Swap chronicles: Transmission, gear swap, LSD, clutch and flywheel

[Tishock]

Another half day today 09/14/2013. Cant move on without answers to my 2 questions. I added many more measurements and pics today.

[reklipz]

Good work! It looks to me as though all you need is the ~2 mm shim between the fifth gear and the bearing on the countershaft, just like you describe.

If those splines don't show through the top of the F22 gear, the bearing on that machined surface has an ID of 23 mm. Honda sells a 23x35x2 "washer" they use in one of their motorcycle transmissions: #24 in this diagram: http://www.partzilla.com/parts/searc...ION/parts.html

[Tishock]

Where did you get 23mm from? When I measured it I got 25mm.

I'm looking through similar sites for a shim/washer. Thanks

A quick search gives me the results below. I keep finding motorcycle washer/shims that would fit the bill. I'm thinking of just using #8 in the first link.

UPDATE: I ordered the shim 25x35x2 from the first link below....

I'm going also to call Synchrotech and see if they have a better option, they're only a few miles from me.

http://www.2wheelpros.com/oem-parts/...-assembly.html

http://www.bmwmcchattanooga.com/prod...211451144.html

http://www.boats.net/parts/detail/ho...5-759-000.html

http://www.gearhead.com/honda-90565-759-000.html#Error

http://user.xmission.com/~wendell/R1100GS/trans.html

[reklipz]

Oh shoot, you're right; my apologies, I was looking at the spacer spring inner dimension, not the bearing. That shows as 25mm.

[Tishock]

So far the f22 gear set does work with some modifications. I was hoping that the f22 gears would be a straight swap but that is not the case. Using a 25x35x2 shim and adding the oil passages is the way to go.

But, with what I know now, I see that going with the f23 gear set would have been the much better choice (see pics). Looks to be a direct replacement. Nothing else would need to be done. It looks to be the same height and it has the oil passages we want.

I'm going to try to get myself a set of f23 gears and I'll share the measurements when and/or if I get them. Also I'm thinking of getting a cheap broken/beat up h22 transmission just to dissect.

The h2a5 counter shaft is about 2mm shorter than the m2s4 counter shaft. This leads me to believe that the oil passages on the m2s4 counter shaft gear were an update made after the h2a5 tranny for better oiling on higher revving engines. And in turn the shaft was lengthen to compensate for the taller gear.

The teeth counts are the same on both the f22 and f23 gears (MS 35 and CS 24).


Here are the fifth gear sets side by side, F23 set up front, H23 set in the rear. (See link http://honda-tech.com/showthread.php?t=2411948)

[Tishock]

Ok, I just found out that the part #s for the f22 5th gear set from a 92-93 Accord are the same as the f23 5th gear set from 98-02 Accord and 98-99 Acura CL . Looks like the update happened for the 92-93 models.

F23 98-02 Accord (0.685) P2A8
23461-PX5-A41 COUNTERSHAFT FIFTH
23581-PX5-A41 MAINSHAFT FIFTH

F22 92-93 Accord (0.685) h2u5
23461-PX5-A41 COUNTERSHAFT FIFTH
23581-PX5-A41 MAINSHAFT FIFTH

F23 98-99 Acura CL (0.685) P2A8
23461-PX5-A41 COUNTERSHAFT FIFTH
23581-PX5-A41 MAINSHAFT FIFTH

F22 90-91 Accord (0.685) h2a5
23461-PX5-A40 COUNTERSHAFT FIFTH
23581-PX5-A40 MAINSHAFT FIFTH

H23 92-96 Prelude (0.812) m2s4
23461-P16-S40 COUNTERSHAFT FIFTH
23581-P16-S40 MAINSHAFT FIFTH

[wildBill83]

I have an H2A5 in my 92 LX, that would be the most gas friendly 5th gear IMO.

The EX had the H2U5 with a more aggressive gearing.

[P5ylance]

Following!

[Tishock]

Just thinking out loud, I maybe completely wrong...

Maybe the reason why you often read about either needing to mill or shim the f22 CS gear to fit the h22/h23 tranny, is that some h22 people are using the taller h2u5 CS gear or the f23 CS gear. When, for a direct replacement on h22 trannys they should be using the shorter h2a5 CS gear. And the taller h2u5 and p2a8 CS gears should be used in the h23 m2s4 as a direct replacement.

See 3rd pic for h22 (m2y4) gear spacing that leads me to my current thinking.

Spacing between H23 (m2s4) gear and bearing


Spacing between F22 (h2a5) gear and bearing



Found the pic below in a CL ad last night. The listing was for a h22 m2y4 tranny. The listing is no longer up but I saved the images. See how the spacing between the h22 gear and bearing looks like the f22 h2a5 image above.

