removing rear subframe bushing pins stuck....can i freeze them?

[blockerb]

I have a 1986 528e automatic. stock.

situation:
I am trying to replace rear subframe bushings with OEM bushings. I proceeded to drop the subframe a bit and tried to pound out the pins as i was going to just replace with new pins and locknuts. I got the passenger side pin removed with about 10-12 whacks and started trying to get the driver side out. No love. The thing won't budge. I had even sprayed a bunch of PB blaster where the pin is under the read seat a week earlier. To further complicate, i forgot to thread the locknut back on before banging on it and damaged the threads a lot in the process, I mean i really whaled on it for a while! So I have to get it out not so i can replace with the new pin.

Here's my question:

I've read about several methods including "rifle drilling" from the top of the pin to allow it to compress some when banging it out. also read about a method to basically use a jack to put load on the underside of the pin and bang on it from the top from inside the car. In conjunction with this, I thought about using "CRC Freeze-off" and spraying into the hole from drilling the head of the pin. My thought is that this would cause the pin to contract a bit from the cold and expand once thawed and possibly loosen any corrosion, etc. that is making it seize up.

Anybody tried this or other methods that worked?

Sidenote - I called a shop here in Atlanta to see what they said and the guy there said he thought those pins were welded in. but i was about the get the other one out and clearly not welded. I'm fairly certain that these aren't welded in.

[jayjaya29]

I had to drill the top of my passenger side pin out to get it release.

[blockerb]

interesting and that worked? and you pounded it out from below after that?

How far/deep did you drill?

I was going to get a 3/8" metal drilling bit and just slowly drill down through the center a little beyond where the splines start.

[jayjaya29]

Been 4 years since I did the job but I do remember drilling quite far down (just a standard drill bit length). I didn't want to risk damaging the sleeve by using too large of a drill bit.

I also used a torch inside the car and under to try to expand the sleeve. I think I also placed the weight of the car onto the pin too at one point and hammering from above.

Keep at it, it'll release eventually.

They are not welded in.

[Mike W.]

If you're going to drill it, start with say an 1/8 inch bit, and center punch it so you can get it started in the middle and not walk. Then progressively go up in size probably to 1/2, I mean it's a 14MM which is 9/16, I doubt 3/8 would be large enough to do any good. Really if you can drill the head off that would be ideal, it's a lot easier to pound down with a hand sledge than pound up over your head. Look at the one you have out to get a better idea of it's full size and shape. But go up in sizes, start with 1/8, then maybe 3/16, etc. Slow with lots of spray to keep it cool, I'm not a big WD40 fan, but anything like that to keep the drill bit cool. If it still doesn't want to come out with the head off, maybe stick a piece of pipe under the bottom, sleeving the bolt pressed against the bushing center sleeve so you've got something solid to hammer against.

While good in theory, I don't think trying to chill it would do any good, I think there would be too much heat/cold transfer if you could get it cold enough. Heat expands both parts, but a propane torch is close to 2,000F, or 1900 degrees hotter than ambient, using a spray to cool it I doubt you would get the body of it even 50 degrees cooler.

[4DSC]

I had this exact same issue with both sides and tried it all. PB blaster weeks ahead, drilling, 4lbs sledge, using the weight of the car. Would not budge. Finally got it with a bigger sledge. Get the car up as high as you can and get a 7/8+lbs sledge and go at it from below with as big of swing as you have space for with the nut threaded on the bottom. I was sweating like a pig but after 10-15 hard swings they finally broke free. Keep at it and I bet you'll get it. Good luck.

[thrty8street]

I had the same issue when I recently did my subframe bushings. I hit the pins several times with a heavy sledgehammer and they would not budge. The solution was to tap the pins with light to moderate force on the sides to loosen the pins. They came out easy after that. Good luck!

[gadget73]

I've always found an oxy-acetylene torch to be an excellent penetrating lube. Get the thing a nice bright red and give it a go with an air hammer.

Cheater trick for keeping air hammers on pins, find a short length of pipe just large enough inside to slip over whichever part is larger so the air hammer basically has to stay positioned over the pin. Use a pair of vise grips as a handle.

[Shawn D.]

Drilling has been the solution that worked best for me, on two different cars.

[Blue Shadow]

I had the same issue when I recently did my subframe bushings. I hit the pins several times with a heavy sledgehammer and they would not budge. The solution was to tap the pins with light to moderate force on the sides to loosen the pins. They came out easy after that. Good luck!

Having done a couple cars a number of years ago and swinging that small sledge it seems to make sense that the side taps would loosen the pins. We just kept swinging at them and all four eventually popped out. Put a sacrificial nut on the end of the pin and hit away to have it pop up.

Rocking the pin in its splined seat should loosen it enough to get the pin to pop. I don't think these get a lot of rust holding them in place.

[gwb72tii]

You do not need to remove the pins to replace the bushings. I just did this very job on Maeve,
You can remove the pin nuts, jack the car up with the stock jack, and then loosen the diff carrier screw that will allow the rear subframe to slide off the pin. It takes a little coaxing but it is doable.
Then you''ll need a proper bushing removal/installation tool and it is easy peasy.

https://www.mye28.com/viewtopic.php?f=2 ... &start=325

[Mike W.]

You do not need to remove the pins to replace the bushings. I just did this very job on Maeve,
You can remove the pin nuts, jack the car up with the stock jack, and then loosen the diff carrier screw that will allow the rear subframe to slide off the pin. It takes a little coaxing but it is doable.
Then you''ll need a proper bushing removal/installation tool and it is easy peasy.

https://www.mye28.com/viewtopic.php?f=2 ... &start=325

I agree, the sawzall method I used seems way too easy, 2-2.5 hours for both sides. I was all braced up for a fight and a little disappointed that it was so easy. But OP mentioned he's already mushroomed the studs so I'm thinking he's past that point.

[Blue Shadow]

But OP mentioned he's already mushroomed the studs so I'm thinking he's past that point.

Unfortunately he forgot to put the nut back on as he said.

Need that nut to protect the threads, easy to get another nut. Pin is about 12 bucks new and a trip to a dealer and a wait for delivery from them or online purchase.

Looking for answer on the hitting the pin from the side a few times to loosen its grip on the chassis...if I ever need to do mine again.

[blockerb]

Updated and successfully removed the stubborn pin and bushings.

for the stubborn pin - drilled out a porting of the head of the bolt which, I guess, relived some of the tension around the edges of the head allowing my PB blaster to seep down in there. It wasn't seeping before. Also took as smaller "chisel's shaped" tool like whay you may use for masonry with a hammerdrill, and used that and a small hammer to tap around the sides of the exposed pin shaft. So next day after about 5-8 good whacks the pin came out.

For the bushings - did as Mike W. suggested and jacked up the car and supported with jack stand at the jacking points on each side and removed the differential moutning bolt so the subframe dropped a good bit. USed an aftermarkte removal/install tool to remove and install the new bushings.

Thanks for the feedaback and help.