6 replies to this topic

[Dakinn]

Hi all,

 

What is the correct process for tightening the upper suspension arm pivot shaft nuts?

 

I've taken all the front suspension parts out, refurbished them and I'm now reinstalling everything. I got the upper arm in place and the bolts done up finger tight, thick/thin washers in the right place (thick towards the front) and everything moving nicely. But I've buggered up my first attempt at tightening it all.

 

What I did:

1. Everything in place - finger tight
2. Tightened the retaining plate bolts
3. Both shaft bolts turn at once so I put a socket wrench on the front nut and used a spanner on the back nut (sub-frame is still in the car so there's no room for a socket or torque wrench)
4. The back nut wasn't really getting tight which made me nervous about damaging the thread so I got it tight enough and switched to the front nut
5. Using a socket wrench and extension from just behind the front grill I tightened the front nut
6. My Haynes manual says the torque is 53lb/ft 72Nm so I switched to the torque wrench and got it to spec
7. Not only was the upper arm movement locked solid but it blew out the lock washer, chewed into the retaining plate and damaged the nut thread

What have I done wrong?

 

Sorry if this is a common question but I couldn't find anything specific via search. Youtube tutorials seem to gloss over torque for some reason.

 

Thanks for the help

Dan

 

 

[nicklouse]

I would say it is more to do with the quality of the parts supplied.

 

I think Spider has given the correct lengths and thicknesses of the parts on these pages somewhere. I am sure he will be here soon to provide the info.

[DeadSquare]

That "spring-washer" is all part of a Chinese plot to sabotage the rest of the world.

[Spider]

There's nothing there I can see you've done wrong.

Usually when the spring washers do that, they are as Nick and Deadsquare have suggested, poor quality. I've also found that they were made for Left Hand Threads and not Rights. I'd say that one was biting on the nut as it was being done up instead of biting to stop it coming undone.

The Correct Grade of Spring Washer here is Medium. These have a section thickness of 3/16" (over the face) x 1/8" (thick).

 

Can I also suggest doing a check of hardness on the shaft here ? Grab a 2nd cut file, towards the outer ends on the main part of shaft, run the file on them. These should be hardened zones and the file should skate over it. If the file bites, then the shaft is too soft and the bearings will eat it.

[Dakinn]

A left thread washer was my first thought too but all the others in my two repair kits are right. They're definitely smaller than the old ones though. The old ones are pretty close to your dimensions above. And I'm not sure if I did it right but a file doesn't really bite into the shaft.

 

The one thing I can think of is I only drove the bearings in flush with the arm ends. I saw tutorials both saying flush and a bit further than flush. One was really tight so I didn't want to push my luck driving them in further.

 

The shaft and bearings make a bit of a squeak now which I didn't notice before the install attempt. It's a bit hard to tell in the photo below, and it might just be perspective, but I'm sure the bearing needles are on an angle. Did the bearing twist? Is that even possible?

 

I'm ocd perfectionist level careful with these things. I can't understand how I got it so bloody wrong! Lesson learned I guess.

 

Appreciate the help

 

 

 

 

 

[Dakinn]

Hi all, I had another go at it with the original lock washers.. much better.

 

Another question though - How loose should the arm movement be? Should it drop freely if you let go of it?

 

It was loose before I torqued it up. I was checking as I tightened and the movement starts to tighten as I got to 52 lb-ft. I backed it off to 45 lb-ft which felt better but still takes a slight push to move it up and down. There's no paint or powder coating.

 

What do you reckon?

[Lplus]

Hi all, I had another go at it with the original lock washers.. much better.

 

Another question though - How loose should the arm movement be? Should it drop freely if you let go of it?

 

It was loose before I torqued it up. I was checking as I tightened and the movement starts to tighten as I got to 52 lb-ft. I backed it off to 45 lb-ft which felt better but still takes a slight push to move it up and down. There's no paint or powder coating.

 

What do you reckon?

The forces moving the supension in use far exceed anything you can apply by hand.  The fact that the rubber covers are squashed in between the ends and the subframe will induce a small amount of friction anyway.  If it really worries you you could reduce the width of the arm between the subframe sides, but the photo shown previously suggests the ends are already worn down by the end washers.  If you can move the arm by hand without undue effort when torqued up, I'd leave it and make sure it's well greased.