740i to M7 transformation - S62 swap

[Alpina7]

Thanks Alpina7!!! We'll have to meet up so you can experience the thrill of the S62/6MT and I can see if I'm going to like those KIDO's.

def man. when things slow down for me ill def be hitting you up for a meet. BTW, congrats man. car sounds great.

[oekundar]

Very well done...so what is the problem with 3rd gear?

[blackknight530i]

Thanks Oekundar!

Not totally sure what's wrong with 3rd, it's like if you don't let the clutch fully grab before accelerating, it slips really bad and doesn't want to catch. Doesn't seem to be a problem in any other gears. My buddy who was driving has a 2006 M3 ZCP and he thought it was odd. It could just be the difference in torque compared to the S54, but I don't really know. In normal driving and under 5k RPM, it doesn't have the problem. Maybe it was just us getting used to it.

[TxDarth]

Thanks Oekundar!

Not totally sure what's wrong with 3rd, it's like if you don't let the clutch fully grab before accelerating, it slips really bad and doesn't want to catch. Doesn't seem to be a problem in any other gears. My buddy who was driving has a 2006 M3 ZCP and he thought it was odd. It could just be the difference in torque compared to the S54, but I don't really know. In normal driving and under 5k RPM, it doesn't have the problem. Maybe it was just us getting used to it.

It has got to be imagination - std trannies can't slip only clutches! The gears are always fully engaged - it just selects which one is coupled to the output shaft.

[geargrinder]

It has got to be imagination - std trannies can't slip only clutches! The gears are always fully engaged - it just selects which one is coupled to the output shaft.

ummmm... i hope this isn't bad news but I have to correct Darth Texar. I happen to know from my own recent adventures that this particular evil bastidge of a tranny, the Getrag 420G, is assembled with some pure press fit on the shafts. From what I was told there are cogs in the box that are not splined or dogged, but just pressed on with extreme high pressure presses into interference fit on the shaft, and no mechanical 'lock'. If this is the case, theoretically, I guess maybe yes a cog in this particular gear box COULD spin on a shaft.

However - that said I have no idea if its a common failure mode with them. Maybe it never happens and this is just something else that's a coincidence.

They are almost impossible to rebuild and you can only do so w/ used parts, and only a very few guys around country can do them due to the tricky assembly and tools required.

[TxDarth]

ummmm... i hope this isn't bad news but I have to correct Darth Texar. I happen to know from my own recent adventures that this particular evil bastidge of a tranny, the Getrag 420G, is assembled with some pure press fit on the shafts. From what I was told there are cogs in the box that are not splined or dogged, but just pressed on with extreme high pressure presses into interference fit on the shaft, and no mechanical 'lock'. If this is the case, theoretically, I guess maybe yes a cog in this particular gear box COULD spin on a shaft.

However - that said I have no idea if its a common failure mode with them. Maybe it never happens and this is just something else that's a coincidence.

They are almost impossible to rebuild and you can only do so w/ used parts, and only a very few guys around country can do them due to the tricky assembly and tools required.

I think this would be be a first - I have never heard of a manual tranny "slipping". By design all the gears feed to a cluster then to an output shaft. The individual gears spin on shafts and are not fixed to it - they are coupled by means of tooth mesh from one to another. I really don't see how they could slip - especially only one gear, i.e. 3rd gear. Don't believe it, sorry.

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[blackknight530i]

I'm beginning to think it's more of a coincidence. I've been driving all over the place yesterday and today and even getting into some pretty high revs without doing too quick of shifts and it seems fine. I think the other day, we were just doing too quick of shifts and the clutch wasn't catching fast enough. The clutch that is on it came with the engine and only had 300 miles, but is not OEM or LUK, so it could just be a little slipperier. It seems to hold very well once in gear though, which tells me it's probably not an internal issue with the transmission and that Darth is probably correct. Thanks for the help guys.

BTW, has anyone figured out why bimmerforums.com has been ridiculously slow lately? It's driving me crazy!

[S62fan]

Hey congrats on getting everything sorted out!. As for the tranny, my take is 3rd gear generally is the most prone to clutch slippage. The stock M5 clutch is notoriously weak, and many upgrades are available. With the 740's weight, I'm sure this slippage is more noticeable. Check the M5 board for gearbox/clutch issues, I'm sure you'll find any answers you need.

I would love to take a ride if I'm ever in your neck of the woods!

[007008]

Do you have that restrictor valve (CDV) installed on the slave cylinder? That stupid thing slows the clutch engagement.

