I found out my driveshaft has a dying U-joint on my highly modded, tracked MSM. Unfortunately, I heard the U-joint on the OEM part isn't serviceable, so I'm looking at this as a chance to upgrade to a lighter, stronger unit.

I was given a quoted price in the $300 range from one place in Southern California that offers an aluminum piece with serviceable U-joints. Sounds enticing to me, but is there anything I should know before buying such a driveshaft like strength compared to an OEM MSM unit?

 

That's a more reasonable price than I'd have expected, actually.

I've heard of shops that will rebuild an OEM driveshaft (with serviceable joints) in the $200s, though I couldn't quote an exact price off the top of my head.

Something to consider, anyway. The stock unit is surprisingly lightweight.

 

stock unit weights like 10-15 lbs man i would take it out and make a few wiegh ins before you make your decission any 1.8 driveshaft will drop right in on your car so a new to you driveshaft can be had for as little as 50 bucks. something to consider imo.

 

Sounds badass, but honestly how much weight will you be saving? The stock one is VERY light last time I picked it up which is a few weeks ago. If you're rolling in cash go ahead and get the baller aluminum unit. If you're not I'd suggest a stock replacement.

 

I know the stock unit's pretty light, but if the replacement is close to the price of the Al unit that's lighter and stronger, I'd say why not. However, I'm just concerned of the strength of an Al unit and to see if anyone's had experience with one.

 

only 800 bucks, haha

 

Never seen aluminum driveshaft failure on a Miata, but it happens quite often on other high power modified cars.





I would just replace it with another OEM one.

 

I'm aware of the CF one. Baller piece indeed, but I'll save that for a more crazy build in the future.


Yikes, that looks like that happened at AAA Auto Club Speedway (Fontana, CA), based on the garage the car's in. I can see that happening there on a high HP car.

 

Having never actually weighed one, I'd still say that the stock 1.8 unit is less than 10 lbs. You can easily pick it up and swing it around with two fingers.

Well, for the reason that Magna points out (good junkyard units are cheap as hell) I'm guessing that there aren't a lot of folks who can actually weigh in here (pun intended) with first-hand experience. Searching turns up nothing...

On the other hand, if someone had experienced a failure with an aluminum unit, I'm sure we'd have heard about it.

On the gripping hand, here is a brand-new steel unit for $197: Car Part Wholesale - Auto Parts and Accessories Catalog - Powertrain Driveshaft For 2004 Mazda Miata

 

There are other reasons to go with aluminum driveshafts. The harmonics are softer, and that puts a little less stress on the drivetrain.

 

The MSM driveshaft has replaceable joints. So just replace the joint and be done.

Or replace it with a non-MSM driveshaft. They interchange. The non-MSM shaft does not have user servicable joints (though not intended by mazda, you still can replace u-joints with some work).

 

There are to many variables to say yes the Aluminum shaft is stronger or not, It depends on the type of Aluminum and wall thickness. It could be stronger or, they could make it out of old soda cans and it would not be stronger. Ask the shop that is making it. I know the shop in my area wont make a shaft unless its stronger than the one its replacing.

 

Stock unit IS surprisingly light. Every time I have gone to pick one up I have put way too much *** into expecting it to be 25-30lbs, then I find it weighs probably less than a gallon of milk. One of those parts that just weigh much less than they look like they would.

 

Just for reference...a gallon of milk is just over 8lbs.

 

IIRC standard 1.8 shaft is 11lbs and MSM shaft is 14lbs

 

I was under the impression that the stock unit is Al. The whole point of this thread for vagaxt is the fact that this new one would have servicable, removable?, u-joints.

 

I'm pretty sure it's steel.

The whole point of the thread is he already has serviceable joints.

 

I'm lost...whatever.

 

is this the one that will not impale you?

 

For you, I'd think that would be considered a desirable trait?