Purging all 4 U-Joint grease seal caps

[darbyjudy]

I am a retired Auto mechanic. I never seen a u joint that you can get all four caps off without pressing . Two of the caps will unbolt but the other two are pressed into the drive shaft. Many times they will not come off with either pressing or using a large hammer and drive it out of the drive shaft tube. For years I took them apart and greased them but then it just made more sense to replace the joints. I also never worry about grease purging from all the caps. If you see rust or feel a vibration then it is time to replace. But normally they will last a long time.

[twinboat]

If you Google " Spicer U Joints ", you will see the type of joints used in medium and heavy duty trucks. The caps are held in with 3/8 bolts.

That is the type that is being discused.

[spritz]

I am glad you started this thread,
My PA has 54,000 miles and after reading all this we went out and crawled under her to find that there was no grease around the u-joint's. So we got the grease gun out and starting at the rear we pumped grease in each one and yes they all had grease come out all four caps. I would have never thought about that. I'm glad this site is here I always learn something everyday.
So now I can't wait to hit the road and see if I notice a difference in the ride. It might be a tough call because I just put new rubber all the way around and that along with new Bilstins its like a different motorhome.
Thanks again for the info.
Tim

[77Travco]

My Dodge Travco (M500 chassis) with only 65K miles still has the original u-joints from 1977. I greased them last year, didn't get all 4 caps to purge but no slop or play. I just carry a spare u-joint and tools.
I went to grease the u-joints on my 2007 Ford Crown Victoria... no zerk fittings and no way to get grease into them... nice.

[holycow]

This tool probably will not be that effective as the oil you force into the joint is going to do just like the grease is doing and take the path of least resistance. In this case the grease fitting is not the problem. It is probably hardened grease wax in one or more passage.

[gemini5362]

Originally Posted by holycow

This tool probably will not be that effective as the oil you force into the joint is going to do just like the grease is doing and take the path of least resistance. In this case the grease fitting is not the problem. It is probably hardened grease wax in one or more passage.

That thought occured to me the idea was that possibly you could get a solvent that would soften any hardened grease. I do not know if it will work or not but compared to the cost of other solutions it is inexpensive and those tools are handy to have around for jerks that decide to be contrary

[Coma]

One of the concerns Monaco has is that the shorter drive shafts found in DP drive lines is that the angular rate of the joint is higher than a Line haul truck. That said, Monaco wants you to grease your front bearings yearly when line haul is 120k miles. If the drive line is under tension they may not purge. I would put a heat gun on it and warm it up, see what happens. BTW mine purge easily.

[skypilot_1]

If they won't purge and your concerned and thinking of resorting to solvent, oil and heat guns. Don't ya think maybe they just need to be replaced...?

[JRPA]

Skypilot 1

If you read my original post, you will see that I did take it in to have the u-joints replaced. The whole purpose of my original post is the fact that just because you take your RV to a certified dealer (Freightliner in this instance) and you explain your problem and service that you want, doesn't guarantee you will get what was promised and/or paid for. I asked for the u-joint to purge all 4 caps or replace both u-joints, I was told twice that all four caps purged grease on both u-joints and replacement wasn't needed on either one of them.

I checked the u-joint when I got home and they had not purged as stated. I want the service done that the the manufacturer recommends and not what some lube tech thinks I need. There are a lot of fellow RV'ers trying to give their advice and experience (and I do appreciate it all) but I trust that the manufacturer knows what is best for their product. I will be crawling back under the RV before I take my next trip and either replace or possibly loosen the bolts and caps to see if I can get it greased as the service manual states.

[GA Navigator]

For your viewing pleasure:
A see-through U-joint
http://youtu.be/wH-fvddVt-g



1994 Holiday Rambler Navigator
Cummins 8.3
Allison MD3060

[twinboat]

Originally Posted by GA Navigator

For your viewing pleasure:
A see-through U-joint
http://youtu.be/wH-fvddVt-g



1994 Holiday Rambler Navigator
Cummins 8.3
Allison MD3060

Yummy, I can almost taste that grease falling in my mouth. :-))

[1ciderdog]

Interesting/informative video, thanks.

[Dutch Star Don]

"JRPA"....I wanted to thank you for bringing up the locking grease gun fitting. Right after reading your post I ordered one. Will use it next lube. It should make lubing the driveshaft slip joint much easier. I use a pneumatic gun, but it can still be tough to lock onto some fittings.

[Pepper2]

Originally Posted by 1ciderdog

Interesting/informative video, thanks.

Ditto!