3.37 Modification Gearing Instructions For 2002 -2006 Twin Cams

[ClassicRider]

I have recently (May Of 2008) put together a PDF file providing installation/modification instructions for going from 3.15 gearing to 3.37 gearing in particular for my 2002 Road King Classic.

Should anyone desire a copy of such feel free to e~mail me and request a copy, I will forward it to you.

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Some of you may be like.....what are you talking about what is this whole thing about modifying one's gearing to a different gearing....so I have attached a couple of the best discussions I have read on the net about modifying one's 3.15 gearing to 3.37 gearing, just click and read:

http://groups.msn.com/HarleyTechTalk...lete=0&CDir=-2

http://www.v-twinforum.com/forums/v-...ill-using.html

Back in 1999, 2000, and 2001 HD introduced the Twin Cam engine on touring bikes with either a carb set up or an EFI option. HD introduced those EFI bikes with the MM EFI throttle body. The carb Touring Bikes were given 3.15 gearing and the MM EFI Touring Bikes were given 3.37 gearing.

The question is why did HD do this, why did they offer a different gearing for the Carb (3.15 gearing) and the MM EFI (3.37) gearing in 1999, 2000, and 2001?

Some feel the reasoning was When HD started with the EFI in 1999 they were using the Marelli system, and I believe the difference in price was something like $750.00. Everything else being equal the carb bikes then had better performance then the MM EFI bikes. It just wouldn't do for a cheaper bike to blow the more expensive one away. In 2002 when they introduced the Delphi on the baggers, if you looked at Sales Literature and then at Owners Manuals there was conflicting information as far as primary ratios for different versions was concerned.

Click and read:

http://www.v-twinforum.com/forums/tw...t-gearing.html

In 2002 HD introduced the Delphi EFI throttle body and HD went back to the 3.15 gearing for EFI bikes, while the carb bikes continued to run 3.15 gearing as well,, thus all Touring Bikes from 2002 to 2006 for sure have 3.15 gearing.

IF your bike falls between 2002 and 2006 and is a touring framed bike then you have a Compensating Sprocket with 25 Teeth HD# 40308-94 and you have a Clutch Shell Basket HD# 37707-98A which is a 36 Tooth Ring Gear, giving you 3.15 gearing.

The gearing of 3.37 which was placed in touring framed bikes in 1999, 2000, and 2001 Twin Cam MM EFI bikes have a Compensating Sprocket with 24 Teeth HD# 40269-85A and a Clutch Shell Basket HD# 37846-99A which is a 37 Tooth Sprocket.

Up until last year (2007) I thought I had the 3.37 gearing in my 2002 RKC (as my "owner's manual" says that I do)....it wasn't until I posted some advantages at Harley Tech Talk that I consider postives for a 2002 year model touring bike as I feel exists over other years and I mentioned the 3.37 gearing as one of those "advantages" for a 2002 Delphi EFI bike but then was informed I was incorrect. I began looking at my parts book and read my service manual and began to notice the presence of the 3.37 gearing was missing. It took calls to HD in Wisconsin to finally convince me that my 2002 Delphi EFI RKC didn't have 3.37 gearing....that is, of course, short of pulling the primary off and counting teeth....which I didn't do....it just became aparent that 3.37 gearing wasn't in the "cards".

So I tabled it, mulled it over, thought about it some more....and continued to research what I could about the "modification" and reached a conclusion that with my very mild 95" set up that I would enjoy the "bang" for the "buck" modification....

So this spring I began putting a part's list together. I haven't performed the modification myself "just yet" as of May of 2008 (but have just finished purchasing all of the parts necessary to perform the modification). After several hours of reading my 2002 service manual I have reached some conclusions about what is going on....

The directions that I have created are specific to a Road King Classic and as you will discover the part that is "specific" to a Road King Classic really is only the routing of a new clutch cable everything else is specific to any "twin cam" installation of the 3.37 gearing.

