Lubing propeller shaft Risky (AKA Drive Shaft)

[ginericLC]

I do try to have a little seep out of the U joints. Sometimes I pull the shaft apart and clean out all the old grease in the spline. It is a messy job. But if you get too much grease in the splines it builds up on the ends and causes pressure on the pinion and transfer case. The grease in the end of the tube gets pretty hard too and limits the travel. I do this thorough of a job ever few years. Otherwise just a squirt.

 

[mudlover]

lube fraud

I took my new to me 04 to the Toy dealer in Santa Fe NM for lube oil and filter. When I got home I looked under the rig and found the lube to the drive shafts was not done. I think this is very common because most modern cars don't have lube points on the drive shaft. They are sending me a refund.
Ronny

 

[rusty_tlc]

I use marine grease most of the time. Whatever Walmart has in the boating section at the time.

Ask yourself what they do in Africa?

 

[2001LC]

NLGI # 2 moly-fortified in rear driveshaft slip joint, per FSM (grease until grease seeps out past seal).

Moly improves "film strength", "dry lube" properties, with reduction in "stiction" of the assembly. (The stiction is apparently what causes the "thud", as slip joint compresses after being at rest for a while, such as happens when starting to roll from a complete stop.)

Is "overgreasing" (until grease seen seeping out past seal) too much grease? Consider:

The slip joint retains pressure due to air in cavity alone, even if there is no grease at all inside the cavity. This will result in residual axial thrust.

A grease-filled cavity may increase that axial thrust under compression somewhat, but how much? Maybe not that much...

I expect that the thrust bearings (tranny, rearend) should be designed to handle thrust loads exceeding those developed by the overgrease condition. (My opinion...this is, after all, Toyota, and their "worldwide application rugged vehicle", with FSM telling us to overgrease the slip joint, which has thrust resultant from trapped air alone in any case.)

Also, look at the total slip joint axial travel: It doesn't compress/extend very much at all under normal conditions.

Where/how did folks conclude that overgreasing slip joint per FSM is "bad"? Did anyone run objective long-term testing - e.g., identical vehicles with identical use patterns, one with overgrease and one without?

Great post Tinkerer,

I started this thread after reading a thread in FAQ (see link in my first post #1) I became very concerned as my seals are air tight, as i have stated above, to the point that the excessive pressure might cause damage.

I did find that the "thud" i was hearing has disappated since i lubed the propeller shafts about 1,000 miles ago. I hadn't notices this until reading your post. Go call Tinkerer.

I don't have my FSM in front of me but as i remember it did not say Moly-fortified. However it did say molybdenum-disulfide at Toyota web page when talking about the wheel bearing and thrust bushing which is different than the FSM or OM said. This indicates a change in thinking (grease) by Toyota, from the time the 2001 FSM and OM were wirtten, or yet one more error from source to source at Toyota. I mention this because it indicates Toyota dose make changes to procedures as well as design over time bases on real world use and feed-back form techs and the consumers. As see by Toyoa changing transmission and going to large diamiter propeller shafts in 2004 or so.

You may be right that the Diffs' and T-case maybe designed to handle such heave pressure, or it could be that some of these seals are so tight that they are creating excessive pressure on the components. The fact that some here have seen no or little extension of shafts and grease passing the seals easily when greasing and others see excessive extension of the shafts with little or no grease seeping out. Is and indication that their is a difference in the seals beween vechicals on the same moldel, this could be do to different suppliers to the OEM of the seals or some other reason possible a wear issue, but their is many here that recommend only 3 to 4 pumps with the grease gun and not putting pressure (extending) on the Shafts.

I would love to have a tech call Toyota Tech support and get and official call on this issue or white paper. Toyota tech will not talk with the consumer, at least when i called is what they told me. I would love to have their position on the Thrust bushing and bearing, as well as their recommended procedure for greasing and what grease to use, as the dealer and Toyota shops are not follow the FSM or OM at least not by my 2001 FSM and OM.

