BMR Tech Tip: Check those axle-to-spindle retaining nuts!

Demon Coyote said:

Hopefully I didn't over tighten them since I used the impact to put them on until they stopped moving. Took off the impact as soon as I saw them stop. When I checked the torque specs, the torque wrench clicked immediately at 150 ft-lbs.

Click to expand...

Risky. Impact guns are by no means created equal; the good ones can deliver SEVERAL HUNDRED ft/lbs. of torque...whereas maybe yours tops out at 175. Regardless, these nuts are one of several that should be tightened to a specification - which you only get reliably with a decent torque wrench.

Further - and please know that I am not accusing you, but - many people believe that if you put a torque wrench on a fastener that was secured by a tool other than that torque wrench (as you did) - and it clicks - you have verified the torque. Not so. All that does is verify that the fastener is AT LEAST that tight. But who's to say it isn't actually 25% or 75% or 150% HIGHER?

Very risky - not just for over-tightening, but also for stripped threads! Imagine how inconvenient THAT would be!

ronemca said:

Risky. Impact guns are by no means created equal; the good ones can deliver SEVERAL HUNDRED ft/lbs. of torque...whereas maybe yours tops out at 175. Regardless, these nuts are one of several that should be tightened to a specification - which you only get reliably with a decent torque wrench.

Further - and please know that I am not accusing you, but - many people believe that if you put a torque wrench on a fastener that was secured by a tool other than that torque wrench (as you did) - and it clicks - you have verified the torque. Not so. All that does is verify that the fastener is AT LEAST that tight. But who's to say it isn't actually 25% or 75% or 150% HIGHER?

Very risky - not just for over-tightening, but also for stripped threads! Imagine how inconvenient THAT would be!

Click to expand...

Yes I agree, I just didn't want to mess with it further in case I did mess anything up along the way.

The torque wrench we have is good for sure, so I trust it for sure. I'll just have to take some time out to redo the process and torque it to spec without using the impact at a high setting lol.

Wanting to get the toe link bearings anyway, I just ordered the Ford Performance kit that replaces both hubs/bearings and both knuckles, with the toe link bearings already installed in the knuckles. So spending more, but with any luck will take care of these bearing issues for awhile and will save some hassle with pressing toe link bearings in and out. With a discount code about $404 from AM. Part number M-5970-M

If anyone wants some OEM knuckles in good shape, PM me. Make you a deal on them . Same goes for my wheel bearings! Haha.

I find it interesting that they include the hubs with the knuckles for this kit; almost like they know the rear hubs are a maintenance item rather than a solid part that will last the life of the car. At least they're cheap.

My track guys keep spares on the trailer [MENTION=32628]DPE[/MENTION]

As in, like 3 per side spares. lol

Wow, ok! I guess they are just service replacement parts then. At least they had the common courtesy to make them relatively easily serviceable. I think I'd prefer they just make them better, but we don't always get what we prefer.

I would like to say „thanks“ to Kelly@BMR Tech for this thread and all the pieces of valuable information.

My 17 GT Convertible is 14months old with 15,000mls on it and some weeks ago I encountered the same problems with a loose spindle nut (left rear) and a damaged wheel bearing.

The only difference was, that I first noticed it while driving the A3 Autobahn in Germany between Würzburg, Kassel and Hannover (for all the folks who maybe know that Autobahn section) at speeds between 140 and 150mph. Yes sirs, miles per hour, not kilometers.

I wondered why I had severe problems in keeping the car in the left lane while I noticed the left rear suspension pumping wildly in one of the tighter curves. My guardian angel and me managed to avoid hitting something, and stopping the car at the next autobahn station for a quick check. Back at home I found out that the left rear wheel had a play of more than 1cm, worse than in most YouTube videos of bad wheel bearings.

It felt like having a big hole where the stomach used to be when I saw this and remembered me fighting for staying on the road.

At the dealers, they ignored the Ford rule of applying 133Nm (=98 ft lbs) plus 45 degrees to the spindle nut. Instead of that they did it the same way as Kelly mentioned, which is 200Nm (=150 ft lbs) plus 45 degrees.

