popping sound during take off

[Motorhead350]

Ok here's a weird problem and hope someone could shead some light on this. When I put the throttle half way down the car makes a popping sound/ click. It's not from the engine. It sounds like the front suspension or maybe the differential. I can also hear it when it shifts from 1st to 2nd gear. Any takers? :confused: Also the rear end was taken apart to change the gear ratio and the little bolt couldn't come lose and is very stripped. This noise was around before we messed with it, but wasn't as loud at all.

[BillyGman]

You've left a lot to the imagination here. What do you mean that "the little bolt wouldn't come loose and is stripped"??? What bolt? The cross shaft bolt? And was it put back together with the stripped bolt? Please expain a little better, if you expect some answers that will be applicable. And BTW, if the popping isn't coming from your engine, then you should be able to rev it up while the transmission is in park w/out hearing any popping noise.

[MarauderMark]

I had a clicking noise from my rear once and this is what it was..
http://www.mercurymarauder.net/forums/attachment.php?attachmentid=38 15 Get it checed right away..

[Motorhead350]

I had a clicking noise from my rear once and this is what it was..
http://www.mercurymarauder.net/forums/attachment.php?attachmentid=38 15 Get it checed right away..
Thank you thats where I thought it was and that little bolt is in there too. The one you need to loosen to get the gear changed.

[BillyGman]

Thank you thats where I thought it was and that little bolt is in there too. The one you need to loosen to get the gear changed.That sounds to me like you're talking about the cross shaft bolt. But if it was stripped as you've stated, then a new one should've been used, and if it didn't thread into the differenetial properly, then the differential needed to be taken back out and tapped for new threads BEFORE everything was buttoned up to complete the gear change. So your comments suggest that the job wasn't done properly, or if it was done properly, then that bolt shouldn't be the problem at all.

My intention is to help you out if I can, but we need to be certain which bolt you're talking about. Unless you're talking about the fill plug being stripped. Is that what you mean? I'm not meaning to argue with you, I'm simply trying to understand what bolt you're talking about, so that I might be able to help you. :)

When the cover was removed to replace the fluid, did you see a loose bolt in there? And if so, was it a long thin one?

[Motorhead350]

When the cover was removed it was a little bolt you had to rotate the gear see. I was told it was the one bolt needed to get the process going. It was never taken out and the stock 3.55 is still in. I'm sorry I can't really describe where the bolt is.

[BillyGman]

When the cover was removed it was a little bolt you had to rotate the gear see. I was told it was the one bolt needed to get the process going. It was never taken out and the stock 3.55 is still in. I'm sorry I can't really describe where the bolt is.Okay, let's use the process of elimination here.....

There are only four types of bolts in the entire rear end of our cars, and they are as follows:

#1. The cover bolts. There are ten of them which secure the cover. I know that you're not talking about these, so we can eliminate these from this topic.;)

#2. The ring gear bolts. There are also ten of these, and they hold the ring gear on the differential. Since there are ten of these, you obvioulsy aren't talking about these bolts either.;)

#3. The differential bearing cap bolts. There are four of these two to the right, and two to the left. So we can eliminate these from this thread too since there are four of them.;)

#4. That leaves us with only one other bolt in the entire rear end. And that is the cross shaft bolt(aka "cross shaft bin retaining bolt"). There is only one of these in the rear end, and it threads into the differential, and no matter what ring & pinion gear ratio is used, this same bolt is still needed. In other words, although this bolt is removed during a gear swap procedure, it is also put back in place at the end of the job. It can be, and usually is, re-used unless for some reason it is damaged.

However, it must be installed again before the cover is put back on. It cannot be left out, or left untightened. And if it was in your case, then the installer failed to do the job correctly. Below is a sketch that I've taken right from the 2003 Ford shop manual that is for our cars. Look at number 3 in the sketch. That is this cross shaft pin retaining bolt that I am talking about.

So my question to you still stands. Is that the bolt you're talking about? And if so, was it out of the threaded hole when you removed the cover? I'm trying to figure out exactly how you know that it is "loose". Did you see it hanging out of the threaded hole, or has someone told you that it was? If it is, then look at the threads on the bolt. Are they stripped? If not, then you can simply thread the bolt back into the hole, and tighten it making sure that the cross shaft pin that it holds in place is not sticking out, and is flush.

I always use blue LOC-TITE thread locker on this bolt, so that it will not come loose. But if this bolt was out of the threaded hole and just laying somewhere in the rear end housing, then I strongly suggest that after you thread the bolt back into the hole, and retighten it, that you turn one of the rear wheels, or that you use some other means to rotate the entire ring & pinion gears to take a good look at the ring gear teeth to make sure that they weren't damaged at all.

[Motorhead350]

Thanks so much! It's NUMBER 3 THATS THE BOLT THATS STRIPPED AND WON'T COME OUT. By changing it and checking it out, will this solve the problem?

[BillyGman]

Thanks so much! It's NUMBER 3 THATS THE BOLT THATS STRIPPED AND WON'T COME OUT. By changing it and checking it out, will this solve the problem?Going by your very brief desciption, I'm assuming that you mean that the bolt turns counterclockwise, but it won't come out of the hole (right?). That sounds very odd to me. I can't imagine why it wouldn't come out. Even if the threads on the bolts are stripped, then it should slide out of the hole with a little persuasion using a pair of pliars or small vice grips.