[blackknight530i]

Hey congrats on getting everything sorted out!. As for the tranny, my take is 3rd gear generally is the most prone to clutch slippage. The stock M5 clutch is notoriously weak, and many upgrades are available. With the 740's weight, I'm sure this slippage is more noticeable. Check the M5 board for gearbox/clutch issues, I'm sure you'll find any answers you need.

I would love to take a ride if I'm ever in your neck of the woods!

Thanks S62fan! Definitely if you're around here, I'd be happy to show it to you. That goes for anyone else that happens to be in my area that has given me support throughout this build.

Trevor, It's a brand new M5 slave cylinder, so I don't really know what restrictor valve you mean. The clutch feels great in most cases, it's very easy to push the clutch pedal, but the grab point is pretty high up on the pedal. It feels normal to me, but my buddy who was driving it said his is much lower. He has the 420G in his M3, so it should be pretty close, but what do I know?

[007008]

It's a little gizmo that slows the fluid in and out of the slave. If its there just remove it.
http://www.zeckhausen.com/images/Mod...lview_mod1.jpg
And did you bleed the clutch with the slave in a fixture or while it was still bolted in the trans.
Realview_mod1.jpg

[blackknight530i]

It's a little gizmo that slows the fluid in and out of the slave. If its there just remove it.
http://www.zeckhausen.com/images/Mod...lview_mod1.jpg
And did you bleed the clutch with the slave in a fixture or while it was still bolted in the trans.
Realview_mod1.jpg

Definitely don't have that CDV on my slave cylinder. Maybe that's what my friend has, but I don't know for sure. It was bled while unbolted from the transmission, but I don't know what you mean by fixture. I held my finger over the bleed screw hole while my mechanic pushed the pin in several times until I couldn't hold my finger over it anymore, then put the bleeder screw back in. It seemed to work well and I don't feel like the clutch isn't fully engaging. Fluid was coming out without bubbles when we stopped. Kind of a crazy method, but it worked.

[blackknight530i]

Ok, so here's the first update after driving it for a week.

She's still been running very good and I've been using it all week to and from work (25 mi each way). She got roughly 25mi/gal all the way back from Alabama to Charlotte, but only about 17 or so all week with combined city and highway. The thing is, it would probably be better than that, but every time I get on the freeway, I just feel like getting to 80mph as fast as possible to hear the noise. She's been running smooth all week, though earlier in the week, the rear suspension was squeaking really bad, but now it doesn't seem to do it as much or at all. It's been an absolute blast driving it and I'm loving every bit of work that went into getting it to this stage.

I've ordered a few parts this week like clear sidemarker lights, a new parking brake shock, a new driver side grille, a M5 fuel pump relay module, and some wire to do the servotronic off of the DME. The only thing not yet installed is the fuel pump relay module. The servotronic required running two new wires through the ebox passthrough on the firewall and wiring them to the servotronic wires going to the general module which were cut. That went pretty smoothly. I was also going to wire the third wire for my DTML pump, but when I hooked it up and it still wasn't working right without codes, I decided to scrap it for another day. I now know why it wasn't working, but I decided to just code the DTC's out of the DME instead as it's much easier and I'm not going to be needing to get the car inspected any time soon anyways. I'm also getting an intermittent "signal, crank position" error that doesn't seem to be keeping the car from starting or anything, but I do notice that the car runs a little rougher when I get the code. I'm probably going to swap the sensor for the one off of my broken manual transmission when I get back to Alabama to see if it fixes the problem. I'm also getting a "oil pressure sensor" error that always says it's not currently present when I check it, but I know it's not because of low oil pressure. I'm thinking it has something to do with the oil pressure switch on the oil filter housing having two pins where the 740i plug only has one wire. It might require running a wire from the switch to the IKE or something. Other than those, I'm not getting any other codes.

Things that still need to be done:

Get a new clutch pedal position switch that will send the right information to the DME so I can enable Sport mode. Right now, the gear position switch and clutch switch are not being used and it goes into a failsafe of not allowing the sport button to work. It's a $65 part, so I've been reluctant to buy one, but I probably will eventually. I'm just worried about running 12V to the DME on that line in case it's expecting 5V or something.

Replace struts with KIDO coilovers. This might be a while seeing as I want to do the suspension refresh at least in the back at the same time. I've refreshed the suspension on my 530i before and done the rear struts separately and it was a total pain, so I'm hoping doing it all at once will go much more smoothly.

