Top strut mount query

[Jarfar]

Hi,

I have a Renault Master van 2013 registration (UK). The MOT failed stating "Macpherson strut pin or bush excessively worn Offside Front (Top strut mount)"

I purchased a new top strut mount and also the drop link and swapped them out. All seems to have went okay, however, the reinforced rubber washer that bolts on to top inside engine bay does not sit down on the chassis mount. See images - the image that shows my finger in gap is the offside and other image is the nearside and it is sitting on chassis mount

What have I done wrong here? Is this a concern and how do I fix please?

Thanks in advance

[GreenV8S]

Have you fitted it upside down? It seems to me that outer flange should be underneath the shell, not above it. Did the replacement parts match what you took off and did you refit them in the same order and orientation?

[GreenV8S]

The other possibility is that perhaps this car uses the strut top bearing design where the damper rod clamps to the lower part of the thrust bearing (instead of the top part), and the compression sleeve that takes the clamping force through the top part of the bearing hasn't dropped through the hole in the top part of the bearing and is sitting on top of it.

[E-bmw]

New pic is a bit too fuzzy to actually tell, but it looks like the threaded section is not coming through the nut top as much as the other, so it likely isn't sat correctly underneath as GV8 has said above.

[Jarfar]

GreenV8S said:

Have you fitted it upside down? It seems to me that outer flange should be underneath the shell, not above it. Did the replacement parts match what you took off and did you refit them in the same order and orientation?

Hi,

Yes, I fitted everything in same fashion as I removed them, the old worn strut mount looked exactly like new one. The rubber flange washer is fitted the same way on other side except it sits down on chassis with no gap

Thanks

[Jarfar]

GreenV8S said:

The other possibility is that perhaps this car uses the strut top bearing design where the damper rod clamps to the lower part of the thrust bearing (instead of the top part), and the compression sleeve that takes the clamping force through the top part of the bearing hasn't dropped through the hole in the top part of the bearing and is sitting on top of it.

Sorry I am not sure what you mean

[Jarfar]

E-bmw said:

New pic is a bit too fuzzy to actually tell, but it looks like the threaded section is not coming through the nut top as much as the other, so it likely isn't sat correctly underneath as GV8 has said above.

Thanks - As I said to GV8, I mounted everything in same fashion it was removed. Everything seemed seated and tightened up okay. I have attached a clearer picture.

Two things though - first, when I fitted everything, it was on an axle stand and the rubber flange washer was just about toughing the chassis, when I put van back on its wheel the gap appeared. Also, before I removed old components there was a gap in old rubber flange washer. I actually thought that was part of the MOT fail

[GreenV8S]

Jarfar said:

Sorry I am not sure what you mean

A strut top mount usually has a big bearing that sits between the spring seat and the shell. That nut shown in your picture connects the damper rod to either the top or bottom part of the bearing. If it connects to the top part, the rod and nut trap the top part of the bearing directly. If it connects to the bottom part, there will be a sleeve carrying the clamping load from the nut to the bottom part of the bearing. It would make more sense if you have a picture of the old parts showing how the rod attaches to the bearing.

[E-bmw]

Jarfar said:

E-bmw said:

New pic is a bit too fuzzy to actually tell, but it looks like the threaded section is not coming through the nut top as much as the other, so it likely isn't sat correctly underneath as GV8 has said above.

Thanks - As I said to GV8, I mounted everything in same fashion it was removed. Everything seemed seated and tightened up okay. I have attached a clearer picture.

Two things though - first, when I fitted everything, it was on an axle stand and the rubber flange washer was just about toughing the chassis, when I put van back on its wheel the gap appeared. Also, before I removed old components there was a gap in old rubber flange washer. I actually thought that was part of the MOT fail

That is definitely not as far down the thread as the pic of the other side, I suggest you take it apart & have a closer look as something isn't fitted right.

[Jarfar]

e-bmw and GV8 thanks your assistance is appreciated

I took the rubber flange washer off the top of both sides and used a clear ruler to show the difference. I am thinking maybe the nut that bolts on the strut mount to the strut pin needs to be tighter if possible, although the new nut might be slightly thicker maybe, we are only talking about 5 - 8mm that is the problem.

This is nearside - note the nut is slightly lower down with slightly more thread


This is offside - note the nut is slightly higher up in chassis mount


Old and new rubber flange washers

Edited by Jarfar on Tuesday 10th June 16:05

Edited by Jarfar on Tuesday 10th June 16:06

[GreenV8S]

Those pictures show you can screw the strut retaining nut down below the level of the shell, so clearly it isn't running out of thread. What's stopping you from screwing the nut down further in your original picture?

[Jarfar]

Thanks GV8 - yes I am hoping I can screw the strut retaining nut down a little further if I take it out again quickly. Also, the new nut height\depth is about 3mm more

[Krikkit]

The new nut is a nyloc, which isn't needed with the rubber coupler above it. I'd grind the extra height off the nyloc (where the nyloc lock is) and fit as original.

[E-bmw]

Krikkit said:

The new nut is a nyloc, which isn't needed with the rubber coupler above it. I'd grind the extra height off the nyloc (where the nyloc lock is) and fit as original.

^^^^ Wot 'e said.

The flanged nyloc nut is incorrect & looks like that is causing the issue.

Replace it with a normal & un-flanged nut.

[Jarfar]

E-bmw said:

That is definitely not as far down the thread as the pic of the other side, I suggest you take it apart & have a closer look as something isn't fitted right.

Hmmm!! I took everything out again and redid it ensuring everything was in place. I then didn't tighten everything up completely until the wheel was on ground again. If anything the gap is more when wheel is down on ground, when jacked up there is no gap.

As Krikitt and yourself said and I agree, the nut retaining the strut mount looks different than other side (deeper) however, I was at 4 ironmongers today and they could not even tell me the thread. I thought it was M14 but it is not (probably imperial). I don't have time again to grind back the nut as MOT re-test is tomorrow. If it fails again then its back to drawing board.

The only good thing I can say is that with wheel jacked up and I place hands at 12 o'clock and 6 o'clock there does not seem to be any play

Thanks again for all your help

[Jarfar]

Krikkit said:

The new nut is a nyloc, which isn't needed with the rubber coupler above it. I'd grind the extra height off the nyloc (where the nyloc lock is) and fit as original.

See my answer to e-bmw. I agree, the nut retaining the strut mount looks different than other side (deeper) however, I was at 4 ironmongers today and they could not even tell me the thread. I thought it was M14 but it is not (probably imperial). I don't have time again to grind back the nut as MOT re-test is tomorrow. If it fails again then its back to drawing board

Thanks for help

[silentbrown]

Can you clean up and refit the old nut? Would confirm its the issue, and likely get you through the test until you source the correct one.

[Jarfar]

silentbrown said:

Can you clean up and refit the old nut? Would confirm its the issue, and likely get you through the test until you source the correct one.

That is the old nut - the nut that was supplied with new strut mount was a different thread. Although it did not have the flange on it, but because different thread (probably M14) I could not use it

[Jakg]

Jarfar said:

I have a Renault Master van 2013 registration (UK). The MOT failed stating "Macpherson strut pin or bush excessively worn Offside Front (Top strut mount)"

Jarfar said:

I thought it was M14 but it is not (probably imperial)

Bit confused - the odds of an imperial nut on a new European vehicle is very low. Sure it's not just a different pitch?

[Jarfar]

Jakg said:

Bit confused - the odds of an imperial nut on a new European vehicle is very low. Sure it's not just a different pitch?

I agree - however I tried 4 ironmongers to try and buy a shallower nut and none of them could tell me the thread!!!!!