gearbox oil change

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
E

eldescans

senior member
Posts
101
Location
Xativa Nr Valencia Spain
Good morning looking for a bit of advice please just changed gearbox filter and there was a small amount of grey sludge in gearbox sump is this normal or am I looking at future problems oil was fairly clean
 
Great thanks a lot will sleep better now the reason I changed filter and oil is I get no drive when car has been stood have to leave it running for about 5 mins before I get any drive changing oil and filters hasnt made any difference any ideas
 
eldescans said:
Great thanks a lot will sleep better now the reason I changed filter and oil is I get no drive when car has been stood have to leave it running for about 5 mins before I get any drive changing oil and filters hasnt made any difference any ideas
Click to expand...

It would of course been better had you said this in the first place. You have something sticking in the box. As the oil and box warms it is freeing off. Possibly a piston in the valve block. Or a solenoid valve sticking.
 
Datatek said:
Try selecting 1st gear manually, if that works it's the sprag clutch.
Click to expand...

Keith i think if either of the sprag clutches fail no amount of warming up or running of engine is going to make them work. They just fail to grip and that's and end to it.
 
wammers said:
Keith i think if either of the sprag clutches fail no amount of warming up or running of engine is going to make them work. They just fail to grip and that's and end to it.
Click to expand...

You are most likely right Tony, but looking at the cam mechanism that operates the 1st gear sprag I just thought it could be sticking.
 
Datatek said:
You are most likely right Tony, but looking at the cam mechanism that operates the 1st gear sprag I just thought it could be sticking.
Click to expand...

If he had not just changed the oil, maybe you would say warm up is thinning oil, then thinner oil is getting through parially blocked filter. Common enough problem for sticky gear changes when cold. But as he has changed oil and filter it sounds to me like it's a sticky valve not engaging drive clutch. Then when the oil and gearbox internals get warm it frees off. Possibly a valve block clean would sort it. But that is not really a job you want to try unless you have done a few before or have a full set of service sheets to work with. Even then it's a bloody mine field with all the different rate springs to contend with. Used to do the old model 35s almost blindfold, but these things look a bit more of a proposition. You can buy a service tray for them i believe with compartments for each component so you strip and rebuild in a logical sequence. But my days of stripping these things are long gone. :):):)
 
cleaning them in jizer tank can make one lock up that wasnt (sticking),and so presumably fresh oil will as oil has high detergent qualities,how log that lasts in p38s is something i have no experience as often whole unit is loose and beyond sticking up in classics and disco 200 and 300 would often work again fine
 
jamesmartin said:
cleaning them in jizer tank can make one lock up that wasnt (sticking),and so presumably fresh oil will as oil has high detergent qualities,how log that lasts in p38s is something i have no experience as often whole unit is loose and beyond sticking up in classics and disco 200 and 300 would often work again fine
Click to expand...

Yeah your right James. They can be bloody finicky things to play with. Specially if you've never seen inside one before. You only need a knats whisker in some to screw them up, others seem to work fine full of ****.
 
wammers said:
Yeah your right James. They can be bloody finicky things to play with. Specially if you've never seen inside one before. You only need a knats whisker in some to screw them up, others seem to work fine full of ****.
Click to expand...

Just changed the oil for the third time and this time I dropped the sump and fitted a new filter. Not a lot of **** in the bottom but a thin coat of a sort of grey slime. It's made a little difference to the dodgy changes, 1st to 2nd is now normal but 2nd to 3rd is still accompanied by a burst of revs. So it looks like the box will have to come out. Can't make up my mind whether to use the one out of my spares dog with 162K on it or to go for a re-con from Ashcrofts. Will have to decide soon.
Looks a bloody great lump to get out, any tips welcome, like is it better to take the transfer box off first and then the box or hit it all in one lump?
 
Datatek said:
Just changed the oil for the third time and this time I dropped the sump and fitted a new filter. Not a lot of **** in the bottom but a thin coat of a sort of grey slime. It's made a little difference to the dodgy changes, 1st to 2nd is now normal but 2nd to 3rd is still accompanied by a burst of revs. So it looks like the box will have to come out. Can't make up my mind whether to use the one out of my spares dog with 162K on it or to go for a re-con from Ashcrofts. Will have to decide soon.
Looks a bloody great lump to get out, any tips welcome, like is it better to take the transfer box off first and then the box or hit it all in one lump?
Click to expand...

The burst of revs is caused by one clutch letting go and the next one not acting quickly enough. Changing from 2nd to 3rd, clutch 6 disengages and clutch 5 engages. That is supposed to happen simultaniously but there is obviously a pause occuring. Still say you have a sticky valve block.
 
wammers said:
The burst of revs is caused by one clutch letting go and the next one not acting quickly enough. Changing from 2nd to 3rd, clutch 6 disengages and clutch 5 engages. That is supposed to happen simultaniously but there is obviously a pause occuring. Still say you have a sticky valve block.
Click to expand...

From a base of no knowledge, that is what it has always seemed to me. Don't fancy dropping the valve block in situe though. I've tried swapping the ECU and just about everything else I can think of. Others seem to think it's a clutch pack, but it engages with such a jolt it does not feel like a slipping clutch to me. I'm using it as a manual at the moment and it changes fine if I back off the throttle and it will pull with no slip (apart from the torque converter until it locks) in third, with the torque convertor locked the drive is solid in third.
 
if you have spare box for parts they are reasonably easy for competent person to do ,although dont strip valve block theres nothing you can do to it that washing in paraffin or such wont do + thers a few tiny plastic ball that fit in specfic places easily lost if worn you cant repair as machined fit parts ,since no black in oil it is probably oneway clutch or sprag clutch same thing easy checked as should only turn one way and grab instantly the other
 
Many thanks for your replies I was thinking about having a go at the valve block but judging by your advise I think not. Do you know if ashcrofts do a repair to these blocks as I am going to England later this year
 
You must log in or register to reply here.

Similar threads

ar1g3
P38A P38 rattle at idle
2
Replies
26
Views
3K
roythebus
R
L
L322 4.4v8 m62 with lpg
Replies
5
Views
215
Littlelionman
L
Montyjohn
P38A Slow to change gear
Replies
1
Views
654
Datatek
Datatek
feyniriel
P38 1999 2.5 diesel automatic transmission grinding?
2
Replies
31
Views
2K
Rubberknees
Rubberknees
Chris1993
Sport Range Rover oil leak
Replies
2
Views
845
Graculus
Graculus
Back
Top