Can thicker oil cause shifting problems?

Joined
Jan 30, 2014
Messages
55
Location
nyc
This is probably a dumb question but can a thicker oil then required cause your tranny to shift abnormally,or does one have nothing to do with another?
 
Joined
Aug 20, 2003
Messages
16,767
Location
NE,Ohio
Originally Posted By: Bloodknights
This is probably a dumb question but can a thicker oil then required cause your tranny to shift abnormally,or does one have nothing to do with another?
uh thicker oil in the transmission can, engine oil... no.
 
Joined
Oct 24, 2011
Messages
6,170
Location
North Coast
Originally Posted By: Bloodknights
This is probably a dumb question but can a thicker oil then required cause your tranny to shift abnormally,or does one have nothing to do with another?
Yes, switch your trans to Redline products or Amsoil and it will shift better.
 

Bloodknights

Thread starter
Joined
Jan 30, 2014
Messages
55
Location
nyc
I should have been more specific I meant to say if the motor oil is thicker then required but no harm is being done to the engine,does the tranny feel different or behave differently shifting smoothly from one gear to the next(automatic)cuz of what is in the engine(thicker oil) or could one have nothing to do with each other,just a random thought thank u .
 
Joined
May 25, 2005
Messages
13,816
Location
ROCHESTER, NY
One doesn't have anything to do with the other, as you stated! Although, I guess in the colder temps, I may feel as though it does!
 

Bloodknights

Thread starter
Joined
Jan 30, 2014
Messages
55
Location
nyc
Originally Posted By: Char Baby
One doesn't have anything to do with the other, as you stated! Although, I guess in the colder temps, I may feel as though it does!
Ok thank u
 
Joined
Oct 28, 2002
Messages
48,068
Location
Everson WA - Pacific NW USA
Originally Posted By: Bloodknights
This is probably a dumb question but can a thicker oil then required cause your tranny to shift abnormally,or does one have nothing to do with another?
It can, and yours is actually an excellent question. But shifting is not always worse. Example. I switched to 75W-110 v. the recommended 75W-90 in my 2014 WRX and it actually (IMHO) shifts slightly BETTER when 17°F than 75°F. It really surprised me.
 
Joined
Dec 29, 2012
Messages
673
Location
Ohio
Just to clearly spell out what folks are saying: Motor oil goes into your motor. Transmission oil goes into your transmission. These are two separate systems that are mechanically linked, and motor oil selection in your motor will not impact shifting in the transmission. It is transmission fluid that will determine shifting performance, not motor oil.
 
Joined
Jan 5, 2008
Messages
3,561
Location
Central Iowa
On a manual transmission that is not synchronized, like a commercial heavy truck, a thicker oil in the engine can make an experienced driver look like a newbie on a real cold morning. The engine will drop off RPM's on the shift faster and throw the driver off his rhythm. Remember, to make the shift in a semi truck, you have to match the road speed, RPM, and the gear. Not anything like someone's car or pickup where a synchronized transmission makes up for incompetence.
 
Joined
Apr 8, 2013
Messages
3,506
Location
Delaware
I think what the OP was asking is can a thicker oil affect any of the engine sensors or cause the engine to run in a way the ECU and sensor inputs do not expect thus causing issues with the transmission. Many transmission issues are actually engine sensor issues. I don't know the answer but I think it is a good question considering the complexities of today's engines.
 
Joined
Dec 29, 2010
Messages
5,442
Location
Paramount, California
Originally Posted By: Bloodknights
This is probably a dumb question but can a thicker oil then required cause your tranny to shift abnormally,or does one have nothing to do with another?
Yes, absolutely so. Engine and transmission problems are very closely related, as the two work in tandem. Thicker engine oil results in sluggish low-throttle response because of increased engine friction, which in turn results in harsher transmission shifts from first gear to second gear at low throttle. That's because the decrease of engine output power due to thicker, high-friction oil will affect your programmed transmission shift points, which assume a certain engine output power. You may not notice this in powerful engines or with small viscosity changes, but it's easily noticeable in my car when I use 15W-40.
 
Top