Last summer I changed my handle bars to Wild One WO515 which are the 10" baby apes and so while I am currently running the "stock" clutch cable, I see this specific modifcation the opportune time to make the change to a +2" over stock "black vinyl" clutch cable as well. The directions will take one through replacing their clutch cable, but obviously if that is not important to you it's easy to read over....just remember however that doing the clutch adjustment is very important.

I found that the Service Manual (and if you have one I am sure you would agree) is designed to deal with maintenance and replacement of parts which doesn't lend itself to a clear step by step chronological progression for doing modifcations. You end up reading a section in one place, to have to skip over to another place, to go to some where else to get it all together and while that works "ok" when reading at a desk, it's very distracting and frustrating when actually working on the bike. So whenever I do a "modification" I research it well enough to create my own directions, thus here we are. Some of you obviously do not need directions and see the "modification" as a very simple process while other's like me with the help of some "specific" directions may gain the confidence to even attempt the "modification" themselves.

Below you will see an attachement to a thread, all you need to do is click and read. I am bringing to your attention as it may have some application to this procedure, such as when to use "blue" loctite....You will see in my directions that I reference using Aviation Gasket Cement and sometimes the word "cement" can scare the heck out of someone, but....this thread will help to explain why I use what I use and where....so places where you might use say "anti~seize" I might use Aviation Gasket Cement....(except for spark plugs where I do use Anti~seize for example).

Also realize that these are directions as I see them making sense. I have cut, copied, and pasted different schematics ie: drawings and pasted them where I thought they should go, I believe the directions are clear enough that you will find really no need to reference a service manual. I did this with the idea that I could take a note book computer out to their garage and go through this step by step, or one could print the directions and work with them that way as well.

Before you purchase anything understand what you will be purchasing a 24 Tooth Compensating Sprocket HD# 40269-A which retails @ $135.00 and a 37 Tooth Clutch Shell Basket HD# 37846-99A which retails @ $320.00 (which includes the HD# 37906-90 KOYO 5207 CD3 FG Double Row Angular Contact Bearing and HD# 37905-00 which is the "Large" Retaining Ring that secures the HD #37904-90 KOYO 5207 CD3 FG Bearing into the Clutch Shell Basket). If you happen to have purchased the "Clutch Shell Basket" HD# 37846-99A "gently used / previously owned" then you may find these parts included as well depending on what the previous owner passes along to you.

SO, if you end up purchasing the Clutch Shell Basket HD# 37846-99A from HD you will now know you don't have to also buy the HD#37906-90 KOYO 5207 CDE FG Bearing, HD retail for this bearing is $62.00. On some things HD does that...you think you need this and that then you find out you only need that....lol...

Once you have purchased the Clutch Shell Basket and you have the HD# 37906-90 KOYO 5207 CD3 FG Bearing pressed into it, you will need to press the HD# 37550-98 Clutch Hub into the inner race of the HD# 37906-90 KOYO 5207 CD3 FG Bearing (don't worry this is explained more clearly in the directions) and you're good to go as you proceed through the project. HOWEVER, if in fact you have purchased the HD# 37846-99A Clutch Shell Basket [37 tooth] "gently used / previously owned" and you do see the HD# 37906-90 ball bearing remaining within the clutch shell basket, you will have a decision to make........

It seems there is very little information about what many are doing in regards to the pressing out and into the "radial" angular bearing. For your information this bearing is not an axial (thrust) bearing, thus it doesn't take much to "side load" and to ruin the bearing. So if again you are using a "gently used / previously owned" clutch shell basket which has the HD# 37906-90 Koyo 5207CD3 FG double row angular contact ball bearing already installed that would mean that the previous owner of the "clutch shell basket" pressed the "clutch hub" from or out of or away from the "clutch shell basket".

Pressing the bearing into the clutch shell basket is no problem as you introduce the pressure onto the outer race of the bearing. When you press the clutch hub into the inner race of the bearing, you support the inner race and press the clutch hub into the bearing, again no problem. However, to remove the clutch "hub" away from the bearing, there is no way to support the inner race and you can't get to the retaining ring for the outer race to remove it. Your only option is to press the clutch "hub" out of the bearing which puts significant side load on the balls and races and MAY cause flat spots depending on the amount of pressure needed. Only as a last resort would I ever consider reusing the bearing. Thus it seems a logical thing to do which sounds extreme perhaps is to "potentially" replace the bearing.

