Outer Limits 4x4 Board

Have developed a noise in the front diff only evident above 60km/h on lift off in H4wd (rig has part time conversion). (never noticed this before as never driven on blacktop in H4WD in the year of owning the truck, have been on gravel and corrugations and then there is so much noise/shaking you dont notice the diff noise!)

I have recently lifted the truck 3" had an alignment check (which they must have done wrong) and fitted 5deg castor plates based on the results. Found it to be far too much castor as tie rod clashed with the radius arms too much. The noise was bad due to the tie rods clashing with the radius arms and transferring the noise/vibration from the diff.

Took the plates off and still have the noise although no way near as bad as with the plates fitted.

Changed the diff oil on sunday, found no chunks of metal.

Any ideas if this noise could be the main bearing in the diff???

There is no noise under load/drive. took the front propshaft out and no noise so I dont think its the transfer case.

Can the bearing be changed with diff on the car???

if its a slight metallic ringing sound when you back off after acceleration then its most likely just driveline backlash as the front hubs are locked in. If you unlock them and repeat the test the noise shouldnt be there.

If you'd had the vehicle when it was constant 4wd you would have noticed the noise but the part time kit stops this unless the front hubs are locked and in 4wd.

hope this helps. if not try searching as this topic has been covered 14274398464849657494094000 times b4 (well atleast 10 times anyway)

I had a slight noise in my front diff.........now its a loud one

I too checked my oil but it was fine. So bearing has to come out

read alot of the backlash queries from the search and I dont think this noise is back lash as the noise is more of a drone during lift off than clunk (had the clunk happen a bit a v low speed before, a grease up sorted that!)

Will get a diff specialist to look at it and see what diagnosis is.

Problem started when you lifted 3 inches....then put plates on, then took em off....you haveuneven front driveshaft uni angles and it is not balanced anymore...a double cardon from a real lux shaft will fix it. You are not alone, quite common, goes away when the shaft isnt turning right? Have a look, at the transfer there is a angle, at the diff there is....nothing right...so the rear angle flops the slip yoke around and it is noisy.

Thing is I dont actually know if it did it before as never driven in H4wd on the blacktop. Would not say that uni angles are excessive and I do have angles at ends of the propshaft (need to measure them to check they are equal tho!)

Thanks for the pointers tho, still gotta consider it. Will see what the diff guy says.

dow50r wrote:Problem started when you lifted 3 inches....then put plates on, then took em off....you haveuneven front driveshaft uni angles and it is not balanced anymore...a double cardon from a real lux shaft will fix it. You are not alone, quite common, goes away when the shaft isnt turning right? Have a look, at the transfer there is a angle, at the diff there is....nothing right...so the rear angle flops the slip yoke around and it is noisy.

my 100 series dose the same thing
jimbo