LT230 compatability

[sdt463]

I'm thinking of buying a LT230 from a disco to lift the gear ratio on my remaped 99 TD5 Defender. Can anyone please tell me if it has to be from a disco 2 or could i use a 230 from a disco 1 300tdi or v8. Also do's it have to be from a manual or could it be from an auto. I'm after something I can bolt strait in.
Cheers dave

[isuzurover]

They main case of the LT230s are all basically interchangeable. (Manual/Auto/RRC/Defender/Disco). The differences are in things like the handbrake, which you will need to swap from your old case. Also the high/low positions will be reversed if you fit a disco case.

However, it is best to avoid the Disco 2 cases as they are generally (weaker) 1.211 Q cases and many do not have a CDL.

A disco 1 28D case is probably the best option to go for. Just make sure the intermediate shaft hole is not flogged out.

[Tusker]

Going for 1.2 gears will change the gearing by about 15%, you'll need to sort out the speedo. I went with a Truspeed.

In my view the 1.2Q gears are the ones to go for. Yes they aren't as strong in theory, but I've never had any problems since the conversion some years ago. Chipped TD5 with big intercooler. But it makes the car so much quieter, more refined, much much better for long drives.

I can't remember now how it was done. Pretty sure it wasn't a t/case swap, from memory the internals were changed.

Others will chime in with which D2 cases to go for & which to avoid. The series in the middle didn't have provision for the CDL. At least with a D2 t/case you'll have the big front flange if a double carden front shaft is on your shopping list.

Regards
Max P

[Slunnie]

I've not heard of a D2 transfer breaking gears before. The 99 until late 01 are good. No CDL then until the MY03 when it was returned. What is different about the D2 LT230 is extra switches to indicate lo/hi range (for electronic throttle mapping) which you don't have to use and there is no cable speedo drive output because it reads speed from the ABS.

[uninformed]

I've not heard of a D2 transfer breaking gears before. The 99 until late 01 are good. No CDL then until the MY03 when it was returned. What is different about the D2 LT230 is extra switches to indicate lo/hi range (for electronic throttle mapping) which you don't have to use and there is no cable speedo drive output because it reads speed from the ABS.

before Ben's or at all? Ben's did

[isuzurover]

...
In my view the 1.2Q gears are the ones to go for. Yes they aren't as strong in theory, but I've never had any problems since the conversion some years ago. ...

I've not heard of a D2 transfer breaking gears before. ...

Justin would tend to disagree?

Yes they are weaker Ben, significantly 'quieter' but I also reckon by the same amount weaker. Never seen any early LT230 with gear damage except through abuse, but seen a few 'Q' boxes with fatigue or stress damage to gear teeth.

JC

Q gears look like electric golf cart stuff compared to LT95....


JC

My LT230Q




This image compares T and Q gear tooth thicknesses

[Slunnie]

Nice! I don't know what you lot are doing to them!

[isuzurover]

Nice! I don't know what you lot are doing to them!

I'm sure the ones JC is commenting on are just in ordinary(ish) D2s...

Until mine broke (pottering round the burbs, not offroad) I thought all the talk about them being weak was just that. It remained quiet and with clean oil right up until failure - i.e. no warning.

[Bush65]

BTW, changing the high range gear ratio will not affect your speedo.

The speedo is driven from the output shaft, and it will only be affected by changing the diff ratio, or tyre diameter. But using a complete transfer from a disco or rangie, they will have the speedo drive set for smaller diameter tyres than a Defender uses. You can swap the speedo drive pinion from your old Defender transfer to fix this.

[isuzurover]

BTW, changing the high range gear ratio will not affect your speedo.

The speedo is driven from the output shaft, and it will only be affected by changing the diff ratio, or tyre diameter. But using a complete transfer from a disco or rangie, they will have the speedo drive set for smaller diameter tyres than a Defender uses. You can swap the speedo drive pinion from your old Defender transfer to fix this.

AFAIK the new fangled vehicles get the speedo signal from the ABS system??? No more drive pinion to swap...

[However I cannot see how changing the t-case would change the speedo if that is the case???]