GWR Con Rods

Hi All,
The following is a bit long winded so please bear with me..

We have on the Gwili an 03 diesel which is leaking oil from behind the con rod on the leading axle. We have had the rods off. However on closer inspection looking through the oiling point the bush seems to be held in place by a triangular shaped bolt, what tool do we need to remove this ?

The reason I have asked about GWR rods is I'm led to believe that It is the same technology as used on 03???

Any help much appreciate,

 

Presumably you are talking about the coupling rods on the 03?

If you are looking down to hole with the cork removed on a set of GW coupling rods you will normally see a 3 fluted oil restrictor which looks a bit like a thread tap. There is a purpose made tool to remove these. This restrictor is however purely to restrict the flow of oil to the coupling rod bearing oil pad and in no way does it secure the bearing bush.

The oil will continue to leak if it is filled above the level of the restrictor and the loco is parked. It is intended to work so that by filling only to the level of the top of the restrictor tube the bearing will receive oil which is splashed around by movement of the rod.

On old GW rods (still a few around) the bush is secured in the rod by press fitting and by a hexagon head set bolt from below. On more modern rods the bushes are a press fit in the rod eyes with a key to prevent rotation.

 

I must admit I only glanced at it at the time as we where rushing to get the rod back on. The tool you refer to what does it look like?

 

The mirror image of the part you would be unscrewing! - but something could be made by drilling 3 holes at the right PCD (one for each flute) and a fourth central one in the end of a suitable bit of bar?

On steam locos these restrictors can sometimes be difficult to unscrew but the oilways can usually be cleared without unsrewing them so there is usually no need anyway.

 

The restrictor in the con rod oiler hole is to stop you fitting a trimming as the oil is delivered by a felt pad in contact with the journal. The restrictor will have no effect on the volume of oil flowing to the bearing.

 

Right I've been down the railway today and took the following photo. Can anyway tell me what it is?

http://flic.kr/p/fqFQA1

 

It is the restrictor referred to in the previous posts.

 

Right, so how do you remove it or don't you?

 

If you want to remove it, you unscrew it, as stated in previous posts! Why do you want to remove it, though?

 

Hi Guys,
Thanks for the answers I know I repeated myself but that was purely because I had someone else approach me with a completely different response to the ones above. The reason for stripping the rod is to get to the route cause of why it is throwing its oil on to the driving wheel as seen below ?
http://flic.kr/p/fqVPvN

Thanks again for all the responses so far

 

I've never had the privilege(?) of working on an 03 but, assuming it is the same as 99% of rod drive locomotives, the lubrication works on a 'once through' system. In other words, you put the oil in at the top and it eventually comes out at the bottom. The rate at which the oil passes through will vary from bearing to bearing, depending on several factors, such as clearance, viscosity, etc but will eventually drip out onto whatever is underneath it; usually the ground. That is why you 'oil up' each day. It stands to reason that a lot of this oil will find its way onto the wheel. There are no oil seals on the crankpin to retain the oil within the bearing. That is the case with all rods unless they re fitted with rolling contact bearings.

If you are only getting it on one wheel, I'd be surprised, although one wheel may be worse than others. If the other crankpins aren't using any oil, I'd be more worried about why.

You could always convert it to grease lubrication!

 

Hi Steve,
It is confined to the one wheel. As you say you obviously expect it to use oil but what is noticeable is that this one use considerably more oil to the point of needing to be topped up during the day. I assume then going on what you've said that we must have excessive clearance some where on the rod, thus allowing the oil to pass through quicker than expected ?

 

It should be fairly easy to tell whether it is a 'rattle' fit, or not! Have they got felt pads in them ? (I don't know). If the felt is missing, this could be a symptom. Have you had the rods off?

 

If you have only one bearing throwing lots of oil the cause will undoubtedly be the felt pad in the rod. It is either missing or a very loose fit. As was stated earlier in the thread the restrictor does nothing other than restrict someone from putting a trimming in the hole, and incidentally projects above the syphon tube to stop some chump from pushing a cork down too far and blocking off the syphon tube; the flow of oil is restricted solely by the density of felt and the slight interference of the pad in its slot (normally a medium grade of felt neither hard or soft, and about 1/16 inch bigger than the slot all round), so if lots of oil is running out it means two things - the oil is getting through the syphon tube, so no need to remove it, and the felt pad which is meant to control the flow is not doing its job and needs renewing.

QED
Bob

 

Hi all,
Thank you for your responses so far. Out of interest what sort of felt specification would you recommend. Having had a look online there appears to be a million and one options?

 

Try Hardy & Hanson of Dewsbury W Yorks .( they have a website).
They do felt for lubrication purposes in a variety of densities. Never found a proper written spec for this but comparison on unused old items suggests density of 0.30 is somewhere near. (usual disclaimer).
The pad should be a snug but not tight fit in the pad recess & should protrude about 1/16" towards the journal to ensure contact post assembly.
GW steam loco pads had a corrugated perforated metal strip to ensure distribution of the oil across the pad but this is probably unnecessary on a low speed application like an 03.
Pads should be soaked in lub oil for at least 24 hrs & then drained for a similar period before fitting.