Bottom line is: Toyota not only relies on its engineers but the techs in the field and the consumer. People in forums likes this are probable one of the best sources for Toyota to monitor real world use, or at least it should as be. Their are some very knowlegeable Toyota lovers here, some have been driving TLC and working on them for 20, 30 years or more.

I apprecaite your comments and would love to here more from you or anyone else here concerning these issues.

Currently 100% agree on NLGI #2 (FSM recommended)
Most say less grease is better in the propeller shaft (not FSM recommended)
Some say pump until it flows (FSM recommended)
One said cost him $2,000 from over greasing (on different thread)

Have yet to see and expert on grease chime in that know if the NLGI #1 will work as well or better than #2 grease and the difference between the two?

THX
2001LC

 

[rusty_tlc]

Bottom line is: Toyota not only relies on its engineers but the techs in the field and the consumer. People in forums likes this are probable one of the best sources for Toyota to monitor real world use, or at least it should as be. Their are some very knowlegeable Toyota lovers here, some have been driving TLC and working on them for 20, 30 years or more.

I just wonder what percentage of the worlds population of Toyota 4WD owners live in countries where they access to the internet and the free time to spend on discussion forums.

 

[SINCITY100]

Lubing propeller shaft (AKA Drive Shaft)

With NLGI #1Grease; Manufacture recommends NLGI #2

Has anyone here tried this, have any opinion or can offer and knowledgably comments on using this lighter #1 grease for this application?

My concern is: will the NLGI #1 give me sufficient shear protection

I’m using: Amsoil MP synthetic lithium complex grease EP fortified GC LB NLGI #1 (the same grease I have for the thrust bushing and roller bearing for the front axles of my 2001 Toyota Land Cruiser (The manual recommends lithium SOAP base for the thrust bushing, this was the closest I could find) and Mobil 1 NLGI #2 for U-joints & wheel bearings

A little background of why I used this #1 grease:

I had finally gotten around to lubing my U-joints and sleeve’s on the front and rear PShaft (Propeller Shaft, AKA Driver Shaft) while doing my 90,000 mile maintenance, well closer to 100,000 miles. I noticed the PShaft sleeve yoke kept extending but no grease was coming out around the seal, I pump and pump that NLGI #2 lithium grease in until finally a small amount of old grease followed by a small amount of new grease started coming out around the seams of the metal plate in the end of the shaft (the pocket of the sleeve yoke) then just a bit from around the seal, but only after extending the yoke a great deal more than one would think was advisable. This was the front shaft the rear extended much more without any grease coming out. I became concerned about the amount of pressure on the bearing of the transfer case and differential’s even more so once I read a thread in FAQ under 100-series Cruiser titled:

Lubing the Driveshafts: too much grease?

So I pulled the front PShaft and cleaned it, while spending about and hour and half cleaning I came up with the idea of using NLGI # 1 grease, to see if it would flow better. Most of the grease I cleaned out was what I put in 1000 miles ago, not much old grease in their (probably not lubed in 70,000 miles if at all) I followed the manual (except I used NLGI #1 grease) and applied greased to the propeller shaft spline and sleeve yoke surface during assembly. Found it necessary to remove the grease zerk to alleviate the pressure before I could slide the yoke in. the manual then said to install the PShaft and pump in grease until it begins to flow. I decide to fill this with grease on the bench, placing the PShaft between to concert structures with wooden blocks on each end for protection. I pump until grease started flowing out the cup end of the sleeve yoke then the seal. I’m sure I put much more than 500lb of pressure on the assembly before any grease came out, glade I did this off the TLC. I then pump in grease to extend the PShaft (1 inch short) short of the length I needed to install, I did this to make install easier and create a void to help the grease flow and the sleeve yoke compress the inch or so easier during operation on the road. I extending the yoke the last inch or so by hand, applied thread lock and tighten the nuts to spec 59 ft lb.

