1st Gen Rear Drive Shaft/ U-joints help

Hey guys.

Hope everyone is enjoying their holidays. I'm fairly new to Toyotas and would appreciate any help or wisdom here. After searching through the Haynes manual and numerous forums, I haven't found any concise info.

https://postimg.org/image/u31p7fngv/

I have a 1998 2.7l 4x4 with a M/T. I believe I have to replace my u-joints. It started as a light squeal almost. Whenever I was in a low gear and let off the gas and coasted I could hear it coming from what seemed like the passenger side towards the rear. (driveshaft) I also seem to be getting some driveline vibration, especially when braking from higher speeds. I did a thorough inspection the the brakes to rule out any other possible causes (9-8: 5 in Haynes manual.) After some research on here and other forums, I found it may be as simple as some grease. I went to lube the driveshaft only to discover the zerks were rusted over and a few looked like they'd been in a fight with a hammer. After removing and replacing them, I greased until I saw fresh grease come out (not sure if that's what Toyota calls for, but it's the standard at work.) the rear took a good amount of grease, about a tube and some change. Seemed to help for a day or so and then the squeal came back just as bad. since the zerks looked in pretty bad shape and the truck has pretty low miles (50k for a 98) I assumed it's been sitting most of its life and maintenance hasn't been routinely performed.



Here's where I hit a wall..

Almost all threads and the Haynes manual mention a center support or carrier bearing, absent on my truck. I've also read the double cardan (cv) joint is non-repairable and I'd have to replace the entire shaft. (500 bones...)

https://postimg.org/image/emftrc1nn/
https://postimg.org/image/3sworbl4v/

Upon further investigation, I've found some single cab tacoma's were manufactured with a single piece, two joint shaft but this was extremely rare. Inspection of the joints led me to find it's made by Koyo. (part # "KC1720AD") It seems to be used in older Tacomas, I'm not too familiar with this though.

https://postimg.org/image/hqx3h2ygd/
https://postimg.org/image/x5ynitch5/
https://postimg.org/image/k93ojtpqb/

My question is was this put in by the factory, or maybe a mod used by the previous owner? Also, is a single piece drive shaft alright to use? I'm not sure if the angle would be too great and cause possible premature wearing of the u-joint. (Only 50k miles, but also presumably almost 20 years old.)
Does this merit replacing the entire rear shaft?

Any info would be great and hopefully this helps others as well. Thanks again.

 

https://www.tacomaworld.com/threads/cv-joint-drive-shaft-rebuild-help.312864/
@Dirty Pool
Based off of what we read in this thread and more importantly that it comes from dirty pool, it's safe to assume you have one of those rare one piece drivelines.
So what are your options now? You can replace with a used 'more normal' 2 piece driveshaft. If you're not lifted, I don't see why you couldn't continue running the original after rebuilding it. Any other options?

 

What did you end up doing? I have a 98 like that only the rear joint I get from the local parts are a little too long to get the clips in.