So I need a drive shaft for my conversion. I'm putting a tt engine and manual box in a car that was na auto 2+2. I split my drive shaft and put the back half of my original drive shaft on the front half of a manual drive shaft, then dropped it off to my local Spicer drive shaft mob to have the front uni replaced and get the whole lot balanced. This is where it became a problem... They can't get the bigger tt uni joints, and according to their calculator the skinnier back half of the shaft won't be up to the task. So they have quoted me to change the yokes to suit a bigger Spicer u joint, and use a 3.5 inch tube for the back half, all of which sounds like a good, strong drive shaft, but quite expensive. Interestingly too, I asked them to consider a one piece shaft, and again, running it through their engineering calculator, even up to a 4 inch shaft wouldn't be safe to handle high speed operation due to the length of the shaft. I'm curious what other people have done with driveshafts? I'm a heavy vehicle mechanic so the idea of using an aluminum drive shaft just seems too alien to me!
They're probably doing the right thing but what you originally suggested (front half TT rear half NA) will be fine. Most aftermarket one piece tail-shafts use 3" tube and the smaller unis and don't fail.
If the front uni is stuffed you'll need to get something made up -a garden variety 1310 uni should be about the right size I think? For all the expense you're going too maybe it would be easier to just get a new shaft from shaftmaster or similar in the USA?
They said they can machine out the stakes and stake in a new uni, but they are just slightly different size to the standard 1310
As you are a heavy vehicle mechanic, have a look at how the universal joints are staked into the yokes. This is the major problem with changing universal joints, if they are machined incorrectly it will induce vibration & you won't find out there is a problem until after you have paid & installed. When it comes to repair or replacements most on the forum have opted for a replacement one piece tailshaft. You're not the first to run an NA diff behind a TT engine & gearbox. Perhaps contact COZ or Z1 & see what they can do. I've replaced two tailshafts in Z32's with one piece units & obtained both replacements from Z1.
Ha of course they are, wouldn't want to make life easy... If I were you I'd compare the cost of a one piece from Coz with getting a one piece made up (3" tube is fine) and go with whichever is cheaper.
The way there are staked is no issue, but the wrong size uni definitely is haha. The Spicer quote is pretty much on par with the cost of importing a one piece from the states. There are definitely advantages to working for a big company in the industry... I'm leaning towards getting Spicer to do it, at least if I have any trouble they are just around the corner
Hi, If dropthebass doesn't take the one piece tailshaft, I would be interested. Just have to sort out shipping to Perth, unless someone knows of one available in Perth. Damned staked uni joints....
I ended up pussying out and paying for Spicer to do it. I'm not trying to start a shit fight with the guys running a 1 piece, but I have seen the results of people not following engineers advise. If they say that it's only good to 5000 or so rpm (about 150ks with my diff if I remember correctly), I'm not going to argue. Thanks for opinions though. Btw if anyone's interested there's a safe speed calculator on the Spicer website
