The subframe bolts are one-time use, they are stretch bolts, so no matter what, they will come loose again.
If you have a search through the forum, you will find a topic on this, it's best to use the Audi bolts for the subframe...
https://www.mk5golfgti.co.uk/forum/index.php?topic=44832.0https://www.mk5golfgti.co.uk/forum/index.php?topic=115046.15https://www.mk5golfgti.co.uk/forum/index.php?topic=115046.0https://www.mk5golfgti.co.uk/forum/index.php?topic=96741.0https://www.mk5golfgti.co.uk/forum/index.php?page=mods&mod=15or these from AKS Tuning : TyrolSport DeadSet Rigid Subframe Collar Kit for all MK5/6,Jetta GLI and MK2 Audi TT
https://www.akstuning.co.uk/tyrolsport/395-tyrolsport-deadset-rigid-subframe-collar-kit-for-all-mk56jetta-gli-and-mk2-audi-tt.htmlDescription
With the TyrolSport Deadset kit you can finally eliminate the subframe clunk that plagues every Mk5/Mk6 VW/Audi/Seat/Skoda chassis. The clunk manifests itself as a pop or a creak, especially when turning into sloped driveways, or when stopping/starting. VAG has issued a Technical Service Bulletin(TSB) for this problem. The TSB has your dealership replace the subframe bolts and install new friction shims. This TSB fix does not last long, as it does not address the root cause of the clunk. It is not long before the clunking returns. Tyrolsport has a true solution that works long term, is easy to install, and cost effective.
Tyrolsport has developed custom locating collars to ensure the subframe stays in place and does not shift under load. The collars are machined out of 954 Bronze alloy for the ultimate strength and corrosion resistance. The use of 954 is critical to prevent galvanic corrosion, and also adds needed lubricity. Tyrolsport spent a significant amount of time during R&D process in order to choose the absolute best material for this application. Each collar is machined for a specific location on the subframe, and includes dual-sided machining for a perfect fit. The dual-sided machining is necessary for exactly locating the subframe. The collars also have unique recessed features to positively locate the bolt head. This is critical to functionality.
Once the subframe is located perfectly, it must be held in place. The failure of the OEM stretch bolts is another reason for the clunking subframe, and they must be replaced. Tyrolsport has worked with world-renowned fastener company ARP to develop custom hardware for this application. We were able to develop a TyrolSport exclusive bolt that exceeds the OEM tensile strength, yet mimics the OEM hardware in shear. Some of the proprietary features of these exclusive fasteners are a carefully specified thread engagement area, and a chamfered “bull nose” tip. The bull nose tip helps locate the bolt to the body, and makes the installation process a breeze. Without this bull nose, aligning and installing a subframe deadset kit is much more difficult, and prone to thread stripping. It is the combination of collars and this hardware that makes the Tyrolsport Deadset kit so successful in solving the subframe clunk.
Deadset Kit Benefits
All Tyrolsport Deadset kits are designed to not only eliminate annoying subframe popping and shifting but also isolate the suspension
Notable Benefits:
Better steering response
Tighter turn in
Better braking performance
Improvement over all road surfaces
Better chassis to road feel / Driver feedback Allows for tighter / consistant alignment specs.
The Deadset kit works on the following vehicles and is compatible with any combination of aftermarket control arm bushings currently available, including SuperPro Anti-Lift kit.
Mk5 VW Rabbit, Jetta, Jetta GLI, GTI, and R32
Mk6 VW Golf, Jetta, Jetta GLI, GTI and Golf R
8P Audi A3
Mk2 Audi TT/TTS/TTRS
B6 VW Passat
VW Tiguan
Mk5/Mk6 chassis Seat/Skoda
NOT FOR USE ON STEEL SUBFRAME
Or check to see if you ARB brackets is tight...
Or your Drop links could be hitting off your wish bone...