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Can You Switch Over................?

harleybiker

Member
Can you switch over from standard fossil oil to fully syn oil under 10,000 miles without any problems? I own an 05 Deluxe and want to change my oil to fully syn. Thanks

hb
 
Yes. No problems. If you don't like the new noises from the rocker boxes, you can change back. Syn oil is thinner as such, doesn't hurt anything, but some riders report more engine noise. I changed to Lucas Synthetic straight 50W and engine was alot quieter than either the HD 20W50 or the Mobil1 15W50 I was running. Stay'n with the Lucas for me.
wilks3
:USA
 
No need to hesitate...time for a oil change. M1 20W/50 synth is one of the top recommendations on my list & almost always on sale at one of the major auto store chains (Checker, Advance, Auto Zone, or OReilly's).
 
Yes. Just do it!

Engine: FULL synthetic 20W50 VTwin engine oil
Tranny: FULL snythetic 75W140 GL-5 gear lube
Primary: Fit-for-purpose chaincase/wet clutch lubricant (like HD Formula + or Spectro Primary, Redline Primary, etc.)

TQ
 
Any time , look in the self help section check out the oil polls:s
 
Yes. Just do it!

Engine: FULL synthetic 20W50 VTwin engine oil
Tranny: FULL snythetic 75W140 GL-5 gear lube
Primary: Fit-for-purpose chaincase/wet clutch lubricant (like HD Formula + or Spectro Primary, Redline Primary, etc.)

TQ

TQ, I confused now. The poster has an '05 Softail, meaning a five speed tranny. Shouldn't he use a GL-1 transmission fluid instead? I thought the GL-5 was for the six speed.
 
TQ, I confused now. The poster has an '05 Softail, meaning a five speed tranny. Shouldn't he use a GL-1 transmission fluid instead? I thought the GL-5 was for the six speed.

You can use the GL5 in either but it isn't necessary in the 5 speed because of the different gear cuts. (no helical gears)
 
TQ, I confused now. The poster has an '05 Softail, meaning a five speed tranny. Shouldn't he use a GL-1 transmission fluid instead? I thought the GL-5 was for the six speed.

You are right, the OEM 5-spd does not NEED a GL-5 rated gear lube, but for the difference in price, why not use one?

Check this:

API ratings

Gear oils are classified by the American Petroleum Institute using GL ratings. For example, most modern gearboxes require a GL-4 oil, and separate differentials (where fitted) require a GL-5 oil. It is important that purchasers check the oil against the vehicle manufacturer's specification to ensure it does not contain any aggressive chemicals that may attack yellow metal gear components, such as phosphor bronze.

API viscosity ratings for gear oils are not directly comparable with those for motor oil, and they are thinner than the figures suggest. For example, many modern gearboxes use a 75W90 gear oil, which is actually of equivalent viscosity to a 10W40 motor oil. Multigrade gear oils are becoming more common; while gear oil does not reach the temperatures of motor oil, it does warm up appreciably as the car is driven, due mostly to shear friction (with a small amount of heat conduction through the bellhousing from the engine block).

Fully synthetic gear oils are also used in many vehicles, and have a greater resistance to shear breakdown than mineral oils.

API classification subdivides all transmission oils into 6 classes:
  • API GL-1. Oils for light conditions. They consist of base oils without additives. Sometimes they contain small amounts of antioxidizing additives, corrosion inhibitors, depresants and antifoam additives. API GL-1 oils are designed for spiral-bevel, worm gears and manual transmissions without synchronizers in trucks and farming machines.
  • API GL-2. Oils for moderate conditions. They contain antiwear additives and are designed for worm gears. Recommended for proper lubrication of tractor and farming machine transmissions.
  • API GL-3. Oils for moderate conditions. Contain up to 2.7% antiwear additives. Designed for lubricating bevel and other gears of truck transmissions. Not recommended for hypoid gears.
  • API GL-4. Oils for various conditions - light to heavy. They contain up to 4.0% effective antiscuffing additives. Designed for bevel and hypoid gears which have small displacement of axes, the gearboxes of trucks, and axle units. Recommended for non-synchronized gearboxes of US trucks, tractors and buses and for main and other gears of all vehicles. These oils are basic for synchronized gearboxes, especially in Europe.
  • API GL-5. Oils for severe conditions. They contain up to 6.5% effective antiscuffing additives. The general application of oils in this class are for hypoid gears having significant displacement of axes. They are recommended as universal oils to all other units of mechanical transmission (except gearboxes). Oils in this class, which have special approval of vehicle manufacturers, can be used in synchronized manual gearboxes only. API GL-5 oils can be used in limited slip differentials if they correspond to the requirements of specification MIL-L-2105D or ZF TE-ML-05. In this case the designation of class will be another, for example API GL-5+ or API GL-5 LS.
  • API GL-6 is not applied any more as it is considered that class API GL-5 well enough meets the most severe requirements. When API GL-6 was still in use, it denoted oils for very heavy conditions (high speeds of sliding and significant shock loadings). They contained up to 10% high performance antiscuffing additives. They were designed for hypoid gears with significant displacement of axes. However in 2011 at least one company offers new polyol ester based API GL-6 oil, mostly for racing applications[1]. Such API GL-6 oil can replace higher viscosity GL-4 gear oil, thus increasing the efficiency of the car transmission where it is used. The application is limited to certain types of manual transmissions, but improvements in BSFC of about 5% in standard weather and driving conditions and up to 15-20% in cold extremes (arctic weather conditions) can be expected.
 
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