View Full Version : CV Axle Nut torque…..how often?
Had the vehicle on jacks and noticed both rear wheels had minimal movement. For reference, whether you hold the wheel at 6 and 12 or 3 and 9, you can rock the wheel slightly. I’ve had the car a few years now and never noticed the issue prior. It’s a Mark 3 with the IRS so I suspect it’s the older T bird set up. Does the axle nut loosen ever, or is there something else I should be looking at. Not much of a suspension person so any advice would be appreciated. Thanks
rich grsc
03-04-2023, 09:59 PM
The axle nut wouldn't be the cause of wheel movement. If you have excessive movement, the hub bearings would be where it would show up.
edwardb
03-04-2023, 10:01 PM
A Mk3 with IRS will be the older T-Bird setup. The current setup was introduced in 2015 during the Mk4 run. Yes, your version can have issues with the axle nut loosening. So definitely something to check. Now and as part of your ongoing maintenance going forward. For the actual movement, it's not usual for there to be a slight amount of back and forth movement of the back wheels when elevated. Reflects gear lash in the diff and also perhaps in the trans if in gear.
A Mk3 with IRS will be the older T-Bird setup. The current setup was introduced in 2015 during the Mk4 run. Yes, your version can have issues with the axle nut loosening. So definitely something to check. Now and as part of your ongoing maintenance going forward. For the actual movement, it's not usual for there to be a slight amount of back and forth movement of the back wheels when elevated. Reflects gear lash in the diff and also perhaps in the trans if in gear.
Sounds good. I will tighten….from what I’ve read here is 98 lbs plus 45 degrees. Thank you.
MSumners
03-04-2023, 10:27 PM
A Mk3 with IRS will be the older T-Bird setup. The current setup was introduced in 2015 during the Mk4 run. Yes, your version can have issues with the axle nut loosening. So definitely something to check. Now and as part of your ongoing maintenance going forward. For the actual movement, it's not usual for there to be a slight amount of back and forth movement of the back wheels when elevated. Reflects gear lash in the diff and also perhaps in the trans if in gear.
I am not an expert on this whatsoever but worried the OP is referring to looseness laterally in the wheel not front-to-back.
That’s correct. Not forward - reverse, but more in and out if that makes sense.
edwardb
03-05-2023, 06:40 AM
Sounds good. I will tighten….from what I’ve read here is 98 lbs plus 45 degrees. Thank you.
That's the spec for the newer 2015+ IRS setup. Your version is a straight 250 ft/lbs. This older thread on the other forum discusses axle nuts on your setup in some detail. https://www.ffcars.com/threads/check-your-irs-axle-nuts.291159/page-4
That’s correct. Not forward - reverse, but more in and out if that makes sense.
Ok, different than what I was talking about. In/out is definitely concerning. If the axle nuts are to spec, something else is wrong, e.g. maybe bearings? I have no experience with your version IRS. But shouldn't do that.
CraigS
03-05-2023, 07:57 AM
It was fairly common for the T-bird IRS to have the nuts work loose. Stickier tires and autocross were particularly hard on it. That's what happens when you use things that were designed for ride comfort on 6 in wide tires. No big deal though. Just torque them back tight. I would probably loosen the nut 5-6 turns and work some gear oil into the threads and on the back side of the nut where it contacts the hub. A given # of torque will actually tighten the assembly tighter when it is well lubed because you lose less of the torque to overcoming friction. Then TQ. You can put a paint mark on the nut and another on the hub so you can see if it moves. Much easier than retorqueing only to find it hadn't loosened.
MPTech
03-05-2023, 10:14 AM
I am experiencing the exact same issue right now. I jacked up my roadster to remove the rear wheel and noticed a wobble. I have an early MK4 with the T-Bird IRS. If you grab the tire @ 3 and 9, and the right hand pushes in while the left hand pulls and vice-versa, that sounds like a bearing issue (not rotational).
I removed the T-bird axle carrier (3 bolts) and took the whole unit and a new bearing to a local machine shop. He charged me $65 to press out the old bearing and install a new one.
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