Transmission Removal, 540 Auto, Fishing for ideas.

[blue540]

Seasons greetings,

I am about to perform a driveway transmission swap on my 540 auto. Great timing on my part, I will have to endure the worst the UK has to throw at me in terms of weather.

Trans is toast, see previous thread. Here I have sourced a used one, risky I know but these cars are worth a lot less over here. I have a rebuilt valve body to go into it.

What I am looking for is do's and don'ts, tips and tricks and any other priceless nuggets of information from people who have carried this out in the past.

Having been under the car for about a day already to remove the exhaust and heatshields I can see it looks like a pretty tight squeeze getting the box out past the headers. Do i need to remove the roll bar? Should I remove the torque converter with the box or slide it out over it and leave it attached to the flywheel? Any tips on removing the flex disc bolts (very tight, and big)? will the engine flop forward when the trans comes off or is it quite well balanced on it's own mounts?

That sort of thing .....

It would be silly not to put the questions out there with all the combined knowledge on this board.... so.... there we go.


Many thanks in advance.

Stephen.

[yaofeng]

I did the hard way. But it is a 6 speed conversion.

[winfred]

the engine will rest fine, the converter bolts are no big deal as when the engine trys to turn over the socket that you are using on the bolt hits the side of the hole and stops it's rotation, that tranny is massive and ungodly heavy so be prepared, make damn sure you have the converter all of the way into the tranny when you are installing it, if it's not all of the way in and you force it in with the bellhousing bolts you will destroy the pump and booger up the snout of the converter at best, at worst frag the whole tranny

[blue540]

Right.... Happy New year everyone... Here I am with an update on my progress and another question.

The Trans is out now . All went suprisingly smoothly, no major PITA bolts to remove from the bellhousing, no clearance issues when dropping the trans, prop came off easily etc. Really pleased with progress so far, and thanks to Winfred for the reassurance.

I don't know if I've done the right thing here, but I left the Torque Convertor bolted to the flywheel when dropping the box. From your post Winfred, I see that your prefered method would be to unbolt the torque convertor and drop it with the Trans? So my first question is, should I mount it into the bellhousing for reinstallation to ensure a good 'mating' of the splined nose?

Secondly, when manhandling my used tranny (upside down and still containing some fluid) I notice fluid weeping from the input shaft. Anyone know if this is to be expected? Is this a sign of a shot input bearing seal? Should such items be replaced as a matter of course during a job such as this? What is invloved?

Is there any other maintenance that I should carry out while I have access to these areas of the vehicle that rarely see daylight?

In the mean time, I'll be swapping in my rebuilt valve body and trying to recruit a helper for the install, next weekend if all goes well.

Look forward to reading any advice you all may have.

Many thanks

Steve

Thanks

[whiskychaser]

I don't know if I've done the right thing here, but I left the Torque Convertor bolted to the flywheel when dropping the box. From your post Winfred, I see that your prefered method would be to unbolt the torque convertor and drop it with the Trans? So my first question is, should I mount it into the bellhousing for reinstallation to ensure a good 'mating' of the splined nose?
Thanks

Maybe the 540 is different from mine but IMHO the torque converter MUST be in the gearbox before you install. Apart from damaging the seal, you need to spin the TC and push it inwards to get it to seat in the gearbox fully. If you are dropping the valve body anyway, check that the resistances of the speed sensors and valves are to spec. If any are duff now is the time to replace them. I found the box easier to install than a manual but it is VERY heavy-maybe 80kg+ on yours. I put mine with a forklift - the sideshift was great for the 'up a bit, right a bit' phase. You wont have one in your drive so you might want to rig up some kind of cradle for your trolley jack to make sure the box doesnt fall off.

[blue540]

Right, I'll get it off the flywheel tomorrow.

Any ideas on the input shaft oil seal anyone? I dont think this should be allowing fluid past.

Any suggestions as to what could be going on here. Bodged removal by dismantler?????

[whiskychaser]

Right, I'll get it off the flywheel tomorrow.

Any ideas on the input shaft oil seal anyone? I dont think this should be allowing fluid past.

Any suggestions as to what could be going on here. Bodged removal by dismantler?????

This may sound a little stupid. If you dont have the TC in and you tip up the back end of the gearbox, ATF will pour out of the front seal. The TC fits in there and stops the oil coming out Well it should do - so its prudent to check that seal is OK before you put the TC back in. By the way, are you using the TC from the 'new' box or your old one?

[leicesterboy15]

Very interesting, keep us posted with progress, I'm watching this closely. Are you taking pics? Is this a pro only job or can a DIY mechanic do it as well?

Can you replace the torque converter without removing the whole box?

What was wrong with your old box? Sorry I can't give any advice but you wouldn't want any from me anyway when it comes to gearboxes.

[blue540]

This may sound a little stupid. If you dont have the TC in and you tip up the back end of the gearbox, ATF will pour out of the front seal. The TC fits in there and stops the oil coming out Well it should do - so its prudent to check that seal is OK before you put the TC back in. By the way, are you using the TC from the 'new' box or your old one?

Thanks for that, could be just what is happening. Guess I just saw the fluid and paniced a little, assuming it was coming form the shaft seal. Seems silly now I think about it properly.

By the way, are you using the TC from the 'new' box or your old one?

I dont have another torque convertor so the old one is going back in. While on the subject, I've read that it's very important to mark where the torque convertor sits on the shaft. Why is this critical?

http://bimmerboard.com/forums/posts/64818

I would have thought that the position of the torque convertor on the shaft would not be 'adjustable' so to speak?

[blue540]

Very interesting, keep us posted with progress, I'm watching this closely. Are you taking pics? Is this a pro only job or can a DIY mechanic do it as well?

I will grab some pictures tomorrow (today). Particulary of the nasty exhaust down pipe bolt configuration, total nightmare to remove. Especially when nuts have all but rusted away.

As for being a DIY job, kind of depends on how much of gluten for punishment you are. I am totally prepared for this not to work at all. No guarantee with a second hand box from ebay. I have swapped a 5hp18 in an E38 before, so I kind of knew what I was expecting. Hardest bit is getting the car high enough in the air. Creative use of concrete blocks required.

Can you replace the torque converter without removing the whole box?

In short, No.

What was wrong with your old box? Sorry I can't give any advice but you wouldn't want any from me anyway when it comes to gearboxes.

Old box suffered snapped off reverse clutch pack retaining clips (I think), lost reverse all together and found small bits of metal on top of the valve body upon removal. See link in first post for pics. I was pleased not to find similar pieces of broken metal in the 'New' box.