philmag

Hi Guys,

My 4.7 Grand Auto has developed a whining noise and its driving me nuts. It cant be heard below 30mph but remains more or less constant over and beyond that speed. I suspect that it maybe gear train problem but how do I isolate where it is coming from? I had hoped it was down to the front axle so I drained that off and renewed the oil and friction additive but there was no differance what so ever, it does tend to very mildly increase in noise when turning the steering wheel but apart from that I not got a clue. Any advice please????

redfox

Whining sounds like your typical Jeep Driver! LOL

Mine does the same and am in the process of hunting the problem down. Mine quitens when I back right off the accelerator. just replaced transfer case fluid last night will test run and report for you.

trucker

Most of the time, whining noise under load and no noise when coasting, indicate bad differential pinion bearing. It start at 25-30mph and gets louder as the speed is increase, but stop when no acceleration(load). That what was driving me nuts as mine both rear ends had that problem. Noise gone after replacing both end pinion bearings.

philmag

Many thanks for your input guys I will certainly look into your suggestions. Speaking of pinion bearings the whining noise on my Jeep does not decrease when the load drops off ( not unless the speed drops below 30mph that is) So I am hopeful that it may not be the pinions that are causing the problem. I bought the car about 4 months ago and even though it came with a partial service history the last 20000 miles were not documented at all. The engine oil was in a bad way and the plugs were in a terrible state so I think its only fair to assume that the oil in the both axles, transfer box and auto transmission must be in a equally bad condition. One of the biggest headaches I have over here in the UK is sourcing the correct oils When I do find them they have gone through so many middlemen that the price goes through the roof, for example, Axle oil from a Jeep dealership came in at £22 plus tax a litre, tax being 17.5% on top. dont know how much that comes in at in US Dollars but bloody hell its too much for me to spend on a low budget. There! I feel much better now that I have had a moan lol. Cheers guys.

redfox

see! I told you that whining noise was the driver !

philmag

Lol yea thanks for that. I can moan and whinge with the best of them. Had a chance to get under the Jeep today and horror upon horrors I got hold of the front drive shaft and checked for rotational backlash and there is a lot of it, Now that is telling me I got problems with the pinion /crown wheel? Please tell me I am wrong.

shaneo417

mine did the same, turned out it was the front wheel bearings, swaped them out fixed the noise