Strange buzzing/grinding sound...

[Apebrains]

Hey guys, dropping in with another glitch I'm hoping you can help me solve. Today a new noise popped up. Nobody likes new noises... This one is new for me, like nothing I've heard, but you guys have a hell of a lot more experience than I do, so let's hear your thoughts.

So when I'm driving along, things are going well through first, then into second, but then when I shift to third, there's a very slight strange feeling between second and third, but it will continue to drive fine in third. The sound comes when I let off of the gas. At the very bottom of the gas pedal, there suddenly smack in this loud clicky, buzzy, almost grinding sound. Like if you gently poked a stick into a fan. But if I back completely off the pedal, the sound stops. I can feel a little vibration from the sound through the vehicle. Then when I drop out of third to downshift into second, I can feel it still there between the gears, and I can still hear it when I'm at the bottom of the gas pedal (though it still goes away when I completely let off the pedal). I worry that it's something rubbing/grinding in the tranny, or maybe the clutch. I thought maybe something was in the flywheel gears, but it wouldn't make sense that it only does it at certain points in the shift pattern. And why do I only really get the sound and feeling at that one point in the throttle pedal? FRUSTATING! But this is the fun of driving an old Jeep I guess.

Anyway:

1965 Jeep CJ5
Ford 289 Mustang V8
BW T-90 3 speed Tranny which was recently rebuilt

Any help you guys could give would be greatly appreciated. I can't seem to find any info on this specific issue. Thanks!

 

[JR74CJ5]

Have you greased your u joints on the drive shaft in a while? Checked the fluid level in the rear end in a while?

What kind of fluid did you put into the T-90 after the re-build?



~ JR

 

[Apebrains]

Have you greased your u joints on the drive shaft in a while? Checked the fluid level in the rear end in a while?

What kind of fluid did you put into the T-90 after the re-build?



~ JR

Well, considering that I just got it recently, it might not be a bad idea to do that. But why would these things only make a sound around 3rd gear, and why only at the bottom of the throttle pedal? Moving forward, full throttle, all that, no sound. Only when I've almost released the pedal.

I'm not sure what's in the T-90 , since it was rebuilt at a tranny shop. I have the papers for it, but I'll need to call them and see if they remember what they put in it.

 

[Purple77CJ7]

Drive shafts under load don't make noise because everything is tight. Unloaded it can move a little, and cause vibration. Learned that from owning a Kenworth truck. Can be dry u-joints or worn u-joints.

 

[Apebrains]

Drive shafts under load don't make noise because everything is tight. Unloaded it can move a little, and cause vibration. Learned that from owning a Kenworth truck. Can be dry u-joints or worn u-joints.

That's good to know. I'll check that out as soon as I get home. But then why wouldn't it buzz when I let completely off the gas pedal?

 

[Purple77CJ7]

When you let completely off the gas your under load from forward momentum slowing the vehicle. When you let off a little and coast there is no load on the drive shaft.

 

[Apebrains]

When you let completely off the gas your under load from forward momentum slowing the vehicle. When you let off a little and coast there is no load on the drive shaft.

Gotcha. Alrighty then, I'll get under there in a couple of hours and see what I can see, then report back promptly! Thanks for the advice so far guys! I'll let you know what I find.

 

[JR74CJ5]

Thank Purple77CJ7 Couldn't have explained my assumption better myself

I've been busy at work, neglecting my internet time for once

Yeah Apebrains I'm not sure thats going to for sure be your issue, but I can tell you the piece of mind of knowing they are greased is very valuable. I just lost one at 645mph on the freeway from the rear driveshaft to Transfer Case ... yeah the bad one to loose on the freeway... Fully loaded and on my way to camp and wheel... 2 Dogs, 5 Kids, and 5 Adults all waiting for me to scramble around the nearest town and get her fixed up...

So... Good to do it even if not the problem was my main point, and with any luck it may be the issue.

Check that rear end fluid too, same basic principal on when hearing / load no load...

 

[Apebrains]

Thank Purple77CJ7 Couldn't have explained my assumption better myself

I've been busy at work, neglecting my internet time for once

Yeah Apebrains I'm not sure thats going to for sure be your issue, but I can tell you the piece of mind of knowing they are greased is very valuable. I just lost one at 645mph on the freeway from the rear driveshaft to Transfer Case ... yeah the bad one to loose on the freeway... Fully loaded and on my way to camp and wheel... 2 Dogs, 5 Kids, and 5 Adults all waiting for me to scramble around the nearest town and get her fixed up...

So... Good to do it even if not the problem was my main point, and with any luck it may be the issue.

Check that rear end fluid too, same basic principal on when hearing / load no load...

You were going 645 mph??!?!?! That does sound like a mess!

 

[JR74CJ5]

You were going 645 mph??!?!?! That does sound like a mess!

oops...

That would be sweet! Though very scary in a CJ

65mph meant...



~ JR

 

[Apebrains]

oops...

That would be sweet! Though very scary in a CJ

65mph meant...



