Mk4 IRS Question

[lewma]

All

I'm concerned that the amount of play on my IRS is too much. In the video below I'm able to move the hub by hand. Any idea if this is normal or do I have to dig deeper ?

Any insight would be greatly appreciated!!
Mark

https://photos.app.goo.gl/aNU4ye8B3w1iW0KT2

[edwardb]

No, it shouldn't move like that. Do you have the large nut on the end of the axle installed and tight as you can get it for now? You likely won't be able to get the nut to its full torque without the wheel/tire mounted, on the ground, brakes, etc. to hold it. But you should be able to get it tight enough to take up the slack. Looks like the bearings in the hub aren't seated.

[lewma]

Yep. I have that but at 250lbs torque. I wonder if I damaged the bearing when I removed the old lug nuts

[lewma]

Edwardb you're right. I looked back at my notes and I've not yet torqued down that axle nut. I swore I did but apparently not. Thanks again for your help

Stuff like this makes me wonder if I'm out of my depth building this car

[michael everson]

250 seems a bit tight. I think the manual says 175.
Mike

[Bob-STL]

Stuff like this makes me wonder if I'm out of my depth building this car

The answer to that is NO.

Same thing happened to me. We realized it on the drive back from Huntington Beach 2017. Furthermore, we fixed it in an Autozone parking lot....funniest thing car wouldn't move after we torqued the nuts....then realized it was still on the jack(we were pretty exhausted at that point).

Bob

[CraigS]

250 seems a bit tight. I think the manual says 175.
Mike

Crap I did mine at 250. Oh well, it's been fine for 1.5 years and about 20 autocrosses.

[edwardb]

Factory Five 2015+ IRS instructions for the CV axle nut: 98 ft/lbs then rotate 45°.

[rich grsc]

Factory Five 2015+ IRS instructions for the CV axle nut: 98 ft/lbs then rotate 45°.

WHAT?? The old IRS torque was 250# on that nut.

[michael everson]

Hmm Manual i looked at was 175

[Hotyacht]

WHAT?? The old IRS torque was 250# on that nut.

My manual says 180-200ft/lbs..........245-270Nm......maybe you read the wrong column?

[Mark Eaton]

Mine says exactly what Edwardb just said

[phileas_fogg]

The torque spec edwardb quotes is for the 2015+ IRS. (#1)

The 180-200 ft-lbs spec is from the F5 manual for the 80's Thunderbird IRS. (#2)

The 250 ft-lbs spec is Ford's OE spec for the 80's Thunderbird IRS. (#3)

I can see how #1 would be different; after all, it's for a completely different suspension. But why #2 and #3 are different I can't say.


John

[cv2065]

Mine says the same....98 ft/lbs., then rotate 45 degrees. Just got my manual yesterday. :)

[lewma]

Mine says the same.

Sorry to everyone for the fire alarm here. I should have 1) checked my notes and 2) checked the axle nut before running the flag up the pole ;)

[42Bfast]

Stuff like this makes me wonder if I'm out of my depth building this car

X2 The answer is NO, you are not.

Any build is a series of steps and processes. Your processes should help insure you did everything correctly.
(Ok, cannot help myself here, coming out of a 30 year career in aerospace manufacturing (Industrial Engineering and Finance.....strange mix) our processes were not just a check to see if we completed something, they were to insure the aircraft was built correctly and would be safe to operate,...thus, not being over dramatic, were of life and death importance.) (I think the same applies here)

The fact that you had notes demonstrated you have a process in place. This is good!
Continuous improvement mindset says we should test our processes periodically to make sure they are working.

Did your process work, no, and yes. Taking notes did not prevent you from missing the torque step. However, it did help you diagnose the problem once recognized.

Therefore, you don’t need to give up your project, just refine your processes.

The suggestion: We frequently used visual aids to help identify completed, or not completed steps. (Very important in multiple shift operations where the job is handed off to another person or crew. Equally important in our builds where it may be days, weeks, or months between steps.)

For torque, we used a stripe of paint that went from the rotation surface to the stationary surface, if possible.
You will see that process mentioned in some of the better build threads.

This process provides a quick confirmation the step was completed AND if the stripe goes from rotation surface to stationary surface, it provides a quick maintenance check that nothing has moved.

Thus, notes are good, visuals are better, notes and visuals combined are best practice.

Using good processes is a skill that can be learned and improved, just like any other new skill we learn in this wonderful endeavor of building our dreams. For many of us, THIS is why we build rather than buy!

Are you over your head? Absolutely not!!! Do you have some new skills to learn? Brother don’t we all!!!

Oh, another process we stressed was, If something doesn’t look right, stop,.... and ask.
Your process seems to be working quite well! And aren’t we all lucky to have such a wonderful source of willing experienced folks to ask!!

Hang in there! You’ll make this happen!