Unofficial Royal Enfield Community Forum
Royal Enfield Motorcycles => Bullet Electra & AVL => Topic started by: KB8ANY on September 17, 2013, 12:59:53 pm
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Back when my bike had 17,000 miles on it the service man at the dealer, one of the associates at our esteemed importer, one of my manufacturing buddies, and the self-appointed expert down the street all insisted I should switch to ATF in the primary drive. Against my better judgment (I have to admit) I decided to try it.
I have just had the primary drive apart again, at 29,000 miles, and cannot find any appreciable wear in the primary chain. The shop manual calls out 190 to 191 mm across 21 pins, with a service limit of 195 mm. Averaged across several overlapping runs of the chain I do not find that the length has changed at all from 190.5. The loosest run is within spec. The friction plates look like they did the last time, with nice sharp cuts and no hint of glazing.
There are tight and loose sections, as always. Also, I think the 5 to 6 mm of slack called out in the shop manual is too tight, so I used Kentucky-windage finger pressure. If I had not taken the assembly apart, I would have just left the adjuster where it was.
I had been using 15W40 (called out in the shop manual) in the winter, and 20W50 in the summer, and had been griping about how hard it was to find neutral when coming to a stop - which was why these guys suggested the ATF.
I've seen some posts recently about ATF or not, so decided to throw my results in there.
Bye-th-bye: if you ever inspect the throw-out bearing or the outer clutch disc closely, you will think twice about sitting at a red light holding the clutch in.
Good luck.
Paul
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Thanks for the results! I've used ATF since the get-go with my AVL, thus haven't compared it to anything.
Thanks also for the pointer about the clutch bearing. I've generally always put it in neutral, but recently have been holding it at lights... figured it was one of those old wives tales. Good to know now that it's serious so I don't do any more harm.
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The heavy engine oil in the primary cases causes the clutch to drag making finding neutral a real challenge. The ATF reduces the drag a lot. As for keeping the bike in gear at a light is not a good with the old English style clutches. The end of the pushrod and clutch plate bearing go out pretty quickly holding the clutch in.
Bare
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One of the reasons for using motor oil (20w-50 or 15w-40) and filling to 800-1000 ml was to help lube the sprag clutch assembly.
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One of the reasons for using motor oil (20w-50 or 15w-40) and filling to 800-1000 ml was to help lube the sprag clutch assembly.
The sprag clutch assembly in the Bullet is the same one that is used in the torque converter of a Borg-Warner T350 automatic transmission. It normally spends its whole lifetime in ATF. Using ATF in our primary case won't have any adverse effects on its lubrication.
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If i may chime in. I changed out my primary oil for 'F' type ATF 2 seasons ago and have not noticed any change. Maybe this is not typical but that is how i see it. This subject really doesn't need to be overthought, just run what works best for you and use a full quart.
Robert.
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The sprag clutch assembly in the Bullet is the same one that is used in the torque converter of a Borg-Warner T350 automatic transmission. It normally spends its whole lifetime in ATF. Using ATF in our primary case won't have any adverse effects on its lubrication.
Hi Ace,
Let me correct a typo for you please and thank you.
The most common designator for the Borg-Warner automatic transmission that we are talking about is BW-35. T-350 is street slang around my area for GM's Turbo (Hydramatic) 350
Footnote:
AMC used the BW-35 until the early 1970's and they were also wildly popular amongst almost every European car maker well after that.
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If i may chime in. I changed out my primary oil for 'F' type ATF 2 seasons ago and have not noticed any change. Maybe this is not typical but that is how i see it. This subject really doesn't need to be overthought,
I notice no change either so I switched back to engine oil.
Besides easing logistics the oil in my primary can be a source of emergency oil for the engine if it ever came down to that.
just run what works best for you and use a full quart.
Robert.
Big +1, absolutely spot on !
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Yo:
I took the sprag clutch out right at 20,000 miles; three of the dogs were loose. Its a good thing the design kept them captive. This is after I switched over to ATF, but my log shows I had been having running problems for a long time before that, so I don't think I caused it by switching.
The hint about an emergency supply of oil captures my attention. I don't know that would get me to switch back, but I'll sure remember it.
Good luck.
Paul
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Hi Ace,
Let me correct a typo for you please and thank you.
The most common designator for the Borg-Warner automatic transmission that we are talking about is BW-35. T-350 is street slang around my area for GM's Turbo (Hydramatic) 350
Footnote:
AMC used the BW-35 until the early 1970's and they were also wildly popular amongst almost every European car maker well after that.
All right, well it's one of those two.
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The Borg Warner sprag clutch is for the BW-35. They have 24 sprags as opposed to the 18 on the RE sprag clutch. I have two coming that I will offer up at cost to members when they arrive since I am now Iron Barrel Enfield-less.
Either way, in the Borg Warner (Aisin Warner) trans they are run in a constant Dexron bath.
There is German company that makes a sprag clutch that some members of an English forum have used. That manufacturer recommends 10w-40 oil covering at least the bottom portion of the sprag so that it gets circulated into the races and teeth.
It's probably more important to have adequate lubrication than to be specific about ATF, 10w-40, or 20w-50.
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D the D:
At one time I had a line on a sprag-type clutch that used rollers under spring-pressure pins, kind of like the old freewheels on cars. It was a little thinner than the RE sprag, but I was thinking of using spacers to locate it.
You ever had any experience with this, and / or what do you think about it?
Paul
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I have no idea and no experience with it. PM me if you're interested in a Borg Warner sprag when they come next month. I think they were about $27 each.