Because I have been "gathering" parts for this "modification", I have been dealing recently with the bearing itself wondering if there might be a "better" bearing to install. Be aware that there are many choices for different bearings. HD chose to obviously "cool" / "lubricate" the bearing via the primary fluid being "slushed" on to it as the bearing is actually an "open faced" or "unsealed" bearing. The HD# 37906-90 KOYO 5207 CD3 FG Double Row Angular Contact Ball Bearing is considered a "PHENOLIC" bearing which basically identifies that the bearing has a sheet made from a resin that is a hard dense material which covers the bearings in part. If you have one of the 'bearings' in front of you, you will see a "black" shiny surface material in the center that wraps the bearing....this material is referred to as "polyamite" and serves to protect the bearing from some debrie as well as shielding it from excessive heat. I WILL say that obviously it hasn't been reported here or any other websites that I am familar with that anyone has had a "particular" problem with HD's# 37906-90 KOYO 5207 CD3 FG Bearing. After doing all of the research about different bearings to use, I have come to the conclusion to simply continue on the path with HD using the HD# 37906-90 Koyo 5207 CDE FG bearing and to purchase it from an HD dealer, perhaps using a HD 20% discount dealer to make the purchase more bearable.

So....deep breath what does all of this mean, when it comes to the bearing...it means you must reach a conclusion as to whether or not you feel it warrants changing out your bearing if you have secured a "gently used / previously owned" clutch shell basket which has the HD# 37906-90 KOYO 5207 CD3 FG Bearing currently installed. Some will say no, some will say yes, definitely. All I wanted to do was inform you of your choices and what you might consider....

Regardless of the path that you choose, be sure to PROPERLY adjust the primary chain as over tightening will cause shortened bearing life.

Here is the Thread I was referring to....Just Click and Read....I am "ClassicRider2002" at HTT with regards to the use of Aviation Gasket Cement:

http://groups.msn.com/HarleyTechTalk...73001162765620

Also note that I suggest using "rags" to lock the comp sprocket and clutch basic while removal and putting back together....while I did this a couple of years ago with my FXR2 (which by the way has many of the very same components with matching part numbers in the primary as does my 2002 Road King Classic) I recently did go to a local "iron" shop and had a actual primary tool made for $11.00 with tax (a photo of this tool is provided in the link you can click and see below)....I also went back to the same "iron" shop and had them cut a "breaker bar" out of a metal pipe approximately 36" long....(you will notice that it is referenced in the same photo journal below as well).....I also must state that I have successfully used a impact wrench before when taking off the compensating sprocket nut 1 1/2" since it is secured at 150+ ft lbs it's requires quite a bit of effort to remove it. The clutch basket nut 1 3/16" is only secured at approximately 80 ft lbs so it's not as difficult to remove and would never require the use of an impact wrench even with the use of red loctite/thread locker. I have photos of "mechanics" from American Iron Magazine using both the "rag" technique" to lock the comp sprocket as well as the clutch shell basket to remove and resecure the respected nuts. I also have similar photos from the same magazine showing the use of an impact wrench being used in the removal of the comp sprocket nut as well....so while people will 'cringe" at either of these being suggested in the "real" world they are definitely tools which are used....However, I would refrain from both if desiring to take the "most" safest path. So I finally as mentioned above "broke down" lol and went to my local "iron" shop and provided the measurements for the "primary tool" you will see below in the attached photo journal, for $11.00 I said what the heck and had one made....I was originally quoted $60.00 to have one on made on their CnC machine. I then went to the guys out in the shop and said can you do anything for me and in about 10 minutes I had what you will see in the photos like I said for $11.00. So if you haven't had one made don't be shy about being persistant if you hear a "outlandish" price....it doesn't need to be machined formed....lol, just a chop saw with a diamond blade able to cut steel and some 1 1/2" steel stock to start with....Just have them pay attention so when they cut it they don't intersect the cuts weakening the metal....(It will make sense when you see the photo).

