Herbmiester 931 Report post Posted 15 hours ago I am looking to swap the GM 6L45 in my 130i for a ZF6HP. Some of you may wonder whey swap an auto for an auto, but bear with me I do have what I think are solid reasons. Firstly and probably the big one for me, is the GM6L45 is an average box. It's not that smooth, especially when being pushed. It clunks up and down and does have a habit of chopping down when its not needed or holding on when it should drop down. I find it a bit of a guessing game. It does work ok when you use the paddle shifters. My 6l45 has had a service ad works as it should. In comparison the ZF box's I have had are noticeably smoother. The y have a much more refined converter lock/unlock and shifts are smoother. It also seems to be a lot smarter about when it shifts up and down. Finally it can be made very sharp with an XHP flash tune. Having had 6HP boxes in a few cars now and have always been impressed. The question of why not manual convert is a simple one, at best its a 5k job and could easily be 7k plus. One the other hand the ZF swap is a 1 to 1.5k job. Also my wife drives the car in Wellington traffic and is not interested in having a manual. I can get my manual fix driving the E34. Getting the right ZF box is the key and there are a few small parts needed. I am pretty sure I can do it myself (using a lift), and again if the right box is used, no reprogmaing of the TCU or DME is required. I am still gathering information but this article from XHP covers it. I am in the market for a ZF 6HP19/21. https://www.xautomotive.com/blogs/news/from-gm-to-zf-6hp Quote Share this post Link to post Share on other sites
Eagle 1672 Report post Posted 15 hours ago Biggest issue for me would be the used auto box gamble. You'd probably do a service, mechatronic seals etc and probably a few drain and fills so that's another $700-800 on top. Then you kinda have to hope the rest is ok because they do have quite a few potential faults that can occur. Getting one from a damaged working car or something the you can at least test drive, check adaption values and fluid condition would be good, or even having it inspected\rebuilt. Quote Share this post Link to post Share on other sites
Herbmiester 931 Report post Posted 14 hours ago Yes getting the right box is the key. My research, including a good chat with the local transmission guy, painted a decent picture on ZF6 reliability. He really doesn't like the 6L45. Quote Share this post Link to post Share on other sites
