Wrong Grease on Shaft - How Bad?

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alleycat

alleycat

10 Year 15 Year
Joined
Jun 3, 2007
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29
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Location
Charleston, South Carolina
Well I got around to replacing lube in diffs and T-Case on my new to me 2000 model and decided to grease her up as well. I lubed shafts and u joints with what I thought was Lithium Bearing Grease in the gun but when I went to change grease tubes I discovered I had used Moly. How bad a screw up is this? Suggestions? Thanks
 
I use moly in both. If it's a big deal to you pump out the moly with lithium.
 
I too have used moly in both, it's ok just not best practice. Just keep in mind moly doesn't dissipate heat well. Next time go without moly and you'll be fine.
 
sseaman said:
I thought people were recommending moly to help with the clunk that happens with age
Click to expand...
I thought it was moly in the shafts and lithium in the u joints?
 
Moly is a mineral additive in some greases. I've seen testimonials of how it repairs bearing surfaces by filling in microspores. Unfortunately moly doesn't displace heat well, and is use in EP (Extreme Pressure) greases. I've not seen any wheel bearing grease, which is a high speed grease, with moly added to it. Someone may make it in the newer polymeric greases on the market, but I've not seen or looked for it.

The slip yoke of the propeller shafts (AKA: rear drive shafts) are not really subject to high speed. But IMHO the clunk is not do to stiction like on the GM trucks, which is helped by moly. Rather in our 100's is do to the seals being so tight it they trap air, which in turn builds pressure in the yoke cavity. The thicker NGLI #2 grease with moly may make the seals even tighter. A Lexus mechanic total me a dirty little secret: They got tired of replacing propeller shaft do to "clunk" and just started drilling a little hole in the back plate to relieve the pressure.

I learned this the hard way: I cleaned the yokes on my shafts, then used a NGLI #1 with moly. Still the seals wouldn't let old grease pass while pumping in new, the shaft just keep extending. Finally the back plate bowed out just a bit under the pressure of pumping in new grease. Now grease passes (leaks) by the back plate and the Clunk is gone. Someday I need test this theory, by cleaning the yokes again, tighten the back plate seal and trying an NGLI #1 without moly.

Tip from Toyota shop foreman: Pump grease in shafts while wheels on ground (don't lift truck). This way the propeller shaft is not extend and you'll not over grease.
 
So 2001LC do you agree that its ok to run regular lithium Grease in behind the moly that I pumped in when its time for more grease again? Also FSM calls for "Synthetic Oil and lithium soap base chassis grease" on front drive shaft thrust bushings. Never heard of that and where are those thrust bushings they are referencing? Thanks for the help
 
I agree. They will be fine with moly until next service, then pump none moly behind the old grease.

Front drive shaft thrust bushing & needle bearing are in the back/inside of your spindles. The bushing is brass and axle goes through it and rides on needle bearing. The outer end of the front drive shaft (AKA CV's) presses on brass bushing. You'll lube these during front wheel bearing service.

You can see brass bushing in the last few pictures at Slee Off Road, they have a great time saving tool for this: Slee - Spindle Grease Tool

NGLI#1 is recommended but #2 is used all the time, in fact I'll bet you can't find a shop with #1 in their grease guns. A Toyota Shop foreman told me they use the black stuff (grease with moly). I have NGLI #1 with moly in now. But I'll be using grease without moly in the future. Moly fortified grease on the bushing is a great idea as it holds in place well and has the EP properties we spoke of. But not so great on needle bearing inside shaft, I say this do to concerns of heat buildup IMHO. But the Toyota and Lexus shop are very comfortable either way. They just don't like moly in wheel ball bearings.

EDIT: "Synthetic Oil and lithium soap base chassis grease" is confusing "soap base". Just find a Synthetic NGLI #1 grease that states for Chassis or wheel bearing (GC-LB) or equivalent. If NGLI #2 is used, you may hear a slight groan on cold mornings before bushing & needled bearing warmed up, as you turn through gutters in the road.

No big deal #1 or #2. Most just use NGLI #2 throughout i.e wheel, bushing & needle bearings, shafts and u-joints.
 
Last edited:
Im doing brakes and bearings this week, this is what im using:

http://www.amazon.com/gp/product/B002KCWWFC?tag=ihco-20


Product Description
Ultra-Performance Grease (UPG) is a high performance, multi-service, aluminum-complex, synthetic grease which significantly increases bearing life and equipment reliability. It also makes bearings run smoother, cooler and quieter. UPG satisfies a wide range of grease requirements from the lubrication of bearings to U-joints and general purpose use. It has outstanding extreme pressure capabilities and excellent water resistance to both emulsion and washout. UPG is stable at high temperatures. It also has excellent oxidation resistance for extended service life and to provide a margin of safety between lubrication intervals. When the China Star Bullet Train was having heat problems keeping them from achieving optimal speed, they evaluated 26 of the best lubricants available. After careful testing, senior engineers selected Royal Purple's Ultra-Performance Grease. Not only did Ultra-Performance Grease help them resolve their heat problems, it also, enabled them to set a new land-speed record for bullet trains. UPG is made using a superior blend of synthetic base oils plus Royal Purple's unique, proprietary, non-corrosive Synerlec additive technology.


Seeing as the LC's are lighter than the bullet trains, in theory, i should go faster. :clap:
 
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