30 replies to this topic

[Steve8274]

Interesting to hear about the grease. Seems the synthetic grease is a bit harder to find thus making it more expensive. Doesnt look like the normal motor factors sell it. Also, some sites say it shouldnt come into contact with rubber. Wonder how that would affect the rubber seals around the radius arms for example.

 
Mmm considering we have various seals that come into contact with synthetic greases and do not have an issue.
 
I happen to have a Aeroshell bible that confirms what is compatible with what and for us Aeroshell 7 is compatible with grease 33 and Mobil 28. We have Mil-Prf codes as well and believe me we do not go randomly changing seals. What we do to use a different grease is to flush it through and thats it.
 
When i rebuild everything i will be using 33.

I wasnt having a go at what you used. I just read what you originally posted about it and then searched where to buy it. That brought up some articles that mentioned about the seals which is why I mentioned it. Obviously you use it regularly so your experience with it is more than my quick search.
I am interested in purchasing some of it since I am refurbishing all my components now. Any ideas of best place to buy? Again quick search shows it to be around £15

[sonikk4]

 

 

Interesting to hear about the grease. Seems the synthetic grease is a bit harder to find thus making it more expensive. Doesnt look like the normal motor factors sell it. Also, some sites say it shouldnt come into contact with rubber. Wonder how that would affect the rubber seals around the radius arms for example.

 
Mmm considering we have various seals that come into contact with synthetic greases and do not have an issue.
 
I happen to have a Aeroshell bible that confirms what is compatible with what and for us Aeroshell 7 is compatible with grease 33 and Mobil 28. We have Mil-Prf codes as well and believe me we do not go randomly changing seals. What we do to use a different grease is to flush it through and thats it.
 
When i rebuild everything i will be using 33.

I wasnt having a go at what you used. I just read what you originally posted about it and then searched where to buy it. That brought up some articles that mentioned about the seals which is why I mentioned it. Obviously you use it regularly so your experience with it is more than my quick search.
I am interested in purchasing some of it since I am refurbishing all my components now. Any ideas of best place to buy? Again quick search shows it to be around £15

 

 

To be honest no i don't know as we get ours bought in in bulk. The biggest issue with anything Aviation based is the instant markup in price. And i see the ebay ad for 33 at £15. When we do a standard relube of a B747 flap system we go through anything up to 8 tubes on a 8 hr session. Add in a full gear lube as well then you are looking at at least another 6 tubes.

And this is the Aeroshell book.

http://www.shell.com...roshellbook.pdf

[Rorf]

Clay based grease is hydroscopic  - BS!

[sonikk4]

Clay based grease is hydroscopic  - BS!

 

Ok far shout, poor terminology BUT instead of you calling BS try explaining instead. So going on from there i will add a bit more info into the mix.

 

Clay is used as a thickener as are other products. Now some of these are hydroscopic by design but in doing so create their own issues. Now this is where i made my mistake and will stick my hands up here, Clay based greases are moisture resistant BUT has very poor corrosion resistance.  

 

This one of the primary reasons why we changed over from this product due to finding increased corrosion in bearings, bearing surface etc. No grease is perfect, each is used for its properties in specific areas, high temp, low temp, pressure etc etc etc. And yes there is also a compatibility issue with some seals and this depends entirely of the composition of the seal, gaiter etc.

 

As i previously mentioned Grease 7, 33 and mobil 28 are compatible but not mixed, they MUST be purged / flushed fully. This is made very clear in the relevant Aircraft maintenance manual. For us some operators determine what product they want used on their Aircraft, that is their choice whether its due to cost supply availability etc. They still follow the Aircraft specification as laid down by the manufacturer.

 

Anyway i digress, if you do change the type of grease you want to use then purge it completely by pumping through until there is no trace of the old grease. 

 

Although not a grease, brake fluid does absorb moisture over time which is why most cars its recommended the fluid is replaced every two years. Again certain types of Hydraulic fluid has different properties Some mineral based, some synthetic. Each have their own flaws. For us Skydrol is the primary Hydraulic fluid in use on Large Civil Aircraft. It has a good operating range BUT when its get too hot it becomes acidic. get it in your eyes and it feels like you have burning lava in them. This is not an exaggeration and is painful beyond belief. It can in certain circumstances end up with a trip to A@E to deal with it.

[Mervyn]

It's Hygroscopic. No such thing as Hydroscopic gents..

[sonikk4]

Yup you are right, ill step away from the keyboard now then.

[Mervyn]

Sorry, just bugs me. I study the cultivation of seeds and had a ethnobiologist argue this with me last month

If youre reading this Terry...

Hygro !

Merv

[Rorf]

Grease is definitely not hygroscopic either, it is totally the opposite - brake fluid yes.

[sonikk4]

Grease is definitely not hygroscopic either, it is totally the opposite - brake fluid yes.

 

Yes you are correct which i did sate but i also added in the explanation as to why there was change from one type of grease to another.

[mikal]

What effect would worn radius arms have on the handling of the car? If you were throwing it around a bit would it be obvious something was not right with the arms?

[sonikk4]

Yes it would feel unsettled, uneven tyre wear, a lurching feeling depending on how bad the wear actually was.

[xrocketengineer]

What effect would worn radius arms have on the handling of the car? If you were throwing it around a bit would it be obvious something was not right with the arms?

Not necessarily handling, on mine the right rear tyre would rub on the rear inside when turning left. It went from a "little bit of play" on the radius arm to that extreme with almost no use.

Edited by xrocketengineer, 13 December 2017 - 03:42 PM.

[cal844]

What effect would worn radius arms have on the handling of the car? If you were throwing it around a bit would it be obvious something was not right with the arms?

Not necessarily handling, on mine the right rear tyre would rub on the rear inside when turning left. It went from a "little bit of play" on the radius arm to that extreme with almost no use.

In extremis(inner bearing failure, elongated mount holes and slightly loose inner nut) causes the car to be unpredictable

[JonC]

I'm using a waterproof synthetic grease which we use in work in salt water service, it feels really weird quite silicone like. Those rubber ring things don't seem upto the job of keeping water out.

[Alice Dooper]

Does anyone have a link for cc minis please?

CC minis are spot on and I would recommend them. He did a radius arm for me. I’ve physically seen his stock. All good stuff, timkin only bearings etc.... I even have new old stock and genuine MG Rover oil filter fitted now. Got a set of 8.4” refurbed calipers a few months ago - proper original AP with new stainless pistons, seals and valves.

He just has a Facebook page to keep costs low.