primary fluid

mml03102

Active Member
was at the hd dealer yesterday and picked up stuff for fluids change .

Is the Harley tranny fluid good for the big dog primary as well , changed the oil but will hang on to hear if its ok or not..

also oil drain plug head was a lil stripped able to change the oil and all put the plug back in with teflon tape and did not drive completly in ,still a few threads showing, is that normal, goint to go start it up and look for leaks now
 

woodbutcher

Mr. Old Fart member #145
Staff member
you asked if "Is the Harley tranny fluid good for the big dog primary as well", tranny fluid should be a lot heavier weight, like 75-140 or better, which would be too thick for the primary. some use ATF for the primary. just as long as it is not synthetic because that causes slippage in the clutch pack.

check the plug to see if it isn't torx instead of allen. just thinkin'
 

mml03102

Active Member
Its a hex head bolt and Im thinking its not the original is why its not going all the way in also its not magnetic so maybe should try to find the right plug?
 

mymastiff

Active Member
Had to replace my plug recently, stripped so bad I could not even remove it. Harley has one for about $5 bucks that will fix you up.
 

mml03102

Active Member
I eneded up finding this in a big dog service manual so should be ok to use hd lube in it and will call The HD dealer for a new plug thanks.

PRIMARY LUBE
Big Dog uses RevTech primary lube, although any lube specially designed for V-Twin style
primaries will work. Remember the lube is designed not only to lube the primary chain, but also
to keep the clutch assembly working properly. This type of clutch set-up is a WET system and
MUST be run in lube continuously or failure will result. The primary requires 32 oz. of lube and
can be filled from either the inspection cover or the derby cover. The drain for the primary is
located directly below the derby cover and is either an allen or torx plug. Synthetic lube is not
recommended for the primary.
 

woodbutcher

Mr. Old Fart member #145
Staff member
I eneded up finding this in a big dog service manual so should be ok to use hd lube in it and will call The HD dealer for a new plug thanks.

PRIMARY LUBE
Big Dog uses RevTech primary lube, although any lube specially designed for V-Twin style
primaries will work. Remember the lube is designed not only to lube the primary chain, but also
to keep the clutch assembly working properly. This type of clutch set-up is a WET system and
MUST be run in lube continuously or failure will result. The primary requires 32 oz. of lube and
can be filled from either the inspection cover or the derby cover. The drain for the primary is
located directly below the derby cover and is either an allen or torx plug. Synthetic lube is not
recommended for the primary.
yes, if you are using "primary lube" that is OK, what you first stated was "Trans lube" 2 different animals. Rev-tech is good. :up::up:
 

rsorf203

New Member
I have a electra glide which harley recommends their syn oil in all 3 holes I have close to 40k on my 07 I finally switched to Spectro fluids correct for each hole. The primary you should really use a primary rated fluid preferably non synthetic. once I made that switch in mine Neutral was a breeze to find and after couple changes i have had little to no build up on the magnetic plug anymore also my gear noise is much less. i am not trying topush you to Spectro but defiantly use a Heavy duty primary oil in chain case. Another word of caution if you happen to remove primary cover it may take more than 32 oz to get the clutch pack wet we just did a job on my buddies pitbull last weekend and had to add a few extra oz to get clutches wet ended up around 40 oz total i am hoping someone out ther can verify this is normal for now though the pitbull runs and shifts better than ever.
 

mml03102

Active Member
Harley Tranny and primary lube is one of the same .

I also changed the Tranny fluid but used red line not the Harley lube there
 

woodbutcher

Mr. Old Fart member #145
Staff member
I have a electra glide which harley recommends their syn oil in all 3 holes I have close to 40k on my 07 I finally switched to Spectro fluids correct for each hole. The primary you should really use a primary rated fluid preferably non synthetic. once I made that switch in mine Neutral was a breeze to find and after couple changes i have had little to no build up on the magnetic plug anymore also my gear noise is much less. i am not trying topush you to Spectro but defiantly use a Heavy duty primary oil in chain case. Another word of caution if you happen to remove primary cover it may take more than 32 oz to get the clutch pack wet we just did a job on my buddies pitbull last weekend and had to add a few extra oz to get clutches wet ended up around 40 oz total i am hoping someone out ther can verify this is normal for now though the pitbull runs and shifts better than ever.
only problem is if you put much over the recommended 32 oz., it tends to get pushed into the starter causing big issues. personally haven't had a problem with 32 doing the job.
 

erldawg

Guru
B&M Trick Shift in the primary for me. No issues with slippage..


@ Rick is this what u use in the primary?
 
Last edited:

Germanbiker

Active Member
Yes, Milco ;) !

I highly recommend to use the Spectro heavy duty primary oil. With the ATF I had a slipping clutch and a hard to find neutral.

I got my Spectro from Ebay Germany. So easy to get here in europe.

Jochen
 
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