| Author | Message | ||
     Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 552 Registered: 9-2004 |
As time passes i am getting concerned with the many SSI and SS11's that when the uj's are greased the grease that is emitted is not in the best condition{rusty colour as in picture] Also it seems that the recomended service schedule for these at 24000 miles or two years is much to high. The power transmitted through these needle rollers is colossal. If the car is not used much through the winter months the damp air can play havock. I have found it best to grease them every year or 12000 miles which ever is sooner. If with the needle gun the grease does not show itself from every cup the the uj needs to be replaced.  | ||
| Peter Colwell Experienced User Username: peter_colwell Post Number: 12 Registered: 3-2005 |
I would respectfully disagree that the best way to service universal joints is to pump new grease in until the old grease is forced out past the seals. The main enemy of joints, - and just about everything else, - is the ingress of water and dust, and the best way to keep moisture out is to maintain the seals in good condition. Normally with light pressure on the handle of the grease gun, resistance can easily be felt when the joint is full. Further pressure will force the grease out, as in the picture, which destroys the seal's integrity, and therefore makes it easier for water to enter. The grease in the picture has been contaminated with water and the internals have rusted. Universal joints will last almost indefinitely if not over greased and the seals remain intact. This is evident from the enormous mileages that heavy truck joints achieve. Also, many cars of today have no grease nipples at all, but failure even at extremely high mileages is rare. Peter | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 987 Registered: 4-2003 |
Peter, I couldn't agree more. A light refilling may be safe periodically, allowing a little grease to ooze out over some months. Exactly as you write, just a gentle pump until resistance is felt in the gun handle is the safe limit, and no grease should be seen to come out during the operation unless the joint is in need of immediate replacement. However, if you use the gun to purge the old grease, then the seals will surely rupture and the joints are then on borrowed time. As you imply, if the grease gun causes horrible stuff to come out past the seals, it's all over already. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 988 Registered: 4-2003 |
ps with this method, all my original universal joints are still like new. That includes my R-Type: 52 years and over 700,000 km I must add. I wish I could say the same for my Turbo R steering rack after a few years, but at least its universal joints are fine at almost 300,000 km. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 555 Registered: 9-2004 |
The quality Hardy Spicers have seals made of a type of strong neoprene rubber. The seal sits on the inner spider radii, the more grease pressure the better the inner seal works. The outer large part of the seal sits in the grove of the cup, Picture showing seal removed from the cup. This is where the grease is purged and checked for condition. If any of the joints fail to emit grease or if any movement can be found then a new joint must be fitted. Now the staked type small in the picture. Have replaced many of this type due to the not being able to grease the joints. Most of the cars etc that still are rear wheel drive have other means than the staked type. However many cars use the staked type on power steering columns with all sorts of steering and rack failings through the uj,s failing through siezure. This found problem had concerned me because the car had covered a low mileage since a 24,000 service carried out from a Specialist of the marque. My veiw because of this is that the joints should be greased every 12000 miles or every year which ever is soonest. picture of the Hardy Spicer seal and the new Staked type to recon a prop etc that do fail.  Picture of the seal removed from the cup, this is where the grease should purge from in a perfect world.  | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 556 Registered: 9-2004 |
Peter,Richard i can beat the 52 with originals on a 55 year old car. Still with the cork type but running with improved grease these days. In my early days of routine maintenance the UJ,s were lubricated every 1000 miles with SAE 140 [oil] the seals were made of cork. Was always stated that that grease was not a suitable lubricant for the needle bearings. The intervals were increased to 2500-3000 miles with the cork replaced if oil emitted in a great amount from any. Seizure failure on them was rare but replacements were more frequent due to wear taking place causing vibration. Thereafter improvements with the neoprene type seals and grease then used made longer maintenance intervals possible. But Specialists note, not so long as the SH schedule states it seems, 24,000 miles is given. | ||
| bobuk Unregistered guest Posted From: 80.3.64.11 |
The seals on UJs are very flexible and have a good memory for the original shape. This means that grease being pump out via the seals will not damage them. Notice that the prop shaft from the gear box to the final drive is not in a straight line. This is so that as the shaft turns the joints move causing the needle rollers to roll which stops them from denting the running surfaces of the trunions and cups and spreads the grease around. ( Common auto-motive design practice). I have been told that the UJs from a Bamford dump truck are the same. Bamford is the B out of JCB (Message approved by david_gore) |