Harley Hog's Lair who is a contributer to Harley Tech Talk has a web page that shows various "modifications" "procedures" being done to his bike, in this particular "photo thread" he is replacing a drive belt on his 2000 Road King Classic, while this is not the exact procedure you or I am preparing for he does show the use of a "specific" primary tool he made which has been mentioned many times since on HTT and referenced as a great tool to use for locking the Comp Sprocket and and the clutch basket while both removing and securing the respected nuts. (I will indeed wrap it with a thin "rag" so it doesn't scare the metal of the comp sprocket teeth or the clutch basket teeth.) He also mentions the use of a breaker bar too so just click and see, (I start this out on page 2 of his photo journal but you can go back to page 1 to the beginning if you so desire):

http://www.harleyhog.co.uk/belt%20install%202.htm

Hopefully this is helpful to others.

Regards,

"ClassicRider"

[YankeeBob]

This post is worthy of becoming a "sticky".
Good work.
Thank you!

[ClassicRider]

Update:

Finally completed this modification on my 2002 RKC as of June 28th 2008.

Here are some further things to be aware of:
1) Compensating Sprocket Nut, make sure to clean out the inner threads of the nut, removing the previously installed red loctite, using a dremel tool with a wire brush works wonderfully for this task, be sure to also clean the outer threads that the nut attaches to as well.

2) Clutch Shell Basket Nut, make sure to clean out the innner threads of the nut, removing the previously installed red loctite, using a dremmel tool with a wire brush works wonderfully for this task, be sure to clean the outer threads that the nut attaches to as well.

Doing both of the procedures mentioned above will offer one the security that they will have every thread channel available to them for properly "tightening" the nuts to the outer threads. I have read too many times where folks are reporting that they have found one of these particular nuts had loosened. Now it can only be the result of three variables:

A) the person did not properly torque to spec.

However I believe these two additional items could just as much be responsible given the "particular" amount of "clamping" force the "compensating sprocket nut" specifically is expected to receive....when you think about it up to 165 ft-lbs of clamping force is pretty significant:

B) the inner threads channels were NOT properly cleaned from the previous loctite used, thus affording the potential for less clamping force. If you take the time to "peer" into the compensating sprocket nut you will see just how much of that "old" red loctite is left behind, so I definitely would pay attention to making sure one throughly cleans the inner thread channels as well.

C) the person did not allow the loctite to "properly" cure before starting the engine.....the loctite instructions inform one that "proper" curing takes 24 hours.

3) I ended up using a indy shop to press off my stock "clutch hub" from my stock "36 Tooth Clutch Shell Basket", while then having them press on the stock "clutch hub" on to the "37 Tooth Clutch Shell Basket" that I had recently purchased which had been previously used for approximately 1,800 miles. Based upon careful examination of the Double Angular Bearing which was currently installed in the "37 Tooth Clutch Shell Basket" and based on how the indy mechanic was able to seperate and dislodge the stock "clutch hub" from the stock "36 Tooth Clutch Shell Basket" the indy mechanic felt very comfortable suggesting the continued use of the "used" bearing that was within the "37 Tooth Clutch Shell Basket", thus I did NOT replace the Double Angular Bearing at the time of pressing my stock "clutch hub" into the Double Angular Bearing of the previously owned "37 Tooth Clutch Shell Basket".

