transmission and power steering fluid levels

[pm26]

Well, I never thought I would ask such simple questions, but here is the issue:

 

On my '05 Z71 with the 5.3 V8 and factory tow package, when I check the transmission fluid level with transmission hot, engine idling in Park, the level is not within the HOT crosshatched area on the dipstick. I checked the owner's manual and they recommend checking the fluid cold with engine idling, in Park first. I did that and the fluid level is slightly above the COLD crosshatched area on the bottom of the dipstick. Which should mean that the level is correct. However, the manual says that "the cold level is for reference only". What exactly does this mean? If I add fluid to the transmission to bring the level up to the middle of the HOT crosshatched area, the level will be substantially above the COLD area when checking the fluid cold. What gives? Looks like they did not place these marks properly based on hot fluid expansion. Or do you need to get the transmission fluid REALLY hot before it expands enough to register full in the HOT area of the dipstick?

 

The same goes for power steering fluid. When checked cold, it is slightly above the FULL COLD line. When checked hot, it is substantially below the FULL HOT line.

However, in this case I can see that there is plenty of fluid in the pump reservoir, so this does not bother me.

[CombatTalon2]

Well, I never thought I would ask such simple questions, but here is the issue:

 

On my '05 Z71 with the 5.3 V8 and factory tow package, when I check the transmission fluid level with transmission hot, engine idling in Park, the level is not within the HOT crosshatched area on the dipstick.  I checked the owner's manual and they recommend checking the fluid cold with engine idling, in Park first.  I did that and the fluid level is slightly above the COLD crosshatched area on the bottom of the dipstick.  Which should mean that the level is correct.  However, the manual says that "the cold level is for reference only".  What exactly does this mean?  If I add fluid to the transmission to bring the level up to the middle of the HOT crosshatched area, the level will be substantially above the COLD area when checking the fluid cold.  What gives?  Looks like they did not place these marks properly based on hot fluid expansion.  Or do you need to get the transmission fluid REALLY hot before it expands enough to register full in the HOT area of the dipstick?

 

The same goes for power steering fluid.  When checked cold, it is slightly above the FULL COLD line.  When checked hot, it is substantially below the FULL HOT line.

However, in this case I can see that there is plenty of fluid in the pump reservoir, so this does not bother me.

 

<{POST_SNAPBACK}>

 

 

 

I checked my trans fluid today as well. I have 15,000 miles on the truck. When checking Hot (after driving for 15 minutes) and then going thru the procedure of shifting the trans while the engine is running, i was getting readings below the hot area as well. I added half of a quart to bring it up to the middle of the HOT area. I will check it cold after it has set all night.

[ken1mod]

don't sweat the p/s level, as long as you can see oil on the stick its great, overfill will simply blow out.

 

Trans needs to be close to spec. overfill causes oil to rise to touch gears causing foaming and instant trans failure . do not overfill.

 

i have similar problem with my silvy. the oil never really gets hot because of the trans coolers.

 

Very important not to overfill.

 

ken

[pm26]

don't sweat the p/s level, as long as you can see oil on the stick its great, overfill will simply blow out.

 

Trans needs to be close to spec.  overfill causes oil to rise to touch gears causing foaming and instant trans failure . do not overfill.

 

i have similar problem with my silvy.  the oil never really gets hot because of the trans coolers.

 

Very important not to overfill.

 

ken

 

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Instant transmission failure in case of overfill? I think you are exaggerating here. One extra quart probably would do nothing. Three or four extra quarts might cause some oil foaming, but I do not believe instantaneous failure would occur even then.

[ozfam4]

 

Trans needs to be close to spec.  overfill causes oil to rise to touch gears causing foaming and instant trans failure . do not overfill.

 

 

Very important not to overfill.

 

ken

 

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Instant transmission failure in case of overfill? I think you are exaggerating here. One extra quart probably would do nothing. Three or four extra quarts might cause some oil foaming, but I do not believe instantaneous failure would occur even then.

 

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I second Ken1mods post

Trans needs to be close to spec.  overfill causes oil to rise to touch gears causing foaming and instant trans failure . do not overfill.

I've done this, scared the cr$p out me. Thought I blown the pump in my rebuilt trans.

 

Do not overfill.

[dewfpo]

The best way (that I have found) to check the trans fluid is to check it after a long, hot run. Check it in PARK on a level surface. The fluid level should be in the middle of the HOT cross hatched area.

 

ATF expands as it gets hot. If your level is below the cross hatched HOT zone, then you trans temp is not at the right temp for a 'hot' check or you are a little low on ATF.

 

On my Allison, the manual says the correct temperature to check the trans HOT is between 180-200F.

 

DEWFPO