TJ Whining Noise in Drivetrain?

[BO00YA]

Hey guys,

I have been floating around on the forum here for a while now. Been getting alot of tips and info so thanks to everyone.

Got a little problem i think. I have a 1999 TJ Wrangler Renegade and it has an awkward whining noise. This noise is only evident when coasting i.e. when i let off the accelerator. When i have the throttle applied, it doesn't do it.

Sounds to me like it could be something to do with the gearbox? but i'm not sure. What makes me think this is because i have noticed if i try reverse up a steep driveway the gearbox makes a rattly kind of sound with an element of slipping to the noise and it seems to struggle. (If all that makes sense)

Not sure if both things are related. If anyone can shed some light on this, i would greatly appreciate it.

Thanks in advance.
Ben

[Jeepin It]

Check all your unis, change your diff oils, your transfer case oils and your gearbox oil with the best you can afford and see what happens :)

[BO00YA]

Check all your unis, change your diff oils, your transfer case oils and your gearbox oil with the best you can afford and see what happens :)

Thanks for that. I know my rear diff uni is a little loose. Was planing on changing that soon. Was also going to buy Redline MTL for the gearbox. My diff oils were changed last major service. About 7,000km's ago.

What oils should i be using?

You think it could be as simple as that?

[bonza]

checking fluid levels is the first place to start, and I would replace that uni immediately, but sounds like you may have a gearbox problem by your description of reverse.

be careful what oil you use for your gearbox. do some research and make sure it is correct for your unit. wrong oil means a long slow death to the box, and dont forget the transfer. it take ATF#3 or #4 but Dexron II is fine

is the sound there no matter what gear you are in, if so it could be your diffs. has it been regeared? often get a whine if the gears havent been set up correctly on the coast side of the gears. I use 80/90 diff oil for front and 80/140 LSD oil for the rear

you may have to get an experienced mecho to take it for a drive, hard to figure out what causes a noise on a forum

oh yes, reverse gears do whine BTW when you go hard

[BO00YA]

Thanks Bonza,

I'll definitely be doing all the fluids then. Any idea where i can start my research for finding UNIs?


be careful what oil you use for your gearbox. do some research and make sure it is correct for your unit. wrong oil means a long slow death to the box, and dont forget the transfer. it take ATF#3 or #4 but Dexron II is fine
I have done some research before and Redline MTL has been hot topic of conversation for TJs. Very expensive but worth it apparently.

is the sound there no matter what gear you are in, if so it could be your diffs. has it been regeared? often get a whine if the gears havent been set up correctly on the coast side of the gears. I use 80/90 diff oil for front and 80/140 LSD oil for the rear
The sound is in all gears. Not sure if the diff have been regeared. Previous owner never said anything. Is there a way that i can tell if i take the diff hat off?

oh yes, reverse gears do whine BTW when you go hard
If i'm on level ground, reverse makes the normal whine like most cars do. But when trying to put more load on it, i.e.uphill it sounds like it's slipping. Like a grinding sliping noise if that makes sense.

[turbomart]

If its a manual (sounds like it is ) then gearbox cant slip its either in gear or not.If you have slipping then it is clutch.
That said the noise sounds like worn gearbox bearings but could also be diff (sound tends to travel thro metal) from your description.Its hard to tell via forum as mentioned.

[bonza]

this guy has done tons of write ups, pretty sure unis and oil for gearboxes get a mention

[BO00YA]

Thanks Turbomart.

this guy has done tons of write ups, pretty sure unis and oil for gearboxes get a mention

Sorry..but which guy? You referring to Turbomart?

[BO00YA]

checking fluid levels is the first place to start, and I would replace that uni immediately, but sounds like you may have a gearbox problem by your description of reverse.

be careful what oil you use for your gearbox. do some research and make sure it is correct for your unit. wrong oil means a long slow death to the box, and dont forget the transfer. it take ATF#3 or #4 but Dexron II is fine

is the sound there no matter what gear you are in, if so it could be your diffs. has it been regeared? often get a whine if the gears havent been set up correctly on the coast side of the gears. I use 80/90 diff oil for front and 80/140 LSD oil for the rear

you may have to get an experienced mecho to take it for a drive, hard to figure out what causes a noise on a forum

oh yes, reverse gears do whine BTW when you go hard

Hey Bonza, What oil do you recommend for the transfer in particular?

Or if anyone else can help?

Thanks.

[bonza]

Thanks Turbomart.



Sorry..but which guy? You referring to Turbomart?

sorry, must have forgot to paste and I havent been back to check this thread

I meant this guy http://www.stu-offroad.com/index.html
jeep guru in the states. heeps of info and write ups

I just use dexron ii in my transfer for the past 80,000 kilometers

[BO00YA]

Yeh i have been all over his site as well as 4x4Xplor. These guys are life savers.

What brand if you don't mind me asking?

[BO00YA]

Hey guys, Got an update. Had a couple mechanics listen to the sound. Both said that it is the rear diff and that it needs a rebuild or replace it with a good second hand one.

Not the best of news i suppose!

Does any one know what i am looking at cost wise or any alternatives etc?

Thanks

[bonza]

not the best news

look up a diff rebuilder and shop around or search thru some posts here to get ideas

glad you let us know what the upshot was to the noise

[RenegadeDom]

if your going to get it rebuilt think about regearing at the same time and possibly lockers if you were ever thinking about doing that, you will have to do the front also but you will save on labour costs in the long run.

[BO00YA]

Change of luck! :D

Did a full service on the TJ. When i went under to change the rear diff oil i noticed the yoke was loose. Therefore the pinion was loose as well.

I tightened up the pinion nut and to my surprise the whining noise has gone completely.

I suppose the pinion gear wasn't making proper contact with the ring gear. After taking off the diff hat and inspecting it was quite clear that the pinion was quite loose.

Very happy that i do not have to rebuild the diff.

I have pics and video if people are interested..

Thanks for the help.

[itchy]

Good work Booya!:D