This service by the indy was done for me at a cost of $30.00. Another indy dealer quoted me $60.00, I walked out, and another machine shop quoted me $45.00 of which I also walked out. If anyone desires to purchase a new Arbor Press, based upon the circumference of the clutch shell basket and the height required to provide enough room to seperate the clutch shell basket from the clutch hub along with using a 1" or 1 1/4" high socket to press the clutch hub out with, one would need to acquire an Arbor Press with the ability to accomodate aprox 6 5/8" of depth and aprx 10" of height I only found one "Arbor Press" on the internet capable of handling these height and depth/width requirements which would end up costing around $150.00. So one has to make the choice if an Arbor Press is warranted or not. I was about to make the decision to simply try taping out the clutch hub myself with a hammer and a socket, and then attempt to place the clutch shell basket w/bearing already installed as previously mentioned, in the freezer and then putting the clutch hub in the oven and attempt to join the two together in that manner, however since I found an "indy" who would do the service for me at what I felt was a reasonable price I simply settled on his services.... It cost me two days however. Also remember that after applying red loctite to the compensating sprocket and the clutch shell basket once you get it put back together, it is suggested that the red loctite be able to "cure" for a 24 hour period, once you have tightened both of the nuts....so techincally you are capable of loosing 3 full days of riding.....unless you are able to schedule the pressing off and pressing on of the clutch hub without such a loss of time.


Also here are some other instructions which I found helpful in addressing how one is to "adjust one"s clutch properly" The Factory Service Manual on this issue can leave you sratching your head, so these instructions @ least for me helped to clarify the procedure a bit more:

If possible, try the following adjustment procedure first. The procedure was recommended by Hippo in previous threads:

1. Loosen the clutch CABLE jam nut and using the adjuster, remove ALL slack (zero clearance between the clutch cable ferrule and the clutch lever bracket) in the cable.
2. Loosen the lock nut on the clutch pack PUSHROD adjuster screw.

The bottom line is that during #1 and #2 what you do is fully collapse the cable adjuster on the cable sleeve while attempting to pull the cable sleeve away from the perch at the lever.

3. Pull in the clutch lever, it should just touch or be close to touching the handle bars. If it does not touch the bars, back out the PUSHROD adjuster screw at the clutch pack while keeping a slight pressure on the clutch lever until it just touches the bars.
4. When the clutch lever just touches the handle bar, turn IN the PUSHROD adjuster screw while keeping a slight pressure on the clutch lever. When you turn IN the PUSHROD adjuster screw, it will start to pull the lever OFF the handle bars. Back the PUSHROD adjuster screw OUT until the lever returns to just touching the handle bars. Do this a couple of times until you know you are at the point where the lever is just touching the bar. When you find this point - back the PUSHROD adjuster screw out 1/2 to 1 turn and torque the lock nut to 6-10 ft-lbs (96 in-lbs).
5. Using the CABLE adjuster, adjust the clutch cable to 1/16-1/8 inch gap between the clutch cable ferrule and the clutch lever bracket and secure it with the jam nut.

Sometimes when new cables are used or if the mechanism is worn, it is possible to push the "hook" the end of the cable engages to over center in the housing. This sometimes may correct itself with above, and sometimes this can be checked/corrected thru the gearbox oil fill hole. It may also be possible, if the center position of the ball and ramp was lost that above procedure may have to be done more then once. Picture in your mind that you are playing the two adjustments against each other in order to perfectly center the ball and ramp mechanism so as to achieve the max disengagement travel while still having correct free play at one and the other.

If the clutch still does not function properly, verify the following: cable lubed, routed, connected and ball and ramp assembled properly.

I might also add, that after I had thought I successfully adjusted my clutch cable with the bike still on my bike stand, I turned the ignition key to on, (lights turned on and instrument panel lit up but NO "N" neutral light lit up.....I turned the key off....and sat there....pondering....back to the drawing board....it was then that I incorporated the above instructions from HIPPO which really seemed to clarify what was trying to be accomplished......another 45 minutes later....after everything was "readjusted" I turned the key back on and was greeted with the "N" neutral light being lit...."success"....

After the "neutral" light appeared on my dash, I then put fluids in for both the primary and the transmission.