I have not done the rear Propeller Shaft yet, when I do, I plan on leaving at least a 2 inch void and kept the weight of the vehicle on the rear axle so that the rear PShaft will be in the most neutral compressed position I can get it in during install of the PShaft.

I will wait until I hear from all the great people on this board, before I decide on which grease I use in the rear Propeller shaft AKA rear Driver shaft and if I leave the NLGI #1 in the front or not.

THX From Colorado
2001LC

Great post Tinkerer,

I started this thread after reading a thread in FAQ (see link in my first post #1) I became very concerned as my seals are air tight, as i have stated above, to the point that the excessive pressure might cause damage.

I did find that the "thud" i was hearing has disappated since i lubed the propeller shafts about 1,000 miles ago. I hadn't notices this until reading your post. Go call Tinkerer.

I don't have my FSM in front of me but as i remember it did not say Moly-fortified. However it did say molybdenum-disulfide at Toyota web page when talking about the wheel bearing and thrust bushing which is different than the FSM or OM said. This indicates a change in thinking (grease) by Toyota, from the time the 2001 FSM and OM were wirtten, or yet one more error from source to source at Toyota. I mention this because it indicates Toyota dose make changes to procedures as well as design over time bases on real world use and feed-back form techs and the consumers. As see by Toyoa changing transmission and going to large diamiter propeller shafts in 2004 or so.

You may be right that the Diffs' and T-case maybe designed to handle such heave pressure, or it could be that some of these seals are so tight that they are creating excessive pressure on the components. The fact that some here have seen no or little extension of shafts and grease passing the seals easily when greasing and others see excessive extension of the shafts with little or no grease seeping out. Is and indication that their is a difference in the seals beween vechicals on the same moldel, this could be do to different suppliers to the OEM of the seals or some other reason possible a wear issue, but their is many here that recommend only 3 to 4 pumps with the grease gun and not putting pressure (extending) on the Shafts.

I would love to have a tech call Toyota Tech support and get and official call on this issue or white paper. Toyota tech will not talk with the consumer, at least when i called is what they told me. I would love to have their position on the Thrust bushing and bearing, as well as their recommended procedure for greasing and what grease to use, as the dealer and Toyota shops are not follow the FSM or OM at least not by my 2001 FSM and OM.

Bottom line is: Toyota not only relies on its engineers but the techs in the field and the consumer. People in forums likes this are probable one of the best sources for Toyota to monitor real world use, or at least it should as be. Their are some very knowlegeable Toyota lovers here, some have been driving TLC and working on them for 20, 30 years or more.

I apprecaite your comments and would love to here more from you or anyone else here concerning these issues.

Currently 100% agree on NLGI #2 (FSM recommended)
Most say less grease is better in the propeller shaft (not FSM recommended)
Some say pump until it flows (FSM recommended)
One said cost him $2,000 from over greasing (on different thread)

Have yet to see and expert on grease chime in that know if the NLGI #1 will work as well or better than #2 grease and the difference between the two?

THX
2001LC

The FSM and the OM do recommend #2.

I found the FSM to have about 10% errors in it.

The FSM and OM also said use: synthetic oil and lithium soap base #1 on the front axle thrust bushings were as the Toyota web service page said: molybdenum-disulfide lithium-base chassis grease for both the wheel bearings and bushings, did not specify #1 or #2 and add moly.

I talked to three different top Toyota shop in Denver, each used a different type grease, not one using NLGI #1, probable because the grease comes out of one barrel "it's cost effective". One tech told me that he counted 8 different greases that were recommend in the LC FSM, he carries one.

I agree, most of the time, follow the FSM and the OM to the letter is the best practice, but it also said to pump grease in the propeller shaft until it flows out the seal which is not good advice in this case. The advise I got here to only put 3 or 4 pumps is sound advise.

I tried the #1 on the front Propeller shaft to see if it would flow better past the seal which it did not on the bench test. My seals are air tight to over 500 PSI, one post i found here said to cut the seals to reduce the pressure, that i can't bring myself to do.

