Engine mount bolts stuck

[Tom '74 911]

Is it OK to use an impact driver on these? They aren't budging and I'm putting enough pressure on them w/my socket that the engine mount crossbar is starting to bend - not bent yet, but I don't want to put too much more muscle into it. Any other tricks?

Also - is 58 ft.lbs. the correct torque for these and the trans. mounts? I couldn't find a value in my books.

Thanks,
Tom

[Hawks911]

Tom,

There is a lot of thread engagement with these bolts and the rolled boss of the cross-member. I'd recommend a good soak with penetrating oil to see if that might help before hitting it with the air gun.

Mike

[don911]

If your mount is flexing when you're trying to remove the bolt, make sure you check the weld on the mount. I had a stuck bolt and when I was trying to remove, I cracked the weld on the mount. The bolt never come out and I ended up breaking the end off the mount.

[the]

One of the best tools that you can have, that it seems almost no one does, is a cheap propane torch.

They are $10-15 at your local hardware store, they last 4-5 hours.

Put some heat on them and you'll be surprised how easily they come loose.

[911pcars]

After you remove the bolt, consider removing the internal threads, then use a nut/bolt arrangement as in earlier 911s. Without some means of holding the small end of the crossbar, the weld becomes stressed with repeated torque.

Sherwood

[Tom '74 911]

Thanks for the tips so far.

How does one PB blast these? Just from the top? I tried to get it from the bottom, but couldn't get enough access.

I do have a propane torch. I'll give it the heat next.

That's a good thought to convert it to the earlier set up.

So, an impact wrench - maybe not such a good idea?
and is the torque indeed 58 ft.lbs?

Thanks,
Tom

[MobileWrks]

Jack up the engine from the center with a floor mat or a mat to cushion it. Pre load it just untill the car is about to lift. Take a Reg size hammer & a LARGE punch, or if your good enough.. WACK the BOLT to shock it with the hammer. While preloaded zap it but "dont" hold it cause it will bend and break from the impact... Wack it again and zap.. By then it sould come off.. Works every time.. with No torch, or pb..
GOOD LUCK...

[Gunter]

Originally posted by 911pcars
After you remove the bolt, consider removing the internal threads, then use a nut/bolt arrangement as in earlier 911s. Without some means of holding the small end of the crossbar, the weld becomes stressed with repeated torque.
Sherwood

You can leave the threads.
My plan was to get a longer 12 x 115mm bolt and put a 12mm nut on the end but.............

I cannot get only 2; would have to order a case of 100.

Where to get just 2 of these 12mm bolts?

[Tom '74 911]

Originally posted by MobileWrks
Jack up the engine from the center with a floor mat or a mat to cushion it. Pre load it just untill the car is about to lift. Take a Reg size hammer & a LARGE punch, or if your good enough.. WACK the BOLT to shock it with the hammer. While preloaded zap it but "dont" hold it cause it will bend and break from the impact... Wack it again and zap.. By then it sould come off.. Works every time.. with No torch, or pb..
GOOD LUCK...

I thought for sure that this would work, but alas - they have not budged yet. I've wacked them w/a hammer and 1/2" socket extension, directly w/the hammer, impact driver, PB'd the tops. . . I'm out of ideas. I did try heat, but backed off when I started smoking the rubber air seal/flap. They seem pretty stuck. The trans. mounts came right out w/no issues at all. Anyone else have any other ideas? These bolts and one oil line connection at the oil tank are puttin' the hurt on me!

Tom

[sjf911]

Mine did the same thing. I finally had to put so much torque that the cross bar bent. They did come free but I had to replace the mount.

[911pcars]

Originally posted by Gunter
You can leave the threads.
My plan was to get a longer 12 x 115mm bolt and put a 12mm nut on the end but.............

I cannot get only 2; would have to order a case of 100.

Where to get just 2 of these 12mm bolts?

You still would end up with a bolt threaded into the crossbar with or without the nut. In this case, holding the nut while applying torque on the bolt head still won't prevent the crossbar end from bending while being torqued.

You could support the engine, then cut the bolt head off, then deal with removing the remaining threads after removing it.

Find an early crossbar mount to replace the current one.

I've run out of non-destructive ideas to remove this bolt.

Sherwood

[C4 Pazzo]

I recently had a similar problem with one of the engine mounts on my '70T. Propane wasn't hot enough, so I picked up an inexpensive MAPP torch (less than $30) and plumbers heat shield fabric. I doubled over the fabric and put it between the mount bar and the rubber seal. Got it good and hot and then hit a two foot break bar with the palm of my hand to break it loose. My mount bar isn't threaded through like yours, but it might be worth a try. I would guess you'd need to heat the mount bar, rather than the nut.

