18mm trans mount bolts ... not coming out ?

[Miller88]

Went to replace the trans mount tonight and that 18 mm bolts will just not budge.

doing the following ... does anyone think this will work?

Started feeling around and saw that the top was covered in dirt. Cleaned out the threads (there's maybe 1/4 inch exposed on top). Ended up tieing some cotton rope and spraying with pb blaster. I expect the rope to help keep the blaster close and go on the threads.

So ... for removing the steel bolt in aluminum ... I'm thinking the following: low psi with impact gun. That should break it free without breaking the bolt like a pipe om breaker bar would.

Any other ideas ?

 

[rockclimber]

a little heat on the alum (read little) and an Impact will help break the bond.

anti-seize for the future.

 

[anthrax323]

Had to use a breaker bar on mine, and they squealed like hell the whole way out.

 

[Miller88]

Should I start with low or high peessure? I generally never use power tools (just bigger breaker bars ) but afraid that method would snap the head.

I'm hoping the pb blaster helps.

 

[Miller88]

To the point of anti-seize compound - yes, that's a must here in NY anyway. I won't even start working on something unless I have a jar ready to go!

Had to use a breaker bar on mine, and they squealed like hell the whole way out.

I started to do that on mine. Nothing with a 2' pipe on the end of a 12'' breaker bar

When I changed the motor mount on my car, it fought with me and made bad noises on the way out. And that was only 3.5 years old at the time ...

It's getting a healthy exposure to penetrant and I have cleared off the threads. I'm hoping it will work its way down.

 

[anthrax323]

1. Heat.

2. Penetrant (as a quench).

3. Try to tighten the bolt 5° or so, then try to loosen again. Repeat this as necessary. Apply more force loosening than tightening.

Once you've got movement, switch to the tool of your choice. Something about the thought of using an impact on aluminum threads makes my skin crawl (at least when it comes to breaking it loose).

 

[old_man]

To the point of anti-seize compound - yes, that's a must here in NY anyway. I won't even start working on something unless I have a jar ready to go!

Here in Colorado, you rarely see antiseize, we use Loctite. Antiseize is not a bad idea because steel into aluminum is a problem. A mild Loctite can do both, keep the corrosion causing the seizing to a minimum, while keeping them from backing out (common here in Colorado).

 

[Miller88]

Since there is a bit of space on top, I think if I took the threads with me when I removed the bolts (I'd like to avoid that). Seems like I would be able to stick a longer bolt in and just use a nut and washer on the top to remove it.

It's still soaking in PB Blaster. Going to bring back the acetone and ATF tonight and spray it. Then more on to another penetrant. Heat.

Hopefully it will come out!

 

[md21722]

Watch out for stripping the threads out of the aluminum. It can be like getting the bolts out of the air compressor mount.

 

[Sidewinder CC]

If you do pull the threads out of the adaptor you can Helicoil them. M12x1.75.

Bolt is M12x1.75x25 MM

 

[Sidewinder CC]

Since there is a bit of space on top, I think if I took the threads with me when I removed the bolts (I'd like to avoid that). Seems like I would be able to stick a longer bolt in and just use a nut and washer on the top to remove it.

It's still soaking in PB Blaster. Going to bring back the acetone and ATF tonight and spray it. Then more on to another penetrant. Heat.

Hopefully it will come out!

If you do need to install a longer bolt you will need to drill out the buggered up holes to 13.5 mm (or 9/16"). Use self lock nuts.

 

[Miller88]

What are the odds that I snap the bolt head off and leave it in the transmission? Stripping the threads out of the aluminum wouldn't be good - but at least I could get the bolts out.

I was yarning on it pretty good and it wasn't coming. It is a 10.9 metric bolt, so should be reasonably strong.

 

[Miller88]

Sprayed them with penetrating oils (PB Blaster, ATF/Acetone) and they came right out! No airgun needed.


And I also feel stupid. Been throwing a ton of money at this thing trying to figure out driveline vibes and that's what it was.

The mount delaminated, so under power, the entire drivetrane would move over.

 

[Sidewinder CC]

Sprayed them with penetrating oils (PB Blaster, ATF/Acetone) and they came right out! No airgun needed.


And I also feel stupid. Been throwing a ton of money at this thing trying to figure out driveline vibes and that's what it was.

The mount delaminated, so under power, the entire drivetrane would move over.

Good work.

 

[djgrayxj]

Question from DJ?
Did you use Automatic Transmission Fluid then Acetone or ATF thinned with Acetone?

Originally Posted by Miller88
Sprayed them with penetrating oils (PB Blaster, ATF/Acetone) and they came right out! No airgun needed.

 

[cal]

When they get tight like that, I just impact them anyways. Maybe 40 transmission pulls, never had one even act like it wanted to break.

 

[Miller88]

Question from DJ?
Did you use Automatic Transmission Fluid then Acetone or ATF thinned with Acetone?

Originally Posted by Miller88
Sprayed them with penetrating oils (PB Blaster, ATF/Acetone) and they came right out! No airgun needed.

I mix the atf and Acetone in the spray bottle and spray on.

 

[djgrayxj]

Note from DJ
Thank You!

 

[Miller88]

I don't know if it's a mental thing or what, but I think it's the best I have used. We sprayed it with PB Blaster the night we tried it the first time, but after that, I had sprayed it with the ATF/Acetone every day of the week.

In the past, I used it to remove drums that had rusted to the hubs. Came back a week later and I just picked them off by hand.

When sprayed on rust, it kind of bubbles - I am assuming that's the capillary action "sucking" it in. Then the Acetone evaporates and you just are left with ATF on the threads, freeing them up.

I don't believe it's as destructive as PB Blaster, either. I've had it sitting in various spray bottles for well over a year now and it has not eaten through any of them. When I had PB Blaster in spray bottles, it would usually eat the spray mechanism up pretty quickly.

 

[djgrayxj]

Question from DJ
Do you have an approximate ratio for mixing the ATF with the Acetone?