Regal AWD PTU(transfer case) fluid change DIY

[mike69440]

Yea, most likely a non LS Hypoid type gear oil. The Hypoid designation would satisfy the Extreme temp and pressure requirements...

Anyone call Royal Purple?

 

[Hunter Mike]

Anyone call Royal Purple?

I looked at their sir a while ago and iirc, they have a LS additive.

I wouldn’t use them anyway as I rank them with Lucas...yuck!

I think Redline has a gear lube that would work too. Since they’re now owned by Phillips 66 I’m not sure about them either.

 

[sined240]

Since our cars are European manufactured and spec'd, many of the Fuchs, Febi Bilstein, Pentosin, Liqui Moly brand, Hypoid 75-90W gear oil would work. Most MB, BMW, Audi specifies these as OE suppliers and work well. The dealer prices for these 1 liter bottles of MB, BMW branded fluids are similar to what our AC Delco PTU fluid is...

 

[Hunter Mike]

Since our cars are European manufactured and spec'd, many of the Fuchs, Febi Bilstein, Pentosin, Liqui Moly brand, Hypoid 75-90W gear oil would work. Most MB, BMW, Audi specifies these as OE suppliers and work well. The dealer prices for these 1 liter bottles of MB, BMW branded fluids are similar to what our AC Delco PTU fluid is...

The PTU is made by an American company AAM, American Axle, sorry. Most likely made outside Detroit and shipped as a unit with engine to Germany for assembly. Engine and PTU from US, transmission from Japan, so it could be assembled onsite or from a subsidiary in Germany.

Ravenol makes a PTU lubricant for many VAG, BMW, and MB vehicles but it doesn’t list GM on it’s approved list. Gear Oil - Transfer Case Oil - RAVENOL TF-0870

 

[sined240]

The PTU is made by an American company AAM, American Axle, sorry. Most likely made outside Detroit and shipped as a unit with engine to Germany for assembly. Engine and PTU from US, transmission from Japan, so it could be assembled onsite or from a subsidiary in Germany.

Ravenol makes a PTU lubricant for many VAG, BMW, and MB vehicles but it doesn’t list GM on it’s approved list. Gear Oil - Transfer Case Oil - RAVENOL TF-0870

Interesting, still trying to figure out why this PTU needs such an expensive fluid with unknown sources. Any unique mechanical reason?

 

[Hunter Mike]

Interesting, still trying to figure out why this PTU needs such an expensive fluid with unknown sources. Any unique mechanical reason?

No idea. At this point I’m not willing to risk an expensive part for an unknown fluid to save $30. That’s why I sent it to be analyzed. There are some additives that don’t show up in the lab so I’m apprehensive.

The same company makes the PTU for Ford and they spec a 75w-140.

I’m changing mine again soon and found a good price fromGenuine OEM GM Parts Online | Look Up GM Parts

 

[sined240]

No idea. At this point I’m not willing to risk an expensive part for an unknown fluid to save $30. That’s why I sent it to be analyzed. There are some additives that don’t show up in the lab so I’m apprehensive.

The same company makes the PTU for Ford and they spec a 75w-140.

I’m changing mine again soon and found a good price fromGenuine OEM GM Parts Online | Look Up GM Parts

So much for changing the PTU fluid this week, the whole PTU unit will be replaced due to a tranny fluid leak🤣

Anyone wondering why a tranny leak leads to a PTU replacement is because on most AWD vehicles they mate with each other at the front axle. That's my best guess...

 

[Hunter Mike]

It's been awhile since I was under the car. The right output shaft of the tranny goes to the PTU and then out to the right front wheel and to the rear. The power flow appears to come out of the transmission directly to the left front wheel.

 

[Crispy]

Thanks Hunter Mike for all the info. I too do early gearbox/diff/t-case changes and it has served me well. About the tranny.. I have read only one write-up and it seemed a little unclear (don’t really remember). Wasn’t a simple “fill til it runs out” deal as I remember. Have you done your trans yet? Comments? Thanks! I will be doing that PTU pronto! C.

 

[Hunter Mike]

I’ve done the trans,PTU, and rear diff. PTU and diff are drain & fill while level and the trans is similar by has to be at a temp range read by a scan tool. 35-45C comes to mind. There’s an overflow pipe inside the drain plug. Search my posts as I believe I did a write up here. If not I can send instructions. I have the directions from both GM and Toyota. It’s easy but you need to be able to read the temp.

edit: here’s the writeup TourX transaxle drain & fill today. A DIY tutorial.

 

[Crispy]

One more question please.... After reading all these posts and the links, I'm not clear on the rear diff lube. Looking at the dealer invoice posted by Jack GS above, it looks like an additive (or second addittion) was included with the diff oil change for "clutches". Reading Hunter's post, it sounds like there is a second housing (my words) for the actuator that gets it's own bit of lube. Can you all just clarify this please and again THANKS for the great info. C.

 

[Hunter Mike]

The actuator is filled with Pentosin CHF11S fluid. It's a hydraulic fluid that activates the clutches. It is not in the hypoid gears where the most wear is.

I don't plan on changing mine.

The rear diff lube is 75w-90 with a limited slip additive, like Mobil 1 75w-90LS, Castrol Syntrax 75w-90LS, and others. You can buy it from your dealer or the aftermarket, your choice.

 

[Hunter Mike]

Here’s a PTU common on Ford AWD vehicles. AFAIK it’s the same vendor, AAM, as our PTU. This should give caution to anyone to change it early and often. Luckily ours comes with drain and fill plugs.

 

[clemson995]

Here’s a PTU common on Ford AWD vehicles. AFAIK it’s the same vendor, AAM, as our PTU. This should give caution to anyone to change it early and often. Luckily ours comes with drain and fill plugs.

Awesome write ups! I got a 2018 red needle With 11,000 miles. My question is, what are the recommended service intervals for the PTU and rear diff? I know the trans is 45k. I just changed my rear Diff with some 75w-90 redline. But I was wanting to change the rear Diff every 30k miles or so but I have no clue how often to change out the PTU fluid.

 

[Hunter Mike]

Lifetime fluid, fwiw.

 

[clemson995]

Lifetime fluid, fwiw.

ah okay. Well I may just change the PTU fluid soon and leave it as is for the remainder of time I have the car.And since that fluid is expensive....

 

[Hunter Mike]

ah okay. Well I may just change the PTU fluid soon and leave it as is for the remainder of time I have the car.And since that fluid is expensive....

Not compared to the price of a PTU replacement!

 

[mike69440]

Not compared to the price of a PTU replacement!

Mike

What is GM PN for PTU Lube?

Thanks

 

[Hunter Mike]

Mike

What is GM PN for PTU Lube?

Thanks

Post #1

 

[BenD]

O

For those interested I just got the analysis for new fluid. My goal was to see if a less expensive 75w-90 fluid was usable.

Hopefully BITOG will add to the discussion. VOA-ACDelco 19351882 PTU lubricant

View attachment 21129

Is this a fresh oil analyses? If yes, and you’re looking to compare 2 different brand, it should compared with used oil after the same interval.