center of fan fills with dirt and causes vibration, blow out center of fan

my truck runs in a timber yard and its rough going in parts plus the rivet driving the truck doesn,t back off at the potholes. cheers carl v

We have seen the brackets break when excessive debris and dirt is collected in fan hub causing out-of-balance condition. Depends on the application of the truck (block yards, unpaved areas, etc)
Take time to clean this area.

Hi kevin the fan does'nt spin very fast until truck is really hot if you do the mod it should sort out the problem,the bracket could have broke because of fan always on full speed for long periods good luck herald.
ps if the modification does'nt work drop me a line on here again i will get u more info.

hello herald.i,ll have a go at that modification when i,m next at the truck.i think the fan was spinning slowly no matter how hot the truck got ,but the guys would shut it down as soon as the light came on. is the module easy to identify as it may be the next thing to change if i still have problems. the customer is happy enough to run the truck with the fan at full speed but it can,t have helped with the brackets breaking !! and it good to see something fixed properly. cheers mate

Hi Kevin the problem with the fan bracket snapped i have never seen happen,its more than likely a one off.If you ever take the fan off mark around the brackets with marker to make it easier to realign after refit.
Regarding your overheating this is quite common,when the first 39 trucks came out there was problems with leaks from the fan shaft more so when shrink wrap got in,so they beefed up the seal,this made the fan a bit tight especially when new,so when the truck gets to temp the fan should start off slow then build up speed as the temp rises.It works off both engine temp+hyd temp through the module you can check operation with lap top.(if you have one).
Sometimes the fan won't start to turn and truck overheats,disconnecting the fan works but the fan then runs at full speed all the time.
If you remove the fan speed control valve by removing the 4 mounting cap screws and pull off the valve(nothing will fall out you may need to catch a bit of oil).
Put the valve in your vice when you look in the end you will see a circlip with a spring behind it,remove the circlip and fit a linde 8mm washer between the circlip and spring.(use one of the washers from the side cover this is exactly the correct size)this just lifts the valve off its seat.Then refit the valve to the fan motor,refit the plug and the fan will run at 400rpm when cold then speed up as needed when told to by the module.This is the recommended Linde mod and easy to do,
A bit long winded but hope this helps Herald.

hello herald.yes it,s a 39 truck i think the serial number is h2x a01043. something like that. i can get it from my book if it makes a difference. vw engine. also has problem with temp sensing. i had to disconnect plug from fan speed control valve to stop truck constantly overheating. must be fault temp sensor on engine but which sensor is a different matter.regards

Hi Kevin what is the serial number is it 39 truck?