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Regal GS shifting issues?

BowtieGuy

Buick Newbie
Hello all,

I have been doing some research on picking up a 2014-2015 Regal GS 6MT in the future, and I happened to be researching the gear ratios to compare to the ratios on my current Cruze Eco MT when I made a discovery: The Cruze M32 transmission uses the same Castrol BOT 402 OEM fluid that the Regal GS F40 transmission uses!

Furthermore, on the Cruze forums, there have been many, many complaints on the 1-2 shift grind, as well as notchy shifting with the stock GM/Castrol BOT 402 fluid. So I began looking here, and sure enough, I have found some of the same complaints about shift grinds and notchy shifting. Fortunately, some members on the Cruze forum began experimenting with other MT fluids for the M32, specifically Amsoil Synchromesh MTF and 75W-90 MTF. Amsoil makes no recommendation for the Cruze M32 (or Regal F40), but the results have been overwhelmingly positive. I personally have swapped my Cruze MT's factory MTF for Amsoil Synchromesh, and it made a definite difference in the shifting of the car. Some tried Redline's MTF, but the results were mixed.

That being said, now that some Cruze users have put some miles on both the Amsoil Synchromesh and the Amsoil 75W-90 MTF, The 75W-90 is looking to be the better fluid overall. If i were to make a recommendation for the F40, it would be to go for the 75W-90. As an added bonus, the 75W-90 is still much cheaper than the factory fluid at the dealer.

Part numbers:
OEM Cruze MTF: 19259104
OEM Regal MTF: 19259104
Amsoil 75W-90 MTF: MTGQT-EA
Amsoil Synchromesh: MTFQT-EA

I figured I would pass along this information if any of you Regal GS owners out there find it helpful.

Here are some links for reference to the Cruze forum if anyone is interested:
http://www.cruzetalk.com/forum/25-service-issues/7303-does-your-transmission-grind.html
http://www.cruzetalk.com/forum/10-powertrain/8637-eco-6-speed-manual-grind.html
http://www.cruzetalk.com/forum/129-engine-transmission-tutorials/6627-how-change-manual-transmission-fluid.html
 

kgoebz

Full Member
66
3
8
Ottawa ON
Buick Ownership
2012 Buick Regal GS
Ehh whatever. It's only rough when its really cold from 1-2 and 2-3. Not worth screwing around with IMO. Just take an extra second to shift between the gears and you're good lol
 

Walt G

Full Member
815
39
28
25 miles SW of Chicago
Buick Ownership
'12 Regal GS
The problem is that the fluid in the transmission is striking a compromise between shift feel (synchro performance) and gear protection. Synchros need to 'grip', and gears need to 'slip'.

It's easy to notice the improvement in shift feel immediately, but you wouldn't notice that the gears are wearing too fast until it's too late. Such a compact transmission combined with high torque capacity means the internal gears are under tremendous pressure where the teeth make contact, especially in the final drive gears.

I'm not saying this can't be done (change the fluid to something that works 'better'), but there is a risk to doing it. I'm sure the engineers that specified the fluid in this transmission were not idiots. They must have weighed the pros and cons and came to this conclusion (the BOT fluid), so to second guess them without any of the engineering information they have seems risky.
 

BowtieGuy

Buick Newbie
A key point to remember is that it is not just engineers involved. Bean counters get their say too.

From the research done on the Cruze forum, the conclusion is that the Castrol BOT 402 fluid used in these transmissions was chosen mainly for one purpose: fuel economy.

As far as longevity goes, if you dig into the threads linked on the Cruze forum, many members with the M32 transmission have put 30-50k+ on the Amsoil Synchromesh and/or 75W-90 without a single reported failure. On the same line, there have been reports of transmission failures (albeit most were replaced under the Chevrolet 5yr/100k powertrain warranty) on the stock OEM Castrol BOT 402 fluid. Of course we are not all engineers, but the results (as far as the Cruze M32 goes) speak for themselves.
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XtremeRevolution

Buick Newbie
2
0
0
Buick Ownership
Buick
Ehh whatever. It's only rough when its really cold from 1-2 and 2-3. Not worth screwing around with IMO. Just take an extra second to shift between the gears and you're good lol
It would be strange to think that Cruze owners, who purchased a car that costs half as much as yours, are more concerned with a transmission fluid that shifts properly. I don't want my transmission to shift rough ANY of the time, and if I know from experience that this is abnormal, I would want that issue to be resolved. Taking extra time to shift between gears because my fluid isn't doing its job kinda defeats the purpose of owning a sporty car, wouldn't you think?

GM has gone through three revisions of MTF in the Cruze M32. Three. None of those revisions meet the specifications we have learned about in Europe for these transmissions.

