MTL-R or MTL-P (or pennzoil/gm syncromesh) in VW tranny??

[robnitro]

Got a 2001 VW jetta TDI and the redline mt90/mtl mix in the tranny sucks. 2nd gear and 3rd are notchy, and sometimes can grind if I push too easy.

The stock VW fluid is like a 70w85 , a thinner 90 you could say, but is rated 70w90. Specialty formulations mtl-p is a 70w85, and mtl-r is a 70w90. Pennzoil syncromesh, that I bought a few days ago, is like a 70w80, like MTL is.

What is the benefit of running a thicker 70w90 fluid like MTL-R over a thinner but as good in terms of shear MTL-P or pennzoil syncromesh?

Wouldnt a thinner oil be better for syncro engagement/life? Woudln't it be close enough to protect the gears but not be as thick especially in the cold (which IMO creates the most wear)?

 

[robnitro]

Also, forgot to ask, what is a good interval on the SF MTL-R or mtl-p fluids?
What about pennzoil/gm syncromesh fluid? I heard that fluid loses its effectiveness after a while.

Anyhow syncromesh and mtl-r and mtl-p are known to be great in terms of shifting quality, which is what matters most to me.

 

[crew219]

no . . . . vw oem fluid is a 75w90 . . . get MTL-R

 

[MolaKule]

quote:

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Also, forgot to ask, what is a good interval on the SF MTL-R or mtl-p fluids?
What about pennzoil/gm syncromesh fluid? I heard that fluid loses its effectiveness after a while.

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We recommend 30,000 miles unless you work with an oil analyst and then you could extend or change depending on the analyst report. Terry Dyson knows the oils well so he would be a great asset.

Pennzoil and GM synchromesh are too thin according to VW specs, since VW specs a 75W90. MTL-P would only be advantageous for extreme northern climates.

 

[robnitro]

Wow, 30k? The oem VW fluid was good until about 80k when I changed to MT-90/MTL. I know it probably sheared hard, but it shifted pretty well.

I went with syncromesh as I got it a few days ago, and had a chance to use my friend's garage just today. The streets here suck for work as they aren't level (hilly and the crown).

Winter is coming soon, so I felt to change it asap! It shifts great, and no whine at all, but I will keep an 'eye' on it.

I will probably analyze it after 30k, and then see if it is wearing anything. If it is doing bad, I definately will go to MTL-R. Is it neccessary to run TBN tests or is oxidation/nitration sufficient? I think Terry's CAT testing service doesn't do TBN?

I'm not worried about the viscosity, as the OEM fluid is a pretty thin 90 at that, even thinner than the MTL-R you sell. Also, the slightly thinner visc would help with mileage as there is less drag.

 

[MolaKule]

quote:

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I'm not worried about the viscosity, as the OEM fluid is a pretty thin 90 at that, even thinner than the MTL-R you sell. Also, the slightly thinner visc would help with mileage as there is less drag.

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I would be worried unless you tested the OEM fluid for viscosity @100 C.

quote:

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Pennzoil and GM synchromesh are too thin according to VW specs, since VW specs a 75W90.

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Our fluids are speced for max EP protection and proper viscosity.

 

[Terry]

ALL our kit offerings give TBN and or TAN as appropriate.

The Premium and In house kits both offer FTIR, Blackstone/Dyson kit offer centrifuged insolubles,flash, for a good alternatative cross section to FTIR.

Any of the 3 kit options will give me enough data to properly evaluate the trans and the lubricant chosen.

Terry

 

[crew219]

quote:

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Originally posted by robnitro:


I'm not worried about the viscosity, as the OEM fluid is a pretty thin 90 at that, even thinner than the MTL-R you sell. Also, the slightly thinner visc would help with mileage as there is less drag.

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OEM is .7 cst @100C thinner than MTL-R. I don't know where you're getting these ideas from.