Now here is something I would also suggest.....while keeping the bike on the lift with the rear tire free from the ground......I started the bike, and ran through all of the gears along with putting it in "neutral" to make sure while it was on the stand that I had no "drag" while the clutch was engaged through with each gear....essentially I put it into 1st gear while engaging the clutch lever, then releasing the clutch lever I would give the bike a bit of the throttle and watch the rear wheel move signifying it was indeed in gear, then I would engage the clutch, take my foot and stop the motion of the rear wheel and while the clutch was still engaged make sure that once I stopped the rear tire that it didn't start moving again.....then I would release the clutch again and resulting in the rear wheel moving once again and then would move to 2nd gear etc following the same procedure through 5th gear and then from 5th gear back down to 1st gear, then back to "neutral" to make sure it would engage to "neutral" smoothly....I did all of this in about 90 seconds of running the bike on the lift....then I felt comfortable it was ready for a "test" run.....locating "Neutral" has never been so so so smooth....everything works wonderfully....So I would suggest doing this while the bike is on a lift to make sure there is no "drag" occuring on your clutch, thus confirming that everything is working properly. Once this is confirmed then you are prepared to take it for your first "test" ride.

Regards,

"Classic"

[dcfatboy]

Which arbor press were you looking at, and what do you think of the Harbor Freight 12 ton press?

Thanks

[ClassicRider]

dcfatboy,

sorry it took so long to respond, didn't notice I was asked a question, hopefully this isn't too late for you, but if it is perhaps it will help someone else in the future.

Here is the arbor press I was referring to above:
http://www.grainger.com/Grainger/items/3Z949

Grainger is simply a retailer selling the arbor press made by Palmgren and while Grainger lists it for $244.00. If one does enough looking on the net via a "google" search with "Palmgren" as part of their search one can find this exact model for around $150.00.

As for the Harbor Frieght 12 ton press, yes that would work as well....and I looked at this type of press, although at the time Harbor Frieght did not have one in stock when I was actually needing it. While that of course would work, I would prefer the table mount press I listed above.....and like I said it can be purchased for $150.00.

But here again, with a bit of planning one should be able to get this done via a local shop for around $30.00 as I also previously mentioned.

There is also something to be said for a big socket, hammer, lube, some dry ice, and an oven too....which I was about to resort to with my son-in-law before spending either $60.00 or $200 for an arbor press.

Regards,

"Classic"

[dcfatboy]

Originally Posted by ClassicRider

As for the Harbor Frieght 12 ton press, yes that would work as well....and I looked at this type of press, although at the time Harbor Frieght did not have one in stock when I was actually needing it. While that of course would work, I would prefer the table mount press I listed above.....and like I said it can be purchased for $150.00.

Now problem CR. Thanks for responding.

My indy pressed in my new mainshaft bearing and seal for $25. (I will do the 3.37 gearing change when I have to take apart my clutch basket.)

Why would you prefer the table press? It would seem to me that the HF-type design would be more useful, and it has 4 times the tonnage (?).

Thanks

[ClassicRider]

Why would you prefer the table press? It would seem to me that the HF-type design would be more useful, and it has 4 times the tonnage (?).

It just seems the only thing I have needed a press for my bikes has been while dealing with gears....and of course now with this particular modification. I like the "compactness" of the "table" arbor press while the other "style" takes up floor space....

As I have mentioned above, it seems every time I have needed a "press" that some dry ice, an oven, a hammer, and a socket have always seemed to do the trick, and based on how easily the indy mechanic mentioned that he was able to transfer the clutch hub along with the double angular bearing between the two different clutch shell baskets, had I not received a $30.00 cost for pressing the clutch hub out of my oem clutch shell basket into my newly acquired previously owned clutch shell basket I would have taken that route with this project as well....

But I get your point about the other style having more uses.....but my little "shop" area is limited on space so any "speciality" tool I don't require to work on my bikes I would rather not have.....

As far as needing more "tonnage" most of what we are working on a motorcycle doesn't require that much tonnage anyway....and the only reason for the 4 ton press mentioned above was the height that it provided to actually perform the work as well as the depth of the "cylinder" formation of being able to line up the bearing within the clutch shell basket for either removal or installation.

I would tend to agree with you however, that the one you mentioned above has a wider and greater use......

Regards,

"Classic"

[dcfatboy]

Thanks Classic!!