Without knowing of this forum or this thread they told me that they got experience with Mustangs with loosened spindle nuts and that the higher torque figures will solve the issue with the loosened spindle nuts and destroyed wheel bearings.

Still, I'm quite concerned whether a higher torque of 200 Nm + 45° = 150 ft lbs + 45° will put a harming preload to the wheel bearings. Some other guys keep telling this and the Ford MoCo instructions point it out the same way since Ford still says: 98 ft lbs + 45° !
I haven't studied a technical drawing of the bearing hub nor could I inspect the old bearing for that until now, so I don't know what's right.

Anyone here with additional help/info if there is a bigger bearing preload by giving it 150 ft lbs instead of 98 ?
And if so, does this harm the bearings ?

These are the two questions I'd like to have answered before installing new rear bearing hubs, a new left halfshaft and a pair of new spindle nuts.

My personal view is, that this wheel bearing hub/spindle nut construction is really dangerous and I can‘t understand why a car with a bug like this got an approval for driving it at high speeds. It may be okay for the US with its widespread (sometimes quite low) highway und interstate speed limits, but for us here in Germany it's a different thing. If a car is going 155mph, it will be occasionally driven by most drivers with that speed when there's an autobahn without a limited section. Any car has to withstand it and bring back the driver home safe and sound.

Don't get me wrong, my 2017 GT convertible Mustang (EU spec=premium+performance package) is a dream come true for me and I will keep the pony for hopefully many years coming, but...... the last time when I had a wheel bearing going bad was in the late 80s as the 6th or 7th owner of a rundown car from the early seventies (when I was young and needed the money ;-) ) .

It's nothing I can accept on a 2017 car going 155mph (limited) and with a price tag of more than 63,000 $ (todays exchange rate).
A modern car‘s wheel bearings should last 50,000mls or more and not letting the wheel go loose after only one year of normal street driving, much of it at slow cruising speeds with the top down and the wife on board.
Espescially on a car with so much power and high velocity capability.
Right at this moment I‘m a bit pissed about bad quality and dangerous details.
Could have been dead right now and that‘s nothing I like.

Thanks for all the Information here :clap2:

OK, here is my input to the thread.

About 2 months ago I had to replace the rear wheel bearings. Used OEM Ford kit. New bolts supplied with the kit and torqued to factory spec.

Ever since then had an ever worsening click problem from the axle.

I finally went and ordered a new set of bolts from my European Ford dealer.

Part number:



They look quite different to the parts that came off:

Top (new), bottom (old)



The new ones dont have the retained washer of the old ones.

Now torqued up to the BMR specs with Loctite. Problem is gone!

Now to see if it comes back.

Anyone know why the design has changed so radically on the bolts?

kapiteinlangzaam said:

OK, here is my input to the thread.

About 2 months ago I had to replace the rear wheel bearings. Used OEM Ford kit. New bolts supplied with the kit and torqued to factory spec.

Ever since then had an ever worsening click problem from the axle.

I finally went and ordered a new set of bolts from my European Ford dealer.

Part number:

They look quite different to the parts that came off:

Top (new), bottom (old)

The new ones dont have the retained washer of the old ones.

Now torqued up to the BMR specs with Loctite. Problem is gone!

Now to see if it comes back.

Anyone know why the design has changed so radically on the bolts?

Click to expand...

That's odd.
The (new) axle retaining nut in your picture is what I got when I ordered new axle nuts back in November when I swapped in the 3.55 pumpkin into my '17. No noise / clicking etc here and that was 10K miles ago.

So I read that a lot of people have the issue coming back even after using Loctite and 150 ft-lbs torque spec. Since the popping on my driver side is really bad, I was thinking if replacing the nuts and retorquing would help considering so many other stated that the issue comes back.

One thing I know from empirical testing at work is that if you get even the slightest amount of oil into the thread locker, the holding force of the product falls significantly. I mean it basically feels like as if there was no thread locker whatsoever on the mating threads. This may be more significant with smaller thread size fasteners than larger thread sizes since if you had the same amount of contamination on both large and small threads, the ratio of contamination would be larger for a small thread compared to a small thread.