I have the #1 grease in the front Propeller shaft now, it took me three hours to RR, and most of that time was cleaning old grease out. I don't mind doing it again if makes a diffrence to life and operation of my TLC i just want what best for my TLC (my baby)

I was hoping to find someone here that is a real expert with respect the difference in Greases', oils and ATFs' as i am changing all my fluids and lubs. The only thing i belive is true here is that #1 and #2 have very simlar properties and that #1 flows easier than #2.


So the question here is will #1 work as good or better than #2 in this application?

so far the consensus here is NLGI #2, anyone else care to commit.

THX for the advice, it is appreciated;
2001LC

For the first time in my life ... I have been rendered speechless by this
" greasy novel "



PS..Would a chemist who specializes in lubricants PLEEEAAASE chime in !!

 

[2001LC]

The bottom line on propeller shaft lubrication from the expert:

I was at the A Toyota Dealer today picking up some parts and took the time to speak with the Shop Forman, he runs about 50 bays in one of the top shop in Denver. I've gone to him before on issues and have found him to be the most knowledgeable and helpful that I've found in years. I try not to use him to much as i really don't give the shop much work other then alignments and part from the dealer.

Here's' what he said: The propeller shafts should move freely without excessive resistance when assembled full of grease, you should be able to slide it all the way in, the grease should flow past the seals relatively easily.

They see three scenarios:

One; Dry propeller shaft caused by not lubing often enuff.
Sympton while driving:
A) Thump, on take off and/or going over light bumps (low speed most noticeable) like when driving over the cut on a concret road where you wouldn't think you would feel the bump.

Two; Seals will not let grease pass through freely, shaft will extend excessively while lubing, resistance in movement hydro lock not normoal.
Symptom;Same as above

Three: The tool marks on the propeller shaft spline and sleeve yoke get hung up. Causing the Shaft(s) to stick (not move freely).
Sympton while driving: Same as above.


Hydro lock, dry shaft sleeve or sticky spline can cause damage to the shaft(s) t-case and Diff(s)

He went on to say ""Toyotas' position on the thump is it's normal" it is not normal and can cause damage, well lubricated propeller shafts which seals allow grease to pass through should not thump".

The temp fix: remove one end of propeller shaft, remove the grease zerk and compress the shaft removing some of the grease. This will lesson the hydro lock, but with really tight seals hydro lock will still be a problem. He also recommended cleaning the rusty part of the shaft with emery cloth.

For sticky shaft(s). What they found worked best is to remove and clean the shafts and assemble with special grease from GM called; Special Lubricant, High Temperature, PTFE Filled, #12345879, GR. 8.800. They found the shaft moves freely with this grease. I'll have to ask him the next time i see him if they maintain with the same grease.

As to my question on the NLGI #1 "it will be fine, the grease is not going to come out anyway with my seals and if it did I would just need to lub more often as it has a lower viscosity and will flows more easily although #2 would be better.

As to the thrust bushing & bearing on the front axles moly or no moly grease, ask and i will post are findings.

THX to all,
2001LC

 

[1loudLX]

For the first time in my life ... I have been rendered speechless by this
" greasy novel "

+1, makes you wonder sometimes huh?

 

[Tinkerer]

The bottom line on propeller shaft lubrication from the expert:

I was at the A Toyota Dealer today picking up some parts and took the time to speak with the Shop Forman, he runs about 50 bays in one of the top shop in Denver. I've gone to him before on issues and have found him to be the most knowledgeable and helpful that I've found in years. I try not to use him to much as i really don't give the shop much work other then alignments and part from the dealer.

Here's' what he said: The propeller shafts should move freely without any resistance when assembled full of grease, you should be able to slide it all the way in and out by hand, the grease should flow past the seals relatively easily.

They see two scenarios:

One; free movement normal, regular lub interval, old grease pass thought the seals with little or no shaft extension.