The problem is that the fluid in the transmission is striking a compromise between shift feel (synchro performance) and gear protection. Synchros need to 'grip', and gears need to 'slip'.

It's easy to notice the improvement in shift feel immediately, but you wouldn't notice that the gears are wearing too fast until it's too late. Such a compact transmission combined with high torque capacity means the internal gears are under tremendous pressure where the teeth make contact, especially in the final drive gears.

I'm not saying this can't be done (change the fluid to something that works 'better'), but there is a risk to doing it. I'm sure the engineers that specified the fluid in this transmission were not idiots. They must have weighed the pros and cons and came to this conclusion (the BOT fluid), so to second guess them without any of the engineering information they have seems risky.
There are many factors at play here, such as the viscosity of the oil (under all temperature conditions,) the traction coefficient of the gear oil itself, and the friction modifiers in the additive package. With the OE fluid in the Cruze, we had people who had to call off of work because they couldn't get their car into reverse until the fluid was warmed up. It was that bad. These transmissions were literally freezing up, and it was a number of people complaining about it.

Gears wear isn't exactly a concern with manual transmissions. This is why most manual transmissions spec either a GL-3 or GL-4 gear oil, which refers to the EP (extreme pressure) concentration in the additive package. It is uncommon to find manuals that require a GL-5 (some Subaru transmissions are included). With compact transmissions, more gears are fitted into a smaller package, but the gears are sized appropriately for the load. Your real concern is actually heat dissipation and how the transmission fluid handles that. One of the symptoms we noticed with the Cruze is inconsistent shift quality as the fluid warmed up.

The engineers that specified this fluid were not idiots, but they weren't operating alone either. The cons to using a better fluid involve things such as CAFE requirements cold weather performance. If cars were built by engineers, we'd have far better cars than we do today.

You guys are free to make your own decisions on what fluid to use, but having researched this issue thoroughly on UK forums with the same transmissions, having tested two TRUE synthetic lubricants, having received feedback on no fewer than 200 people who have switched to either AMSOIL fluid, and having received oil analysis reports that validate that the fluid is performing admirably with no abnormal synchro or gear wear, I and MANY people have come to the conclusion that BOT 402 is not the best oil to use in these transmissions. I've sold over 200 *changes* of manual transmission fluid, with most people getting the 75W-90 GL-4 oil. While this is admittedly just anecdote, there has been a 100% satisfaction rate.

The improved shift quality blatantly indicates less synchro slip and quicker engagements, and the thicker oil with the correct EP additives would inherently reduce gear metal to metal contact and therefore reduce wear as well. To be completely honest, people are way over-thinking gear oils.
 

Walt G

Full Member
815
39
28
25 miles SW of Chicago
Buick Ownership
'12 Regal GS
I'm all for letting people make their own decisions, that's for sure.

If anyone does want to try a trans fluid swap, according to the service manual the fill plug is on top of this transmission (I know, sounds stupid, but some are on the side, that way you can just fill until you reach the fill hole and you know you're at the correct level). I just checked on my car and it looks easy to get to. Allen head BTW.

The drain plug is located under the spot where the driver's side half-shaft exits (I didn't attempt to look at mine). Both are torqued to 22 lb-ft. Manual says to use new plugs... not sure why.

The manual says the trans holds 2.4 liters, but about 0.2 liters will stay in when you drain, so it says to fill with 2.2 liters.

I have not verified any of this (other than the location of the fill plug). It is just what the '12 Factory Service Manual says.
 

nizerims

SUPPORTING MEMBER
846
27
28
Buick Ownership
:(s)kciuB yM
How the hell do all you Canadiens (did I spell it right) know each other??

Walt G,
Feel I should chime in here for us with the 2014+ F40 manual transmission...... Slight difference, but not much.......



(damn you LIFX)
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GOT2B GM

Full Member
206
1
18
Woodstock Ontario Canada
Buick Ownership
2012 Regal GS 6MT, 1997 LeSabre Custom Supercharged
Did the trans oil change yesterday in my '12 GS.

1.7L of oem Castrol BOT came out.

Put 2L of AMSOIL 75W90 GL4 MTF back in.

Drain and fill plugs were a 8mm allen bit.

Fill plug being below the PCM on the front side of the trans.

Drain plug being on the bottom of the trans. No shields or guards had to be removed.

A long neck flexible funnel, or a funnel with a hose on the end is useful for refilling.

I haven't driven it yet, I'll chime in later with impressions.
 

wungun

Full Member
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0
Buick Ownership
Buick
I thought it took 3.1L of oil....?
Did you warm it up before you drained it? Looking forward to your feedback.
 