~ JR

Man, that must have been rough... Mine gets a bit shaky up at 65, so I tend to stay south of that. Did it beat the out of your undercarriage? I had the same thing happen in a van I was driving in Australia at 8 am in a rainstorm on the freeway, in the fast lane, with no shoulder, in rush hour traffic. This was the same storm that eventually caused all of Brisbane to go underwater. Man, a bad U joint can mess up your whole day... Wish me luck getting home today!

 

[JR74CJ5]

Yeah beat under pretty good, beat hole in secret storage box, ripped fuel line to main tank in half...

So there i sat on the side of the freeway being thankful i didn't just get catapulted by the driveshaft remaining hitting a rut and catching... Got out, noticed fuel was dangerously close to a red hot broken u-joint... Surprisingly I moved pretty quick though, tied fuel line in a knot and tucked it away from work area, disconnected the hot driveline from the rear end, hooked a chain to uncles CJ and got it moved off the road...

Got lucky and found a parts / service palce called Varozza 4x4 Outfitters... Dude saved my weekend.

 

[MN CJ7]

Hey guys, dropping in with another glitch I'm hoping you can help me solve. Today a new noise popped up. Nobody likes new noises... This one is new for me, like nothing I've heard, but you guys have a hell of a lot more experience than I do, so let's hear your thoughts.

So when I'm driving along, things are going well through first, then into second, but then when I shift to third, there's a very slight strange feeling between second and third, but it will continue to drive fine in third. The sound comes when I let off of the gas. At the very bottom of the gas pedal, there suddenly smack in this loud clicky, buzzy, almost grinding sound. Like if you gently poked a stick into a fan. But if I back completely off the pedal, the sound stops. I can feel a little vibration from the sound through the vehicle. Then when I drop out of third to downshift into second, I can feel it still there between the gears, and I can still hear it when I'm at the bottom of the gas pedal (though it still goes away when I completely let off the pedal). I worry that it's something rubbing/grinding in the tranny, or maybe the clutch. I thought maybe something was in the flywheel gears, but it wouldn't make sense that it only does it at certain points in the shift pattern. And why do I only really get the sound and feeling at that one point in the throttle pedal? FRUSTATING! But this is the fun of driving an old Jeep I guess.

Anyway:

1965 Jeep CJ5
Ford 289 Mustang V8
BW T-90 3 speed Tranny which was recently rebuilt

Any help you guys could give would be greatly appreciated. I can't seem to find any info on this specific issue. Thanks!

Hi,

I will give this a guess... I have heard this in my T-18 w/granny with the wrong fluid... Put in GL5 Gear Lube and lots of guys are sorry to say and its all you will find on the shelves.... Wrong gear lube, GL5, will cause your Transmission to rattle... I think its the syncros.

Put in some GL4 or the Amsoil MTF in the Transmission and Transf and it will correct in day, and get better over the next few wks.. I recently put in the Amsoil MTF and very impressed shifts even better.... So I would now say get the Amsoil MTF, manual Transmission fluid, since it is similar in price 11/qt to the Gl4 that is now $8/qt. Napa has now doubled the price of the GL4 since I recommned it 3 years ago..

No bull, this is most likley your issue.. You will find nothing on the shelves for Gear Lube but GL5, I cked 20 stores the first time looking for GL4 like my FSM says.... its not there..

Here is where to get it...

Here is a POST from me a few years ago.... I just copied and pasted here so hope nobody minds. YOU WILL FIND NOTHING BUT GL5 GEAR LUBE ON THE STORE SHELVES, NOTHING BUT.... The GL5 GEAR LUBE is the wrong fluid for old JEEP CJ Manual Transmissions and Transfer Cases, can also cause the SYNCROS to start rattle/noise and not work well or shift well. GL5 HAS THE WRONG.... LUBRICATION PROPERTIES.... AND.... IT IS CORROSIVE TO YELLOW METALS USED IN MANUAL TRANSMISSIONS. Some have posted, many posted, they could hardly shift after some time. Changed to GL4 and got better and quieter. I have done this dozens of times with great results.

So Please copy this to your hard drive and spread the word. This could stop a lot of JEEP MANUAL Transmission FROM FAILURE AND REBUILD BEFORE THEIR TIME. TRY IT YOU WILL SEE.................

The confusion with the AMSOIL product its rated as oil viscosity and not Gear Lube viscosity. The TWO OIL VISCOSITY SCALES cross or equal at these weights…..AMSOIL MTF is what I am going to change to since I do not WATER CROSS so the installed life will be of benefit. I currently have the Napa GL4 installed and very pleased with the correction of operation and is getting even better over time…. Almost no syncro rattle now

THE AMSOIL MARINE GEAR LUBE CAN ALSO BE USED FOR......... GL4 GEAR LUBE, it meets the GL4 spec, it can absorb more water before oil failure. SO... for those of you that play in the water alot that may be a good choice.

This info has been posted lots….. and many times on the forums. MOST of the Jeep Field Service Manuals say use GL4….. the only place Jeep messed it up was 1982 they said GL5 and had INDUSTRY RECALL ON ALL MODELS and changed the gear lubes and transmissions left and right…. Or very often.

The Amsoil White paper on gear lubes is a very good read.

The Novak Web site does have a little blurb on gear lubes/Transmission and its very confusing, not well written, and its leading many down the wrong path. I wish Novak would rewrite and update their info.

