The Stovebolt Site Forums The Shop Area General Truck Talk Plugged grease fitting and oil the u-joint?

I did the first grease job that my old ’50 3600 has seem for more than twenty years, is my guess. I was really surprised when all 13 fittings, (I have the spindles and steering rods off) took grease. All except for one lower front spring eye. I cleaned the bushing with a drill but she is still blocked up. I suppose the best thing to do is pull the bushing and clean it out. I’ve had a heat tape on it and wrapped it with tin foil, for the last couple of hours, hoping it would soften the old grease, hope that works. Any other ideas?
Also, something I never noticed nor heard before. I was reading the lube specs and there is a very clear instruction to use transmission (hypoid oil) oil in the center and rear u-joints. All those years that I worked in service stations, dealerships, and worked on my own cars I always used chassis grease. Now how in the world am I going to get 90wt oil in a grease gun????
Denny Graham
Sandwich, IL

they make pumps for oil... but are you going to try and put it in through the zerk?

I've had success with fittings that won't take grease, by removing the fitting, removing the end off of the hose or tube, and turning the grease gun hose/tube into the empty hole. This eliminates the leaky fitting joint, and you can really pump on the pressure. Moving the parts may help, striking around the parts may help.
keep the presure on! till it pops!

A grease gun will pump gear oil easier than it will pump grease....it's just that it runs out the bottom when the gun is held in the normal position.

Hold the gun upside down and fool gravity, or do like everyone else has done since the dawn of time and use a good chassis grease.

Stuart

Well a couple of hours with a 1/2" wide x 36” long heat tape and the old grease was dripping out of the bushing, I pumped all of the old grease out with fresh and it was taking the grease like a new bushing. Wish I had thought of, or known about heat tapes back in ’58 when I was a greaser at the Chevy dealership and Sinclair grease monkey. We had to pass on many a grease fitting that wouldn’t take the lube, even with the pneumatic grease guns.

Rusty, I think ya missed what I was getting at. Every trunnion I have ever seen with a zerk, (and some don’t come with a zerk) I have always lubed with chassis lube.
If you read in the Chevy Shop Manual, under General Lubrication 0-5, in the middle of the right hand column it says, speaking about the two types of u-joints that are used;

“The second type is of needle bearing construction, equipped with lubrication fittings and should be lubricated with the same type of lubricant used in the transmission. This type of universal joint is used on the rear propeller shaft of the ¾ ton vehicle and on the front and rear of all other truck models.”
“CAUTION: Under no circumstances should any of the soap type lubricants such as chassis lubricant, fibrous universal joint lubricants, etc., be used in lubricating either the enclosed bushing type universal or the needle bearing type.“
I don’t see how the open universal joint could possibly retain a S.A.E. 90w oil, I would think it would be thrown out past the seal. And yes they are equipped with a standard zerk fitting. I do have a couple of old grease guns that look like a pistol and inject the lube when you push in the direction of the fitting. I suppose they could handle 90w. so how many of you use chassis lube in your needle bearing u-joints?
Denny Graham
Sandwich, IL

From my shop manual for 42 to 46 trucks

Universal Joint Lubrication
Passenger car and 1/2 ton truck

The universal joint is directly conected to and recieves its lubrication from the transmission. The universal joint housing should be filled through the speedometer driven gear hole, for initial lubrication after a repair opeation. This initial lubrication is necessary to take care of the universal joint until normal lubrication takes place from the transmission.

NOTE --- The pipe plug in the top of the front universal joint housing onthe 1/2 ton optional 4-speed transmission is for manufacturing purposes and is used to fill the universal joint at the time of assembly.

3/4 and 3/4 ton special (124 I/4" wheelbase) Models

(3-speed transmission)

The front universal joint, immediatly to the rear of the transmission is of the trunnion bearing type and recieves its lubrication from the transmission. Additional lubrication at this point is unnecessary. The battery ground strap bolt hole in the housing is used to fill the front univeral joint at the time of assembly and after repair operation.

