Noisey Lo gears

[Paul UK]

Hi,

I've just noticed a high pitched whirring sound if I drive in 4-Lo. It doesn't happen in 2-Hi or TOD modes and it seems to rise in pitch with revs to a certain point then stay stable.

I took it to my 'local' Isuzu dealer with the owner observation "transfer box making whirring noise" and received their detailed diagnosis of "transmission working but making noise". They suggested they look at importing a replacement transmission for £4k ($7k). Lucky they were there to help!!

Any ideas before I find a specialist automatic transmission place and hand myself over to their mercy? In particular - I know it'll be a guess - but am I safe to drive it on 2-Hi until I can find someone who can diagnose and fix the problem??

Thanks for any help
Paul

[Ldub]

My guess would be, that you are OK to drive it in 2 hi since it doesn't make the noise then.
Also, ALL of the 4wd vehicles I've owned make more noise when the trans. is in 4 lo.
Ldub

[Mantronix7]

I have a similar problem. My VX is a JDM and so it has an override on the TOD. It runs mostly on rear wheel drive unless it is shifted into 4Hi which in this case the Auto mode lights up with the rear and front wheel indicator or 4Lo which all TOD wheels indicators light up.

It seems that when the VX is running in 4Hi, there is a whirrling noise in the rear and the engine sounds pretty loud. Is this normal with the US specs which run on Auto TOD full time?

[Numba1goalie]

a whiring noise is often quite normal for a 4lo operation. I have a 93 wrangler and when I am in 4lo I also ave a whirring or high pitched whine noise coming from the undercarrage. I wouldnt worry to much about it. Just make sure your fluids are up to date. You might want to have someone check out your spider gears, ring and pinions, ect. It deffinatly shouldnt cost $7k. good luck.

[deermagnet]

Paul, it's possible everything is working fine. 4L should sound much different than 2H or TOD, kinda like you're describing. Have you driven in 4L before without any strange noise? What kind of terrain are you driving on in 4L? Never use 4L on bare pavement. This applies to all 4WD vehicles. It can cause bad tire wear, bad noises, worse fuel economy, and eventually, damage to front end drive components. When turning in 4L one wheel needs to slip a little. You need to be on grass, mud, dirt, gravel, snow, ice and such when using 4L. There are also speed limits in each gear you need to be aware of in 4L.

Engage and disengage 4L briefly every few months to keep it working right. You probably rarely need to use 4L ever. From the manual- "Use this for maximum power and traction. Use '4L' for climbing or descending steep hills, off-road driving, and hard pulling in sand, mud or deep snow."

[Paul UK]

Thanks for all your responses - I guess I'm just being paranoid. I'll check the fluids and maybe have a diagnostics run anyway just for total peace of mind. I don't go off road often so I suppose I can sit comfortably in TOD or 2-hi and not worry for the time being.

Thanks again
Paul