enough about keeping it clean as is.

also how would you hold it? you would either need a massive spindle bore or a couple of meters between centers.
i suppose you could drop the tailstock off the end and use a steady to hold the back, but in terms or keeping it all aligned..... i dunno.
if i supply the uni's my tailshaft guy charges under 200 to give it back to me as a done and balanced 1 piece.

[1JZ-Rolla]

^^^ I have a mate with access to a very large lathe with many chuck and support accessories I hear ya about keeping the lathe clean though, you guys are much more fastidious than the majority of workshop owners, haha. I visited an engine builder locally once that had to lean over almost on a 45 degree angle to reach his lathe, the pile of swarf on both sides was so big! Dunno how people work like that.....

No harm in tacking it (in aligned position) before sitting it in the lathe for a full circumference weld. I'm sure the big workshops have a jig setup specifically for the purpose above, the lathe is just a cheat way to get the same result without additional equipment. Obviously your lathe needs to be able to turn dead slow too.

Andrew, your tailshaft guy sounds like a good bloke to know!

[RA35GT]

Hardy Spicer wanted $600 for a new two piece, most of the cost is in the fittings man

There are some things best left to the experts!

[andrew_mx83]

Fuck that! Every night when I finish working - even if its after midnight - ill grab a glass of scotch and spend a good 20 mins cleaning the machine, get all the swarf/dust/coolant off it then coat the thing in crc. Doesn't matter if that ill use it again first thing in the morning, its nice to start working on a pristine machine, plus I find it almost theraputic to wind down from the day and get my lathe clean.
Moral of the story is that if u want to do good work you look after your tools.

[1JZ-Rolla]

That's exactly the reason why i've not used that workshop since It was a brothel! Needless to say, parts of mine went missing while there also, some taken by the owners dog who stole and hid other customers stuff also......

Anyways, i'm getting off topic

[mxracer92]

who did the quote ?? try final drive in oconner !! he know his stuff and isnt a rip !!

[dnegative]

The biggest issue is welding the bits together so the thing is dead straight. Welding two bits of pipe together and having the thing be perfectly true is a hard feat unless you do it in a lathe.
I've gotten pretty fucking close with a spirit level and V blocks, probably close enough that you could straighten the thing in a press to have fuck all runout, regardless, most driveshaft places are pretty cheap for what you get.

That being said, most driveshaft shops charge heaps because when most blokes come in with a shaft off a truck or peice of earth-moving equipment the price they nominate is not questioned, its accepted on the spot (or over the phone) and thus the market price

[dnegative]

Uni joints need to be indexed very accurately to keep them in phase & avoid vibration/wear

Just line the fuckers up and make sure there is some joint working angle (a dead straight driveshaft is bad folks) otherwise you fuck the needle bearings

[allencr]

Search for the Youtube on replacing non-serviceable joints, the new U-Joint you gotta search for takes the circlip on its caps, inside the yoke, no machining needed but a little cleanup with a file..