Driveshaft Lubrication - Again... (1 Viewer)

[PACNW96]

I have been researching how to properly grease the driveshafts as described in 80 series FAQ which includes threads about removing the shafts to directly lube the splines.

For general driveshaft lubrication (without removing the shaft - assuming grease is getting through) is installing grease till slight driveshaft expansion the correct amount? I have heard others claiming this is too much.

Sorry if any of this is a repeat, but looking for some more feedback on this issue.

Thanks for the help.

Russell

 

[OGBeno]

Russell:

Check out this thread, especially posts 1 and 4...

This pertains specifically to the rear drive shaft, but I think we can intuit that it would apply to the front one as well.

Best.
-onur
Akron, OH

 

[PACNW96]

Beno,

Thanks for the response. This is the thread I am getting most of my information from and have been going back to the statements made by Doug:

Post 14 "...I got it installed as described above and pumped more in until the shaft barely began to move - as usual and as has been recommended here by me and others."

Post 14 "So, clearly cleaning the splines (though as mentioned I didn't find the expected dried crusty stuff blocking them) did zero to help grease come through them. They're just incredibly tightly machined and my feeling is that I'll pull the shaft apart every couple years and simply clean and hand grease them from now on."

I have found that grease is getting through both drivelines on my 80 so I am just wondering for a non hydrolocked driveline that is operating normally how much grease should I add? Till slight driveline expansion per Doug?

Thanks again,

Russell

 

[tarbe]

I think it is a good idea to separate the shafts, clean all the old gunk out and hand grease to baseline the shafts. This is the route I took on my used truck after a half-dozen greasings through the zerks(as you stated, until the shaft just started to move) failed to rid me of the grabbing/clunking at stop/start.

Since the hand greasing, I noticed a slight grabbing starting to develop so I hit the zerks. Amazing but I put 20 handle pumps into each zerk without the least bit of movement of the shafts. I guess there is lots of room in there now with all the old stuff cleaned out! BTW, the grabbing went away.

 

[turbocruiser]

As another data point, after reading and re-reading all the available information here, I too disassembled my driveshafts and expected to find the crusty crappy grease blocking up both shafts. To my surprise neither shaft showed these things, in fact, when I grease my shafts I religiously pump four pumps of grease and within a few slow short miles I see some grease migrating out of the shaft. I think some people's seals simply seal too tightly (probably from getting dried out once) and other people's seals allow an amount of grease out. Also, as another data point, with the four pumps pumped in, I never notice the driveshaft actually expanding. I would think if the driveshaft expands after four pumps it is indicating an almost airtight seal, I would also think that an almost airtight seal indicated a much much much higher risk of damage to the TC. The theories that many here mentioned regarding the hydraulic ram effect of a too tightly sealed driveshaft and a too powerfully packed greasage make perfect sense, but again, only if the seals are so tight that they wont allow the migration of grease. I suggest that the standard grease procedure should include a thorough wiping of all old grimy grease off of the shafts followed by a few slow short miles to see if any grease is migrating out. If it is not, then at that time the proper thing to do would be to disassemble the shafts, clean the splines, and wait til the next time that the grease refuses to migrate. I suspect, although I am not sure, that until the seals get crusty, and as long as you do not overfill, you will never have these heartaches. HTH.

 

[Tools R Us]

I add 4 pumps at every oil change, the spinning shaft distributes it nicely, looks to be about the right amount. You want just enough to lube the splines, too much will hydraulic lock the shaft putting big load on the bearings in the transfer case and diff.

 

[PACNW96]

Hey thanks for the detailed feedback. It is much appreciated.

Russell

 

[OGBeno]

Russell:

Both of my drive shafts just got rebuilt, so they were fully filled with grease when I picked them up at the drive line shop.

While I was there I asked them what they recommended.

FOOTNOTE: They do mainly big rig drive shafts 18-wheelers, military stuff, etc. They know their stuff.

They basically said that with every oil change (roughly 3K miles) just pump four or five pumps in and you should be good to go till the next oil change. He said that the grease does more than a good job in making sure the splines are greased and that the u-joints are full of grease enough to rotate on their axes in a smooth manner.

That said, he also recommended that every three or four oil changes (equals out to about once a year), pull the drive shafts and clean them by hand with a good degreaser. Then hand grease them and then put them back on. He also said put one or two pumps after they are on the rig and have been driven after about a day or so.

He was very impressed with the LC driveshaft. He mainly deal with Volvo, International, etc., and said that he was pretty amazed at how solid and how well machined the splines on the yoke were and how solid the u-joints were.

He thought a well-maintained Toy. drive shaft assy. could easily last 200K miles....

Hope this helps.
best.
-onur
Akron, OH

 

[PACNW96]

Definitely helps Beno! Thanks.