Pettit high tip trailer ram

[John 1594]

Using the trailer yesterday and the high lift ram springs a leak, such a leak that the trailer wont even lift off its stops

Took it off this morning, stripped it out, and found all the seals and backing rings laying loose in the bottom of the tube

Looking at the machined grooves on the piston rods, i was excepting to find a pair of snap rings holding the seals/backing rings on, but it appears that all what holds them on is a lip on the seal itself

The large seal does snap into the groove, but doesnt leave enough clearnace for the backing ring to fit behind it

Small seal is totally destroyed and no chance of getting any numbers from it

To me it looks a poor design, with no way of securing the seals tightly, unless the ram has pressure on it the seals can work off the rods

its definately not the original ram either, having taken many pettit rams apart over the years

Scrap it and find another ram, or is it repairable?

 

[76masseyman]

Larrington Hydraulics at Boston ??
Seen them repair all sorts.

 

[John 1594]

Its an option, looking for a cheaper fix than that tbh...know of a few scrap trailers locally, once xmas is out the way i may have to go on the scrounge....have about 4" travel either way on the bottom mount if i cut a fresh pair of holes for the mounting pin

Whoever replaced this ram last time severly bodged it, the ram is a touch too long, so instead of moving the holes they welded spacers onto the chassis rests to hold it up far enough to fit a bit longer ram!

 

[Exfarmer]

Dennis Lee at Little Snoring or Wymondham, but they were never quick unless it was just a reseal job.

 

[ACEngineering]

Shearforth I think it is do new rams and they wont be as expensive as you would think.

Whats the snap ring doing on the rod in one of them pics?

 

[John 1594]

Shearforth I think it is do new rams and they wont be as expensive as you would think.

Whats the snap ring doing on the rod in one of them pics?

Stroke limiter i think, there two snap rings per rod...bottom one hits the retaining collar when ram is fully extended, leaving about 5" of the rod, with seal still in the bore. Second snap ring is under the backing collar what the seal sits on, its a strange setup, had plenty of rams apart and never seen one as cheaply made as this. As i said, its only the tightness of the seal on the rod what holds it all together

 

[ACEngineering]

Stroke limiter i think, there two snap rings per rod...bottom one hits the retaining collar when ram is fully extended, leaving about 5" of the rod, with seal still in the bore. Second snap ring is under the backing collar what the seal sits on, its a strange setup, had plenty of rams apart and never seen one as cheaply made as this. As i said, its only the tightness of the seal on the rod what holds it all together

If you got your own lathe you could turn a circlip grove on it and then make a washer to sit between seal and circlip to hold it in place.

In theory there will always be the oil holding the seal on even if trailer is down. Only time it can fall off is if you lift the body with something other than the ram ie a forklift with ram still connected. Or if maybe you prop the body and then the ram sinks back under its own weight?

 

[John 1594]

If you got your own lathe you could turn a circlip grove on it and then make a washer to sit between seal and circlip to hold it in place.

In theory there will always be the oil holding the seal on even if trailer is down. Only time it can fall off is if you lift the body with something other than the ram ie a forklift with ram still connected. Or if maybe you prop the body and then the ram sinks back under its own weight?

The issue is getting replacement seals, large one has legible numbers on, but the smaller one is totally destroyed. Its odd, with the orange backing ring fitted onto the collar and the purple seal on top, the seal doesnt go down far enough to engage in the groove on the rod. When i pulled it apart, both metal collar, the remains of both seals and backing rings were all loose in the base of the cylinder, so something cant be right with it?

 

[YELROM]

We had a twin rammed Marshall trailer with the same rams on
The plastic orange circlips were always breaking on ours so in the end we just welded a piece of tube where the circlip went

 

[Netherfield]

You already know the answer,if you manage to find a seal it'll only do it again,when you most need it.

 

[John 1594]

Just dialled the part no into the Hallite oil seal finder and no trace of it at all...so looks like its find another ram!

 

[YELROM]

I think they are schoolhill rams, you can get the clips from Eriks but not sure about the seals.If it is a 4ton ram like ours was I might have the smaller seal

 

[YELROM]

@Marshall Trailers might know where to get parts as ours was a twin rammed marshall

 

[Marshall Trailers]

We do have parts for schoolhill rams and looking at the photos I think we might be able to help. If you message us the best measurements you can get from the seals we can see what we can do.

Thanks,
Charles

 

[John 1594]

We do have parts for schoolhill rams and looking at the photos I think we might be able to help. If you message us the best measurements you can get from the seals we can see what we can do.

Thanks,
Charles

Will have a measure up tommorrow

from the pictures, would you say im missing any crucial parts, or does the seal simply snap into the last groove on the end of the ram? I could modify it to take a snap ring....if i lathe another groove slightly below the one holding the metal collar, so the seal goes on a bit further, i could use the spring clip from a suitable sized lynch pin as a snap ring to fit in the top groove and prevent the seal falling off

either way, it seems that with current setup, if i fit the orange backing ring the seal wont go down far enough to engage in the groove?

 

[YELROM]

The seal should be pushed tight to the metal collar and then the plastic circlip fits in the groove to hold it on, but if it is like ours it will keep breaking the plastic clips.
On ours I opened the spring clip below the metal collar then slide the metal collar and the seal down the tube (so it did not melt) then cut about 10mm piece of tube that fitted over the end of the ram, them welded it where the plastic circlip should be then side the seal and metal collar back down and pushed spring clip down, never any more problem

 

[Forever Fendt]

The issue is getting replacement seals, large one has legible numbers on, but the smaller one is totally destroyed. Its odd, with the orange backing ring fitted onto the collar and the purple seal on top, the seal doesnt go down far enough to engage in the groove on the rod. When i pulled it apart, both metal collar, the remains of both seals and backing rings were all loose in the base of the cylinder, so something cant be right with it?

if its got the orange wear rings in that will be a hendry ram, Hendry hydraulics pine field ind estate elgin Scotland if it is one of theres they will sort it for you

 

[John 1594]

Seals are stamped Hellite....large one is a 41600.....small one...or whats left of it....anybodys guess!!!!

 

[Forever Fendt]

Seals are stamped Hellite....large one is a 41600.....small one...or whats left of it....anybodys guess!!!!

looking at post from marshall i may be wrong about hendry but i got some from them for a neighbours west trailer with the orange rings on is it a 2 or 3 stage ram a new one may not be as expensive as you think try hendry or wray ram at hereford

 

[John 1594]

2 stage....need to have a word with a chap i work for first...in one of his horse paddocks is the remains of a 3 tonne pettit, its not no floor or sides and he uses it for carting an IBC about to water the horses

providing it has a genuine pettit ram....i may be in business....in exchange for a few beer tokens obviously