[I]Q: why the diff is making that sound in the 4th n 5th gear only? if its due to the reason that 4th n 5th gear is normally for high speeds thats y its making sound at high speed, it also makes sound even if i m driving it at as low as 30-35km/hr. Please dont mind educating a Rookie
Ans: Sound is there even in 1st gear but due to high revs of engine in initials gears you cant hear it, also the sound increases with the speed so you start hearing it easily.
If you press the clutch when its giving sound you might not hear the sound due to less load on worn out diff.
Q: if i want to change the diff fluid and add a new diff oil in it along with a good STP oil, will it reduce the sound upto some extent?
Ans: Don't waste your money on temporary solutions, find out a proper diff expert. He can fix the sound by adjusting ring & pinion gap but again it depends at what level the diff is worn out.
Q: It also has a seal inside it which has to be changed when fitting the cover back. i m in doubt if that seal would be available here in KHI at Mehmood Motor Store in garden East who has all CJ parts available. If i dont get the seal is there any replacement to it like putting a silicon sealant etc? The person from whom i bought my rig told me to change its big ring and pinion gear inside the diff. Will that help me out to eradicate that sound?
Ans: Replace new seal which you can find easily from any seal shop, you just need the exact size of seal. Or remove the seal and take it to any seal shop & he will give you the exact matching seal. Not expensive. Silicon will not help.
It looks like the person who sd you the rig already knew the fault, so there is no need to trace the fault. He is telling you to replace the main parts in a diff. Also if the seal is leaking it means the diff might be running on low oil level which causes the damage to diff.
must replace new seals when you install new diff or fix the gap of existing diff.
Regards
Janj[/I]