Rear Beam Rebuild

[stu8v 68 1 Cars]

As above really what grease are you folks using?

 

i.e. Anything super special to make the bugger last.........

[Anthony 1,002]

Just normal LM or Moly grease is fine for the shafts/bearings and lasts for years.

[stu8v 68 1 Cars]

That was the plan initially, well unless there was universal approval on go-faster grease. lol

[SurGie 54]

I only use THIS stuff. From the tests iv carried out its very water resistant. Its also very tacky. So if any water did try to get on the bearings this should stop it getting onto the bearings. Its also good for high temp's from reading the details. Although moly is good stuff it didn't do as well at repelling the water in my experiment.

[marksorrento205 80]

I only use THIS stuff. From the tests iv carried out its very water resistant. Its also very tacky. So if any water did try to get on the bearings this should stop it getting onto the bearings. Its also good for high temp's from reading the details. Although moly is good stuff it didn't do as well at repelling the water in my experiment.

 

George,

 

Can you give us details of the experiment/s you carried out and the results that came from these?

[SurGie 54]

I used the tops of two old big milk tanker type things. I cut of the tops where the steel caps screws into thick threads then applied both types of grease around the threads then did them up. I left them in salt water for a long time, about 3 months or so. The moly one did unscrew but there was some difficulty, the red grease one came undone well easy. These tanks and their tops are standard steel that rusts, i know this because i use to use them for my garage piss pot No toilet any where near by so needs must and all that.

[Daviewonder 533 3 Cars]

I used the tops of two old big milk tanker type things. I cut of the tops where the steel caps screws into thick threads then applied both types of grease around the threads then did them up. I left them in salt water for a long time, about 3 months or so. The moly one did unscrew but there was some difficulty, the red grease one came undone well easy. These tanks and their tops are standard steel that rusts, i know this because i use to use them for my garage piss pot No toilet any where near by so needs must and all that.

 

Where do you empty this piss pot? Why not just piss there and cut out the middle man?

[Tom Fenton 1,536]

From looking at the data sheets I don't think that grease is ideal, it is very viscous which in the very limited articulation of the arm shaft to the bearings isn't great.

 

Like Anthony I use lithium EP2, I also do a mod to the bearings and install grease nipples to allow fresh grease to be pushed over the needles to remove contaminants.

[SurGie 54]

i would do but house's etc are in view of the mud area i use which means no smell, tipping liquid out a pot looks better.

 

I forgot to add that i use oilite bearings, i put the grease around the edges to help stop water/dirt getting in. Iv used grease nipples as well.

 

Can you link us the info about this grease, im only going from its instructions and experience of it ?

 

Looking through Wiki this is what it says >

 

Lithium-based greases are the most commonly used; sodium and lithium-based greases have higher melting point (dropping point) than calcium-based greases but are not resistant to the action of water. Lithium-based grease has a dropping point at 190 to 220 °C (350 to 400 °F). However the maximum usable temperature for lithium-based grease is 120 °C.

 

So you have a few choices on the best way to avoid the friction and water together. My choice is red grease then oilite bearings with grease nipples.

Edited February 2, 2012 by SurGie

[EdCherry 34 1 Cars]

Dont think the problem is water getting onto the bearings Surgie, its washing grease out. Adding extra grease to stop dirt getting in wont help, It just attracts dirt.

[SurGie 54]

If dirt can get in then surely the water can as well ?

 

The oilite bearing iv used are a good tight fit, wont the needles move up and down more when around the shaft ?

[Rippthrough 98]

I'd go with Toms recommendation, he's right, the grease Surgies is using is far too viscous to be of much use in an oscillating application for normal bearings, it'll just push out of the way and stay there, you ideally want either a 00 or a 0 grade so it creeps back in fairly quickly, EP2 will do though as it doesn't have the tackifiers to the same extent as the Lucas stuff.

 

If the water has got to the grease it's too late already, unless you intend to push fresh grease through some nipples every week/day to push the water out, just make sure your seals fit properly.

Edited February 2, 2012 by Rippthrough

[Anthony 1,002]

Nothing should be getting in there - that's the whole point of the seals!

 

If the seals aren't doing their job, all extra or special grease will possibly do is buy you time - the underlying fault is still there and will eventually kill it.

 

To give you some idea, my old 309 that was submerged in 3 foot odd of flood water back in 2007 was still dry inside the (only just refurbished) beam when I knocked it apart to check it over - I was surprised that they sealed that well, but sealed it was and perfect as a result. Sadly the rest of the car didn't fair so well...

[allanallen 528 2 Cars]

Sadly the rest of the car didn't fair so well...

 

The back bumper is still live and kicking

[SurGie 54]

Would you put the same grease around the seal surface against the beam or leave it clean ?

