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Regal AWD PTU(transfer case) fluid change DIY

Hunter Mike

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193
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America’s Dairyland
Dark Moon 19 Buick Opel Vauxhall Insignia Country Tourer Regal TourX Essence Estate Avant Wagon
I took the time today to change the factory fill in the PTU unit. For someone who has a lift this is an easy 15 minute job using minimal tools. I did it on my garage floor using ramps and jacks and it took about an hour. Mileage was 15,400, 90% highway.

The PTU uses a ACDelco specific fluid p/n 19351882. It has a list price of over $90USD/quart! The description shows it's a 75w-90 synthetic gear lube with EP additives. I was tempted to use some 75w-90 gear lube I have in the stash but with a new transfer case price of $1k or more plus install I bought the fluid from the dealer. I knew it was pricey so I told my dealer to help me out on the price so I walked out for $55+tax. Several online sellers are close in price but charge a ton for shipping so I was happy with the price.

I drove the car up on my Rhino ramps and then jacked up the rear. Making sure the car was level front to back and left to right I then added jack stands under the rear for extra safety.
IMG_1056.jpeg

The fill plug and drain plug are closest to the right side of the PTU and I found going under the front of the car to be the easiest to get a good view.
Fill:
IMG_1051.jpeg
Drain: (sorry about the angle)
IMG_1052.jpeg

You can see that both are identical and have a 3/8" square drive head and there was plenty of room to fit my 3/8" drive ratchet into both.

First step on any differential change is to make sure you can refill it! Remove the filler plug first, then the drain plug. I estimate the torque was between 15-20lb-ft. I put a clean drain pan underneath so I could get a visual on the fluid. It was a bit darker than new but not horrible.
IMG_1057.jpeg
The drain and fill plugs were identical and both were magnetic. The drain plug on the right has most of the metallic crud on it.
IMG_1054.jpeg
IMG_1055.jpeg
If you have the car on a lift over your head filling is pretty easy but there is limited access. I needs to be pumped up to the PTU. I chose to fill it from the top using 3 feet of 1/4" clear tubing that I ran behind the engine. I bought a new 2oz/60cc syringe from a hardware store from the equine section. If I did it again I would use 3/8" tubing as it was the bottleneck and try to find a bigger syringe. The specified capacity is 0.69qts according to GM. That translates to 22oz. I put 23ish oz. in mine before the fluid was dripping out.

I didn't want to waste any of this precious proprietary fluid and only lost about an ounce in the process.

Let me know if you have any questions.
 
Last edited:

Uniqez

Active member
331
120
43
2018 Regal TourX Essence
I took the time today to change the factory fill in the PTU unit. For someone who has a lift this is an easy 15 minute job using minimal tools. I did it on my garage floor using ramps and jacks and it took about an hour. Mileage was 15,400, 90% highway.

The PTU uses a ACDelco specific fluid p/n 19351882. It has a list price of over $90USD/quart! The description shows it's a 75w-90 synthetic gear lube with EP additives. I was tempted to use some 75w-90 gear lube I have in the stash but with a new transfer case price of $1k or more plus install I bought the fluid from the dealer. I knew it was pricey so I told my dealer to help me out on the price so I walked out for $55+tax. Several online sellers are close in price but charge a ton for shipping so I was happy with the price.

I drove the car up on my Rhino ramps and then jacked up the rear. Making sure the car was level front to back and left to right I then added jack stands under the rear for extra safety.
View attachment 20654

The fill plug and drain plug are closest to the right side of the PTU and I found going under the front of the car to be the easiest to get a good view.
Fill:
View attachment 20655
Drain: (sorry about the angle)
View attachment 20656

You can see that both are identical and have a 3/8" square drive head and there was plenty of room to fit my 3/8" drive ratchet into both.

First step on any differential change is to make sure you can refill it! Remove the filler plug first, then the drain plug. I estimate the torque was between 15-20lb-ft. I put a clean drain pan underneath so I could get a visual on the fluid. It was a bit darker than new but not horrible.
View attachment 20657
The drain and fill plugs were identical and both were magnetic. The drain plug on the right has most of the metallic crud on it.
View attachment 20658
View attachment 20659
If you have the car on a lift over your head filling is pretty easy but there is limited access. I needs to be pumped up to the PTU. I chose to fill it from the top using 3 feet of 1/4" clear tubing that I ran behind the engine. I bought a new 2oz/60cc syringe from a hardware store from the equine section. If I did it again I would use 3/8" tubing as it was the bottleneck and try to find a bigger syringe. The specified capacity is 0.69qts according to GM. That translates to 22oz. I put 23ish oz. in mine before the fluid was dripping out.

I didn't want to waste any of this precious proprietary fluid and only lost about an ounce in the process.

Let me know if you have any questions.
Nice write up mate. Do you know how often you have to do this?
 

Hunter Mike

Active member
319
193
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America’s Dairyland
Dark Moon 19 Buick Opel Vauxhall Insignia Country Tourer Regal TourX Essence Estate Avant Wagon
Nice write up mate. Do you know how often you have to do this?
Thanks. There is no interval in the owners manual. Lifetime fluid...when it fails, it’s life is done!

