Updated warning on greasing the rear drive shaft

[rdublin]

Well, I just got my '96 FSM so now I will be completely insufferable. Anyway, in section PR-9 under the title "Propeller Shaft Installation" it says:

HINT: After installation, pump MP grease into each fitting with a grease gun until the grease begins to flow around the oil seal.

Based on that it would seem that the oil seal is NOT intended to be "air tight" and if it were, it probably needs replacing. This is the procedure I use on my 40 series so I'm feeling a little bit better about that, but I still think I will pull the drive shafts this weekend. The xfer case tailstock tear down will probably wait two weeks because 1) one of our sprinkler system feed lines decided to give up the ghost this morning and flood the yard and 2) the alternator tensioning bolt failed on my 80 last night so I have to go out and try to find a 8 mm X 90 mm bolt. Dealer won't have one in 'til Wednesday.

 

[Junk]

So is someone gonna answer my question posed about bearing grease? Landtank, you saying it's not cool to use amSPOIL red bearing grease in the driveshaft?

 

[landtank]

I just have a lot of concerns about how well these synthetics flow down the shaft and out the splines. I can't say that it will be an issue but if the grease is so thick you can't pump it in then how could it lubricate?

I use regular old grease. The stuff Toyota recommends. I fill until a slight expansion of the shaft and soon after I start driving I can smell the grease burning off the muffler from flinging out through the splines. I get that grease ring from both shafts.

I did try some valvoline synthetic once but my pneumatic gun wouldn't push it into the U-Joints and out through the caps so that was the end of that.

Use whatever you want Junk, this is just my experience with the stuff and opinion from that experience and reading all the post concerning bearing setup and such with this stuff.

 

[Junk]

No, that's cool. Just wanted to understand your thinking on it and greatly appreciate it. Shees, now you made me blow it. I hate saying thank you and such

 

[RavenTai]

If you want a thinner synthetic grease try MobilGrease 28 (the link is a good read) it is PAO (group IV synthetic same as Mobil 1) oil with a clay thickener, it is between NLGI #1 & #2, and is designed to lubricate well in extremes in temperature (-65 to 350 *F)

I am trying it out in my wheel bearings, drive shafts and U-joints, I can not recommend it to some one else in wheel bearings until I confirm that it does not damage automotive seals but that should not be a problem in the drive shaft,

We use it in wheel bearings that soak at –55 *f for many hours then instantly spin up to 150-200 MPH carrying 30K pounds each wheel and then are exposed to high heat from braking for a mile or more, I have never seen a failed wheel bearing in this application but the tires are changes after 200 or so cycles and the bearing is changed with it, this equals out to only 500 or so miles of this torture,

It was about $8/tube at a local lubrication distributor

On my front shaft the grease readily comes out of the splines during driving after greasing them, the rear does not seam to, I think I need to take it apart and see what is happening

 

[IdahoDoug]

I disagree with the synthetic theory, Rick. I don't see a difference in the way synthetic or non synthetic greases come out of my hand grease gun. I routinely use 5 different types of grease with it, only one of which is synthetic.

Also, if you can fill your shaft until it expands then the normal grease is also not flowing down the splines - it's building up pressure instead. Mine worked its way out in the same way now that I've cleaned the fibrous seal of the factory's normal grease.

I also don't think it matters what any of us use in the scenario that I've outlined. You could use cherry pudding to fill your driveshaft spline zirks and it's fully hydrolocked. I've got a question in to Tom Woods driveshafts to see what they do.

DougM

 

[landtank]

Doug I've had this Synthpower stuff in both a hand gun as well as a pneumatic gun and it just doesn't pump easily. I've also read that others have experienced the same. I've only tried that one type of grease so maybe others are different, but when Eric was up here and we were doing his axle he had some red Mobil grease and it seemed pretty much the same as this synth stuff and it was real heavy also.

If regularly greased how many driveshafts are you guys seeing fail? I think while the synth stuff specs out as having better protection properties it's un warrented and it's heavier nature is providing a worse situation with this hydro comcern.

