Pennzoil Syncromesh oil

[Gary R.]

I am building a Muncie and want to use this product to coat the parts. I have not used it before and my local retailers do not stock a GL4 gear oil, about as common as hens teeth these days. So has anyone used this product?It is supposed to work with GM#12345349 or 12345577. According to the label it is safe for Bronze, Brass, and Copper.Thanks guysGary

[Gene M.]

Re: Pennzoil Syncromesh oil

Gary,
I used Pennzoil Syncromesh oil in the new 5 speed Tremec as the mftg'er requires. Not an easy product to find. Tranny is quiet and will keep using it as Brad Penn does not offer anything equal to it.

[Gary R.]

Re: Pennzoil Syncromesh oil

Gene........ I found Summit has the Brad Penn GL4 oil but I just want to lube parts so the Pennzoil should be fine. Thanks

[Gene M.]

Re: Pennzoil Syncromesh oil

Gene........ I found Summit has the Brad Penn GL4 oil but I just want to lube parts so the Pennzoil should be fine. Thanks

Gary
From information available it (Pennzoil Syncromesh oil) looks to be that it is specific for the gearing and syncros. I get Brad Penn locally the engine shop carries it in all different weights on the shelf. They are known for the "break in oil" so cams last.

[Gary R.]

Re: Pennzoil Syncromesh oil

Gene.... I use Brad Penn 10w40 now in my 72. I ran the 15w40 Rotella since I built the engine but always had a pegged oil press gauge. I was thinking the spring in the M55 oil pump was wrong and I was going to pull the pan but first switched over to the "green oil" and the gauge is normal now, yes more to do with going from 15w40 to 10w40 but I like it. I pick it up at Carlisle from the local distributor there.

[Donald A.]

Re: Pennzoil Syncromesh oil

Gary

i did a lot of study on this subject regarding what to use in my 63 Muncie. I came to the conclusion that only a straight GL-4 oil would be proper in it. If you have a NAPA store then you can get GL-4. It is made by Sta-Lube and is in their catalog and at many stores. I read article after article in the subject and learned that the Penn Syncro (GL-5's) can be harmful to "yellow" metals

[Gary R.]

Re: Pennzoil Syncromesh oil

Thanks Don, That is what I was looking for. My local NAPA was clueless and then I saw the syncromesh oil. I am just lubing the gears with it so it should be ok since it will be filled with GL4. I do appreciate it and it seems to be the last of the GL4 oil that might be commonly found at local stores.

[Duke W.]

Re: Pennzoil Syncromesh oil

Gary

I read article after article in the subject and learned that the Penn Syncro (GL-5's) can be harmful to "yellow" metals

Synchromesh transmissions that use the same basic internal design and materials as T-10s and Muncies have been around for about 70 years, and the Mil-L-2105/GL-5 spec is what GM always recommended.

I have never personally seen nor heard of any disassembled old manual transmission ever showing evidence of "yellow metal corrosion".

Have you?

Anyone else?

The GL-5 sulfur-based EP additive can cause such corrosion, but only at elevated temperatures significantly above the the typical warmed up operating temperature of the transmission. Yet the internet and car magazines are full of dire warnings about GL-5 and "yellow metal corrosion". They are also full of articles claiming that "they took all the zinc out of engine oil" and other various conspiracy theories.

GL-5 won't corrode your transmission, there is still plenty of zinc in C-category oils, and the sky is not falling, but there was a black helicopter circling my house all night, so I put a couple of extra layers of aluminum foil under my hat.

Duke

[Gary R.]

Re: Pennzoil Syncromesh oil

Hi Duke,......... I have to say I have not opened any used or trannies I rebuilt and found corroded syncros. Never was concerned about it with diff's because the only "yellow" metal in them are in the c2's where they used brass posi thrust washers. Those always get replaced with steel anyway.