Manual Transmission Rattle in Neutral

I have a 2010, Toyota, Prerunner, 2.7 Litre, 4 cly with a 5 speed manual transmission. It has a terrible "rattle" in neutral with the clutch out (engaged). If I hold the gear shift so it touches the synchromesh of any gear the rattle goes away. If I depress the clutch pedal (stop the gears from turning) it goes away. In normal driving it is quiet.

Has anyone else experienced this? Are all manual transmissions like this or am I the only lucky one?

 

If I coast in neutral over a bumpy road it rattles like hell. seems consistent w/ others' experiences from what I've gathered.

 

Mine makes sort of a droning noise when in neutral and the clutch out (engaged). I honestly don't think it's a big deal though, just the sound of part of the transmission turning.

I would not describe what I have as a rattle though.

 

Hossbuilder

Check out this thread:

http://www.tacomaworld.com/forum/4-cylinder/50626-poll-diesel-like-noise-clutch-determinative.html

Carp

 

My brother's wrangler does it in neutral every time when stopped.

 

Proably just throwout bearing noise.... which is normal... hard to say without actually hearing it tho...

 

Throwout bearings do not rattle. They whine. Totally different noises.

 

OK, Thanks to Carp for the link. It describes my rattle to a tee. I did some Google research and found a technical article that explains the phenomenom. Oil Squeeze between meshing gear teeth and harmonics.

http://journals.pepublishing.com/content/yv6p12022764uu24/

So...now I am trying to find a lubricant or an additive that will minimize or eliminate the rattle.

 

let us know what ya find

 

dont worry. i met a guy with a company 05 with like 340k on the odo. it rattled from day one and 340k later not any louder. nothing to worry about

 

i had toyota techs look at it and "document" it. They said it was normal.

 

^^ they always say its normal.

 

hell if they consider strange sounds like that normal...they'd probably consider me normal

 

My local tech and Toyota enthusiast recommended we try Schaeffer gear oil. He thinks it might at least dampen the noise and certainly do no harm. I ordered 4 qts and he will put it in next week. I will keep you all posted.

Carp

http://beansdieselperformance.com/store/index.php?act=viewProd&productId=135

 

I found this description of the problem and a Redline solution. It is the "NS" classification that seems to set this product apart from the rest. In addition, I talked to these folks and they recommended adding an antifriction additive "MOS2" from http://www.worldimpex.com/search_by_partno.html?searchmode=partno&partno=mos2 to the Redline "brew".

What do you guys think?

Top of Form​

Bottom of Form​

Make:​

BMW

Models:​

All BMW models including E46, E39, E36, Z3, and Z4

BMW Transmission Rattle / Gear rattle / Gear lash noise
With most any lightened flywheel, everyone sees the benefits immediately due to the reduction of the rotation weight. However, if there is a downside, it's the possibility of a rattle sound that may be evident at idle/low rpm. Note that this particular effect is only evident at idle with the clutch let out.

For details on what actually causes the sound, click here.
Heavier weight transmission fluid will damp the rattle effect, but may not be suitable for cold climates or high-mileage transmissions. The goal, then, would be to find a fluid that would have the high-temp heavy viscosity to damp the rattle but retain the low-temp thin viscosity and synchro additives to ensure all-condition smooth operation.

After experimenting with different weight transmission lubricants, we have come up with a formula that eliminates the gear rattle in the majority of test cars.

The recipe:

1 quart bottle of Redline 75W140NS Gear Oil. ( click here to order ) The "NS" oils have no friction modifiers, thus does not increase shifting effort. From the Redline information about the gear oil: "a GL-5 which does not contain the friction modifiers for limited-slip hypoid differentials. This makes the transmission synchronizers come to equal speeds more quickly, allowing faster shifting and much easier low-temperature shifting."
and...

1 quart bottle of Redline D4 Synthetic ATF. ( click here to order ) "D4 ATF is designed to satisfy the improved low-temperature requirements which will be in the new Dexron IV specification, and the improved shear-stability requirements which will be part of the new Mercon specifications. The balanced frictional characteristics provide smooth and consistent shifts for extended drain intervals. Provides improved shifting in cold weather."

How to use:

Drain the transmission (preferably when warm so as to allow as much of the original fluid to drain). Put in the full bottle of 75W140NS, then fill the remainder with the D4 ATF. Note that the majority of BMW transmissions will not take 2 complete quarts, so you will be left with approximately 1/5th of the bottle of D4.

HOT CLIMATE MIX

If you live in an area that is normally hotter than average (California or any Southern or SouthWestern state) then the ambient temps might make your transmission run hotter. In turn, this lowers the viscosity of the transmission fluid, which lessens it's ability to damp the gearbox rattle. Such being the case, we suggest substituting Redline MT-90 for the D4 ATF. So the mix is 1 bottle 75W140NS and the remainder of 1 bottle of MT-90.

MT-90: "MT-90 Manual Transmission Lubricant; a 75W90 GL-4 gear oil designed for use in manual transmissions and transaxles. Provides excellent protection of gears and synchronizers and its balanced slipperiness provides a perfect coefficient of friction, allowing easier shifting." ( click here to order )

 

http://beansdieselperformance.com/store/index.php?act=viewProd&productId=135

This appears to have done the trick. I would say 75% to 80% reduction in the noise. I can live with it!

Carp

 

I thought this was the story with all manual transmissions. Like mentioned, I hear it most at the drive through when its echoing off the building wall. It happens in my 6-speed and my old Infiniti G35. In fact, it was worse in the G35.

 

From the Internet research I have done on the Internet and the comments in the Forums, I believe this is a typical problem that occurs in a lot of manual transmissions regardless of genre. I believe it is a harmonic, gear problem that can be silenced with the proper lubrication. It is not a real problem that will cause destruction but rather an annoyance.

After lots of digging and talking to "experts" I decided to change my fluid to Royal Purple, MaxGear, 75w-140. I have a 2010, 4 cyl with a 5 speed manual transmission. It has 5,800 miles on the odometer. I did this yesterday and thus far the noise is completely gone. I will report back in a couple of weeks.

 

isnt 75 90 recommended for the tranny? just wondering because i'd be worried how 75 140 would shift in the winter time up here

 

I have experienced that on a VW and later I found out that it was the trany.