8spd Whine? Low Trans Fluid?

[Logan-Kn]

I recently noticed that my 8spd has been making an audible but not loud whining noise in 5th & 6th gear while climbing a grade on the highway. It kind of sounds like my Jeep has a little super charger or something. I have heard that this may mean the transmission is low of fluid. I understand that these trans are “sealed for life”.
I have an extended warranty on my Jeep so I’m not exactly keen to crack open my transmission to check the fluid level myself. has anyone had this experience with these transmissions?

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[rohdawg]

Any chance it does it at start up? I had the alternator begin to go bad on my ‘21 and it made a noise very similar to what you describe.
I heard it at start up/idle and when it was around 4,5 and 6th. It would calm down once it settled into a gear.
Changed the alt and that solved the problem. I’ll add it was extremely hard to pinpoint the location of the whine just from the noise alone.

 

[Logan-Kn]

Definitely will pay attention if it’s in start up. it’s rpm dependent for sure, starts around 3-4k. Would definitely rather an alternator than a transmission.

 

[rohdawg]

Definitely will pay attention if it’s in start up. it’s rpm dependent for sure, starts around 3-4k. Would definitely rather an alternator than a transmission.

My thoughts exactly when I was trying to figure out what it was.
Good luck!

 

[Gorilla57]

If you don’t have a puddle of trans fluid under the Jeep, the trans fluid level should be fine.

 

[mwilk012]

Sounds like an RPM dependent whine. Alternator bearing, idler, tensioner pulleys, all are suspects. Transmission would be wayyy down the line unless its visibly leaking or having a rough shift.

 

[Logan-Kn]

Found a couple possible culprits today. I noticed that one of the lower pulleys was super caked in mud around the bearing. I also noticed that my water pump has a small deep around the mating surface. Lastly one of the pulleys on top seems like it is moving in and out. No noticeable noise at idle/startup or while reving Let me know that you guys think! ?

 

[Heimkehr]

I recently noticed that my 8spd has been making an audible but not loud whining noise in 5th & 6th gear while climbing a grade on the highway.

I have an extended warranty on my Jeep so I’m not exactly keen to crack open my transmission to check the fluid level myself. has anyone had this experience with these transmissions?

I'll second the idea of investigating bearings and pulleys, as you've already started to do.

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As for the 850RE, that's a whole 'nother conversation. Briefly, ZF themselves recommend fluid and filter replacement at approx. 60K miles. I've done it twice now. This thread is an excellent resource for if or when you decide to go down that particular rabbit hole.

 

[SargeDiesel]

When you go to check it out again, if RPM dependant, use a helper on the gas peddle... get yourself a decent 3-4' piece of water hose or a 1/2" diameter 2-3' dowel to help you pinpoint the noise, just hold either up to your ear... the noise will jump out at you.

 

[Logan-Kn]

When you go to check it out again, if RPM dependant, use a helper on the vas peddle... get yourself a decent 3-4' piece of water hose or atleast a 1/2" diameter 2-3' dowel to help you pinpoint the noise, just hold either up to your ear... the noise will jump out at you.

Great idea thank you!

 

[davewald]

If you're worried that it's low transmission fluid, just check the transmission fluid dipstick.

Oh, wait...

 

[mwilk012]

If you're worried that it's low transmission fluid, just check the transmission fluid dipstick.

Oh, wait...

It's even simpler than that, if you think it's low fluid, where did it go?

 

[mwilk012]

That engine bay is filthy man, I would start by cleaning it off. If the noise does not occur in park with RPM ~2000, check the driveshaft. It wouldn't surprise me to see the rzeppa joints failing due to mud intrusion.

 

[Logan-Kn]

That engine bay is filthy man, I would start by cleaning it off. If the noise does not occur in park with RPM ~2000, check the driveshaft. It wouldn't surprise me to see the rzeppa joints failing due to mud intrusion.

Doing a deep clean today! Going to clean and try to throw some lube in the bearings and joints. Will inspect the Rzeppa joints too.

 

[Logan-Kn]

Update! The whine is gone! Looks like the whine was just her screaming for a good engine wash?. definitely learned my lesson regarding cleaning after off-roading.

I think ones of the bearings on the pulleys is still bad though. I put a long screwdriver on each one and noticed that the one that the one furthest of the passenger side sounds a bit more rough than the rest.

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