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I found some polybushes for the top shock mounts front and rear plus the rear subframe mounts, is it worth having it done or is it best to stick with rubber all round. I don't relaly want poly bushes for the rotational parts of the suspension as I feel like this will remove too much give in the suspension. These are the parts in question
Kuddlesworth,
I have fully Polybushed my XKR with the exception of the shock mounts.
Whilst this does provide longevity, it does certainly reduces ride quality. Suppleness is lost and the car feels more like a racer. I feel that the only ride quality that remains is mainly due to my factory shock mounts - so I'm not going to Poly those!!
Kuddlesworth,
I have fully Polybushed my XKR with the exception of the shock mounts.
Whilst this does provide longevity, it does certainly reduces ride quality. Suppleness is lost and the car feels more like a racer. I feel that the only ride quality that remains is mainly due to my factory shock mounts - so I'm not going to Poly those!!
I would like to maintain ride quality as it's my daily driver and my roads are pretty bad so I do need some softness in the suspension otherwise you will end up having a bad day. Would you say the ride wouldn't change much if I replaced all the rubber bushings with new rubber and then just the shock mounts and rear subframe mounts with poly items. I mostly want them changed because the foam bushings don't last very long whereas a poly item will last a very long time indeed. I just don't want it to effect the ride comfort much if at all. I already have the 20" wheels so they are somewhat less comfortable then 18"'s already. Although I am debating having the sway bars done with polybushes as well as to be honest those would probably benefit most. I can see that your rear subframe mount has the polybush on it in yellow.
Last edited by Kuddlesworth; Oct 30, 2021 at 12:28 PM.
Hmmm, it's a difficult thing to judge because I haven't tried the set-up you describe.
We all call them Shock Mounts, but in reality they are Spring mounts that work hard to absorb the transmission of road vibration.
The only sure statement I can make is to change Rubber with Rubber. Like for like.
I do feel that the rear subframe mounts could be changed for poly (The 2 Yellow versions) without loss of ride quality. My reasoning is looking at their apparent geometry - they are more like supporting pivots than weight bearers.
Hmmm, it's a difficult thing to judge because I haven't tried the set-up you describe.
We all call them Shock Mounts, but in reality they are Spring mounts that work hard to absorb the transmission of road vibration.
The only sure statement I can make is to change Rubber with Rubber. Like for like.
I do feel that the rear subframe mounts could be changed for poly (The 2 Yellow versions) without loss of ride quality. My reasoning is looking at their apparent geometry - they are more like supporting pivots than weight bearers.
I don't really like the idea of increasing the vibration in the cabin. Might be a good idea like you said to stay with rubber. Thanks for your input. I'm just trying to plan for a suspension overhaul.upgrade and attempting to make a decision on what can be done if anything to improve the cars setup without loss of ride quality. I guess that isn't really possible.
guy,
About 4yrs ago, I needed to address corrosion of my suspension parts. Nothing unique there! But I wanted a permanent solution that was way better than OEM. I live in the UK where roads are wet perhaps more than half the time and in winter there is a lot of salt applied.
I discounted Powder coating. Although it has excellent coverage, looks great and is durable to a point, it is easily compromised by stone chips and frankly not strong enough for my application or the gravelly surfaces in my area.
I considered Galvanizing but there are major issues doing this. As a thermal dip at 449 DegC, Galvanizing can cause annealing, normalizing and embrittlement to certain base alloys of Iron. Jaguar did not share alloy specs for their components so there is great risk of damage to physical properties with this level of heat. Galvanized coating has a thickness applied everywhere in an uncontrolled manner. This reduces bore sizes by ~0.15mm diameter which will put many parts out-of-spec and will make re-assembly an absolute nightmare (Especially for Wishbones and Half shafts). Also, the result can look patchy and only an expensive pre-etch treatment with a special paint/primer combination can cover it.
In the end, this is what I settled for and what you see:-
All steels / Irons were shotblast and then hand painted for better control of application. Used Bilt Hamber 93% Zinc (42micron thick) galvanic primer. Then a grey top-coat which is long-life anti-corrosion protection consisting Bilt Hamber (100micron thick) 2-Pack Epoxy Mastic Zinc Phosphate. The combination has self-healing properties against stone chips. A stone chip sort of heals over with a bit of discoloration and this is visible in places in the below image which is after 2000miles. This primer and duplex bond are considered overkill for cars as it is marine grade and suitable for salt-water boats.
The Springs were shot blast and sprayed with Bilt Hamber primer plus black heat resistant engine enamel top-coat.
The Aluminium rear Hub carriers and front subframe have anti-corrosion coating consisting of sprayed tough PPB Heat resistant acid Etch primer plus sprayed on durable Hycote silver heat-resistant engine enamel top-coat.
For cleanliness, I do not steam clean the suspension but do wipe it over with a degreaser once a year .
Subframe and top shock rear and front polybushes?
