Frozen driveshaft bolts

Thought I would swap in a new steeda (Dana Spicer) aluminum driveshaft in a couple hours. Diff bolts and center support came out immediately but I can't budge the old transmission flange bolts (odd 12-point heads). Tons of PB Blaster, pneumatic impact (supposedly 700 lb-ft breakaway torque), won't move. I'm on my back under the car, so there isn't room for a breaker bar and come along pipe. Flange and bolts are rusty but undamaged. What works best on rust?

2009 GT coupe, 77K miles, South Carolina but not on the coast.

How long since you sprayed them? Sometimes you need a good 2-3 days of soaking (hit them 2x per day) before it can soak in far enough to break loose. For me the hardest part was rounding up a 12 point 12mm socket (I never buy 12 points). If your impact doesn't have enough ass then a good breaker bar with a couple feet of heavy pipe for extra leverage will do the trick. If it doesn't break the socket.

Any local transmission shops or repair shops you can offer $40-50 to break them loose for you? Or better yet, play ignorant and see what they will charge you to swap the driveshaft for you.

Started with the PB yesterday, so it's going on 30+ hours. I'm with you on 12-point sockets. Had to go buy one. Car is on jacks, so there's no room for a pipe. I have a shop in town I trust if the Blaster won't work by mid-week. Thanks for answering!

Move the stands if they're in the way. There's always room for a bar, you only need a few degrees of swing to break the bolts. I've also used a jack to jack up the end of the breaker bar vs a pipe extension before.

wdrlaw said:

What works best on rust?

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Still stuck? Try using a 50/50 mix of acetone & ATF.

In all my years I can't remember ever using the jack trick. Good one.

crjackson2134 said:

Still stuck? Try using a 50/50 mix of acetone & ATF.

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The 50-50 acetone / automatic tranny fluid concoction works superb..... 5 X better than PB blaster.

The jack under the breaker bar is a good one, dead simple, and extremely effective.

skwerl said:

In all my years I can't remember ever using the jack trick. Good one.

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We always do this in the field. A jack provides great muscle.

crjackson2134 said:

Still stuck? Try using a 50/50 mix of acetone & ATF.

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What type of ATF? I have a clutch swap coming up.

A 'technique' I've used, but don't really like, is to use a box-end 12pt wrench, and hit it with a hammer to break it loose; as long as it doesn't round off the head.
Soaking with atk/acetone is an interesting approach, for sure!
As far as using a jack, also a good idea; but be careful of it slipping off the bar!

Rick Simons said:

What type of ATF? I have a clutch swap coming up.

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Doesn’t Matter. Actually, any light weight oil will work. A 10W non detergent oil works great too. ATF is usually around a 10W oil. The acetone will thin the oil which will allow it to penetrate the rust crystal structure. The high volatility of the acetone then causes it to evaporate leaving the oil residue behind. This lubricates the faster.
Another technique is to heat up the bolts with a torch being very careful. Drape a very wet rag around the end of the transmission body to prevent things from getting too hot.

Have you tried MAP gas? Any hardware store should have it. Heat the bolt gently and it should free it up.

88GT251 is absolutely right. The Ford bolts have hardcore thread locker that comes off easily when heated. It doesn't have to be red hot. About 30 seconds on the bolt head should do it.

Agree with using heat to loosen up the thread locker.

Do you require heat with loctite blue..... or just loctite red ? 2 yrs ago, loctite came out with a new version, called loctite orange. Strong as red, but 'easy' to get off like blue. Never seen it in any stores, just blue + red.

On a side note, loctite also makes loctite purple...which is slightly weaker than loctite blue.

Pentalab said:

Do you require heat with loctite blue..... or just loctite red ? 2 yrs ago, loctite came out with a new version, called loctite orange. Strong as red, but 'easy' to get off like blue. Never seen it in any stores, just blue + red.

On a side note, loctite also makes loctite purple...which is slightly weaker than loctite blue.

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No heat needed with blue. Red takes 500°F to break down. I used it on the safety wire on the Wilwood brakes. Orange is available from Amazon, (what isn’t ) no heat needed and 3X as strong as blue. I’ve used it on my driveshaft at the rear CV joint and on my LCAs.

Finally got up the nerve to use a torch on the last two transmission flange bolts. Shoulda started that way. New shaft went in without a hitch. Drives great and the awful thunk is gone. I think the CV joint in the old shaft was failing. Thanks for all the great advice.

Laga said:

No heat needed with blue. Red takes 500°F to break down. I used it on the safety wire on the Wilwood brakes. Orange is available from Amazon, (what isn’t ) no heat needed and 3X as strong as blue. I’ve used it on my driveshaft at the rear CV joint and on my LCAs.

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Correct. However, if all other options don't work the heat can't hurt trying.