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-   -   Loose lower arm bush bolts (https://www.the75andztclub.co.uk/forum/showthread.php?t=327819)

Matt_75 29th April 2024 20:47

Loose lower arm bush bolts
 
Back in January, at 77000 miles, I had an MoT test done which noted play in the offside front lower arm ball joint. I did have a slight knocking noise over rough ground which I attributed to this and planned to replace both arms and bushes once the weather improved.

Anyway, the car is now on 79000 miles and in the last 50 miles or so the knocking noise has developed quite rapidly into a severe knock and rattle, so bad that I haven't used the car in about a week. I assumed this was the ball joint finally giving up although was confused at it sounded like it was on the nearside...

I ordered a pair of arms and bushes and today set about replacing them. Upon removal I found that one of bolts holding the nearside bush was finger tight and the other was half way out! :eek:

Has anyone ever heard of these working themselves loose?

The lower arm itself looks to be original (it has a Rover part number and 2001 manufacturing date) but the bush looks to have been replaced in the not too distant past. Unfortunately my car came with only part service history and I have no record of this work being done but it definitely doesn't look 23 years old.

My guess is that the mechanic only nipped the bolts up and intended to fully tighten them later, but forgot.

The job is on hold however as I forgot to order new bolts and being single use and finding them loose, I wasn't prepared to risk using them again!

daveo138 29th April 2024 21:49

ISTR from reading the various ‘how to’ guides on this job, everyone says to do the bolts up as tight as you can. I believe it’s not unheard of for them to come loose.

SD1too 30th April 2024 06:00

Quote:

Originally Posted by Matt_75 (Post 2994917)
My guess is that the mechanic only nipped the bolts up and intended to fully tighten them later, but forgot.

Hi Matt,

The problem is that a socket and torque wrench cannot be used on at least one of those bolts without removing the nearby anti-roll bar saddle clamp. The bolts for that are recessed with a non-standard size head, smaller than you'd imagine and probably rusted in. However, with the right tools and patience it can be done. You've found out what can happen when someone thinks that a torque wrench is unnecessary. ;)

Unless damaged, the existing bush housing bolts can be re-used. There's no need for new ones.

Simon

Matt_75 30th April 2024 06:55

Quote:

Originally Posted by daveo138 (Post 2994922)
ISTR from reading the various ‘how to’ guides on this job, everyone says to do the bolts up as tight as you can. I believe it’s not unheard of for them to come loose.

The torque spec is 155Nm but access isn't great, so I can see why people would just do them up as tight as they can. Last time I did this job (on a different 75) I did manage to get a torque wrench on them, but it was a bit of a pain!

Matt_75 30th April 2024 07:06

Quote:

Originally Posted by SD1too (Post 2994926)
The problem is that a socket and torque wrench cannot be used on at least one of those bolts without removing the nearby anti-roll bar saddle clamp.

Last time I did this job (on a different 75), that's exactly what I had to and I've done the same this time too. Personally I couldn't manoeuvre the lower arm out without having the anti-roll bar loose.

Quote:

Originally Posted by SD1too (Post 2994926)
Unless damaged, the existing bush housing bolts can be re-used. There's no need for new ones.

The Rover manual that I have says they should be discarded. Is there a revision to this guidance in a later issue? I'm not sure what the rationale for discarding them is though. Are they torque to yield?

SD1too 30th April 2024 09:41

Quote:

Originally Posted by Matt_75 (Post 2994928)
The Rover manual that I have says they should be discarded ... I'm not sure what the rationale for discarding them is though.

Nor am I. I suspect that it's just playing safe, judging by the high torque figure (which incidentally is slightly lower in the data section at 150 Nm). I refitted my originals; that was three years ago and I've had no trouble since, but you should make the decision that you're happy with.

Simon


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