2.5 DSE gear change

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pshane

Member
Posts
26
hi i changed my gearbox oil filter today but still have the same problem,
1st gear is struggles to change up into 2nd gear i don't have any fault codes coming up on the dash and all gears select as they should,
could anyone guide me in the right direction what to look at next
thanks shane
 
thanks guys its only 1st to 2nd , iv added some Lucas when done the oil filter,
how long would you say it would take for the Lucas to work?
many thanks Shane
 
pshane said:
thanks guys its only 1st to 2nd , iv added some Lucas when done the oil filter,
how long would you say it would take for the Lucas to work?
many thanks Shane
Click to expand...

200 or 300 miles should show an improvement. Maybe more if it's a real stick shuttle valve. Try giving it some welly in first and then relaxing pressure on throttle to try and force a change to exercise it. May work may not.
 
Last edited:
pshane said:
thanks guys its only 1st to 2nd , iv added some Lucas when done the oil filter,
how long would you say it would take for the Lucas to work?
many thanks Shane
Click to expand...
Took about 800 miles and a long motorway run on mine to show a major improvement. Three changes later and three lots of Lucas in 5K miles and the box is almost perfect. Previously it flared on 2 to 3 & 3 to 4 shifts.
 
It seems that the Diesel box suffers more than the petrol's. Am i correct in thinking that the diesel and the 4.0 share a gearbox and the 4.6's are stronger?

Is it because the diesels have probably lead a harder working life that the gearboxes are giving more trouble? I'm assuming that anyone who used a P38 to tow regularly would normally have had a diesel to try and offset the horrific fuel consumption?
 
quavey said:
It seems that the Diesel box suffers more than the petrol's. Am i correct in thinking that the diesel and the 4.0 share a gearbox and the 4.6's are stronger?

Is it because the diesels have probably lead a harder working life that the gearboxes are giving more trouble? I'm assuming that anyone who used a P38 to tow regularly would normally have had a diesel to try and offset the horrific fuel consumption?
Click to expand...

I am more than willing to bet that 99.9% of diesel gearbox problems are due to poor maintenance rather than stress failure. The 4.0 litre petrol uses same box with lots more BHP and lots more torque. Different torque curve though.
 
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ok thanks for all the help guys, im up the motorway most weekends so hope to see some change soon or later,
thanks shane
 
wammers said:
I am more than willing to bet that 99.9% of diesel gearbox problems are due to poor maintenance rather than stress failure. The 4.0 litre petrol uses same box with lots more BHP and lots more torque. Different torque curve though.
Click to expand...
236ftlb for the 4.0, 199 (270Nm) or the diesel. the big difference is that the torque curve on the diesel is much steeper with peak torque around 2000rpm so changes are happening around peak torque most of the time, that plus lack of oil changes IMO is what causes failures as wear from the clutches contaminates the valve block.
 
Datatek said:
236ftlb for the 4.0, 199 (270Nm) or the diesel. the big difference is that the torque curve on the diesel is much steeper with peak torque around 2000rpm so changes are happening around peak torque most of the time, that plus lack of oil changes IMO is what causes failures as wear from the clutches contaminates the valve block.
Click to expand...

Is that not what i said? :D:D
 
Datatek said:
Not exactly, there is only 37ftlb between the 4.0 & the diesel and more torque at 1500/2000rpm on the diesel around the shift points in normal use.
Click to expand...

Max torque for diesel is at 2300 RPM, max torque for early petrol is at 3100 RPM later petrol 2600 RPM. So the torque for the early petrol will not be much different than the diesel at 2300 RPM. The torque available for the later petrol will be significantly higher than the diesel at 2300 RPM.
 
wammers said:
Max torque for diesel is at 2300 RPM, max torque for early petrol is at 3100 RPM later petrol 2600 RPM. So the torque for the early petrol will not be much different than the diesel at 2300 RPM. The torque available for the later petrol will be significantly higher than the diesel at 2300 RPM.
Click to expand...
The max torque figure I have for the diesel is at 2000 rpm.
 
Datatek said:
The max torque figure I have for the diesel is at 2000 rpm.
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Torque for the BMW M51 fitted to Range rover models is 270 nm or 199 lb ft at 2300 RPM. Torque for early 4.0 litre petrol is 320 nm or 266 lb ft at 3100 RPM and last 4.0 version 340 nm or 250 lb ft at 2600 RPM. Although i do not know if the later petrol was ever fitted to the P38.
 
So going on this if you wanted to improve the torque of your diesel and it sounds like the same box was fitted to the 4ltr but it was stronger. Would you be able to just straight swap the two boxes? I know with the 4.6 box alterations need to be made i.e bell housing swap... Just a thought
 
Littelwill said:
So going on this if you wanted to improve the torque of your diesel and it sounds like the same box was fitted to the 4ltr but it was stronger. Would you be able to just straight swap the two boxes? I know with the 4.6 box alterations need to be made i.e bell housing swap... Just a thought
Click to expand...

The diesel box and the 4.0 litre box are identical so no point in doing that.
 
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