Two; Seals will not let grease pass through freely shaft will extend while lubing, resistance in movement not normoal.
Symptom while lubing;
A) Seals will not let grease pass through freely shaft will extend while lubing, causing hydro lock (not normal)
Sympton while driving:
A) Thump, on take off and/or going over light bumps (low speed most noticeable) like when driving over the cut on a concret road where you wouldn't think you would feel the bump. Thump is also caused by dry propeller shaft.


Hydro lock or dry shaft sleeve can cause sever damage to the shaft(s) t-case and Diff(s)
He went on to say ""Toyotas' position on the thump is it's normal" it is not normal and will cause damage, well lubricated propeller shafts which seals allow grease to pass through will not thump".

The temp fix: remove one end of propeller shaft, remove the grease zerk and compress the shaft removing some of the grease. This will lesson the hydro lock, but with really tight seals hydro lock will still be a problem. He also recommended cleaning the rusty part of the shaft with emery cloth.

They tried different things like replacing the seals mixed results. What they found worked best is to remove and clean the shafts and assemble with special grease from GM called; Special Lubricant, High Temperature, PTFE Filled, #12345879, GR. 8.800. They found the shaft moves freely with this grease. I'll have to ask him the next time i see him if they maintain with the same grease.

As to my question on the NLGI #1 "it will be fine, the grease is not going to come out anyway with my seals and if it did I would just need to lub more often as it has a lower viscosity and will flows more easily although #2 would be better.

As to the thrust bushing & bearing on the front axles moly or no moly grease, ask and i will post are findings.

THX to all,
2001LC

Early morning coffee time:

Ask the Shop Foreman if he has seen a 100 series failure caused by driveshaft slip joint pressure (causing shaft axial thrust) due to grease overfill. (Note: Guessing doesn't count.)

Simply put, I think we have a slip joint design that seals "too well": The slip joint cavity is effectively sealed by the sliding lip seal, which causes pressure in the cavity from air alone when the joint is assembled, and that pressure is increased further by grease fill.

As noted, I observed residual air pressure in the cavity when I dis- and re-assembled my rear slip joint. The air pressure was present when I took it apart, and putting it back together created a similar pressure condition in joint, that did not diminish significantly while sitting over a couple of days.

So, even if you don't grease at all (other than a light coating on shafts/splines), the slip joint exerts axial thrust thru the driveshaft to the thrust bearings at the transfer case & rearend input, due to trapped air in joint.

And greasing to the point of grease seeping out past seal increases the pressure & resulting thrust load. If the cavity is absolutely 100% filled with grease, then joint compression cycles will force out a small amount of grease past seal, reducing fill to slightly less than 100%. (Grease is ~ incompressible, compared to air.) "Hydro lock" ? The seal is tight, but not absolutely hermetic - grease WILL seep out past the seal if the joint pressure rises enough.

How much thrust is too much? That's something Toyota (Japan Design Center) engineers could answer, but Toyota Tech Support or Shop Foreman may have erroneous info. (I emphasize Toyota design in Japan here, because that's where this system was designed, if I'm not mistaken, and that means that Toyota USA people will not have complete information on the design.)

Removing the zerk relieves residual pressure, at (whatever) joint position. Sounds like a good thing - but wait: Maybe we don't want negative pressure (suction) in the joint when the shaft is extended? If the joint pressure is ~equal to ambient pressure when the joint is at a neutral position, then the pressure will be negative when the joint is extended, such as happens when the rearend drops (rear suspension extended). Such a suction would tend to draw external contamination past the seal INTO the joint, not a good thing.

So, maybe the positive residual joint pressure is by design, to reduce joint contamination in service?

Stiction: The PTFE grease will alleviate the "stiction" problem for the same reasons that the moly-filled grease will, so that supports what that shop found. I'm not sure which grease is better, long-term - PTFE may or may not provide the same long-term benefit as moly in this application. (To be sure, I would not assume that anything with a GM p/n is very long-lasting, based on GM's historical product performance.) PTFE is frequently touted as a miracle lube additive, but it has some problems in many attempted applications, while moly grease has been proven for a long time.