Gl4 and GL5 are not the same and not interchangeable…….. their applications are different…. Their properties are different….


It your syncors rattling. The gear lube on the shelves is GL5 and is a product made for the pumpkins of these big large towing capacity tow rigs. The GL5 has the wrong lubrication properties and is corrosive to the yellow metals in manual transmisisons. All the BorgWarner Transmissions in the older Jeeps should use Gear Lube.

The RIGHT GEAR LUBE is GL4...... GL4...... GL4.... Napa Sells it, call them and ask them to order you 1-2 gallons and it’s like $30 a gallon….. when I first suggested Napa it was $15/gal now the price has almost doubled.

IN my case……Took out GL5 and put in Napa’s Gl4……You will also find After 50 to 100 miles it will start shifting better and should start to get quite. My T-18 did the same thing after I put the Gear Lube from the shelf.... it was GL5 and started shifting harder the the syncros starting rattle. Now almost silent and shift much better and its 32 years old.

Alternaitves Amsoil Syncromesh is a GL4 or Mobil 1 were both rated very high and and some of the least expensive on the list.

Bromgarrds Farm Stores, IA, NE, Co, Midwest area also have a GL4 gear lube. Sell 2.5 gal container for like $27.


I have posted this up many times, many folks amazed with results. Frankly I am SHOCKED another fluid bad for our Little Jeeps ALL OVER THE SHELVES. I HAVE LOOKED YOU WILL ONLY FIND GL5 ON THE SHELVES. Good for your pumkins but not for the Transmission /transfer. Also add a magnet to both drain plugs to catch the metal particle. I also took a "stick magnet" and rubbed the bottom of Transmission /Transmission and got more out that way.

NAPA
SAE 85w90 Gear Oil GL4 (also meets GL3)
Part #SL24239
Mfg By Sta-Lube, sibisdary of CRC Industries
Bar Code 72213-24239
$25/gallon, phone order take 1-2 days to arrive, then pick it up, easy

I would also consider Amsoil MTF Syncromesh GL4 or the Mobil 1 Gear Lubes they were tops in performance and lower in cost that most. $8-10/quart.





PS
Use GL5 Gear Lube in your Pumpkins and follow any recommendations for Limited slip or locker additives.






APPLICATIONS For GL4 and Amsoil MTF Gear Lube their GL4
Recommended for automotive and light-truck applications that require synchromesh Transmission fluid. Applications include manual transmissions and transaxles such as New Venture NV T350, NV 1500, NV 2550, NV 3500, NV 3550, NV 5600, and Tremec T-4 , T-5 , T-18 , T56, T-176 , TKO500, TKO600, TR 3450 and TR 3550. Replaces MTF-94 fluid for Land Rover, MG, and Mini Cooper. Replaces Honda Genuine MTF fluid for manual transaxles and Texaco MTX fluid. Not for use in engines, hypoid rear axles, Limited -slip or wet clutch applications.



T-5 .....Dexron III / Mercon, Mercon V use.....ATF.......
BUT....(except T-5 from 1985 to 1991 use GL4 Gear Lube)

 

[Apebrains]

Wow, it's a good thing you worked quick! Situations like that are scary as hell...

Well guys, thank you for all of your responses, but I fixed both of the problems I was having. My question is this:

Who wants to give the jack*ss of the year award? Pretty sure I'll win!

Here I am freaking out that I'm going to have to deal with Transmission problems when the fix was this:

Somehow, the Transfer Case was engaged, and I drove the whole way to work in FOUR WHEEL DRIVE.

Luckily, it had rained this morning, so most of the roads were wet, but I still worry that it may have adversely affected my Transfer Case . I don't know how it was shifted into four wheel, considering I haven't been off road in days, but I'm sure glad it wasn't a more serious problem.

I figured this out in that, while making a sharp Uturn, the wheel was bucking against my hand, and my friend suggested that it was acting almost like it was in four wheel drive. I told him I was sure it wasn't, and pushed the case lever, only to feel it then disengage. Yes folks, I am an idiot. In my defense, I hadn't been four wheeling, and I have no idea how it got engaged in the first place.

Anybody think my stupidity could have caused any real damage? Is there a way I should check for damage? Thanks again guys for putting in your two cents and helping me figure things out.

 

[MN CJ7]

still suggest you call the Transmission shop and ask them what Gear Lube they put in there...

Bet it is GL5

We all make mistakes.. Wheeling this wk end must have had part way into 4wd on transf and it poped out... with a bang.... felt pretty bad but all was well... I will be more careful

 

[Apebrains]

still suggest you call the Transmission shop and ask them what Gear Lube they put in there...

Bet it is GL5

We all make mistakes.. Wheeling this wk end must have had part way into 4wd on transf and it poped out... with a bang.... felt pretty bad but all was well... I will be more careful

Good to know they can take a little dumb@ssery. I'll definitely remember this one.

I'll definitely call them up and ask. Hopefully they'll still have the job on file and will thus be able to tell me what they used. If not, I guess it couldn't hurt to change the fluid in the near future anyway.

Thanks again guys!