Dave

 

[robnitro]

Ohh, I see, I thought they ran a 70w85, labeled as a 70w90. I will let the analysis notify me if its harmful to run through summers. I'll probably run a 15k interval instead- to be safe. I feel there is no issue at all as it runs great in crazy applications like vettes, vipers, m3's, s2000's etc but I'm careful.

The thing I've heard at tdiclub that blows up vw o2j trannies are the differential rivets and/or the spider gear pin. I don't think that can be prevented by a thicker fluid.

If indeed the thinness is an issue, is there anything to hear/look for?

Also forgot to add, I read a site from member AEHaas spoke about thinner oils, how at higher temps the spread is smaller. Anyhow, the TDI runs pretty cool. Even the turbo doesn't need much of a cool down, unlike a gasser

[ October 10, 2005, 06:36 PM: Message edited by: robnitro ]

 

[MolaKule]

quote:

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I feel there is no issue at all as it runs great in crazy applications like vettes, vipers, m3's, s2000's etc but I'm careful.

If indeed the thinness is an issue, is there anything to hear/look for?

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Different transmission designs require different viscosities. For example, horsepower, gear type/cut, shaft and bearing diameters, type of bearings, etc all determine what fluid will be used.

Thinness can manifest itself as a coasting whine just below cruise, large metal particles (more than just the gray paste on the magnetic plug) in the oil, lots of brass sparkle, and shifting that feels like the slider is dragging, looseness in the driveline that feels like there is a large clearance somewhere.

 

[robnitro]

quote:

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Originally posted by MolaKule:
Different transmission designs require different viscosities. For example, horsepower, gear type/cut, shaft and bearing diameters, type of bearings, etc all determine what fluid will be used.

Thinness can manifest itself as a coasting whine just below cruise, large metal particles (more than just the gray paste on the magnetic plug) in the oil, lots of brass sparkle, and shifting that feels like the slider is dragging, looseness in the driveline that feels like there is a large clearance somewhere.

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Ohh I see, different bearings in diff trannies, didn't think it would vary that much!

I used to have a coasting whine like that with the MT90 alone, and also when I mixed in 1 qt (2 qt total) of MTL. I think redline isn't as great as it is made to be, heck it came out brown after only about 6k use!

 

[MolaKule]

Bearings, right.

The higher horsepower trannies might have large ball or roller bearings whereas the lower horsepower trannies might have sleeve or pin/needle bearings.

 

[mechtech]

robnitro - When the Penn Synch starts to lose it's performance next spring - put in the S.F. in the proper grade, and be happy.

 

[robnitro]

Next spring? That soon? I doubt it, but yeah I will definately switch it if it starts feeling crappy. Heck, I switched out this MT90/MTL mix early cause the shifting felt notchy.

This syncromesh feels like playing a video game, even tried a 4-2 shift for a hard turn on the way home today without double clutching. It felt like playing the ferrari 355 arcade racing sim, lol.

I also would do sf next change, especially since he knows his stuff. It would be a cool comparison.

 

[Mr Nice]

Is it worth getting a UOA on trans fliud every 50K Miles ??

 

[FTO-UK]

The thing to remember about the viscosity figures quoted above is that they are at 100 deg. C. In my FWD Mitsubishi sportscar the transmission hardly gets above 60 deg. C - even when driving hard on a warm day. The transmission is mounted transversly and there is good airflow to the casing. For me, the KV's quoted at 100deg. C are therefore pretty meaningless. In cool weather I doubt my transmission would even see 50 degrees - unless I was sat in traffic for hours when heat soak from the engine would lift the temps a bit.

What is more important, IMHO, in the KV at 40 degrees and also the Viscosity Index. I went with SF Synchoglide (a Synchromesh-type fluid) in my application (although the manfr. specs a 75W-85) because I mainly do short runs in a cool climate and so benefit from the lower viscosity.

 

[coasterguy]

Can MTL-R (14.7) and MTL-P (11.5) be mixed to achive a fluid in the mid 13's? The OEM VW fluid is a little thick in the snow so I would like to just run MTL-P but I'm a little concerned about next summer.