NOTE -- The pipe plug is the top of the front universal joit housing on the 4 - speed transmission (optional equipment) is for manufacturing purposes and is used to fill the front univeral joint at the time of assembly.

The intermediate and rear universal joints are the needle bearing type equipped with lubrication fittings, and should be lubricated with the same type of lubricant used in the transmission.

CAUTION -- Under no consideration should any of the soap type of greases - such as chassis lubricant, fibrous universal joint lubricants, etc, be used.

The propeller shaft slip joint, located at the rear of the intermediate universal joint is also equipped with a lubrication fitting and should be lubricated with chassis lubricant.

I have wondered about this too.
I have replaced mine with new spicer joints and use the red grease.

On the truck I am building I have one NOS Spicer 1610 series joint that says to use oil. I will buy two more new ones.
I have been looking for an explanation on why I can't use grease on all of them.

There was a discussion about this a while ago on the VCCA site. The conclusion was to ignor that instruction as all the universal joints of similar construction were lubed with chassis grease for many years to come. The concern about chassis grease may have been a reflection of what was availble at the time.

Now for my question: What is heat tape?

like for keeping pipes from freezing.
if that's not what he used then it's the same idea.

I wonder if we are talking about the wrap with electrical elements inside?

I thought so

Jeeez dad, I thought that was what I just quoted out of the Shop Manual, in what I posted right above you on the 13th?
Gregg, it doesn’t matter whether your using Spicer or Precision (FM) or what brand, the point is, that the two rear joints are of needle design and that the manual back then was insisting on using 90w gear oil!
Trucker, Yes, electrical resistance wire wrapped in silicone, McMaster Carr, page 473, “General Purpose Heat Tape”, 450 degF. The one I use does not have the heat control so it’s full throttle as soon as you plug it in. It was a lot cheaper when I got it years ago. I wrapped it around the spring eye and then wrapped it with Alum foil to concentrate the heat. It worked great, I also used it to expand the pitman arm spline when I pulled it. A torch would have worked but would most likely burn up the cork seals and catch the grease on fire. Now right back at cha, what’s a VCCA site?
Denny Graham
Sandwich, IL

Denny,
the site address is:
http://vccachat.org/cgi-bin/ultimatebb.cgi
It is the Vintage Chevrolet Club of America and they make available a wealth of knowledge about Chevrolets, on the site.

That tape sounds like a very valuable tool. The example of using it on the pitman arm is a good one.

Fred

Tks. Fred, I book marked it.
Denny G

My point is that I have an older NOS 1610 series joint that has stamped on the caps to use oil. The new ones I get from the same brand will want grease.

So, to finalize this, the old technology wanted oil. Today we use grease, and can even do so in the old joints with good or better results.

Is this true?

Grigg

was there anymore conclusions on using trans oil or chassis grease on our style u joints?

Well here we are five years after I myself first read the line in the service manual and that
question is still popping up because of what was printed sixty years ago.

I believe the reasoning behind the spec was that the many of the greases back them were
soap based grease and would wash out from repeated exposure to the water splashed up
onto the open joint.
The other possibility is that the manuals were written by "Technical writers" who were
not engineers nor mechanics and they composed the text from what was explained to
them about the repair or maintenance process or what they observed the people doing on
the assembly line.
Back in the early sixties after high school one of my friends got a job as a technical writer
for a large corp. Tom had absolutely no mechanical ability whatsoever, he didn’t know
which end of the screw driver to hold but he did have a way with words. Having been
raised in a family of mechanics I had a pretty good eye for mechanical things by the time I
was in high school. I’d read some of the stuff that Tom had written for the companies
repair manuals and saw many discrepancies in his descriptions of procedures. One would
expect that an engineer would have reviewed the manual before it went to print but often
this didn’t/doesn’t happen. So today when ever I read a repair or assembly manual, I read
it with an air of skepticism, sometimes just plain common sense and years of personal
experience has to prevail.

I have, since the original thread was posted, been in contact with a few of the major
u-joint manufactures thru email messages and have been assured that NLGI #2 grade
chassis grease is an approved lubrication for modern day open universal joints.
Denny Graham
Sandwich, IL