I want to change front crank seal while...

[robspeed325i]

I have the front end apart for the timing belt change I am about to do. How do I hold the crank solidly while removing this 300lb-ft nut, and more importantly, how do I hold it still when putting it back? The factory tool for this is supposed to bolt to the back of the crank, but I dont want to have to drop the trans, clutch, and flywheel, or pull the motor to have to do this. It isnt leaking I dont think but it makes sense to change it while the rest of it is apart. TIA.

[Zyth01]

Find someone who owns an air compressor and an impact gun that can do over 300ft lbs.

[StereoInstaller1]

If it is not leaking, don't fuck with it.

[robspeed325i]

I have big air and a pro airgun (can do 600+ftlbs) but ive read that even moving the bottom a little bit can bend a valve. I was thinking the obvious, which is to put it in gear, push the car forward so its "leaning" against the gear, then yank up on the e-brake. am i figuring that right? Im not so worried about taking it off, since i can do that while the belt is still on it and the valves would move with the bottom, if at all, but when im putting it back I'd have to do it with the belt slackened a bit to get the pulley on. So when I am tightening the bastard back down with a torque wrench and long piece of pipe, the engine will want to turn over clockwise as you are looking at it from the front, which wont happen because it is now locked in gear (all slack taken up by shoving it forward) and held by the brakes. I could also stick a piece of wood against the regular brake pedal to hold it even harder. The m20 spins anti-clockwise (looking at it from the front), right? (I know i should know that but im an e30 noob and its too dark/late to go look.) so shoving it forward and locking it with the brakes, then tightening it clockwise should hold it, no? If i can figure this part out theres a good chance i can save myself a $500+ labor bill coming up. money is tight, and its particularly bitter paying for someone elses labor when you yourself used to be a Mercedes and then BMW tech but cant work on your own car due to a bad back/lack of tools/etc. My brother in law was also a tech for a while (worked at a "general" shop for a while) and he's offered to help, as has my father in law (who knows about enough to hand us tools).

Anyway am I figuring the shoving forward thing right? Or should I shove it backwards... cant think straight at 3am... I think this will work as long as I get the "shove direction" right and the brakes hold it really tightly....

As for not fucking with it, sorry i just cant hepp mahseff! I have a severe case of "while im in there" syndrome... ;-p

[robspeed325i]

AHA! A buddy who is shop foreman at a cali dealership informs me the factory crank holding tool bolts to the FRONT of the crank, not the rear. AAAAAAAAAAAHHHHAHAHAHAHAAAAA!!! duh, i should have known that... now to find the tool... i found it for $100 at one place, gunna shop around... :)

[robspeed325i]

$50 at bav auto! :D

http://www.bavauto.com/fland.asp?part=BMW%203034-2&utm_medium=feed&utm_campaign=googlebase&utm_source=BMW%203034-2

[kishg]

agree with luke, i'd leave it alone. i do understand the "while i'm in there" itch though lol

[robspeed325i]

tool purchased from board member already, arrived last week. 90% likelihood that i will go ahead and replace the seal, but i might decide not to once i look at existing one.

[bioman]

Loosen the seal bolt with the timing belt still on. That way, if the bolt moves, you can just realign it.

[eugeman]

Does the crank bolt tighten in the same direction as the rotation of the engine? If you don't quite get it to 300ft/lbs, will the normal running of the engine keep it on?

[robspeed325i]

bioman: Uh, did i mention I bought the correct tool for the job? No need for tricks anymore! (although that is a good idea.)

eugeman: no, im pretty sure a bolt specc'd to 300ftlbs, you want to get all the way to 300ftlbs. Autozone lender wrench only goes to 250, so im going to spec it to 50, 100, 150, 200, 250, then when i get an idea how much i need to turn it to go up another 50lbs, after i get to 250, I'll put my giant cheater bar on it and wail it up to the 300 area. That and red locktite should do it.