So the fact that you haven't been able to remove it, indicates to me that there's something more going on here than meets the eye. If the bolt is turning counter clockwise, and yet it will not come out of the hole, then I suspect that the installer stripped it by overtightening it, and then used some type of adheasive to actually glue it into place!!!! But then again, if that were the case, then I would think that it wouldn't even turn.

It's difficult for me to determine what's going on with this w/out getting a look at it myself, which uinfortunately isn't possible over the net. You need to get a look at the threads of that bolt to determine what's really going on here. Have you tried yanking it out with pliars, or vice grips? Either way, this doesn't sound too good. At best, just the bolt threads are stripped. At worst, there are threads inside the bolt hole which are actually on the differential which are also stripped, and in that case, the threaded hole would need to be tapped, and I'd strongly recommend that the differential be removed for that since you wouldn't want metal shavings inside the rear end.

From what you've stated, the best thing that can happen here, is that you manage to remove that bolt, and you clearly see that the threads are either stripped or marred in some way, and you obtain a new bolt of the same size, and try and thread it into the hole, and it threads in there just fine. And if that happens, then I'd advise you to buy some of the BLUE LOC-TITE thread locker, clean the threads on the bolt real good, and apply the thread locker to the bolts right before you install it. Good luck. I wish you the best. Let me know how you do. And BTW, if that thread is stripped, and you had nothing to do with that, I would never trust the mechanic who did the last gear change to ever go near your car again!!!! I'm very curious as to what made you even begin to mess with this bolt in the first place since the gear swap was already completed? Was the bolt protruding from the hole? If not, what made you even turn it in the first place?

And as far as the "clicking" noise, all I can do is guess here w/out seeing it for myself, but my guess is that it isn't likely that the cross shaft bolt was causing that noise you heard unless the bolt fell completely out of the hole and was being ground up btween the ring & pinion gear teeth (in which case, that bolt being stripped would now be the least of your worries since it might have caused some serious damage to the ring & pinion gear teeth!). But w/out me getting a look at it for myself, I could be wrong about that, and maybe the noise was in fact due to the cross shaft pin itself moving back and forth since the retaining bolt was loose, and therefore was not holding the cross shaft pin in place. I hope that there isn't something going on with the "C"-clips being broken or lodged loose.

[JACook]

Thanks so much! It's NUMBER 3 THATS THE BOLT THATS STRIPPED AND WON'T COME OUT. By changing it and checking it out, will this solve the problem? Motorhead, please define what you mean by "stripped".
Are we talking about the threads being stripped, such that the bolt spins in it's hole, and won't unthread,
but can't be tightened either? Or are we talking about the head being rounded off, such that the bolt
cannot be loosened? The former is a Bad Thing, becase that bolt will work itself loose. The latter is
but a temporary nuisance, because it's not allowing you to get the rearend apart so's you can change
your gears.

Not that this line of questioning solves your problem, but it might help to clarify things a bit...

[BillyGman]

Motorhead, please define what you mean by "stripped".
Are we talking about the threads being stripped, such that the bolt spins in it's hole, and won't unthread,
but can't be tightened either? Or are we talking about the head being rounded off, such that the bolt
cannot be loosened? .AAAAAAAHHHH.....this^is a very good question, and should be answered FIRST!!! Are you sure that it's simply not the head of the bolt itself that is rounded off, and your socket is spinning on the bolthead? Because if that is the case, then you don't even need to be messing wih that bolt now, as long as it's secured in the hole and fully tightened.

[Motorhead350]

The stock gear is still inside. The bolt will not turn at all. The car was in an accident and they though the rear axel was broken so I assume they went in there. I watched as someone else tried to change the gears but couldn't get that bolt loose. They said someone was in there before and overtightened it. So no mod was done. We tried to get the bolt loose, but it's in the same place it was before we messed with it. Also they disconneced by driveshaft and put it back on. Thats were I think another poissible sound is coming from if they didn't connect it right or all the way. Could that also be it?

[BillyGman]

Thanks for the explanation....


since the cross shaft bolt is still tight, I don't see how any noise can be coming from that. I don't know if the driveshaft can be causing that noise. My gut reaction is to say no it isn't, but who knows? Maybe it can be that. I've heard other people on here state that worn or damaged universal joints (like the ones on the driveshaft) can cause popping noises although I've never heard that myself. So when it comes to that, I'm merely going by what I've read here.

As far as that bolt, it sounds to me like it will have to be drilled out. Which might not be an easy task since it has to be done with the differential in the rear end housing due to the fact that you cannot remove the C-clips from the axle ends, nor slide the axles out of the way in order to remove the differential from the housing until you remove that cross shaft bolt. If the bolthead itself is rounded off, and preventing you from being able to turn it, then you can try getting a pair of vice grips on it to turn it, but that may be a long shot. Otherwise it might have to be drilled, so an "EZ-out" screw extractor can be placed in it, and turned with a wrench to remove the remainder of the bolt. But if you do that, make sure that you do not break the EZ-out inside the hole, because those things are so hard, that it would have to be burned out with a torch to get it out of there!!!! And those EZ-outs are brittle, and do break!

BTW, have you tried reving up the engine a little bit with the transmission in park to see if you hear the popping noise then? because if you can, then it's the engine. ;)

[Motorhead350]

I haven't tried that, but thats a great idea. I'll try it today or tomorrow.