I’ve always been a big proponent of changing gear fluids early because that’s when the most wear occurs.

I plan on doing it with the transmission which has a severe service interval at 45k miles. While it’s up and level I can take care of three things. Tranny, PTU, rear diff.
______________________________
 

Jack GS

SUPPORTING MEMBER
351
381
63
Metro Detroit
2019 Regal GS
+1 on the nice write up. Good stuff.

For the sake of having relevant data in close proximity, I have attached my dealer receipt for a transmission service, AWD service (PTU & rear differential), and rear differential clutch service. Hopefully this is helpful to anyone that is considering this service and would like to compare the price/time to DIY vs. let the dealer handle it.

I was charged $231.36 for the AWD service. Again, this was for the PTU and rear differential. All job totals are highlighted.

Link to @Map18TTourX's rear differential fluid change thread: Rear Diff change 15K
 

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Hunter Mike

Active member
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America’s Dairyland
Dark Moon 19 Buick Opel Vauxhall Insignia Country Tourer Regal TourX Essence Estate Avant Wagon
After a little digging the PTU is made my AAM, who does a lot of differentials, gears, PTU, and machining for the OEM’s. Thankfully our car has a drain and fill plug, owners of Ford cars are burning through PTU’s since there is no service schedule, no drain, and it’s located just over 2 catalytic converters. Owners are sucking the fluid out of the fill plug and refilling. Ford specs a 75w-140 so it looks like the OE’s can choose their own fluids. Ravenol makes a PTU fluid for VAG, BMW, JLR, and others and its still about $50/qt.
 

Banjo

Active member
134
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2018 Reagal GS
All the Expensive tech and no front bash plate underneath to protect the cases and stuff
______________________________
 

Hunter Mike

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193
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America’s Dairyland
Dark Moon 19 Buick Opel Vauxhall Insignia Country Tourer Regal TourX Essence Estate Avant Wagon
Anybody have more information on the Differential Clutch Service? Location of drain and fill plugs?
If you mean the actuator for the rear diff it shouldn’t need service. It’s not exposed to the wear like hypoid gears. It uses a small amount of Pentosin CHF11S hydraulic fluid. Jack GS had his done at the dealer.

if you mean the rear diff I did a DIY post a couple months ago using 75w-90LS.
 

sined240

Member
91
17
8
2018 Regal TourX
If you mean the actuator for the rear diff it shouldn’t need service. It’s not exposed to the wear like hypoid gears. It uses a small amount of Pentosin CHF11S hydraulic fluid. Jack GS had his done at the dealer.

if you mean the rear diff I did a DIY post a couple months ago using 75w-90LS.
Thanks, have done many diff service myself and will be doing it for the TourX soon!
 

sined240

Member
91
17
8
2018 Regal TourX
Was able to complete the PTU fluid change and rear differential fluid change without any issues. One thing I noted when completing the PTU, I noticed some red fluid seepage near the exhaust flex pipe. Most likely tranny fluid but never noticed any drips on the garage floor. Weird, will have it checked out at my oil change this Friday.

Let me know if anyone else noticed theirs...
 

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sined240

Member
91
17
8
2018 Regal TourX
Quick question,

Did your new PTU fluid bottle have any foil seal when you took off the cap? Mine didn't, when you took the cap off, it was open like there never was any seal. For such expensive fluid, it was a crappy bottle and basic labeling and no seal.

Thanks,
Den
______________________________
 

Hunter Mike

Active member
319
193
43
America’s Dairyland
Dark Moon 19 Buick Opel Vauxhall Insignia Country Tourer Regal TourX Essence Estate Avant Wagon
Quick question,

Did your new PTU fluid bottle have any foil seal when you took off the cap? Mine didn't, when you took the cap off, it was open like there never was any seal. For such expensive fluid, it was a crappy bottle and basic labeling and no seal.

Thanks,
Den
I don’t think so.
 

Hunter Mike

Active member
319
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43
America’s Dairyland
Dark Moon 19 Buick Opel Vauxhall Insignia Country Tourer Regal TourX Essence Estate Avant Wagon
Yea, it smelled just like gear oil but weird for it's price. GM is probably laughing at us...
If you look at the VOA I sent to analyze its not a very strong additive package. One of the gear oil guys on BITOG says that a non-LS gear oil would be a good substitute. I’ll wait until after warranty to try Amsoil Severe Gear. An email from Amsoil says that they don’t have a fluid that is suitable so I’m a little apprehensive.
https://amsoilcontent.com/ams/lit/databulletins/g2043.pdf
 

sined240

Member
91
17
8
2018 Regal TourX
If you look at the VOA I sent to analyze its not a very strong additive package. One of the gear oil guys on BITOG says that a non-LS gear oil would be a good substitute. I’ll wait until after warranty to try Amsoil Severe Gear. An email from Amsoil says that they don’t have a fluid that is suitable so I’m a little apprehensive.
https://amsoilcontent.com/ams/lit/databulletins/g2043.pdf
Yea, most likely a non LS Hypoid type gear oil. The Hypoid designation would satisfy the Extreme temp and pressure requirements...
 
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