1990 FLHS help
#1
#2
What oil should i use in the crankcase? I only use Mobil 1 20 w 50 synthetic v twin in any HD I have ever owned but any 20 w 50 oil like screamin eagle, Red Line or Belray are good as well. If it has high miles, I would recommend dino oil to reduce crankcase leaks.
Is there a seperate transmission and primary fluid? yes. Primary generally takes 1 qt (same 20 w 50 oil) and the tranny usually takes the same amount. For the tranny, I only use Red Line shockproof but you can also use the same 20 w 50 oil in there as well
Do yourself a favor and buy a genuine service manual from the MoCo. Worth its' weight in gold. I do all of my own work, always....
Is there a seperate transmission and primary fluid? yes. Primary generally takes 1 qt (same 20 w 50 oil) and the tranny usually takes the same amount. For the tranny, I only use Red Line shockproof but you can also use the same 20 w 50 oil in there as well
Do yourself a favor and buy a genuine service manual from the MoCo. Worth its' weight in gold. I do all of my own work, always....
#3
hold it.
don't use synthetic in that bike, the seals won't take it and it'll leak like a sieve.
i use the H-D 360 20w50 in my Evos, there are equivalent brands at any bike shop- just make sure they are spec'd for V twins ( air cooled bikes).
H-D makes a primary lube which works well, get 2 quarts, 1 will not be enough. Try to use same fluid that is in there now- the clutch plates absorb fluid and changing up lubes may not give best results.
the primary lube is not shared with the tranny.
There are also tranny specific lubes, brand doesn;t matter much- but if you use redline- the red color may be handy if you are tracking leaks...red= tranny!
the first few years of twin cam production, H-D spec'd a synthetic blend 20w50 in all 3 holes- that may be what the previous poster was referencing.
you will NEED a factory service manual ( not a clymer/haynes) OR a good local independent shop, the dealer probably will not support an older bike with parts or service
the oil drain is behind the right side cover, when you have the oil filter off, check the the filter mount is securely bolted under there, they can get loose.
the primary drain is at the rear of the primary case facing down, it's an allen head plug
tranny drain is underneath
mike
don't use synthetic in that bike, the seals won't take it and it'll leak like a sieve.
i use the H-D 360 20w50 in my Evos, there are equivalent brands at any bike shop- just make sure they are spec'd for V twins ( air cooled bikes).
H-D makes a primary lube which works well, get 2 quarts, 1 will not be enough. Try to use same fluid that is in there now- the clutch plates absorb fluid and changing up lubes may not give best results.
the primary lube is not shared with the tranny.
There are also tranny specific lubes, brand doesn;t matter much- but if you use redline- the red color may be handy if you are tracking leaks...red= tranny!
the first few years of twin cam production, H-D spec'd a synthetic blend 20w50 in all 3 holes- that may be what the previous poster was referencing.
you will NEED a factory service manual ( not a clymer/haynes) OR a good local independent shop, the dealer probably will not support an older bike with parts or service
the oil drain is behind the right side cover, when you have the oil filter off, check the the filter mount is securely bolted under there, they can get loose.
the primary drain is at the rear of the primary case facing down, it's an allen head plug
tranny drain is underneath
mike
Last edited by mkguitar; 09-30-2013 at 07:20 PM.
#4
1990 FLHS owner here, owned from new! Welcome to HDF from the UK. Your first step should be to get a factory service manual, from your local dealer, which will answer most of your questions, when you get around to doing oil changes and other service stuff. There are no legal on-line manuals.
As for oils you can get those from your local friendly Harley dealer, or use other brands of V-twin oils for the engine. Your engine oil is carried in the oil bag on the right side of your bike, as the engine is dry sump. It also has separate primary and transmission oil reservoirs.
As for oils you can get those from your local friendly Harley dealer, or use other brands of V-twin oils for the engine. Your engine oil is carried in the oil bag on the right side of your bike, as the engine is dry sump. It also has separate primary and transmission oil reservoirs.
#6
Crankcase - Mobil1 15w/50 (buy the 5 quart jug at Walmart)
Primary - RevTech Primary Fluid (same as the old HD "Primary Chaincase Lubricant" that they don't sell any more). You have to get this from 3rd-party sellers, HD doesn't sell it.
Transmission - Mobil1 75w/90 gear oil
You'll probably have to look hard for an online version of the service manual.
You might try looking for a used copy.
Clymer also had a service manual that (although not as good as Harley's) was usable.
Recommendation:
DO NOT put Locktite on the primary cover bolts. Just hand-tight with a small wrench, and then a little more...
Primary - RevTech Primary Fluid (same as the old HD "Primary Chaincase Lubricant" that they don't sell any more). You have to get this from 3rd-party sellers, HD doesn't sell it.
Transmission - Mobil1 75w/90 gear oil
You'll probably have to look hard for an online version of the service manual.
You might try looking for a used copy.
Clymer also had a service manual that (although not as good as Harley's) was usable.
Recommendation:
DO NOT put Locktite on the primary cover bolts. Just hand-tight with a small wrench, and then a little more...
#7