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 :o

[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....:wasntme:


JC

My LT230Q
http://www.aulro.com/afvb/attachments/members-rides/63428d1374758190-isuzu-county-tourer-20130725_205142.jpg

http://www.aulro.com/afvb/attachments/members-rides/63430d1374758473-isuzu-county-tourer-20130725_205509.jpg

This image compares T and Q gear tooth thicknesses
https://www.aulro.com/afvb/

[Slunnie]

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

[isuzurover]

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

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???]

[sdt463]

Thanks every one. At the moment its just an idea i'm kicking around.
At the present time I have a Roverdrive fitted to the standard defender transfer box and it does a great job leting me tow my 3.2 ton van in 4th overdrive to protect 5th gear, but the egt's often tell me the gearing is to high in overdrive and the speedo tells me its to low in 4th.the disco LT230 would split the diference.
Trouble with the disco box will be having to slip the clutch more in 1st to get the rig moving.
Cheers all Dave
Ps are all the LT230 imput shafts the same size.

[Bush65]

Thanks every one. At the moment its just an idea i'm kicking around.
At the present time I have a Roverdrive fitted to the standard defender transfer box and it does a great job leting me tow my 3.2 ton van in 4th overdrive to protect 5th gear, but the egt's often tell me the gearing is to high in overdrive and the speedo tells me its to low in 4th.the disco LT230 would split the diference.
Trouble with the disco box will be having to slip the clutch more in 1st to get the rig moving.
Cheers all Dave
Ps are all the LT230 imput shafts the same size.
I wonder if you towing practice will change the poor strength issue from 5th gear to the Roverdrive.

Also for towing, as has been mentioned, the LT230Q from many disco I's and all disco II's are weaker.

All LT230's have the same spline size in the input gear. However Land Rover increased the length of the spline to reduce a wear problem that was frequent with earlier LT230's.

[Lotz-A-Landies]

Just going through this.

The 28D prefix are D1 LT230T (tapered roller bearings) boxes with different ratios depending upon suffix letter. Suffix E and earlier are 1.222:1 with 26 teeth input gear.
Suffix F are 1.214:1 with 28 teeth input gear.
Suffix G are 1.211:1 with 38 teeth input gear (same ratio as Ben's but his is a LT230Q (Quiet)).

http://www.aulro.com/afvb/attachments/90-110-130-defender-county/66492d1380692340-lt230-compatability-lt230t.jpg

[isuzurover]

...
Suffix G are 1.211:1 with 38 teeth input gear (same ratio as Ben's but his is a LT230Q (Quiet)).[/LIST]


Diana - 38 tooth input is a Q case.

[Lotz-A-Landies]

Hi Ben

We've had this discussion before, I thought yours was a 36D LT230Q 2.11:1.

Have we had documentary confirmation that the 28D LT230 with 1.211:1 ratios were T or Q? (other than Ashcrofts who's website calculator has been condensed to suggest the LT230 in a D1 were RRc and had only one ratio)

I'm only going by the document (posted above) from the JRA training manual.

Diana

[isuzurover]

Hi Ben

We've had this discussion before, I thought yours was a 36D LT230Q 2.11:1.

Have we had documentary confirmation that the 28D LT230 with 1.211:1 ratios were T or Q? (other than Ashcrofts who's website calculator has been condensed to suggest the LT230 in a D1 were RRc and had only one ratio)

Diana

My case was indeed marked 36D, however had a 38 tooth input gear. A 38 tooth input gear using T-sized teeth would not fit in the case. ALL LT230T's have either a 26 or 28 tooth input gear AFAIK - even the 1.003 ratio.

e.g. http://www.ashcroft-transmissions.co.uk/index.php?act=viewProd&productId=8

Click for company profile

About Us | Contact Us | How To Order | Terms & Conditions
Location: »DIY Rebuild kits» LT230 REBUILD KITS

Input gear
Input gear

Product Information

We can supply both the earlier (26th tooth) and later cross-drilled (26th and 28th tooth) input gears.

To identify which type you need you will need to look at the your transfer case serial number. The last letter of this will denote whether your vehicle is able to accept the later cross-drilled type. A transfer box with the suffix A or B will only accept the earlier 26th tooth, non cross-drilled type (FRC5428). A transfer box with the suffix C onwards will accept the later cross-drilled type. See below to find the serial number :

Defender Guide :

Suffix A or B uses a FRC5428, not available cross drilled @ £ 45

Suffix C to F uses a FTC5089, cross drilled @ £ 45

Suffix G, 300 TDi or TD5 uses a FTC4962 @ £ 65,

Suffix G, 2.4 TDCi uses a IEH500010 @ £ 65,

Disco Guide :

Suffix C to serial number 308626E uses a FTC5089, cross drilled @ £ 45

Serial number 309143E to 551442F uses a FTC5087 @ £ 45,

Suffix G uses a IEH500010 @ £ 65,

If you look up the IEH500010 you will see it is the fine tooth LT230Q gear, the same as fitted to my (broken) case.

e.g.


INPUT GEAR 38 TEETH Q TYPE LT230 OEM 135mm

Input Gear for Transfer Box LT230 'Q' Type Defender V8 1.2 Ratio & Discovery II 1.2 Ratio

38 Teeth 135mm Overall Length

Fits:-

Defender V8 1.2 Ratio From 2003 Suffix G on Boxes
Discovery II 1.2 Ratio Suffix G on Boxes

Note This Gear does not have dog teeth drive gears for PTO so is not suitable if your vehicle has, or you intend to fit a Power Take Off unit.


IEH500010
http://www.shop4autoparts.net/Defender/Gearbox/Transfer-Box/Gears-&-shafts/INPUT_TRANSFER_GEAR_38_TEETH_LT230_Q_135mm.html
https://www.aulro.com/afvb/images/imported/2013/10/1238.jpg

Happy now???

[Lotz-A-Landies]

My case was indeed marked 36D, however had a 38 tooth input gear. A 38 tooth input gear using T-sized teeth would not fit in the case. ALL LT230T's have either a 26 or 28 tooth input gear AFAIK - even the 1.003 ratio.Not suggesting you're wrong, but would like to see something from Land Rover UK that confirms the change over.

I know it seems odd to me that they would have different casings (to fit the different inputs) but use the same prefix. Logic would suggest that the Q case would have a different prefix, however the page I posted up came from JRA so errors wouldn't be a surprise! :D

[Lotz-A-Landies]

...
Happy now???Haven't been unhappy for weeks! ;)

[sdt463]

I wonder if you towing practice will change the poor strength issue from 5th gear to the Roverdrive.

Also for towing, as has been mentioned, the LT230Q from many disco I's and all disco II's are weaker.

All LT230's have the same spline size in the input gear. However Land Rover increased the length of the spline to reduce a wear problem that was frequent with earlier LT230's.
Only time will tell with that one John. I did ask Roverdrive before fitting it and they said it would not be a problem. So far towed the van about 25000 ks without any drama, well not from the Roverdrive anyway.
Dave