Enlarged

[Tishock]

Ok, I found a set of f23 gears which are the same as the f22 gears from 92-93 h2u5 (see previous posts) and 98-99 Acura CL. Should get them next week.

I'm still going to modify the shorter f22 h2a5 gears I have now. By adding the oil passages and using the 2mm shim I got. I'll take pics and video of the reassembly of the tranny with the modified gear. But afterwards I'm probably going to go back and switch out the f22 h2a5 gears with the f23 gears I'm getting soon.

I've also posted in my local classifieds to try to get a cheap, broken or abused h22 tranny just to dissect. May take a trip this weekend to a local junk yard and see what I can find. I would like to prove my theory about the h22 gears f22 compatibility.

[wagon-r]

Just thinking out loud, I maybe completely wrong...

Maybe the reason why you often read about either needing to mill or shim the f22 CS gear to fit the h22/h23 tranny, is that some h22 people are using the taller h2u5 CS gear or the f23 CS gear. When, for a direct replacement on h22 trannys they should be using the shorter h2a5 CS gear. And the taller h2u5 and p2a8 CS gears should be used in the h23 m2s4 for a direct replacement.

The problem here is that the 3rd through 5th gears were designed as a set. So, you can swap 3rd-5th from an h22/h23 to any f-series transmission (and vice-versa). But within the set, Honda designed the individual gears a bit different, so the f-series 5th gear is a bit thicker than the h22/h23 5th gear and must be shimmed a bit if you are only swapping 5th gear.

Also note that the gears are case hardened, so shimming the gear will grind this away. Probably not a major risk, as a lot of people have shimmed the 5th gear and I haven't read of any problems. But I wouldn't do it.

[Tishock]

Maybe I was unclear but gear sets was always implied, meaning the CS and MS 5th gear. I only focused on the Countershaft because that's the only one of the two gears that has to be modified depending on the combination of gear sets you end up using.

Also notice in my previous few posts the goal now is to use gear sets that would not require modification. That's why I ordered the f23/f22 5th gear set to confirm they're a direct swap and I'm trying to get a hold of at least one h22 tranny to dissect. I want to confirm my theory that the proper gear to use in a h22 is the shorter 5th gear set from a f22 h2a5 and not need to modify the CS gear.

or am I reading your post wrong, do you mean that all 6 gears (3rd-5th) have to be swapped together?

[Tishock]

Oh, thank you for your input. Other than Reklipz and yourself (Wagon-r) I've been kinda disappointed with others not sharing their insight on this subject. I realize that I may have covered or have links to what most of us know about this mod. But still their has to be others on here that can contribute something. Links that I have missed, pictures of gear sets with measurements if possible, personal useful experiences with this or similar mod, technical info and so on.

If there's anything any of you think I should add to this thread please let me know. What bits of information on this type of project do you know to be fact? What questions do you feel I should also be asking? Any more measurements I should take or do you have any measurements on other h/f trannys you'd like to divulge?

[reklipz]

or am I reading your post wrong, do you mean that all 6 gears (3rd-5th) have to be swapped together?

This. Though he is not saying that they have to be swapped together, but rather that these three ratios, within the design of a transmission, are very closely related.

Maybe I was unclear but gear sets was always implied, meaning the CS and MS 5th gear.

Let's call this a "gear ratio", or simply "ratio" for short.

Also note that the gears are case hardened, so shimming the gear will grind this away. Probably not a major risk, as a lot of people have shimmed the 5th gear and I haven't read of any problems. But I wouldn't do it.

So, about this: looking at the design, the countershaft's 5th gear is sandwiched between the 4th gear and the bearing, all of which is "clamped" together by the nut on the end of the shaft. I don't think adding a properly sized shim here would create any sort of different situation. What makes you think that it would?

[Tishock]

The problem here is that the 3rd through 5th gears were designed as a set. So, you can swap 3rd-5th from an h22/h23 to any f-series transmission (and vice-versa). But within the set, Honda designed the individual gears a bit different, so the f-series 5th gear is a bit thicker than the h22/h23 5th gear and must be shimmed a bit if you are only swapping 5th gear.

Also note that the gears are case hardened, so shimming the gear will grind this away. Probably not a major risk, as a lot of people have shimmed the 5th gear and I haven't read of any problems. But I wouldn't do it.

Ok, I see what your saying about 3rd-5th. Makes sense.

But about the CS, the gear is splined and like reklipsz mentioned its also sandwiched together with a nut on top. Maybe youre thinking about the MS.