Pennzoil 75-140 Full Synth??

SirKeats · 10-31-2009, 05:11 PM

I use the pennzoil platinum in my engine... I've been very pleased with it. Figured I might consider the 75-140 for the rear diff.

Anyone used this?

SirKeats · 11-02-2009, 01:22 PM

nobody's got an opinion on this synth oil? i've heard great things on here about the platinum engine oil. i would think/hope that the gear oil is equally good, but would prefer input from folks in the know before i spend the money. it'll be for my truetrac i'm having installed, so i wanna make sure i'm not putting in an inferior product.

**Juday** · 11-02-2009, 01:54 PM

White Paper - A Study of Automotive Gear Lubes

Look through that and see how well the Pennzoil does. Me, personally, I'd put in a high quality gear oil to help in every single way I could with a TrueTrac. Don't skimp out on $25 worth of oil to possibly destroy your rear differential.

That's my $0.02.

SirKeats · 11-03-2009, 06:40 PM

for a study posted on the amsoil website that conveniently concludes that amsoil is better than the rest, they aren't very forthcoming regarding information about this "independent laboratory" that conducted many of the tests... and they fully admit that all of the physical property tests were conducted in-house.

while i certainly agree that amsoil is a top quality lubricant, i have a hard time putting a lot of stock in this white paper. it certainly makes for interesting reading though.

flewbyu · 11-03-2009, 06:41 PM

I use royal purple in my diff.

**Juday** · 11-04-2009, 06:46 AM

Quote:

Originally Posted by SirKeats

for a study posted on the amsoil website that conveniently concludes that amsoil is better than the rest, they aren't very forthcoming regarding information about this "independent laboratory" that conducted many of the tests... and they fully admit that all of the physical property tests were conducted in-house.

while i certainly agree that amsoil is a top quality lubricant, i have a hard time putting a lot of stock in this white paper. it certainly makes for interesting reading though.

I'm just providing you with the only gear lubrication test chart that I know of. If you don't believe it, you can check out Welcome for more information about various oils/lubes. There I'm sure you'll find the non-biased folks and see what they're running.

SirKeats · 11-04-2009, 09:07 AM

I know. Didn't mean to suggest you were a shill for Amsoil or anything. Just commenting on the report itself.

Like I said, I actually like Amsoil. I used it at first in my engine... but it's not locally available and was a pain to get so I switched to the penzoil platinum that a number of folks recommended here.

That said, since gear oil is changed so infrequently, I'll probably just order up the 75140 Amsoil for the ol' pumpkin.

Quote:

Originally Posted by Juday

I'm just providing you with the only gear lubrication test chart that I know of. If you don't believe it, you can check out Welcome for more information about various oils/lubes. There I'm sure you'll find the non-biased folks and see what they're running.

**Juday** · 11-04-2009, 09:13 AM

If anything, call up the company who makes the TrueTrac (Detroit, isn't it?) and see what they recommend putting in there. They might prefer one thing over another. Tell them that you're thinking about putting Amsoil 75W-140 and see if they have any problems with that.

Good luck with whatever you decide.

SirKeats · 11-04-2009, 11:00 AM

already did. hehehe. email though rather than call. though i didn't ask them about oil brand and doubt they'd commit anyway (companies have to be careful these days about endorsing a specific brand of something).

what i did ask was two things:

dino or synth oil. the trutrac manual says to use manufacturer recommendations... which for us is synth. however, the FAQ on their page for the exact same trutrac says to NOT use synth. so i asked them to clarify the contradiction for me.

i also asked them to clear up the debate on whether or not a break-in is necessary (i.e. change oil after 500 or 1000 miles). some folks here say yes, others say no. i framed the question to them as what was best, not what was necessary since even if it's not entirely necessay but would be best for the part, i'd prefer to do it.

i'll keep yall posted!

**Juday** · 11-04-2009, 11:08 AM

Thanks, please do. I'm curious to know myself, as I'll be adding a TrueTrac here in the next couple of months.

gary748 · 11-04-2009, 05:35 PM

You'll be fine using a synthetic 75w-140. Myself and others have been running Mobil 1 and any of the other brand name oils with no issues. I did a break in on mine but I tend to error on the side of caution and over maintenance all my vehicles. Eaton won't give you any more insight. If they can't torque some bolts down properly they probably didn't do the required research on the correct oil to use. I just inspected my TT after 9k and it looks brand new. The M1 was nice and golden too. Had a little over 8k on it.

SirKeats · 11-04-2009, 05:55 PM

Quote:

Originally Posted by gary748

Eaton won't give you any more insight. If they can't torque some bolts down properly they probably didn't do the required research on the correct oil to use.

LOL

Thanks for the input. How long did you run your break-in? 500 miles? 1000?

gary748 · 11-04-2009, 06:03 PM

Quote:

Originally Posted by SirKeats

LOL

Thanks for the input. How long did you run your break-in? 500 miles? 1000?

No problem... I split the difference and changed it at 750 miles. I don't think there is a conventional oil in the 75-140 weight that's readily available.

gabriel c. · 11-05-2009, 08:33 PM

so you just drain and fill or do you have to remove the cover and clean something inside.

gary748 · 11-05-2009, 09:23 PM

Just drain and fill. Be sure to clean the magnetic drain plug of the "fuzz" and you'll be good to go. When you get maybe 10k on it you may want to open the cover and check that the bolts haven't loosed up.