Subframe bolt help

[Mister_Fisterr]

There is a locked thread from 2021 regarding the rear subframe bolts not threading in all the way and I'm having the EXACT same issue and it is driving me mad.

https://www.fiestastforum.com/threads/subframe-bolt-wont-go-in-the-whole-way.27428/

Basically the two 18mm rear subframe bolts will not screw in - they're meeting a ton of resistance once wrenched maybe halfway in. So far I've been using pry bars and punches to attempt to align the holes well enough to finally get the bolts started. I even resorted to using my impact wrench in hopes that it would eventually go in but even with that, it is not threading in all the way. I am planning to find time to back it back out and attempt to somehow restart fresh. I even bought new bolts, hit the frame thread with PB blaster, aligned with a punch, and more. The only thing I can think of is the hole not being aligned enough to thread in easily; but even aligning the subframe holes has been super tricky for me. I honestly do not think it is a threading/stripping issue because even before I attempted with the impact wrench, they were having trouble, and when backing them out initially they did back out slightly unevenly/wobbly but I wonder if that was from me removing too many subframe bolts at once (my mistake). Any information anyone can help me out with here? I'd really appreciate any help or info

 

[arlisscm]

My guess would be the same as yours, misalignment. Because the subframe holes are sleeved (so the bolt doesn't crush it) and the fit to the bolt is fairly snug, it doesn't take much to get boltbound.

Visually it may look lined up, but you have to make sure it is good in all radial directions as well as angularly.

What I have done in the past is offer the subframe up to the car close with the jack, got the 4 bolts (2 big ones in the rear, and two small ones up higher and to the sides) started a few threads loosely (may have to jiggle the subframe around), then used the jack to get the subframe fully seated up against the chassis (the 4 stared bolts should help guide it to the right spot). Then check to see if everything threads freely, if not, keep it held in place and take out one or more of the bolts and look up through to see how the alignment is, then you can adjust the position with a few smacks with a dead blow hammer or softer mallet.

I added the Whoosh subframe alignment bushings some time ago, which makes it harder and easier at the same time. Harder because the fit is so tight you can't be off at all, but also easier because once you can get the bolts started, you're good to go.

 

[Mister_Fisterr]

My guess would be the same as yours, misalignment. Because the subframe holes are sleeved (so the bolt doesn't crush it) and the fit to the bolt is fairly snug, it doesn't take much to get boltbound.

Visually it may look lined up, but you have to make sure it is good in all radial directions as well as angularly.

What I have done in the past is offer the subframe up to the car close with the jack, got the 4 bolts (2 big ones in the rear, and two small ones up higher and to the sides) started a few threads loosely (may have to jiggle the subframe around), then used the jack to get the subframe fully seated up against the chassis (the 4 stared bolts should help guide it to the right spot). Then check to see if everything threads freely, if not, keep it held in place and take out one or more of the bolts and look up through to see how the alignment is, then you can adjust the position with a few smacks with a dead blow hammer or softer mallet.

I added the Whoosh subframe alignment bushings some time ago, which makes it harder and easier at the same time. Harder because the fit is so tight you can't be off at all, but also easier because once you can get the bolts started, you're good to go.

Thank you so much for your helpful reply. That is exactly what I've been trying to do, add the Whoosh subframe kit. It's been a huge headache. I'll try to do what you've recommended, but so far I have the front two bolts hand-threaded in, and have the jack underneath the center of the subframe, and getting the rear to line up from there has been the issue. I'll see if I can get it to center better with a dead blow, but it hasn't budged from what I've tried so far. Think I should remove pressure from the jack completely?

 

[arlisscm]

Thank you so much for your helpful reply. That is exactly what I've been trying to do, add the Whoosh subframe kit. It's been a huge headache. I'll try to do what you've recommended, but so far I have the front two bolts hand-threaded in, and have the jack underneath the center of the subframe, and getting the rear to line up from there has been the issue. I'll see if I can get it to center better with a dead blow, but it hasn't budged from what I've tried so far. Think I should remove pressure from the jack completely?

You can relieve pressure to make it easier to move around, sure.

I typically use my transmission jack on the subframe so I can tilt it front to back and/or side to side, so this may make it a bit easier for me. Also, I have a Pierce 6 point brace that I leave attached to the subframe, so it gives me a point further forward to place on the jack.

I haven't actually tried putting the subframe back up in without the brace or transmission jack, so what you are facing may be much more difficult.

I would leave the front two bolts started (not snug or tight, just started) and lower the jack just a small amount so you can move the subframe around, then maybe bust out the punch again and use it to align one of the rear holes as you jack the subframe back up.

If you manage to get one of the rear bolts started, make sure all four connection points of the subframe are flat/seated against the chassis.

As a side note, the TTY on the large rear bolts isn't a super fun time. I usually use a 3/4" drive ratchet with a cheater bar and have to pin myself in place wedging my foot/feet against the jack stands so I don't just slide across the floor rather than turning the bolt..

