Driveshaft and lubrication

Hi, 1999 2WD LTD.
1. The transmission end has a slip joint and a U-type joint, while the differential end has just a U-type joint. Does the slip-joint move in and out of the propeller shaft?
2. The owner's manual specifies grease for the spiders, slide yoke, and double cardan joints. There are no zerk fittings anywhere in the drive shaft system. How then is the lubrication done? Is grease packed in when new? Does this have to be replenished periodically?
3. Are there any splines here? There is a comment made by someone that the splines are lubricated by being bathed in the transmission oil. Have you come across this?
Thanks very much!

 

1. = Yes
2. = Greased from new. Only way to replenish is to disassemble or replace.
3. = There are splines on a driveshaft that are lubricated via grease zerk on the circular part of driveshaft.
If any of your U-joints are bad, replace with U-joint with a grease zerk for future service. If the splines (slip yoke) are bad, you will need to get a driveshaft built.
I'm not real familiar with the 2WD version, also you talked about "slip joint" & "splines", are these the same as you see them?

 

@Toy4X4 do the splines have to go back in a specific orientation? The reason I ask is because my splines disconnected during an accident that happened as I was working on replacing the OEM springs with 2890s. Please help

 

I'm not 100% sure. There is such a thing as "phasing" U-joints to eliminate secondary vibrations. On a large vehicle (like a dump truck) "phasing" the driveshaft is pretty important, I would believe the same for a pass. vehicle. The orientation of the U-joints is a parallel, this provides the best balance scenario. If you are having problems with the orientation, look at your other driveshaft to see how U-joints are lined up, or ask a shop that specializes in drive shafts/rebuilding. Check out the driveshaft for any damage. I hope this helps some.

 

1. Yes, as the rear axle travels over dips and bumps, the slip yoke slides in and out of the driveshave.
2. Your u-joint trunions may have been replaced with sealed ones in which case you don't need to worry about greasing them, but these 4runners had greaseable trunions from the factory I believe. But check if zerks are just missing in case the grease oozed out of the zerk hole and now gunk is covering up the holes where the zerks were. If that's the case, no telling how long they've run without adequate grease so you'd need to disassemble the u-joints to inspect the trunions and needle bearings, but if you're going disassemble the u-joints, you might as well just go ahead replace the trunions with new ones and forget the old ones.
3. The splines are on the slip yoke, they're how the drive shave turns the slip yoke while allowing it to slide in and out. I'd be really surprised if the slip yoke doesn't have a zerk fitting for grease, unless the whole drive shaft is an aftermarket replacement from the factory one, which would also explain no zerks on the u-joints.

 

You are correct. The 4Runner drive shaft comes from the factory with HOLES to put zerks into. usually with a small bolt in them to keep dirt out. If you want zerks in them, you'll have to get your own, and swap them in. One for each U Joint, one for the slip joint, 3 in the double cardan, and so forth. The U Joints include the forward drive shaft. IIRC, it has a slip joint as well.

Don't over grease the slip joints. They have a rubber seal inside to keep the grease in, and the dirt out. A couple pumps from the grease gun is plenty enough. Too much grease will rupture the rubber seal, and let dirt, water, and so on, in.

The U Joints take surprizingly large amounts of grease. You want to pump them until the grease comes out from all four trunions. Excess grease will be slung out as you drive. A bit messy on the underside of the vehicle, but hey, it keeps the rust away
I did all my drive shaft lube twice per year, spring and fall. I had the factory drive line in my 87 4Runner until I sold it a few years ago. It had 175000 mi. on it when I sold it.

Make sure you pull the rear, and front, breather for the 3rd member, and ensure it's clean, and functions well. Otherwise you could end up replacing the rear axle seals.

Good luck!
Pat☺