Subframe rear mounts

[simon.williams]

Hello,

One of these definately looks a bit suspect compared to the other. Is it possible to swap them for new mounts without removing the entire subframe? Thank you.

[johnnydog]

Yes, in answer to your question.
Remove the rear seat base and you will see the head of the bolt that goes through the reinforced panel of the floor pan, through the mount and anti vibration strap. Undo the lower nut of this bolt and the two small bolts that secure the mounting in the subframe, remove the anti-vibration strap, and then the mounting can be removed downwards without having to remove or drop the subframe.
It's beneficial to lubricate the threads of the mounting bolts beforehand. Make a note of which spreader washers are where as there are various thicknesses.
Use the marks left on the underside of the floor pan by the original mounting to ensure the top of the new mounting is positioned exactly as the old one. I usually remove the road spring first just to avoid any possibility of any spring tension attempting to move the subframe slightly. It's only a five minute job to remove the road spring after the lower nut of the shock absorber is removed with the swinging arm supported by a jack.
It's worth checking the condition of the anti-vibration straps whilst you are doing the job (bearing in mind they are handed!).

[simon.williams]

Thanks Johnny!

[simon.williams]

Oh, and would you spend the extra on polyurethane bushes, or will rubber do?

[johnnydog]

I've never used poly bushes on any of my Triumphs as I am fortunate to have an adequate stock of original new 'old stock' parts, so I can't really advise you either way. There are various degrees of the compound of polybushes relative to NVH (noise vibration and harshness), so maybe others can suggest which are preferable for your intended use from their experiences?
Original items now are difficult to find so poly maybe your only option.

[Charles H]

if you are going the rubber route, ONLY use original ones. The repro ones mean you will be doing the job again very soon. I have also used CW poly ones and find they are very good.

[simon.williams]

Thank you.

[Alec]

For what it is worth,

I have used Chris Witor's Superflex bushes for probably thirty years plus, the same ones.

Alec

[simon.williams]

Silly question, should I have an extra washer on top of the subframe bush (as per the old one). It’s not obvious from the manual.

Also, should I put some putty or add some rubber washers where it mounts to the car body?

Thanks!

[johnnydog]

Personally, if you are happy that no one has fitted replacement mountings previously, then I'd replace the washers in the same orientation that they were removed.
If you think they have been removed previously, then maybe CW's info may be of assistance.
I'd put some sealant (the light grey compound used on the strut top mountings is the same) on both sides where the bolt heads where they go through the floor, as well as on the bolts securing the anti-vibration strap to the floor.
I've used DumDum previously for this job.