I just picked up a 99 with a bad trans. I have a spare trans out of an 03, along with all the electronics to run it, but I need some direction. I've read that the 4HP22 in the 99 is a little shorter so I assume the rear driveshaft could be different (I haven't checked), but are there any other concerns with putting the 4HP24 from the 03 D2 into a 99 D2? Do I need to swap the TCU as well? I also expected the 99 to have a CDL however it has the same lever (and console sticker) as the 03. I haven't checked the TC itself but I'm wondering if that's normal?

My plan was to do a straight swap but now I'm not certain of the compatibility. Thanks!

 

‘99’s have the internal mechanisms in the transfer case to lock the CDL but no cable/lever to activate it from the cab. You can retrofit it with a kit or a cable assembly out of a donor or fashion up a DIY solution.

 

He's asking about the transmission, not the transfer case.

 

Both actually. I was aware that the 99 *should* have a CDL, I was not aware the cabling to actuate it was not there. That clears up that mystery for me, so thank you.

I am still wondering if I can direct swap a later 4HP24 from the 2003 into the the 1999, which had a 4HP22 from the factory. And if so, what accommodations have to be made in the 99, like bringing the TCU (or BCU, SLABS, ETC). This quote from the Workshop manual looks promising, but isn't 100% clear so I'm hoping someone out there has some firsthand experience.

 

Also just to mention, having had both, the longer transmission on the 2004 just barely makes it impossible to drain the transfer case fluid without removing the frame cross member in that area. NBD, unless those anemic bolts are rusty, which most tend to be.

 

To also add there is a difference in the transmission/transfer case mounts on 03/04 frames vs earlier. I believe they are welded slightly further back to accommodate the longer transmission. I don’t know if you could enlarge to holes to make it fit or if there is enough play in the mounts to account for this.

 

Interesting. 15mm is just over a half inch and there's a pretty good slot in the mount already, maybe 40mm?? I'd be surprised in LR changed the chassis layout for this as opposed to giving ZF a spec to work from but you may be right. It's easy enough to measure from a reference point though. Good catch.

 

To be clear I have never measured and seen this in person. I found out because when looking into a galvanized frame there are two different skus for this reason.

 

Pretty sure that the rear driveshafts are the same regardless of the transmission. The spline in the shaft should have enough flexibility to accommodate the different in length.

 

I would tend to agree. Same for the slots in the mounts but I will be checking that shortly. Measuring the shafts is a ways down the road.

Edit: AB lists different part numbers for 99-02 D2, and 03-04 D2. Strangely, D1 is the same part number as 03-04 D2 yet has the same trans as the 99-02 D2.