kitto
14th July 2015, 09:55 PM
Hello all.
Long time reader here, but my first actual post for help. Been a member for almost a year now and owned my D2 for the same time.
I'm very cluey and good with cars so i've been able to find out all the info i need for the most part by searching.
However, i have a final drive ratios dilemma...
Vehicle is used for towing (2.5T) and for 4x4 use. I'll feed as much info as i can.
Current vehicle status;
245/70/16s Fitted when normally driving and towing. 285/75/16s fitted when 4x4ing.
Manual TD5 D2a
EGR Blanked
DPF cat removed, factory exhaust
NOT tuned (to my knowledge) - NNN re mappable ECU
3" rear lift
2" front lift
Snorkel
Future modifications to improve response and power:
Better air filter
Centre muffler delete
Remap
If at absolute necessary, VNT turbo upgrade
I find driving the vehicle normally is fine, quite gutsy once on boost but an absolute pig off boost in first or second gear. I find that in 5th @ 110kmh the engine is revving just too high and out of the peak torque range @ around 2,700RPM. Now with a remap, there will be more power and torque available down lower hence me wanting the engine to rev less at 110.
When towing i find that 1st gear is just a pain to get the thing off the line until its on boost. Hill start's are challenging to say the least and the clutch cops it. I have tried the start in low range and then shift into high range on the fly. But no matter how i try and nicely change from low range to high range whilst moving, the TC feels like its about to drop all of its cogs - no synromesh. Diagram says its ok to change from L to H range under 8kmh. It may just be that my TC is almost very dead and does require replacement, but personally i'd prefer not to change the TC ratios on the fly.
So, this leaves me wanting effectively a shorter first gear for towing and in fact 4x4ing with 33" mud tyres. The TD5 R380 already has a 3.692:1 first gear ratio which is a little higher than the V8 R380, no other options available to replace first gear with a higher ratio unit.
So to effectively change first gear ratio to be shorter, i'd be wanting to change High range ratio in the TC to a defender 1.413:1. However that effects all gears in H range and i actually want the engine revving less, especially in 4th and 5th at 110. Same thing goes for diff ratios, which i'm honestly trying to avoid.
I am almost to the point of having to replace the R380 and the TC as they are both on their last legs with 270,000kms on them. The gearbox synchros are badly worn, 5th gear howls (the lovely 5th gear support bearing failure) and the transfer case has more oil on the outside than on the inside thanks to the lovely intermediate shaft leak. I'm currently planning on a replacing both with Ashcroft items, with the R380 having the upgraded 5th bearing support and also the longer V8 R380 5th gear installed. This will drop the rev's slightly in 5th at 110.
Under / Over drives. I've found that Under or Over drive units can be fitted to the LT230, but is there a manufacturer that does a unit that is a combination of both Under drive and Over drive?
When towing, i try very hard to avoid 5th, but do find myself using it at 110 when on very flat road, when i approach an incline, i change back to 4th. If i could find an overdrive unit, i could simply stay in fourth and flick between the direct drive in the OD unit, or going into OD when on the flat to avoid using 5th gear at all.
Sorry this has rambled on ridiculously long... I was trying to keep it short.
I guess my question is, what have some of you done with your gearing, Honestly i'd prefer to set the gearing up so that with normal tyres are on, its comfortable to come off the line with a big load, but also have the engine working at a reasonable speed at 100 - 110kmh.
Your input is appreciated - or maybe i've opened a debate?
Cheers, Dan.
Long time reader here, but my first actual post for help. Been a member for almost a year now and owned my D2 for the same time.
I'm very cluey and good with cars so i've been able to find out all the info i need for the most part by searching.
However, i have a final drive ratios dilemma...
Vehicle is used for towing (2.5T) and for 4x4 use. I'll feed as much info as i can.
Current vehicle status;
245/70/16s Fitted when normally driving and towing. 285/75/16s fitted when 4x4ing.
Manual TD5 D2a
EGR Blanked
DPF cat removed, factory exhaust
NOT tuned (to my knowledge) - NNN re mappable ECU
3" rear lift
2" front lift
Snorkel
Future modifications to improve response and power:
Better air filter
Centre muffler delete
Remap
If at absolute necessary, VNT turbo upgrade
I find driving the vehicle normally is fine, quite gutsy once on boost but an absolute pig off boost in first or second gear. I find that in 5th @ 110kmh the engine is revving just too high and out of the peak torque range @ around 2,700RPM. Now with a remap, there will be more power and torque available down lower hence me wanting the engine to rev less at 110.
When towing i find that 1st gear is just a pain to get the thing off the line until its on boost. Hill start's are challenging to say the least and the clutch cops it. I have tried the start in low range and then shift into high range on the fly. But no matter how i try and nicely change from low range to high range whilst moving, the TC feels like its about to drop all of its cogs - no synromesh. Diagram says its ok to change from L to H range under 8kmh. It may just be that my TC is almost very dead and does require replacement, but personally i'd prefer not to change the TC ratios on the fly.
So, this leaves me wanting effectively a shorter first gear for towing and in fact 4x4ing with 33" mud tyres. The TD5 R380 already has a 3.692:1 first gear ratio which is a little higher than the V8 R380, no other options available to replace first gear with a higher ratio unit.
So to effectively change first gear ratio to be shorter, i'd be wanting to change High range ratio in the TC to a defender 1.413:1. However that effects all gears in H range and i actually want the engine revving less, especially in 4th and 5th at 110. Same thing goes for diff ratios, which i'm honestly trying to avoid.
I am almost to the point of having to replace the R380 and the TC as they are both on their last legs with 270,000kms on them. The gearbox synchros are badly worn, 5th gear howls (the lovely 5th gear support bearing failure) and the transfer case has more oil on the outside than on the inside thanks to the lovely intermediate shaft leak. I'm currently planning on a replacing both with Ashcroft items, with the R380 having the upgraded 5th bearing support and also the longer V8 R380 5th gear installed. This will drop the rev's slightly in 5th at 110.
Under / Over drives. I've found that Under or Over drive units can be fitted to the LT230, but is there a manufacturer that does a unit that is a combination of both Under drive and Over drive?
When towing, i try very hard to avoid 5th, but do find myself using it at 110 when on very flat road, when i approach an incline, i change back to 4th. If i could find an overdrive unit, i could simply stay in fourth and flick between the direct drive in the OD unit, or going into OD when on the flat to avoid using 5th gear at all.
Sorry this has rambled on ridiculously long... I was trying to keep it short.
I guess my question is, what have some of you done with your gearing, Honestly i'd prefer to set the gearing up so that with normal tyres are on, its comfortable to come off the line with a big load, but also have the engine working at a reasonable speed at 100 - 110kmh.
Your input is appreciated - or maybe i've opened a debate?
Cheers, Dan.