Help please - engine drop stopped.

[rob911]

I am ready to drop my first ever engine on my 1984 3.2 cabrio.

Went to loosen Gearbox mount bolts - would not move at all.
Scared to round them off so have soaked them in "Plus Gas" penetrant. Engine mount bolts are fine.

What is best option.
19mm socket and HUGE breaker bar ( only have 6 inch bar)
impact driver ( don't have one yet)
Heat ( don't have gas torch)

The car is going to body and paint shop on monday. I need to remove engine + gearbox, glass, roof and paint

All is disconnected, have double checked with Bentley manual, 101 book and printout form web.

Spent all afternoon building a dolly with tall castors to allow the big trolley jack to fit under it. That way I can do the whole job myself - I hope. Should have tried the nuts first before all the shops close.

[Superman]

I don't think heat can help you much here. Penetrating fluid might. You certainly may need more than a 6 inch breaker bar. I have at least two breaker bars, but the only one I ever touch is the longest one, about 2.5 feet. A smooth but strong pressure is best, so use the long breaker. I know of no safer or more effective way to deal with those stuck fasteners.

I do hope all goes well though. I once heard Warren warn that stripping these particular threads (the female ones in the body, above the tranny mount) are pretty difficult to repair. Still, big breaker bar and smooth strong force is your best bet.

PS - I guess there is another alternative that may be safer but a PITA. Grind the heads off the bolts. Then you would need to remove the fasteners attaching the crossmember to the tranny. You can then deal with those stubborn long bolts later, if they don't just come right out with the crossmember gone.

[Jim Sims]

Some suggestions: (1) use a quality 6-point socket, 3/4" drive with a long breaker bar and/or "cheater" pipe extension if you can get it, (2) have someone, wearing leather gloves press against the socket to keep it seated, (3) make sure you are squarely registered on the screw head, and (4) another thing to do is to push in the tightening direction and then back in the loosening direction. This last move will sometimes help break the corrosion locking the threads. Good luck! Jim

[rob911]

Thanks guys

Guess the toolshop will see me for the third day in a row.

Will get the 19mm socket with 3/4" drive and the longest breaker bar I can swing under the car. My toolkit is "growing up" at a pace now.

Will post a picture of my packed garage once the engine is out. All my new panels arrived today ( in smashed up boxes ), so I am glad to have an old BMW 730 on the drive for extra storage space.

[Doug Zielke]

Rob,
Before you cut off the bolt heads (!) and/or maim yerself........
I'd be very surprised if an electric impact wrench (3/4 drive) and a stout, impact socket would not shift the bolts. You should be able to rent this sort of tool in the UK. Good luck!

[jluetjen]

Ditto the electric impact wrench. I bought one to do the castlated nuts on the rear axles and now use it all the time - but only for removing fasteners and wheel nuts. It has saved so many hours agonizing over how to remove stuck hardware.

BTW: I always torque everything by hand.

[Formerly Steve Wilkinson]

Don't bother with an air impact wrench unles you have a huge, commercial-size compressor and air tank. An air wrench in combination with the typical DIY-size Sears wheeled compresssor is useless for major-torque jobs, which I learned to my own dismay.

Stephan

[KTL]

Originally posted by Stephan Wilkinson
Don't bother with an air impact wrench unles you have a huge, commercial-size compressor and air tank. An air wrench in combination with the typical DIY-size Sears wheeled compresssor is useless for major-torque jobs, which I learned to my own dismay.

Stephan

I don't think they're that bad. I was glad to have the upright 6hp, 30 gal. compressor and my I-R impact when I had to remove the ball joint nuts from the control arms. Those are torqued somewhere in the neighborhood of 180-200 ft-lb. Saved me the opportunity of getting a knuckle-buster by avoiding the recommended hammer and chisel method.

I believe those trans. mount bolts are torqued to 80Nm/58 ft-lb, so they're probably stuck, not tight. Never know though, some gorilla could've muscled up on them in the past. Breaker bar method should get you home.

Good luck.

[John Brandt]

6 point sockets are best, but I really think that when you get a 2 foot pipe over your existing 1/2" wrench. your problem will be solved

[Groesbeck Hurricane]

Just keep the idea of cutting them off as the last resort. I have a dozen or so that I had to cut off, thanks to a certain dealership in Houston who did the clutch replacement for the previous owner. They stripped the bolts when they installed them. When you leave the threaded part of the bolt in, you will have the added chore of drilling it out. Everything else came off (except head bolts) fine with a nice 2.5 or 4 foot breaker bar. Just remember to use even pressure.

[Ned, NYNA11]

Rob,
1/2 inch drive breaker bar 18 inches long will do it. Do not use heat as you will boil the rubber in the mounts. Use a length of pipe with the bar to get leverage. You can't really do any damage as these bolts are big. Just removed and put back the engine in my 87 so it's all fresh in my mind.
Ned Monaghan

[Superman]

Impact wrenches are for sissies. I have one and the only times I use it are when the thing I'm trying to get a fastener off of moves. For example, removing cam sprocket bolts without a flywheel lock. Even then for reinstallation I will put the engine in gear and use a torque wrench since the torque pulls against the straight parts of the chains. Some of you will know what I mean.

At any rate, my vote is still for a long breaker bar or cheater pipe. I have a 2.5 ft breaker bar and about a 5' length of steel pipe, just in case. I have yet to meet a fastener I cannot remove. I can get substantially over 300 lb/ft of torque with these hand tools.

[psoete]

I had trouble breaking loose the lower bolt holding the rear shocks to the frame on my 81sc. Rented an electric impact wrench and it did nothing. What worked was 3/4 impact socket with 3 ft cheater pipe on 2 ft breaker bar, but tightening first to break it loose.

[fred cook]

You've gotten some good advice concerning loosening stuck bolts. Sometimes a long breaker bar is what it takes! However, when working under an automobile, double check that the vehicle is adequately supported, preferably with heavy duty jackstands. It is not a bad idea to position a floor jack so that it will act as a backup if the vehicle is jerked off the stands. That is one BIG advantage of using an air wrench. The torque is applied to the bolt around 360 degrees so there is no tendency to rock or move the entire vehicle. The other thing to remember is that air wrenches are not all created equal. I have a 1/2 inch drive Wal-Mart special that will make 250 ft/lbs of torque on 90 psi line pressure. Does a good job most of the time. However, after failing to remove stubborn fasteners a couple of times, I went looking for a stronger wrench. Ingersol Rand makes a 1/2 inch drive air wrench that makes 600 ft/lbs of torque on 90 lbs of line pressure when unfastening a bolt. I have yet to "encounter" any fastener that it won't unscrew or twist off!!!! This is a classic case of you get what you pay for. The WalMart wrench was $50, the Ingersol Rand wrench runs about $180. Also, if you are using a quick disconnect coupler, sometimes you can gain some torque by removing the coupler and screwing the air hose directly into the wrench.

Good Luck

Fred Cook
'80 911SC

[dickster]

rob, did you crack it??

i gotta get a breaker bar.

i've also seen some powerful electric impact wrenches (bout £250 though)