GOT2B GM

Full Member
206
1
18
Woodstock Ontario Canada
Buick Ownership
2012 Regal GS 6MT, 1997 LeSabre Custom Supercharged
Factory recommended fill is 1.7L according to that FSM scan that niz posted.

Some guys on the cruze board are talking about overfilling to 2.5L to improve oiling.

I drained it relatively cold, but let it drain for quite a while. Even cold the oil is fairly light and drains quickly.
 

Walt G

Full Member
815
39
28
25 miles SW of Chicago
Buick Ownership
'12 Regal GS
My 2012 factory service manual says you'll get 2.2 out if you do a drain.

With my car shifting pretty badly in this cold weather, I also figured I'd try the Amsoil. I did it a few weeks ago. I got 1.8 out of my warmed up trans after letting it drain for 30 minutes, and put 2.0 back in.

Unfortunately, I got no improvement. I really wanted it work. My trans is still pretty bad when the trans is cold, but then is fine once everything is warm.

It was very easy to do the drain and fill, and not very expensive, but no improvement that I can tell. I'm curious to hear if others come to the same conclusion.
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BowtieGuy

Buick Newbie
From other Cruze owners, the experience has been an improvement over the OEM fluid once the fluid warms up. Others who had issues with a 1-2 grind reported it went away after switching to Amsoil. All manual transmissions are a little clunky in the cold in my experience.
 

wungun

Full Member
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0
Buick Ownership
Buick
I'm gonna go with Royal Purple...
And I though you filled MT til it starts draining out of the fill hole?
 

kgoebz

Full Member
66
3
8
Ottawa ON
Buick Ownership
2012 Buick Regal GS
It would be strange to think that Cruze owners, who purchased a car that costs half as much as yours, are more concerned with a transmission fluid that shifts properly. I don't want my transmission to shift rough ANY of the time, and if I know from experience that this is abnormal, I would want that issue to be resolved. Taking extra time to shift between gears because my fluid isn't doing its job kinda defeats the purpose of owning a sporty car, wouldn't you think?

GM has gone through three revisions of MTF in the Cruze M32. Three. None of those revisions meet the specifications we have learned about in Europe for these transmissions.
I had a Cobalt before. IIRC it was the F25 Getrag and same thing would always happen in the cold. This is also a Getrag box as far as I understand so I'm not terribly surprised that it behaves similarly. All transmissions will behave poorly in the cold. It's a fact of life and I see it all the time at work. Some cars are undoubtedly better than others, granted, but I'm not going to waste my time fiddling with changing trans fluid on the car when it wont solve anything.

The other week it was -20C in the morning and I actually had to do a 1-3 shift because it didn't want anything to do with 2nd as I left my spot haha. It's a GM...lower your expectations and you'll be much happier :p
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wungun

Full Member
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0
Buick Ownership
Buick
My Fiesta 5 speed winter beater doesn't have any cold weather issues...but it shifts and sounds like the fluid is the viscosity of water :S
My SVT Focus (Getrag) did have cold weather stiffness.
 

MattyT

Full Member
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0
16
Buick Ownership
Buick
I changed my manual transmission fluid today, I replaced it with Royal Purple Max Gear 75w-90. I drained right about 1.8 liters out and put 2 liters back in. My car has 60k miles so I figured it was due and if it fixes the second gear shift then that's a bonus. After changing the oil I took it for a drive, while cold I didn't notice a huge improvement but once it got warm it was a huge improvement on the 1-2 shift and on the 3-2 shift while downshifting. Changing the oil took all of about 20 minutes and about 10 of them were spent trying to figure out a way to measure how much fluid came out. It cost me 45 bucks and a little time, I would definitely recommend swapping out that factory oil.
 

GoHack

Sustaining Member
8
1
3
SoCal
Buick Ownership
2013 Regal GS, Smokey Grey, 6 Speed M/T, Navigation Package
I've got a 2013 GS w/a 6 Spd. M/T, which I just bought, w/60K miles on it.

I plan to go right through the vehicle, since I have no physical history of it. According to Carfax, the engine oil/filter were changed on a regular basis.

I checked w/the local Buick dealer today as to what manual transmission fluid it uses, and they said Genuine GM Fluid 19259104, for the US , and 19259105 for Canada.

Of course I will need to order it, since they don't carry it.

From what I read here, it takes around 2.2 pints, or 1.1 quarts.

On Amsoil website, it says: No recommendations available, w/a capacity: MR6 3.6 pints; Torques: Manual Transmission Drain Plug...22 ft/lbs, and the Fill Plug...22 ft/lbs

As much as I'd like to put Amsoil gear oil in, but just to be safe, I'm going to go w/the recommended GM Fluid 19259104.
 
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