What else to replace while 6-speed swapping?

[Bob Duato]

Hey everyone. I recently bought a '94 540i auto with a bad transmission. What a perfect opportunity to throw in the clutch/getrag 420g I recently got from an E39.

One question I do have about the swap is if there is any way to use the E39 pedals in the E34? I've read that it doesn't fit, but I'm curious if I could make it fit with some modification.

Anyway, I’m not trying to go too too crazy, but while everything is out and accessible, I'd like to replace as many things as I can. Below is a list of all that I've bought. This is at the recommendation of a friend who is a helluva mechanic, but he doesn't know E34's like a lot of people here do. Chime in if you think he missed anything important. Thanks.

Input shaft seal
Output shaft seal
4 intake manifold gaskets
Front intake manifold gasket
Rear intake manifold gasket
Water pump
Oil filter
Oil filter O-ring
Oil pressure hose inlet
Oil cooler line outlet
Thermostat
Serpentine belt
Crankshaft seal
Rear crankshaft seal
Upper oil pan gasket
Oil pan gasket
Right valve cover gasket
Left valve cover gasket
22 valve cover grommets
Rear main seal carrier gasket
2 brake master cylinder grommets
Oil dipstick seal
Oil dipstick O-ring
Upper radiator hose
Lower radiator hose
Radiator

[moroza]

That's quite a comprehensive list, well beyond the While you're In Theres (WIT) of a manual swap. At this rate, you might as well reseal the entire engine, short of the headgaskets. All I see missing from that benchmark:


valley pan coolant gasket*
valley pipe O-rings (x4)
PCV O-rings, and it's a good time to replace the PCV plate
rear coolant manifold gaskets*
rear coolant cover gasket inside the bellhousing*
upper and lower timing cover gaskets*
three (I think) internal O-rings for oil passages inside the timing cover
chain tensioner gasket ring
oil duct O-rings (x2) between port motormount bracket and block
oil pipe O-rings (x4) at braided hoses
the oil hoses themselves can leak
heater hoses
since you've got the cooling system apart, consider the expansion tank, heater core, heater valve, and auxiliary water pump
replace thermostat housing with metal one (not Üro) if plastic
cylindrical rubber seals where the main intake duct connects to the IACV, throttlebody, MAF, and maybe the whole duct itself
O-ring between MAF and airbox
how old are the motor mounts?


*I'd use RTV instead of the OE thin paper gasket. Up to preference.

Why would you use E39 pedals when E34 are available? I have a set for sale, and they're available new.

420G input shaft seal must be genuine BMW. Search for a few threads that found aftermarket replacements to be the wrong size. IMO, the input and output seals are optional if not actually leaking, which seems uncommon. The selector shaft seal, however, is a very common leak source.

As for the rest of the WIT for a manual swap...

Driveshaft: pilot bushing, CSB, CV joint gasket and some fresh grease.

Shifter: lever ball cup, washers, swivel joint, carrier arm rear mount and front bushing, lever and selector rod if worn, rubber inner shift boot if cracked.

Used clutch? Read up on how to reset the self-adjusting mechanism. I'd get a different clutch and flywheel altogether, something bigger & sprung, and lighter & solid, respectively.

You're going to have a fun car. I built and drove for eight years a 544iTM - E34 Touring with M62 and 420G (https://www.bimmerforums.com/forum/showthread.php?2371293-And-so-it-ends-the-544iT-is-for-sale) - and miss it more than I thought I would.

[amoebamonster]

I just did this same job of converting an auto 540 to a manual (and I'm still wrapping it up) . I'd like to add a few things to consider:

Motor mounts ( I did OEM at first, then they tore pretty quickly, then I went with soft Revshift black poly mounts)
Trans Mounts
Guibo/flex joint
I did a timing chain service while I had the covers off, it's not as big of a problem on the M60B40 but, WIT....
Also did exhaust manifold gaskets and all the intake gaskets
Fan clutch wouldn't be a bad idea also, if that hasn't been done already.
Also, red loctite-ing the oil pump bolts

If you're going with the "motor out" approach, which I would recommend, you will find a few other things that need done. I did a full suspension refresh while the motor was out too, since you can get to everything a bit easier.

I hope you are prepared to get nickled and dimed to death.. It'll be worth it.

[Sir Montalbon]

Pretty good coverage in the posts above. I'd add that if you do engine out, do the oil lines that run from the engine to the oil filter. They do not look fun to swap with the engine in.

Also, power steering hoses is not mentioned. They tend to leak and a couple are hard to get to with the engine in.

Good luck! Very rewarding when done!

[Bob Duato]

Wow, thanks for all the input! Definitely all the info I was looking for and then some. Looks like I have quite a bit of research to do this morning. I'll post a thread when she's all finished. moroza, I PM'ed you about the pedals.

[prash]

A+ thread. Subscribed for the future.

[Bob Duato]

Hey moroza, I tried PMing you a couple times but it seems the messages aren't going through.



Why would you use E39 pedals when E34 are available? I have a set for sale, and they're available new.

I got a set of E39 pedals with the trans/clutch I bought. If they can be relatively easily modded to fit, I would like to just go that route.

If not, how much for your E34 pedals shipped to 90035?

[Layne]

The coolant crossover (at the back of the heads) on a 540 automatic has hose nipples to supply the transmission cooler. You can just loop a hose here, but it's just another thing to blow out later. The crossover for a 540 manual and any 530 (automatic and manual) doesn't have these nipples. I would find one of those and replace it while you're in there.