ATF in the transmission? Never seen that on a Harley before.

Was ATF, now what?

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1957flhchop
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ATF in the transmission? Never seen that on a Harley before.

#1

Post by 1957flhchop »

So, I got a little free time and went out to work on changing the fluids on the new to me Shovel. I pulled the plug on the bottom of the transmission and immediately realized it didn't have oil in it. Rather, it appeared to be automatic transmission fluid. I think I read about some people using ATF in dirt bikes, but never seen this in any of the Harleys I have had. The only non stock things I am aware of regarding the transmission/drive are a belt drive and Rivera clutch. I don't think anything inside the transmission has been altered.
My first question is, why might this have ATF in it?
What do I have to do as far as flushing/cleaning it out before I put oil in?
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Re: ATF in the transmission? Never seen that on a Harley before.

#2

Post by RooDog »

Somebody more anal, or scientific, than me will probably have something bright to say.
But I would just simply leave the drain plug out overnight, put it back in. I know that you know that, but ask me how I know it needs to be stated. Put the plug back in, and then add however much of what ever approved lube you choose.
Now let's hear from the trenches....
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Re: ATF in the transmission? Never seen that on a Harley before.

#3

Post by RUBONE »

H-D used ATF in Sportster transmissions with wet clutches and shared primaries. It is also often used in sealed primary covers. Big twin 4 speed Shovels were all spec'd with motor oil. Later 5 speeds were different using specific transmission lubes. All will work OK, just do not use sulpher based hypoid gear oil in a 4 speed.
As stated, just put in what you want to use, the residual ATF is no issue.
1957flhchop
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Re: ATF in the transmission? Never seen that on a Harley before.

#4

Post by 1957flhchop »

RUBONE wrote: Thu Jun 02, 2022 1:56 am H-D used ATF in Sportster transmissions with wet clutches and shared primaries. It is also often used in sealed primary covers. Big twin 4 speed Shovels were all spec'd with motor oil. Later 5 speeds were different using specific transmission lubes. All will work OK, just do not use sulpher based hypoid gear oil in a 4 speed.
As stated, just put in what you want to use, the residual ATF is no issue.
Good deal. I was planning to use 20w50, same as the engine to attempt to keep things simple.
1957flhchop
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Re: ATF in the transmission? Never seen that on a Harley before.

#5

Post by 1957flhchop »

Also, is the transmission supposed to have one of those plugs with the brass/copper washer on it?

I wonder if the original plug was just lost? Or if the threads won't hold the original plug anymore? It looks like a pipe plug that I took out.
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Re: ATF in the transmission? Never seen that on a Harley before.

#6

Post by panheadrider1961 »

Yes it is with the crush sleeve to prevent stripping
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Re: ATF in the transmission? Never seen that on a Harley before.

#7

Post by FL54 »

Asking any oil related question will bring many different opinions. I just run straight 50 weight in both motor and transmission.
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Re: ATF in the transmission? Never seen that on a Harley before.

#8

Post by doc9339 »

If your plug is an actual pipe plug, they are tapped with NPT (National Pipe Thread) and is a tappered fit and will eventually crack your tranny case: Get rid of it. Previous owner most likely lost the origional drain plug, or the threads in the case got stripped out so he went the pipe plug route, a bad idea
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Re: ATF in the transmission? Never seen that on a Harley before.

#9

Post by doc9339 »

50wt motor oil in a shovel tranny I dont beleive is correct. I beleive it should be gear oil, around 80-90wt. Do some research and use the correct wt and oil. WHat year is yiour bike?
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Re: ATF in the transmission? Never seen that on a Harley before.

#10

Post by 1957flhchop »

doc9339 wrote: Thu Jun 02, 2022 9:04 pm 50wt motor oil in a shovel tranny I dont beleive is correct. I beleive it should be gear oil, around 80-90wt. Do some research and use the correct wt and oil. WHat year is yiour bike?
It is a '73
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Re: ATF in the transmission? Never seen that on a Harley before.

#11

Post by RUBONE »

doc9339 wrote: Thu Jun 02, 2022 9:04 pm 50wt motor oil in a shovel tranny I dont beleive is correct. I beleive it should be gear oil, around 80-90wt. Do some research and use the correct wt and oil. WHat year is yiour bike?
H-D never spec'd gear oil in a 4 speed. And especially Sulphur based types. They destroy the high Sulphur based bronze bushings H-D used.
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Re: ATF in the transmission? Never seen that on a Harley before.

#12

Post by RooDog »

doc9339 wrote: Thu Jun 02, 2022 9:04 pm 50wt motor oil in a shovel tranny I dont beleive is correct. I beleive it should be gear oil, around 80-90wt. Do some research and use the correct wt and oil. WHat year is yiour bike?
Oh, like read the service manual?
The H-D manual calls for H-D grades of oil according to ambiant operating temperatures, 75, 58, and 105. These are Harley rated oil weights and not SAE Engine Oil specs. So more research is required.
Some manuals call for the 4 speed tranny to run the same oil as in the engine.
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Re: ATF in the transmission? Never seen that on a Harley before.

#13

Post by Lowrider »

Are you sure that it's not Redline V-twin transmission fluid, it's red, and seems to be good stuff.
1957flhchop
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Re: ATF in the transmission? Never seen that on a Harley before.

#14

Post by 1957flhchop »

Lowrider wrote: Wed Jun 29, 2022 11:29 pm Are you sure that it's not Redline V-twin transmission fluid, it's red, and seems to be good stuff.
It sure had the stank of ATF.
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Re: ATF in the transmission? Never seen that on a Harley before.

#15

Post by panheadrider1961 »

Have you rode the motorcycle with it in their?
ATF is a high detergent based fluid it should be super clean inside , if ridden usual third gear slight whine is normal , siren sound not good this will be bronze bushing bad ,drain and add 1.5 pints as manual specs and use 60 weight oil if on hand ride and if no siren in 3rd should be ok
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