PRM 260 Hydraulic Gearbox

S

SAMYL

Well-Known Member
Joined
31 Aug 2009
Messages
1,632
Location
Gone Fishing
Visit site
I have a PRM 260 hydraulic gearbox which will not go into reverse, it selects forward and neutral OK but not reverse. Before I start stripping it down to ascertain why, can I call on any readers for advice on possible causes and where I should look first?
I have worked on automotive manual boxes but not on an hydraulic marine box before so would welcome any advice re. dismantling, possible webb links, diagrams etc. etc. I am quite prepared to strip the whole box and use the O-Ring kits to refurbish but I'm hoping some reader will come up with a simpler solution.
I have already contacted PRM who say they have not encountered that problem before!!
Many thanks
Ian
PS I have checked the control cable for stretch and it is OK, manually moving the change lever on the box gives the same fault.
 
no drive

we had the same problem with our alison gearbox,, it would engage reverse ok. but needed high revs to engage forward drive.
turned out after stripping down, a seal had failed, causing a bearing to seize.
i would check your strainer for blockage first and also make sure the oil pressure is correct.
the oil levels are more important in the gearbox than maybe in a engine.
engines can take various levels. ie stil run when low. but ur gearbox is hydraulic so pressure is critical.
please do read ur manual for correct oil levels.
our box repair wil be around £5k so good luck
 
SAMYL said:
I have a PRM 260 hydraulic gearbox which will not go into reverse, it selects forward and neutral OK but not reverse. Before I start stripping it down to ascertain why, can I call on any readers for advice on possible causes and where I should look first?
I have worked on automotive manual boxes but not on an hydraulic marine box before so would welcome any advice re. dismantling, possible webb links, diagrams etc. etc. I am quite prepared to strip the whole box and use the O-Ring kits to refurbish but I'm hoping some reader will come up with a simpler solution.
I have already contacted PRM who say they have not encountered that problem before!!
Many thanks
Ian
PS I have checked the control cable for stretch and it is OK, manually moving the change lever on the box gives the same fault.
Click to expand...

download here

http://www.prm-marine.com/prm260.php
 
I've rebuilt one of the early ones for a friend.They are quite simple boxes.There are two clutches a pump and a diverter valve that actuates either clutch according to position of the selector.The problem probably lies in the selector .If forward can be selected I'd think the pump is working so the selector valve could be the problem.
 
icepatrol said:
we had the same problem with our alison gearbox,, it would engage reverse ok. but needed high revs to engage forward drive.
turned out after stripping down, a seal had failed, causing a bearing to seize.
i would check your strainer for blockage first and also make sure the oil pressure is correct.
the oil levels are more important in the gearbox than maybe in a engine.
engines can take various levels. ie stil run when low. but ur gearbox is hydraulic so pressure is critical.
please do read ur manual for correct oil levels.
our box repair wil be around £5k so good luck
Click to expand...

I thought the PRMs ran off the engine oil?
 
PRMs do not need hydraulic oil, you can use ordinary engine oil in them. The 260 does not use an oil feed from the engine but does have its own oil cooler.

30boat - thanks for that. I may come back to you as rebuild progresses for more advice
 
You must log in or register to reply here.

Share this page

Top