[slodave]

If nothing else and you end up breaking yours, you can always order a replacement from Rennline via Pelican...


Dave

[Tom '74 911]

I thought I'd post my final outcome. . . which was success! I've had a set of Wevo mounts ready to go in for a few weeks and it's been bumming me out that they've been just sitting in the box they came in for so long because of those stuck bolts. I'd been making attempts at least once a week using various methods including heat, PB Blaster, mild force, hammering and an impact gun - all to no avail.

This morning I decided to give it another go. My boys had been driving me crazy (2 & 5 yrs.) and my mother-in-law has been staying w/us for the past week - so I had plenty of aggression built up! I had reached the point where either the bolts were coming out, or something was going to be broken trying.

Something that I finally figured out today, was to spray PB under the mounts - before any jacking happened. I felt like I could wiggle the little spray straw in there and get it close to the bolt. I then jacked up the engine until the bolts were up proud of the top of the mounts and sprayed some more PB from the top. I repeated this up/down process a few times w/lots of hammering in between. Things weren't budging, and my frustration was simmering. So I finally used my jack handle as a breaker bar, applying firm, steady pressure (knowing I was willing to buy a new crossmember at that point helped!) and the suckers loosened up for me. There was some gravelly creaking and squeaking, but the mounts seemed to withstand the pressure w/out cracking or getting bent up.

Wow. That was a battle I'd like to not have to fight again for a long time. The Wevos are in, and I'm a happy guy! Hope the next person that finds this thread searching for answers, has an easier time than me!

Thanks for the tips,
Tom

[74-911]

Originally posted by Tom '74 911

Wow. That was a battle I'd like to not have to fight again for a long time. The Wevos are in, and I'm a happy guy! Hope the next person that finds this thread searching for answers, has an easier time than me!

Very timely thread Tom. I have new motor mounts sitting on the workbench and now know exactly how I will approach the task.

thanks,
Jack

[unimog406]

as they say "Don't force it... Get a bigger hammer!!"

[Howard M]

Hope you used plenty of anti-seize for the "next time".

[john70t]

Before starting the motor mount swap, it probably wouldn't hurt to partially suspend the engine using a a floor jack. The reason being, the original rubber mounts were probably sagging and putting load on the entire cross bar and attachment, which puts additional frition on the bolt assembly.

With air guns, sometimes it helps to give it a couple quick zaps tightening it to break the rust-bond int the threads, then loosen.
If it doesn't come off easy, cut the nut and bolt off with a die-grinder disk on a drill and just replace it. Make sure to use grade8 bolts (has a stronger shear strength than grade5.)

[usesay69]

Sure, i found it in May 15, 2019 and i gonna do just that on a Ford F150. Motor mounts bolts are dead stuck and i have spent months during the winter months to get it loose.

Thanks for this.

Originally Posted by Tom '74 911

I thought I'd post my final outcome. . . which was success! I've had a set of Wevo mounts ready to go in for a few weeks and it's been bumming me out that they've been just sitting in the box they came in for so long because of those stuck bolts. I'd been making attempts at least once a week using various methods including heat, PB Blaster, mild force, hammering and an impact gun - all to no avail.

This morning I decided to give it another go. My boys had been driving me crazy (2 & 5 yrs.) and my mother-in-law has been staying w/us for the past week - so I had plenty of aggression built up! I had reached the point where either the bolts were coming out, or something was going to be broken trying.

Something that I finally figured out today, was to spray PB under the mounts - before any jacking happened. I felt like I could wiggle the little spray straw in there and get it close to the bolt. I then jacked up the engine until the bolts were up proud of the top of the mounts and sprayed some more PB from the top. I repeated this up/down process a few times w/lots of hammering in between. Things weren't budging, and my frustration was simmering. So I finally used my jack handle as a breaker bar, applying firm, steady pressure (knowing I was willing to buy a new crossmember at that point helped!) and the suckers loosened up for me. There was some gravelly creaking and squeaking, but the mounts seemed to withstand the pressure w/out cracking or getting bent up.

Wow. That was a battle I'd like to not have to fight again for a long time. The Wevos are in, and I'm a happy guy! Hope the next person that finds this thread searching for answers, has an easier time than me!

Thanks for the tips,
Tom