Replace right rear window regulator. This was apparently replaced, according to my records when I bought the car, 60k miles/6 years ago, but it just broke last night. I've done those before on my previous 740il I had, so it shouldn't be too bad.

Clean! Clean! Clean! The interior is in desperate need of a good cleaning. The carpets need to be shampooed, the leather reconditioned, and the windows cleaned on the inside. Oh, and the headliner is awfully dirty as well. I'm hoping to get the smell of old car out of it.

Replace wheels with style 95's. This might be a while since I have a brand new set of 18" Michelin Pilot Sport AS+'s on the car right now and I'm not looking to spend $2k for wheels and tires right now when I don't have to.

Plasti-dip the chrome all over the car. I'm not a fan of chrome. The only chrome on my 530i is the rim and crosses of the BMW emblems and I love it that way. I'd really like to paint the moulding around the bumpers and doors body color, but I haven't seen too many e38's with that done. The 740i badge will be removed and the chrome bumper strip as well (it's bubbling up underneath the chrome).

I also need to wire in an aux cable for my iPod or get a Intravee II, but again, a bit too expensive right now and I have an rf modulator that works ok and charges my iPod as well.

Anyways, that's what's been going on so far this week. I'll keep updating as things change. I said in the beginning that this thread was going to be for the full M7 transformation, not just the swap. Thanks for the support everyone!

[007008]

I guess you've heard that Cars & Coffee is back on for next Saturday. I hope to be able to see it then.

[blackknight530i]

Yep, I plan on being there!

[blackknight530i]

Hey guys, had a weird thing happen today. I went over to a friend's place to show him the car and we were taking a drive and we got the revs up to about 6500 or so and everything seemed just fine, then I noticed that it was just a bit harder to move the shifter to the right into 5th and 6th gears. It used to be that when the shifter was centered in neutral, that it was a bit easier to move it to the right and a litter more resistance was felt moving it to the left before hitting the reverse lockout. Now it seems like moving it over to the right is almost as hard as getting into reverse, but not quite that bad. Moving it forward or backwards once it's over to the right is still just as it was, but it is just strange. I'm hoping you guys might have an idea what might have happened.

Here's what it seems like to me, but feel free to point out my stupidity if you know better: It's like the two centering springs that hold the shifter centered are the culprit. In reading about people converting their M3 SMG transmissions to 6MT's, I read about the two centering "pistons" that needed to be drilled and set into the SMG bellhousing. I'm wondering if maybe the one that holds it centered from the right may have been stuck before and wasn't holding the shifter back as much and today I freed it up and maybe now what I'm feeling is what should be normal.

It also could be that something has gone wrong with the shift detent springs, but my understanding of those is that it would make it hard to either get into or out of gear, and that isn't really what's going on.

I hope we can figure it out, because it has me a bit worried. Thanks!

[blackknight530i]

So, I hadn't driven the car since Sunday and tonight I decided to just check it again and as soon as I moved the shifter to the right, it made a click sound and now it's back to normal. It feels exactly as it did before the problem arose on Sunday. This weekend, I'll get under there and check it, but for now, it seems to be fixed.

[geargrinder]

Paul - I assume you read all the shifter detent ball and locking pin threads for the 420G tranny? You're right those usually seem to manifest in being stuck IN gear, but not always. The classic BMW linkage is so simple there's not much that can go wrong with that without being obvious so problems are usually inside the box. Do you know the date of your donor tranny? aka 1999 changeover from the earlier problematic ball-style detents?

The locking pins are relatively cheap to replace, the detent shaft kit is less so, but overall not real expensive. The only danger is not following the process to the letter and losing synchronization of the shifter mechanism. I have been thinking about pulling those parts out of my spare tranny in the basement just to inspect them and see what they are like and 'practice'... Now that I've done more research, I wish I'd just done them preventatively when I was doing the install/swap in the first place just to be sure all was well. My spare I know is from a 2000, but the one that is in the car I'm less sure of the age/date and haven't found a way to date code a tranny so not sure if I should be concerned about the detents or not...

[blackknight530i]

Well, the salvage yard that sold me the transmission said it was from a 2001 540i with 140k miles, but I don't think it had a VIN code to verify. It also has the oval shaped part where the gear recognition switch wire is supposed to clip onto, which is supposed to be on the older type transmissions. The way I see it, I have another 102k mile transmission that I know uses the newer type rear housing, though the housing has a crack in it from when it was shipped. My mechanic is a little weary of opening that end up, so we didn't try to fix it yet, but we could always try to either swap the rear housing with another used one, or weld up the crack and swap the transmissions. The fact that it seems to be fixed now gives me the idea that maybe one of the detents got stuck or something and now it has freed itself. I'm definitely no expert on transmissions, but it's what it seems like.