 

My old beam had no grease along the bearings and no water inside the beam. It had grease around the edges of the bearings yet rusty bearings. The beam had not been touched since new from the other evidence i found from it, so what did Peugeot use when they built them ?

 

How long do the seals last as in time ?

 

 

Here is more wiki details i found and it seems EP is better for my oilite flat surface of them >

 

Additives

 

Teflon is added to some greases to improve their lubricating properties. Gear greases consist of rosin oil, thickened with lime and mixed with mineral oil, with some percentage of water. Special-purpose greases contain glycerol and sorbitan esters. They are used, for example, in low-temperature conditions. Some greases are labeled "EP", which indicates "extreme pressure". Under high pressure or shock loading, normal grease can be compressed to the extent that the greased parts come into physical contact, causing friction and wear. EP grease contains solid lubricants, usually graphite and/or molybdenum disulphide, to provide protection under heavy loadings. The solid lubricants bond to the surface of the metal, and prevent metal-to-metal contact and the resulting friction and wear when the lubricant film gets too thin.[

Edited February 2, 2012 by SurGie

[Anthony 1,002]

I just tend to smear the bearings in grease and then cover the entire shaft - inevitably some of the grease will spill out over the seal when you push the arm home.

 

Just because there's no visible moisture inside the beam doesn't mean that moist air hasn't been getting in past perished or ill-fitting seals. After all, dry things don't tend to rust very much, particularly when they're smeared in grease.

 

I personally believe that seals should be replaced and the beam re-greased every 5 years or so as a sensible precaution, or whenever it's knocked apart to lower it once it has been in use for a while. It doesn't cost a whole lot of money to do nor take much time, but the condition of the seals is absolutely key to the longevity of the beam. The outer bearings at least would be sensible in the same sort of time frame (more frequently on cars with uprated bars) as well given the amount of load/abuse they take.

[Rippthrough 98]

 

Here is more wiki details i found and it seems EP is better for my oilite flat surface of them >

 

 

No grease is good for oilite, it blocks the pores, there's a reason it's called OILite.

[SurGie 54]

So evidently, oilite bearings and a little red grease to block any water/moisture is all thats needed then ?

 

Info

Edited February 2, 2012 by SurGie

[pug_ham 243 3 Cars]

Oilite is self lubricating so why add extra grease to block its natural self lubricating properties?

 

Too much grease can be worse than not enough because the excess will attract dirt that will be drawn into the seals / bearings & cause accelerated wear.

 

Wikipedia isn't the gospel on how things should be done, anyone could edit the text & make it sound like they are a mastermind!!

 

Check the actual material spec sheet for Oilite & see if that recommends any additional grease or oil for lubrication, if it does, use that.

 

If anything you should use the same oil spec that is used in its production (sae30 apparently).

 

g

[Rippthrough 98]

You can lube Oilite with light machine oil - it'll draw it through the pores with a rotating load (although not with oscillation as in the rear beam, so missing out on most of it's self lubricating properties, hence the other versions of Oilite with solid lubricants) - it's how most old lathes used to lube the spindles if they weren't on roller bearings - they'd have an oilite bush with a cotton wick down to an oil reservoir in the bottom of the machine, and the spinning shaft would draw the lubricating oil through the Oilite, and the wick would feed more up, like a candle.

 

You also shouldn't machine the bearing surface on oilite without fresh, razor sharp tooling, otherwise you smear the pores shut as you cut it.

edit: (as it says in the wiki actually)

 

If you're going to that much effort to get oil to something, it's not generally a good idea to smear it in thick, tacky grease

Thin shock absorber oil is ideal for refreshing oilite tbh.

Edited February 2, 2012 by Rippthrough

[welshpug 1,646]

so basically, stick to needle roller bearings

[Tom Fenton 1,536]

SurGineering strikes again......

[SurGie 54]

How very droll & off topic tom

 

I totally understand how wiki works but its better than nothing, there is no other grease data provided here.

 

I dont believe that no moisture can get into the beam due to flexing etc, so i would prefer to avoid grease that hates water. My oilite supplier just told me that the red water resistant grease is fine to use, just not a lot of it. It's to be lightly applied on the surface of the bearings as well as some around the shaft. He also agrees that moisture can get inside the beam no matter how good the seal is. They are the beam engineers that fitted the bearing into my beam in the first place. They will be contacting me to tell me what type of oil these oilite bearings were used.

 

Typical engineers disagreeing again

 

Thing with needle rollers is you have to depend on them not breaking during its life, if they break they mash up the inside of the beam.

 

So you cant provide any evidence of the data for these greases then ?

[Tom Fenton 1,536]

The data sheets are in the public domain. Whether you understand the information contained therein is clearly another matter.

[SurGie 54]

where are they then, the library ?

 

Is that another way of calling me thick ?