 

[97cruiser]

Not to interuptous you folks argumentus: but if you fill the shaft 'til it expands (and I have) are you not completetly filling the shaft thus creating a hydraulic ram. I have heard Christo, ID and others mention this and scares the snot out of me . Now after taking my shafts apart and cleaning them out fairly well I put only a few squirts in every oil change and call it good. After cleaning and before reassembling (about 5,000 miles ago) I filled the splines themselves with grease but did not fill the shaft with grease. My shafts still have grease on them.

Also when we fill our shafts until they move do you think it's the grease touching the male shaft and pushing it out? Or are we just pushing air with the new greases we just squirted in there. I'm guessing the latter.

Vince

 

[rdublin]

On my 40 it's definitely both air and grease, as the exiting material will often pop and hiss depending on whether it's a chunk of grease or a slug of air. In my limited experience the 80 driveshaft doesn't do this, which may be attributed to a clogged up seal?

 

[landtoy80]

RDUBLIN. Are you sure your speedo gear is no leaking. When it leaks, it makes it look like the rear output seal is leaking.

Junk,
Syn vs Dino grease:
The AmsoilHD Syn Grease w/ moly is thicker/harder than the Citgo Moly Grease. I had a problem with some of the Amsoil sys grease getting pushed into the axle when I installed the birfield.
THe Amsoil says on the back of the tube "also available,softer consisteny HD NLGI#1..."
I think I will go beck to dino grease for the birfields. I will stick with dino grease for the wheel bearings and u-joints.

 

[pwolfmanaul]

I have seen the problems you are talking about, I have stopped lubing the shaft through the zerk completely. I remove the shafts periodically clean them out and use antisieze on the splines, I have also installrd a boot over the extendable bit of the shaft to keep all of the crap out. no more lubing or t case problems

Paul

 

[landtoy80]

Antisize:
Are you sure antiseize is good in the yoke splines? You using high temp antiseize?
Wouldn't the heat from the muffler will make the antiseize get hard and dry.

I was told that the antiseize was for non moving parts only. Are you using a antiseize made for moving parts?

 

[rdublin]

Kurt,

I will double check the speedo mount, but I'm pretty sure it's the xfer seal. I will post if otherwise.

 

[dd113]

Just to chime in:

I agree 100% about taking the shafts apart and cleaning and greasing them. Once in a while but not every lube. Most of the 80s I deal with spit grease out just like all other TLCs. I have seen a couple that did not but after cleaning they were fine. The idea of removing the zerk after driving a while is a good one and I will test it out.

62 rear shaftts suffer all the same issues. 60s not as much and no idea why.

 

[Junk]

It's not that I'm seeing mine fail, it's that I keep bustin them up on the rocks and need to constantly get them re-tubed. Was asking so as to minimize abuse to the tcase.

 

[CDN_Cruiser]

A quick update to bring this to the top. I just got my new front OEM shaft. I pulled the shaft apart and the splines are lightly greased. On the female side, where the zerk is, there looks to be about 2 squirts of grease - it's not packed in any way.

Compressing the new shaft is VERY difficult. It is under full pressure until the lkast 1/2 to 1/4" and then air escapes around the seal.

I also noticed the spiders were quite stiff.

Cheers, Hugh

 

[teejnut]

When dropping the driveshafts can I just drop the side one side of each driveshaft or should I drop the entire driveshaft to grease the splines?

 

[scottm]

Bump for an oldie but goodie. Some good reading here for all of us obsessive maintainers.

 

[chapel gate]

hmm, interesting read, fwiw if i go mad with the grease gun the grease simple oozes out of the grease nipple just after the shaft expands slightly.

 

[CruisinGA]

It may ooze out, but that implies that the cavity within the shaft is full, and in the event the shaft needs to compress in length quickly, it won't be able to because the grease will not be able to escape fast enough.

Take it apart and clean it out.