Pennzoil Synchromesh fluid cured my grinding, but…

[TT'ed]

Hey everyone, nice to meet yall.
I have old 02 Audi TT Quattro, with 6 Spd manual. 72000 mi car.

few months ago, I noticed my 1-2 gear shift is grinding when I shift over 4.5K-5K RPM.
So- I poured some pennzoil synchromesh fluid with shifter cable end bushings.
That cured my shift grinding. I push gears in high rpm-no grinding.

Fluid was replaced 1000mi ago.

Still, I feel something is weird- such as small click(not a sound- it is a feeling) when Im putting in gear in 1 or 2nd gear but when I wiggle my shifter, it randomly goes in 1st gear and 2nd gear very smooth. I am not a experienced manual driver but I assume high rpm grind is synchro.

I can’t afford synchro fix. Will be fine to just drive it with Pennzoil? My factory fluid is GL-4.

I am dropping my transmission soon for clutch replacement, so if not- Im thinking trying redline MT-90 this time.

 

[bullwinkle]

I’ve used regular gear oil, Pennzoil Syncromesh, Liqui Moly GL-4 75W90, and RL MT-90 in my xB & Corolla manuals-the Red Line has been the best of all of them. The Syncromesh was too thin and thinned out to the point my xB’s axle seals started leaking it out.

 

[paulo57509]

The 1-2 and 2-3 shift was getting hard to engage at normal engine speeds. Especially when down shifting. Replacing the 10w-30 engine oil with Red Line MTL improved the situation but now years later, it's getting worse again.

A sure sign that it needs synchro replacement is it shifts fine when double clutched. At +440k miles, I'm sure the shift linkage is worn out as well.

 

[TT'ed]

I’ve used regular gear oil, Pennzoil Syncromesh, Liqui Moly GL-4 75W90, and RL MT-90 in my xB & Corolla manuals-the Red Line has been the best of all of them. The Syncromesh was too thin and thinned out to the point my xB’s axle seals started leaking it out.

Thanks. did synchro work well with MT-90?
Did you had grinding gears before?

 

[TT'ed]

The 1-2 and 2-3 shift was getting hard to engage at normal engine speeds. Especially when down shifting. Replacing the 10w-30 engine oil with Red Line MTL improved the situation but now years later, it's getting worse again.

A sure sign that it needs synchro replacement is it shifts fine when double clutched. At +440k miles, I'm sure the shift linkage is worn out as well.

I need at least few years until swapping gearbox- I will save some money for few years.
So- did u used 10W30 in transmission?

 

[paulo57509]

I need at least few years until swapping gearbox- I will save some money for few years.
So- did u used 10W30 in transmission?

10w-30 or 10w-40 is what Honda recommends for this transmission in the Legend. Both had been in the transmission from 0-293k miles. I then switched to MTL.

 

[MolaKule]

You might need a clutch adjustment as the connecting disengagement cable does stretch over time. Not having full clutch disengagement between shifts can cause gear crunching. .

An of course, a new throw-out bearing would be needed as well when you replace the clutch.

 

[TT'ed]

10w-30 or 10w-40 is what Honda recommends for this transmission in the Legend. Both had been in the transmission from 0-293k miles. I then switched to MTL.

Ill try MTL next time when I drain fluid.

 

[TT'ed]

You might need a clutch adjustment as the connecting disengagement cable does stretch over time. Not having full clutch disengagement between shifts can cause gear crunching. .

An of course, a new throw-out bearing would be needed as well when you replace the clutch.

Throw out bearing is clutch slave cylinder? My car uses hydurallic system

 

[MolaKule]

Throw out bearing is clutch slave cylinder? My car uses hydurallic system

OK, many cars still used the cable. You hadn't stated that your clutch system was hydraulic but that's cool.

 

[TT'ed]

OK, many cars still used the cable. You hadn't stated that your clutch system was hydraulic but that's cool.

Oh, I didn’t know cable driven clutch system exists. Im new to manual car so I thought every car uses hydraulic.

But, I am planning to put new clutch soon.

 

[mdocod]

Redline MT-90 has been great in my manual transmission that calls for GL-3/GL-4 75W-90 (non-hypoid) fluids. I believe it is "friction modified" to provide decent syncro behavior. It's been in my H3 for about 4 years, ~40K miles. I had it up on the lift a few weeks ago to check on all fluids. The transmission fluid "sample" (finger dip and wipe on paper towel) I pulled looked like it had been put in the day before. No discoloration, still feels and looks like it did 4 years ago. Meanwhile, the ATF in the T-case (yes it calls for ATF) was beat to heck brown in the same miles.... I think that's sorta telling.

I know that it's out of fashion here but if you're looking for a "fluid fix" prayer I would drain what's in there, then fill with 15W40 conventional HDEO oil with some AutoRX mixed in (about 6 oz) and run that for about 10K miles and see how things go. If cleaning can fix it, this will fix it. If cleaning can't fix it, the transmission rebuild shop will ask you how you got the inside of your old transmission so clean and varnish free, and you can tell them that you tried to fix a hard part problem with liquid prayers. Not much to lose to be honest.

 

[TT'ed]

Redline MT-90 has been great in my manual transmission that calls for GL-3/GL-4 75W-90 (non-hypoid) fluids. I believe it is "friction modified" to provide decent syncro behavior. It's been in my H3 for about 4 years, ~40K miles. I had it up on the lift a few weeks ago to check on all fluids. The transmission fluid "sample" (finger dip and wipe on paper towel) I pulled looked like it had been put in the day before. No discoloration, still feels and looks like it did 4 years ago. Meanwhile, the ATF in the T-case (yes it calls for ATF) was beat to heck brown in the same miles.... I think that's sorta telling.

I know that it's out of fashion here but if you're looking for a "fluid fix" prayer I would drain what's in there, then fill with 15W40 conventional HDEO oil with some AutoRX mixed in (about 6 oz) and run that for about 10K miles and see how things go. If cleaning can fix it, this will fix it. If cleaning can't fix it, the transmission rebuild shop will ask you how you got the inside of your old transmission so clean and varnish free, and you can tell them that you tried to fix a hard part problem with liquid prayers. Not much to lose to be honest.

Lol, thanks a lot. Are they yellow metal safe?

Currently, my transmission is:

If I softly put gear 1->2, I can feel the vibration and one-click just before going in 2 nd gear thru the gear knob. (feels like gear selector clicks between N->D)
So, It does go in without a grinding sound. (with synchromesh fluid!)

If I put a little force while gear changing 1->2, it does go in smoothly, also without grinding.
Not banging, but pushing gear in.

I am definitely trying MT-90 or- your method.

 

[Rygrego]

I’ve used regular gear oil, Pennzoil Syncromesh, Liqui Moly GL-4 75W90, and RL MT-90 in my xB & Corolla manuals-the Red Line has been the best of all of them. The Syncromesh was too thin and thinned out to the point my xB’s axle seals started leaking it out.

The exact same results I obtained. Pennzoil was terrible, then tried Royal Purple and it got a lot better, then finally switched to Redline MT90 and have never looked back.