I'm still running with "overfilled" moly grease in my joints, going on about 15kmiles +. No apparent thrust bearing problems yet, and the "thud" is still completely gone. I'll post if any further problems develop.

 

[e9999]

some interesting points all above...

I would not be surprised if these seals harden and get crudded up and end up more restrictive than intended...

 

[rusty_tlc]

I just did a little research, it turns out many marine greases contain Teflon (PTFE).
I'm still looking for the composition of the stuff I get from Walmart, but it looks like my being cheap is working out pretty well.

 

[2001LC]

I just did a little research, it turns out many marine greases contain Teflon (PTFE).
I'm still looking for the composition of the stuff I get from Walmart, but it looks like my being cheap is working out pretty well.

I am just about to go to the GM dealer they want $38.00 a qt. He will give to me for $30.00, Please let me know what you find out.

Is the walmart stuff in a tube?

 

[2001LC]

some interesting points all above...

I would not be surprised if these seals harden and get crudded up and end up more restrictive than intended...

You maybe right, although my seal was soft and appeared in good shape.

 

[Tinkerer]

Early morning coffee time:

Ask the Shop Foreman if he has seen a 100 series failure caused by driveshaft slip joint pressure (causing shaft axial thrust) due to grease overfill. (Note: Guessing doesn't count.)]



I will ask next time i see him.

Consider this; The FSM and OM recommend lubing Propeller Shafts and U-Joints depending on use of the TLC as often as daily in sever condition, up to 7,500 mile intervals in light use?

Why lube so often if it's air tight?
The wheel bearings are not air tight and the OM recommendation is 30,000 miles.

Why have some here said they only put in 3 or 4 squirts at 15,000 miles or so?
The OM and FSM clearly recommends for more frequent lubing, and doing so until the grease flows out the seal(s).

Why engineer the propeller shaft(s) to exert so much pressure on the t- Case and Diffs?
Are they trying to use the Transfer Case and Differentials as support for a shock abosorbing propeller shaft, why put that kind of stress on the components. I'll let the struts do their job.

I took a peek under a 2008 TLC yesterday, it was evident (by the grease on the sleeve) the shaft was moving freely and the propeller shaft(s) was flowing grease easily past the seal(s)

When my propeller shafts' move freely, full of grease without hydro locking I will be happy.

2001LC

Maybe the service interval is overkill, or maybe the short service interval makes sense for the u-joints (it does imo if the vehicle is seeing a lot of mud & water etc) so the service interval for slip joints was thrown in for good measure, while the grease monkey is doing the u-joints.

I'll tell you what happened to mine: I greased occasionally, only a few squirts. The thud never went away. Finally took the rear joint apart and found inside some grease, some trapped air, and nothing apparently wrong. Cleaned it up and medium-greased the internal splines etc. while it was apart, reassembled it, put a few squirts in the zerk. This stopped the thud for a week or so, but then it came back.

I believe the non-moly type grease was thinned out on the splines by that point, so the stiction returned. (The cavity, being mostly empty of grease, allowed the splines to thin their mating interface grease film out with repeated sliding/loads, until it was too thin to prevent stiction with non-moly grease.)

So, I pumped it full of moly grease, until grease observed coming out past seal.

No more thud. Rear suspension action works normally. Slight amount of grease seeping past seal with continued use, residual on mating shaft.

 

[2001LC]

So, pumped it full of moly grease, until grease observed coming out past seal.

No more thud. Rear suspension action works normally. Slight amount of grease seeping past seal with continued use, residual on mating shaft.

If i read you right your Shaft is now sliding freely with no excessive hydro pressure or hydro lock, that is great news.


While assembling on the bench did it slide fairly easily in an out by hand with the grease zerk in?

When you pumped if full of grease did it flow pass the seal(s) without excessive extension of the propeller shaft and sleeve yoke?

Have you notice a vibration in your high low shifter and if so did it change after you got the shafts (front and rear propeller shafts) moving freely?