My plan is to take the new nuts that I have and get the green thread locker completely off the nut. I will get some Loctite primer (Loctite 7649) and liberally clean up the male thread on the axle-shaft and the female thread on the nut to ensure there is no oil contamination. Then I will use Loctite 272 (red) and torque the nuts down with 150 ft-lbs + 1/8th of a turn. I will let the thread locker have at least 24 hours to cure before driving the car again.

I will report back with results once I get this tested out!

Knock on wood, still not a peep here...

kapiteinlangzaam said:

OK, here is my input to the thread.

About 2 months ago I had to replace the rear wheel bearings. Used OEM Ford kit. New bolts supplied with the kit and torqued to factory spec.

Ever since then had an ever worsening click problem from the axle.

I finally went and ordered a new set of bolts from my European Ford dealer.

Part number:

They look quite different to the parts that came off:

Top (new), bottom (old)

The new ones dont have the retained washer of the old ones.

Now torqued up to the BMR specs with Loctite. Problem is gone!

Now to see if it comes back.

Anyone know why the design has changed so radically on the bolts?

Click to expand...

Let me ask this, as I’m not able to confirm from the angle of the pic showing the new and old retainer nuts... with the new design, is the hole slightly oval instead of being perfectly round? I think the proper terminology for such a nut is “jam nut” or a “locking nut”.

I’m only offering an educated guess that the new design could be a single-use jam nut. Most jam nuts or lock nuts are designed so the top of the opening is very slightly ovaled, so slight that sometimes it’s not detected by the eye. When such a nut is torqued onto a stud (or in this case the axle shaft), it “locks”. The design and purpose of that type of nut is so it won’t and can’t come loose or back off during regular (or extreme use).

Cobra Jet said:

Let me ask this, as I’m not able to confirm from the angle of the pic showing the new and old retainer nuts... with the new design, is the hole slightly oval instead of being perfectly round? I think the proper terminology for such a nut is “jam nut” or a “locking nut”.

I’m only offering an educated guess that the new design could be a single-use jam nut. Most jam nuts or lock nuts are designed so the top of the opening is very slightly ovaled, so slight that sometimes it’s not detected by the eye. When such a nut is torqued onto a stud (or in this case the axle shaft), it “locks”. The design and purpose of that type of nut is so it won’t and can’t come loose or back off during regular (or extreme use).

Click to expand...

It's referred to as a torque prevailing nut. I do not believe that's what it is.

My clicking noise returned after about 2 days / 200 miles. And then it was worse than ever.

The final fix was to replace the half-shafts. The UJ/CV joints were toast.

There are two distinct problems at play here.

1) Simple loose retaining nuts solved by the BMR method.

2) Bad half-shafts... it seems that over-tightening the bolts will hide the symptoms for a short time, but then return.

If you tighten to the BMR specs and the noise either doesnt go away or quickly returns, then be prepared to change your half-shafts.

I went for Ford Racing OEM GT350 items. V. good value (before intl shipping and taxes, LOL)! Been driving with a clicking car since February this year, finally solved last week.

kapiteinlangzaam said:

My clicking noise returned after about 2 days / 200 miles. And then it was worse than ever.

The final fix was to replace the half-shafts. The UJ/CV joints were toast.

There are two distinct problems at play here.

1) Simple loose retaining nuts solved by the BMR method.

2) Bad half-shafts... it seems that over-tightening the bolts will hide the symptoms for a short time, but then return.

If you tighten to the BMR specs and the noise either doesnt go away or quickly returns, then be prepared to change your half-shafts.

I went for Ford Racing OEM GT350 items. V. good value (before intl shipping and taxes, LOL)! Been driving with a clicking car since February this year, finally solved last week.

Click to expand...

Honestly, I was weighing my options. I remember someone mentioning a while ago that replacing the half shafts fixed their issue also. It's either do that or try the nuts out, but I have a feeling that it's the half shafts too.

So the GT350 shafts fit without issue by the sound of it?

mindys said:

Honestly, I was weighing my options. I remember someone mentioning a while ago that replacing the half shafts fixed their issue also. It's either do that or try the nuts out, but I have a feeling that it's the half shafts too.

So the GT350 shafts fit without issue by the sound of it?

Click to expand...

Yes new half shaft was the fix.