 

[Mister_Fisterr]

You can relieve pressure to make it easier to move around, sure.

I typically use my transmission jack on the subframe so I can tilt it front to back and/or side to side, so this may make it a bit easier for me. Also, I have a Pierce 6 point brace that I leave attached to the subframe, so it gives me a point further forward to place on the jack.

I haven't actually tried putting the subframe back up in without the brace or transmission jack, so what you are facing may be much more difficult.

I would leave the front two bolts started (not snug or tight, just started) and lower the jack just a small amount so you can move the subframe around, then maybe bust out the punch again and use it to align one of the rear holes as you jack the subframe back up.

If you manage to get one of the rear bolts started, make sure all four connection points of the subframe are flat/seated against the chassis.

As a side note, the TTY on the large rear bolts isn't a super fun time. I usually use a 3/4" drive ratchet with a cheater bar and have to pin myself in place wedging my foot/feet against the jack stands so I don't just slide across the floor rather than turning the bolt..

I was doing all the work myself so far, so once I had my left hand using a pry bar to pry forward from the rear of subframe to where I felt it was enough-aligned, I tried hitting it with the 1/2 impact wrench and was so surprised it wasn't getting in...

Your tips are so helpful so far. I think getting a punch to pry one of the rear holes into place and then jacking it up from there sounds like a really good idea.

I've read so many mixed messages all over the internet so far, most saying the rear bolts (the 18mm ones) AREN'T TTY bolts (the entire body of the bolt is threaded so this could make sense), but that only the front, e12 bolts are TTY. Of course, I only bought new 18mm bolts for the rear; was going to re-use the front ones.

You're right about the insane torque needed to get those rears to sit (the ones I'm having trouble with so far). Do you think it's simply just that I'm not applying enough torque to truly even get them in? They are thick bolts...

But I was hitting it for quite a while with the impact and they were literally starting to stop turning...

 

[arlisscm]

I was doing all the work myself so far, so once I had my left hand using a pry bar to pry forward from the rear of subframe to where I felt it was enough-aligned, I tried hitting it with the 1/2 impact wrench and was so surprised it wasn't getting in...

Your tips are so helpful so far. I think getting a punch to pry one of the rear holes into place and then jacking it up from there sounds like a really good idea.

I've read so many mixed messages all over the internet so far, most saying the rear bolts (the 18mm ones) AREN'T TTY bolts (the entire body of the bolt is threaded so this could make sense), but that only the front, e12 bolts are TTY. Of course, I only bought new 18mm bolts for the rear; was going to re-use the front ones.

You're right about the insane torque needed to get those rears to sit (the ones I'm having trouble with so far). Do you think it's simply just that I'm not applying enough torque to truly even get them in? They are thick bolts...

But I was hitting it for quite a while with the impact and they were literally starting to stop turning...

I've dropped the subframe 4 times now, and each time i was able to snug the bolts up into place with a 3/8 or 1/2 drive ratchet with minimal resistance. So, if a 1/2 impact is struggling I would imagine something is wrong.

TTY or not, the 270 degrees on the rear bolts is a PITA. haha. I've got a stock of subframe bolts on the shelf since I replace them each time (think I reused the fronts the first time). I'll likely replace them with studs at some point and just math out what to torque them to without the angle and/or TTY stuff.


Since you have tried running them in with an impact and hit a hard stop, are you able to see any witness marks from where the bolt was rubbing?

Alternatively, have you checked to see how the bolts thread in with the subframe out of the picture?

 

[Mister_Fisterr]

I've dropped the subframe 4 times now, and each time i was able to snug the bolts up into place with a 3/8 or 1/2 drive ratchet with minimal resistance. So, if a 1/2 impact is struggling I would imagine something is wrong.

TTY or not, the 270 degrees on the rear bolts is a PITA. haha. I've got a stock of subframe bolts on the shelf since I replace them each time (think I reused the fronts the first time). I'll likely replace them with studs at some point and just math out what to torque them to without the angle and/or TTY stuff.


Since you have tried running them in with an impact and hit a hard stop, are you able to see any witness marks from where the bolt was rubbing?

Alternatively, have you checked to see how the bolts thread in with the subframe out of the picture?

Yeah, it seems something is indeed wrong. I may actually use the same original rear 18mm bolts since all I did was back them out and they both came out cleanly although they didn't necessarily back out straight the entire time, that began to sway a bit at the end of removal. I didn't see any signs of thread damage on either bolt. I'm really really hoping all that is occuring is the bolt binding on entry due to me not having it aligned well.

Regarding the witness marks, I actually haven't been back to the car in 2 days now because I work night shift and won't have time to take a look at everything again until Thursday or Friday.


I was thinking about hitting both the bolt and threads with a little PB blaster to remove the tiny bit of rust present and start fresh with all the good advice you've shared so far.