Defender Source Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
My 300tdi 110 currently runs at 3000 rpm at 55mph and about 3500 at 65 in 5th gear . Vdo rpm gauge, 22d lt230 and 31 inch tires. Speed from gps. According to Ashcroft calculator I'm pretty high, although it does pull very well. Thinking it's been regeared but is there any way of telling without pulling it apart? I would like a little lower rpm for the long interstate drives. And is 3500 harmful over an extended time?
 

·
Premium Member
Joined
·
4,918 Posts
3500 you are nearly bumping off the governor and way way above the power band.

you probably have a 1.6 transfercase and need to be on a 1.4 ?

did you check the tach with a laser tach ? you will need to adjust the settings from out of the box for it to be correct , out of the box will be not ocrrect


you should be "cruising" between 2200-2900 /opinion
 

·
Registered
Joined
·
7 Posts
Discussion Starter #3
3500 you are nearly bumping off the governor and way way above the power band.

you probably have a 1.6 transfercase and need to be on a 1.4 ?

did you check the tach with a laser tach ? you will need to adjust the settings from out of the box for it to be correct , out of the box will be not ocrrect


you should be "cruising" between 2200-2900 /opinion
I have not checked the tach. I should start there before digging to deep. The box is a 1.4 but I am thinking either it or the diffs have been regeared unless the tach is off.
 

·
Super Moderator
Joined
·
12,714 Posts
Your tach is almost certainly wrong.
 

·
Premium Member
Joined
·
4,918 Posts

This will help . Put the reflector on the crank damper. Get a helper to call out the reading at different throttle positions while you adjust the switches and the small potentiometer.
 

·
Registered
Joined
·
740 Posts
I would think it would be obvious at idle.

Does the idle sound right or is it very high? If so, what does the tach read?
 

·
Registered
Joined
·
7 Posts
Discussion Starter #8
The idle sits around 700 or so. I'll pick up a laser tach and check at higher rpms. The truck did come from a farm in Australia and is set up for towing, that was kinda my thoughts as to why it may have gear changes.
 

·
Super Moderator
Joined
·
12,714 Posts
If you think the axle gearing is changed, you can check that in a few minutes. Jack up an axle, spin driveshaft. Count turns to make the wheels turn once. I would seriously doubt it though. Axle regearing is expensive and not something a farm would do.

What gearbox does it have? Serial number.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #10
Checked axel gearing and it's stock. 22D transfer case. The numbers on the transmission appear to be HRC2458 R2 G4 6X. Hard to read so may be off.
 

·
Registered
Joined
·
5,890 Posts
Checked axel gearing and it's stock. 22D transfer case. The numbers on the transmission appear to be HRC2458 R2 G4 6X. Hard to read so may be off.
HRC is a casting number, serial number is on a small flat surface near the drain plug

449494
 

·
Super Moderator
Joined
·
12,714 Posts
It is a stock 300tdi or a conversion?
 

·
Registered
Joined
·
7 Posts
Discussion Starter #13

This will help . Put the reflector on the crank damper. Get a helper to call out the reading at different throttle positions while you adjust the switches and the small potentiometer.
Thanks, got one on order.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #14
If you think the axle gearing is changed, you can check that in a few minutes. Jack up an axle, spin driveshaft. Count turns to make the wheels turn once. I would seriously doubt it though. Axle regearing is expensive and not something a farm would do.

What gearbox does it have? Serial number.
It is a R380, I just can't make out the serial number. Going to check the tach before I end up looking for something that doesn't exist.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #15
Finally got the digital tach in. Gauge was off, dialed it in and now it sits where Ashcroft rpm calculator says. Thanks for the suggestion. After 20 something years of driving a Series I should know better than to trust a gauge.
 
1 - 17 of 17 Posts
Top