confirmation on 99 disco LT230 fitment

Is there any fitment issues with a 99 disco transfer case in my 91 D90? I know the target for parts is 96-98 D1, but was not sure on this part. There's one close by on the cheap. Figured it a good replacement on my leaking one with roughly 35K more miles than on this one. I'd rather put a new rear seal kit and gaskets on that one than on mine if i'm going to spend some money on it.

Thanks.

The 1999 with have the CDL so you are gtg there. It may have a lockout solenoid that will need to be removed.

It will also be 1.2 ratio so keep that in mind if you have something else at the moment.

At a minimum when refreshing it you should replace all external gaskets , both output bearings , seals and the layshaft oring. You must use around thread sealant on all bolts that aren't in blind holes. You will need a slide hammer and a vise to replace the bearings.

I'm ok with 1.2 ratio from what I have read. Currently 1.4 stock case. Will I need any block off plates or anything else related to linkage?

No additional block off plates. Napalm did an excellent recap on seals--I would just add that even with the best layshaft oring, it often leaks there so I also put right stuff around that SOB.

Yup I baste the ouseide of the case to entirely cover the layshaft. You can't replace the oring with the case installed so now is the time !

If you have a 1.4 now the 1.2 is much taller gearing . Will kill you on hills if you have anything other than a later V8.

for common knowledge, does that mean all Disco 2 LT230's are good to go?

WK2Burner said:

for common knowledge, does that mean all Disco 2 LT230's are good to go?

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My understanding is some are missing the CDL internals, some have them, and some are just missing the lever

WK2Burner said:

for common knowledge, does that mean all Disco 2 LT230's are good to go?

Click to expand...

Digging into my D1 era...it's been a long time...correct me please if wrong
04 has linkage and lever
99 has no linkage but had internals
Perhaps 00 as well.
01-03 had neither.

Which bolts get thread sealant? I didn't use any on mine and she leaks

rocky said:

Digging into my D1 era...it's been a long time...correct me please if wrong
04 has linkage and lever
99 has no linkage but had internals
Perhaps 00 as well.
01-03 had neither.

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so 04 is the unicorn here? and the 99 is second runner up?

01.5-03 the case has no CDL inside aka unusable


There are also some other changes that are not related to swapping into a Defender. Namely the shift lock solenoid and Hill descent sensors that come on some but not on others.


Essentially all bolts that you can see heads from the outside of the case need to have thread sealant.
@adam



I I seriously recommend you reconsider swapping a 1.2 t-case unless you know you want the gearing change.


Another note: all discovery transfer cases will have a cross drilled input gear. Earlier Defender transfer cases may not have this and can suffer from transmission output spline wear and transfer case input gear wear due to lack of lubrication. You can fit in oil feed plate into the earlier transfer cases to help with this problem or, you can purchase a new cross drilled input gear and install that. You can check for this wear by removing the PTO cover and looking at the spline mesh while rotating the drive shaft by hand.

Tell tale signs of this wear is clunking while shifting into gear while at speed. It is a different clunk than the a frame ball joint clunk in the rear axle.

WK2Burner said:

so 04 is the unicorn here? and the 99 is second runner up?

Click to expand...

Yup: 04 was special.

Also they do not have a speedo drive so you need to swap rear output housings.

Napalm00 said:

I I seriously recommend you reconsider swapping a 1.2 t-case unless you know you want the gearing change.

Click to expand...

Good point, I'll run through the calculator and decide. In the mean time, when the time comes ill pull the existing and check how it looks under the sump and the PTO plate. I doubt the disco 230 is going anywhere soon and it's only 10 minutes away. Appreciate the info.

Yup. You can also check the input gear by removing the PTO plate with the transfer case in vehicle

99 was a split model year d1's and d2's were available, both should have diff lock on the tcase. I picked up a 2000 model tcase with diff lock, just no linkage. The d1's have a speedo drive. The d2's use the abs sensors. Rather than swap rear housings the easy way to go is a gps speedo sender.