Anyone have a newer model 420G transmission for a core that I could get the rear housing from? What should I be careful of when removing that cover? AAMCO, said they would remove and replace that cover for $75, is it worth it to just have them do it?

[geargrinder]

All I know is if you don't know how to disassemble the 420G you break things as you take it apart, LSCMAN and others have been pretty clear on that. I would DEFINITELY stay away from AAMCO on those, I don't think they are in their wheelhouse.

FWIW LSCMAN (Rick) will does rebuilds on these occasionally but it is only by special arrangement as he's not a pro, he just does it on the side. Eriksson also knows all about them - http://erikssonindustries.com/. I have talked to Eriksson and they have a few guys there who know all the ins and outs of this box and in fact went on in detail to me about some of the failure modes and the problems with getting parts and said they'd def tear down a box for me and tell me what was wrong but couldn't guarantee having a part on the shelf although they do have a few parts donors.

Either one of those people might be able to tell you over the phone if & how you can safely pull the case off. Maybe that part of the job is as simple as we would hope, I don't know.

From my research, normally a 420G 'core' tranny that is not good to install still can go for $400-500 because of the parts value factor. If you're lucky maybe you could stumble on a private seller with one that is totally locked up or blown up inside, and/or a seller who doesn't know that it's anything special like a guy parting out a high-miles wrecked 540, and can get it for $100-200.

[Wintonicus750]

Cool! SO does this mean I can fit a new 2014 760LI twin turbo in mine??? Would it fit?

[blackknight530i]

Well, I'm certainly not going to spend more that $400, since that's what I paid for my working one that is installed in the car now. I can find them on car-part for about $350-400, but since I only need the rear case, I figured somebody has one that they don't want to bother fixing. Plus, if they have one that's busted, maybe they can take some pictures of what's in that case when they take it off so I can see what I'm dealing with. Point is, the spare 420G I have is basically free, so if I break it, I'm not out anything.

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Cool! SO does this mean I can fit a new 2014 760LI twin turbo in mine??? Would it fit?

Not sure i follow how that would work. Seeing how the S62 was of the same generation and based on the same block as the M62TUB44, it was much easier to swap than a brand new engine in which the rest of the car wouldn't have a clue how to talk to, but hey, I am not like the people that say it's too expensive or too unfeasible, so try it and do a write-up. I didn't break new ground in my swap, but I feel like I did document it way more than anyone else who's done it. Good luck finding people that know anything about the new 2014 V12's and is willing to share.

Nice car btw!

[M I C H A E L]

Cool! SO does this mean I can fit a new 2014 760LI twin turbo in mine??? Would it fit?

Nothing would be compatible everything is completely different esp the electronics and engine management system.. bottom line better off just buying one

[blackknight530i]

Nothing would be compatible everything is completely different esp the electronics and engine management system.. bottom line better off just buying one

Thanks Michael for saying what I was thinking, but didn't want to say since I didn't want to discourage anyone from doing engine swaps. Many people could have told me that my swap was impractical and costs too much, but I was determined to do it and did it anyways. It's very likely that people on here don't have 10's of thousands of dollars to throw at an idea like that, but at the same time, how cool would it be if someone did it? Anyways, I can't imagine someone going through with it, but it's still a cool thought. Kind of reminds me of Forza 4 letting me put an S85 and all-wheel-drive and twin-turbo in an e39 M5.

[M I C H A E L]

Thanks Michael for saying what I was thinking, but didn't want to say since I didn't want to discourage anyone from doing engine swaps. Many people could have told me that my swap was impractical and costs too much, but I was determined to do it and did it anyways. It's very likely that people on here don't have 10's of thousands of dollars to throw at an idea like that, but at the same time, how cool would it be if someone did it? Anyways, I can't imagine someone going through with it, but it's still a cool thought. Kind of reminds me of Forza 4 letting me put an S85 and all-wheel-drive and twin-turbo in an e39 M5.

Don't get me wrong I'm all for swaps and especially yours but let's think realistically if you even had all the money in the world to even afford such a swap.

You would have a very hard time figuring all the electronics out plus finding someone who would be an expert with coding. It just wouldn't be worth it. Its just something way difficult and end up costing more than what it would be worth doing so. Hence just buy one...