Whirring Sound between 40/50 MPH

Hi All,

First off an introduction, I've been lurking on the forum for about 6 months but have only just bought a Jimny (57 plate JLX+). We needed a second car mainly to take my daughter to nursery, but I also do a lot of shooting so wanted something that I could drive into fields with

It's in pretty good condition, no corrosion in the usual places but I'll be treating the chassis with Buzzweld soon (any reviews on this?)

However, I have noticed a whirring sound between about 40/50 mph when you're in either 4th or 5th gear. It's not the death wobble, it's not majorly loud and it disappears once you hit about 50mph. It sounds like it's coming from behind the driver and it's only there when your foot is on the accelerator i.e. when you take your foot off the noise stops.

I'm wondering if it's just something vibrating, but does anyone have any idea? It's my first 4x4 so it could just be a normal sound and I'm being paranoid.

Cheers,

James

Welcome along

Buzzweld is good stuff. does what it says on the tin. I used RCP primer and CIO topcoat together with some cavity wax for the tricky bits. Its been on nearly 3 years and still looks good. Key is good prep, prep and more prep. Need to get as much of the old seam sealer and bitumen crap off as possible.

The noise on the driveline could be gearbox, t-box or diffs, but at 57' plate its probably gearbox. R72 gearbox is a known baddie Im afraid (been there, done that). Check and/or change the oils in all of them to see if levels are low would be a good start. The intermediate prop (gearbox to t-box) is known to leak at the gearbox end, causing the early bearing failure in the gearbox. Checking for signs of oil spatter around that would be a giveaway.

Its also worth going through the procedure to check that the 4x4 actually works and engages both front hubs, goes into low box, etc, before you get stuck in a field somewhere

Thank you for the warm welcome!

I've checked the 4x4 system and all is working as it should, no worries there.

Mine has done 94k miles, I thought that I may have gone past any potential gearbox issues at this point? It's also only in a specific speed band, not a consistent noise in every gear.

I got a passenger to record the noise, if you have time to review the following clip you can hear the noise quite clearly:

Jimny Noise

I can't see any splattering oil, but I'll check the levels tomorrow as you suggest.

Thanks for the help,

James

Hi James, just to make sure there's no transmission wind up, reverse on some gravel letting the wheels slip to unwind if needed. The previous owner may have used 4x4 on tarmac.

Thanks for the reply, would that be reverse in 2WD or when in 4WD?

2WD. I had a whirring after using my Jimny last winter in patchy snow I figured I must have had wind up, I unwound it and no whirring since.

Thanks for the suggestion, but after a brisk reverse over gravel the sound is still there.

My gut says this is the start of a bearing issue, but if anyone has chance to listen and has any other idea I'd be grateful to hear them

wind the windows down and see if you can locate the area its coming from, it sounds similar to a noise i had coming from front locking hubs, trying to engage ?

It's definitely not the locking hubs, I've tested those and they lock into place as expected. Thanks for the suggestion though.

I'm sure you'll get to the bottom of this soon. I'd have a look at prop universal joints for play, transfer box mounts/bushes, gearbox mount.

When my gearbox failed it was 3rd and 4th whined which doesn't sound like yours.

I'll check all the points you suggest, many thanks for the help.

Fingers crossed it isn't, I can definitely hear it in 5th. In fact it's probably louder in 5th than 4th or 3rd.

The investigations continue!