That's were i am trying to get too. I am pulling my propeller shafts out again and trying this new $30.00 LB. grease. If this doesn't work i will probable try new seals.

2001LC

 

[2001LC]

I pick up the GM Special Grease 1 #12345879 Gr.8.800

It contains:

Distillates (petroleum), solvent-refined
Light parffinc
Tetrafluoroethene homopolymer
Bentonite

2001LC

 

[rusty_tlc]

I am just about to go to the GM dealer they want $38.00 a qt. He will give to me for $30.00, Please let me know what you find out.

Is the walmart stuff in a tube?

I couldn't find a spec sheet on line and no info on the tube.
Check on line for Teflon filled marine grease.

 

[2001LC]

Tinkerer

The shop Forman also recommended Lithium-base grease with moly, he likes the molys' ability to lube when wet. He said they use it most of the time, the exception being in special situation like problem shaft seals, when they come across them.

I like what you've said about moly and what i've learned about it recently. I will be change to it were i can on my next service interval. I also confirmed that Toyota started recommending it 2002, my FSM and OM are from 2001.

I did lube the shafts about 1,000 miles ago (this was the first time i had ever done my own shaft on the TLC) with a Lithium base moly grease. It is when i first notice the tight seals; i became concerned but not overly. I didn't realize this to be a potential serous problem until this last week. Luckly the shafts were dry when i did some hard off road last summer.

2001TLC

 

[Tinkerer]

If i read you right your Shaft is now sliding freely with no excessive hydro pressure or hydro lock, that is great news.


While assembling on the bench did it slide fairly easily in an out by hand with the grease zerk in?

When you pumped if full of grease did it flow pass the seal(s) without excessive extension of the propeller shaft and sleeve yoke?

Have you notice a vibration in your high low shifter and if so did it change after you got the shafts (front and rear propeller shafts) moving freely?

That's were i am trying to get too. I am pulling my propeller shafts out again and trying this new $30.00 LB. grease. If this doesn't work i will probable try new seals.

2001LC

The suspension works normally as far as I can tell. That doesn't provide much information about the pressure developed in the rear driveshaft slip joint, however. Considering the masses and mechanical ratios, the vehicle/suspension motions will overpower the slip joint quite easily.

You would notice something wrong with suspension motion if the joint was truly locked, probably. (And you do notice a "thud" caused by stiction etc. in the joint - my theory.)

No, the slip joint doesn't "slide freely". It traps air, and when you push it together to shorten it, that air builds internal pressure, resisting the push. It acts like a spring.

I suppose if the zerk were removed to allow air in/out, the joint would slide with minimal resistance. (Didn't remove the zerk on mine.)

When I pumped it (over)full of grease, the shaft extended slightly and grease seeped out past seal.

(High/low shifter: I used to notice the infamous slight buzzing at top gear / 45mph cruising under load; several years ago. It mostly disappeared after I rigged the inner H/L Lever boot to maintain residual force on the lever (to damp vibration) and also changed to synthetic lube in T-Case. But it is occasionally still barely noticeable under noted conditions - it's one of the those things that a person would not notice if they did not know to listen carefully for it, nowadays. I noticed a TSB for replacing T-Case and some H/L Lever linkages etc., AFTER mine was out of warranty.)

Good luck. I doubt a new seal will change the issue much, unless you get a larger I.D. one that is looser on the shaft, allowing air & grease to flatulate out past seal. I think that if seal-to-shaft is snug, this is per design, and the joint simply traps air/grease inside and builds pressure under compression. (Here's hoping those thrust bearings are robust... ) Make sure you put a small amount of grease inside the seal lip.

 

[1loudLX]

can someone lube my shaft? I'd prefer it if it was a wife/daughter of legal age. I dont like to get messy doing my own maintainance....would rather have someone else take care of it for me. I will provide different forms of payment depending on quality of service. Thx, the lexus dealership hasnt been cuttin it lately.